Podcast
Questions and Answers
What is the primary characteristic of neuronal activity during a seizure?
What is the primary characteristic of neuronal activity during a seizure?
- Excessive hypersynchronous neuronal activity (correct)
- Normal neuronal activity
- Decreased synchronous neuronal firing
- Inhibition of neuronal activity
Which term describes the specific area in the brain where a seizure originates?
Which term describes the specific area in the brain where a seizure originates?
- Paroxysmal area
- Hypersynchronous zone
- Neuronal storm center
- Seizure focus (correct)
How long do most seizures typically last?
How long do most seizures typically last?
- 10–20 minutes
- 5–10 minutes
- 30–60 minutes
- 1–3 minutes (correct)
Which of the following is NOT a characteristic used to describe a seizure?
Which of the following is NOT a characteristic used to describe a seizure?
The prosencephalon is also known as which part of the brain?
The prosencephalon is also known as which part of the brain?
What role do glutamate and acetylcholine (AcH) play in the context of neuronal balance?
What role do glutamate and acetylcholine (AcH) play in the context of neuronal balance?
What is the function of GABA and glycine in the context of neuronal balance?
What is the function of GABA and glycine in the context of neuronal balance?
Which of the following best describes 'lateral inhibition' in neuronal communication?
Which of the following best describes 'lateral inhibition' in neuronal communication?
What structural change in the brain is associated with seizure propagation?
What structural change in the brain is associated with seizure propagation?
Which molecular change is associated with seizure propagation?
Which molecular change is associated with seizure propagation?
What is the role of the 'paroxysmal depolarizing shift (PDS)' in the context of seizures?
What is the role of the 'paroxysmal depolarizing shift (PDS)' in the context of seizures?
What is meant by 'seizure threshold'?
What is meant by 'seizure threshold'?
Which of the following can lower the seizure threshold?
Which of the following can lower the seizure threshold?
What is the role of the 'seizure focus' in seizure propagation?
What is the role of the 'seizure focus' in seizure propagation?
Which brain structures are involved in seizure generalization?
Which brain structures are involved in seizure generalization?
What is 'kindling' in the context of seizures?
What is 'kindling' in the context of seizures?
When describing a seizure, what does the term 'prodrome' refer to?
When describing a seizure, what does the term 'prodrome' refer to?
Which of the following best defines 'ictus' in the context of seizures?
Which of the following best defines 'ictus' in the context of seizures?
Which of the following is characteristic of the 'postictal' phase of a seizure?
Which of the following is characteristic of the 'postictal' phase of a seizure?
What is the current recommendation regarding the use of terms like 'simple' or 'complex' when describing seizures?
What is the current recommendation regarding the use of terms like 'simple' or 'complex' when describing seizures?
What is the primary focus of the International Veterinary Epilepsy Task Force (IVETF)?
What is the primary focus of the International Veterinary Epilepsy Task Force (IVETF)?
What defines a 'focal' epileptic seizure?
What defines a 'focal' epileptic seizure?
Which of the following is a common clinical sign associated with focal epileptic seizures?
Which of the following is a common clinical sign associated with focal epileptic seizures?
What is a key characteristic of a 'generalized' epileptic seizure?
What is a key characteristic of a 'generalized' epileptic seizure?
Which of the following is often observed during generalized epileptic seizures?
Which of the following is often observed during generalized epileptic seizures?
What is the significance of determining whether a seizure is generalized versus focal?
What is the significance of determining whether a seizure is generalized versus focal?
What are 'cluster seizures'?
What are 'cluster seizures'?
What defines 'status epilepticus'?
What defines 'status epilepticus'?
Why are both cluster seizures and status epilepticus considered medical emergencies?
Why are both cluster seizures and status epilepticus considered medical emergencies?
Which of the following is a potential effect of prolonged seizures on the brain?
Which of the following is a potential effect of prolonged seizures on the brain?
What systemic effect is most associated with seizures?
What systemic effect is most associated with seizures?
Which of the following is an example of a seizure mimic?
Which of the following is an example of a seizure mimic?
What is the definition of 'epilepsy'?
What is the definition of 'epilepsy'?
What is one of the key criteria used to diagnose epilepsy, as opposed to a single seizure?
What is one of the key criteria used to diagnose epilepsy, as opposed to a single seizure?
What is a reactive seizure?
What is a reactive seizure?
Which of the following is an example of a cause of reactive seizures?
Which of the following is an example of a cause of reactive seizures?
Which of the following best describes 'structural epilepsy'?
Which of the following best describes 'structural epilepsy'?
If structural epilepsy is suspected, what diagnostic should be preformed?
If structural epilepsy is suspected, what diagnostic should be preformed?
Select the best description of idiopathic epilepsy:
Select the best description of idiopathic epilepsy:
What age range is most common for the first seizure in dogs with idiopathic epilepsy?
What age range is most common for the first seizure in dogs with idiopathic epilepsy?
A definitive antemortem diagnosis of idiopathic epilepsy can only be obtained at which IVETF tier?
A definitive antemortem diagnosis of idiopathic epilepsy can only be obtained at which IVETF tier?
Around what age do neoplasias typically cause seizures?
Around what age do neoplasias typically cause seizures?
Which of the following criteria would warrant immediate initiation of maintenance anti-epileptic drug (AED) therapy?
Which of the following criteria would warrant immediate initiation of maintenance anti-epileptic drug (AED) therapy?
Choose the correct order, from shortest to longest duration, of medication usage for the following medications given during seizure events: Clonazepam, Diazepam, and Levetiracetam
Choose the correct order, from shortest to longest duration, of medication usage for the following medications given during seizure events: Clonazepam, Diazepam, and Levetiracetam
What is the typical duration of a seizure?
What is the typical duration of a seizure?
Which of the following is a means of communication between neurons in a normal state?
Which of the following is a means of communication between neurons in a normal state?
Which of the following is NOT considered a structural change associated with seizure propagation?
Which of the following is NOT considered a structural change associated with seizure propagation?
Which of the following best describes the molecular changes that occur during seizure propagation?
Which of the following best describes the molecular changes that occur during seizure propagation?
What is the consequence of exceeding the seizure threshold?
What is the consequence of exceeding the seizure threshold?
Which of the following occurs during the ictal phase of a seizure?
Which of the following occurs during the ictal phase of a seizure?
According to current veterinary guidelines, which terms are no longer accepted to describe seizure presentation?
According to current veterinary guidelines, which terms are no longer accepted to describe seizure presentation?
What is the primary aim of classifying a seizure as either focal or generalized?
What is the primary aim of classifying a seizure as either focal or generalized?
Which of the following best defines 'cluster seizures'?
Which of the following best defines 'cluster seizures'?
What is a key characteristic that defines status epilepticus?
What is a key characteristic that defines status epilepticus?
What is a key characteristic of reactive seizures?
What is a key characteristic of reactive seizures?
Idiopathic epilepsy is usually diagnosed after ruling out other causes of seizures. What age range is most common for the first seizure in dogs with idiopathic epilepsy?
Idiopathic epilepsy is usually diagnosed after ruling out other causes of seizures. What age range is most common for the first seizure in dogs with idiopathic epilepsy?
A dog presents with a history of seizures, and diagnostics are being considered. Which of the following findings on the initial neurological exam would MOST strongly suggest pursuing advanced imaging (MRI) and CSF tap?
A dog presents with a history of seizures, and diagnostics are being considered. Which of the following findings on the initial neurological exam would MOST strongly suggest pursuing advanced imaging (MRI) and CSF tap?
A 4 year old castrated male Golden Retriever presents to you for acute onset seizures. The owner reports that he had a seizure 3 months ago as well. After running a minimum database, you note that his resting bile acids are severely elevated. Of the following options, what is the most accurate diagnosis based on this single piece of information?
A 4 year old castrated male Golden Retriever presents to you for acute onset seizures. The owner reports that he had a seizure 3 months ago as well. After running a minimum database, you note that his resting bile acids are severely elevated. Of the following options, what is the most accurate diagnosis based on this single piece of information?
What is the fundamental characteristic of a paroxysmal event, as it relates to seizures?
What is the fundamental characteristic of a paroxysmal event, as it relates to seizures?
Which anatomical region of the brain is primarily implicated in the pathophysiology of seizures in animals?
Which anatomical region of the brain is primarily implicated in the pathophysiology of seizures in animals?
In a healthy brain, neuronal communication maintains a critical balance. What are the two key opposing processes that are in equilibrium to prevent seizures?
In a healthy brain, neuronal communication maintains a critical balance. What are the two key opposing processes that are in equilibrium to prevent seizures?
Cell loss in certain brain regions can predispose an animal to seizures. Why does the loss of inhibitory cells specifically increase seizure susceptibility?
Cell loss in certain brain regions can predispose an animal to seizures. Why does the loss of inhibitory cells specifically increase seizure susceptibility?
What is the 'paroxysmal depolarizing shift (PDS)' and how does it differ from a normal action potential in neurons?
What is the 'paroxysmal depolarizing shift (PDS)' and how does it differ from a normal action potential in neurons?
The seizure threshold represents the level of neural inhibition that, when overcome, results in uncontrolled paroxysmal shifts. Which of the following factors would generally INCREASE the seizure threshold?
The seizure threshold represents the level of neural inhibition that, when overcome, results in uncontrolled paroxysmal shifts. Which of the following factors would generally INCREASE the seizure threshold?
What is the 'kindling' effect in epilepsy, and why is it clinically significant in managing seizures?
What is the 'kindling' effect in epilepsy, and why is it clinically significant in managing seizures?
During which phase of a seizure is the actual seizure event occurring, characterized by abnormal motor, autonomic, or behavioral manifestations?
During which phase of a seizure is the actual seizure event occurring, characterized by abnormal motor, autonomic, or behavioral manifestations?
Which clinical sign is most indicative of the postictal phase following a seizure event?
Which clinical sign is most indicative of the postictal phase following a seizure event?
Why is the International Veterinary Epilepsy Task Force (IVETF) terminology and classification system important for veterinary medicine?
Why is the International Veterinary Epilepsy Task Force (IVETF) terminology and classification system important for veterinary medicine?
In a focal epileptic seizure, abnormal neuronal activity is localized to one area. What is a key characteristic that distinguishes a focal seizure from a generalized seizure?
In a focal epileptic seizure, abnormal neuronal activity is localized to one area. What is a key characteristic that distinguishes a focal seizure from a generalized seizure?
Autonomic signs are frequently observed during seizures. Which of the following is a common autonomic sign associated with focal epileptic seizures in animals?
Autonomic signs are frequently observed during seizures. Which of the following is a common autonomic sign associated with focal epileptic seizures in animals?
Generalized epileptic seizures involve both cerebral hemispheres. What is the most consistent clinical feature expected during a generalized tonic-clonic seizure?
Generalized epileptic seizures involve both cerebral hemispheres. What is the most consistent clinical feature expected during a generalized tonic-clonic seizure?
Why is differentiating between generalized and focal seizures clinically relevant in veterinary patients?
Why is differentiating between generalized and focal seizures clinically relevant in veterinary patients?
What defines 'cluster seizures' in veterinary epilepsy?
What defines 'cluster seizures' in veterinary epilepsy?
What is the critical defining characteristic of 'status epilepticus' that distinguishes it from cluster seizures or typical seizures?
What is the critical defining characteristic of 'status epilepticus' that distinguishes it from cluster seizures or typical seizures?
Why are both cluster seizures and status epilepticus considered medical emergencies in veterinary patients?
Why are both cluster seizures and status epilepticus considered medical emergencies in veterinary patients?
What is a significant consequence of prolonged seizure activity on neuronal metabolism and cellular function?
What is a significant consequence of prolonged seizure activity on neuronal metabolism and cellular function?
Which systemic effect is most commonly associated with seizures and can contribute to life-threatening complications?
Which systemic effect is most commonly associated with seizures and can contribute to life-threatening complications?
Which of the following conditions is considered a 'seizure mimic', meaning it can resemble a seizure but is not due to abnormal cerebral neuronal activity?
Which of the following conditions is considered a 'seizure mimic', meaning it can resemble a seizure but is not due to abnormal cerebral neuronal activity?
What is the defining criterion for diagnosing 'epilepsy' as a disease, rather than just a single seizure event?
What is the defining criterion for diagnosing 'epilepsy' as a disease, rather than just a single seizure event?
What is a 'reactive seizure', and what is its primary cause?
What is a 'reactive seizure', and what is its primary cause?
Hypoglycemia is a common cause of reactive seizures. Through what mechanism does low blood glucose induce seizure activity?
Hypoglycemia is a common cause of reactive seizures. Through what mechanism does low blood glucose induce seizure activity?
What is 'structural epilepsy' defined by, in contrast to reactive or idiopathic epilepsy?
What is 'structural epilepsy' defined by, in contrast to reactive or idiopathic epilepsy?
If structural epilepsy is suspected in a patient, what is the most appropriate next diagnostic step?
If structural epilepsy is suspected in a patient, what is the most appropriate next diagnostic step?
Which statement best describes 'idiopathic epilepsy'?
Which statement best describes 'idiopathic epilepsy'?
What is the typical age of onset for the first seizure in dogs diagnosed with idiopathic epilepsy?
What is the typical age of onset for the first seizure in dogs diagnosed with idiopathic epilepsy?
According to the IVETF tier system, at which tier can a definitive antemortem diagnosis of idiopathic epilepsy be achieved?
According to the IVETF tier system, at which tier can a definitive antemortem diagnosis of idiopathic epilepsy be achieved?
In older animals, particularly dogs over 6 years of age, new-onset seizures are often suspected to be caused by what underlying condition until proven otherwise?
In older animals, particularly dogs over 6 years of age, new-onset seizures are often suspected to be caused by what underlying condition until proven otherwise?
Which clinical scenario would most strongly warrant immediate initiation of maintenance anti-epileptic drug (AED) therapy, even after a first seizure event?
Which clinical scenario would most strongly warrant immediate initiation of maintenance anti-epileptic drug (AED) therapy, even after a first seizure event?
Considering the urgency of seizure control, which of the following benzodiazepines is typically considered to have the shortest duration of effect when administered during an active seizure event?
Considering the urgency of seizure control, which of the following benzodiazepines is typically considered to have the shortest duration of effect when administered during an active seizure event?
What is the primary goal of emergency treatment in a patient presenting with status epilepticus?
What is the primary goal of emergency treatment in a patient presenting with status epilepticus?
For long-term management of epilepsy, when might a veterinarian consider attempting to wean a patient off anti-epileptic medication?
For long-term management of epilepsy, when might a veterinarian consider attempting to wean a patient off anti-epileptic medication?
What is a potential risk associated with discontinuing anti-epileptic medication in a previously well-controlled epileptic patient?
What is a potential risk associated with discontinuing anti-epileptic medication in a previously well-controlled epileptic patient?
In the context of seizure diagnostics, why are video recordings of episodes provided by owners considered highly valuable?
In the context of seizure diagnostics, why are video recordings of episodes provided by owners considered highly valuable?
When performing a neurological examination on a patient with a history of seizures, what is the significance of identifying lateralizing signs (left vs. right forebrain dysfunction)?
When performing a neurological examination on a patient with a history of seizures, what is the significance of identifying lateralizing signs (left vs. right forebrain dysfunction)?
If an animal presents in status epilepticus for the first time, what does this presentation suggest about the likelihood of an underlying structural or extracranial cause, compared to an animal with a history of less severe seizures?
If an animal presents in status epilepticus for the first time, what does this presentation suggest about the likelihood of an underlying structural or extracranial cause, compared to an animal with a history of less severe seizures?
A 3-year-old Beagle presents with a history of generalized tonic-clonic seizures. Initial blood work (CBC, chemistry, bile acids) is normal. Neurological exam is unremarkable between seizures. According to the IVETF tier system, at which tier of diagnostic confidence would this patient currently be classified?
A 3-year-old Beagle presents with a history of generalized tonic-clonic seizures. Initial blood work (CBC, chemistry, bile acids) is normal. Neurological exam is unremarkable between seizures. According to the IVETF tier system, at which tier of diagnostic confidence would this patient currently be classified?
Considering the pathophysiology of seizures, which of the following cellular events is LEAST likely to contribute to the development or propagation of seizure activity?
Considering the pathophysiology of seizures, which of the following cellular events is LEAST likely to contribute to the development or propagation of seizure activity?
What is the MOST accurate description of a seizure from a neurological perspective?
What is the MOST accurate description of a seizure from a neurological perspective?
The telencephalon and diencephalon are key parts of the prosencephalon. Which of the following brain structures is NOT part of either the telencephalon or diencephalon?
The telencephalon and diencephalon are key parts of the prosencephalon. Which of the following brain structures is NOT part of either the telencephalon or diencephalon?
In the context of seizure pathophysiology, structural changes in the brain can disrupt the normal balance between neuroexcitation and neuroinhibition. Which of the following is an example of such a structural change?
In the context of seizure pathophysiology, structural changes in the brain can disrupt the normal balance between neuroexcitation and neuroinhibition. Which of the following is an example of such a structural change?
What role does the estrous cycle play in the context of seizure threshold in canine patients?
What role does the estrous cycle play in the context of seizure threshold in canine patients?
Following the occurrence of paroxysmal depolarizing shifts, what is the impact of kindling on future seizure activity?
Following the occurrence of paroxysmal depolarizing shifts, what is the impact of kindling on future seizure activity?
During the phases of a seizure, what behavioral change is most indicative of the prodrome period?
During the phases of a seizure, what behavioral change is most indicative of the prodrome period?
When trying to determine if an episode is a seizure, what is the biggest significance of the postictal phase?
When trying to determine if an episode is a seizure, what is the biggest significance of the postictal phase?
What is a key reason that the International Veterinary Epilepsy Task Force (IVETF) recommends avoiding terms like 'grand mal' or 'complex partial' when describing seizures?
What is a key reason that the International Veterinary Epilepsy Task Force (IVETF) recommends avoiding terms like 'grand mal' or 'complex partial' when describing seizures?
What is a key characteristic that differentiates focal seizures from generalized seizures?
What is a key characteristic that differentiates focal seizures from generalized seizures?
An animal exhibits rhythmic blinking, facial twitches, hypersalivation, and anxiety, but appears to remain conscious. Which type of seizure is MOST likely?
An animal exhibits rhythmic blinking, facial twitches, hypersalivation, and anxiety, but appears to remain conscious. Which type of seizure is MOST likely?
What is the primary danger associated with a high metabolic rate during a seizure?
What is the primary danger associated with a high metabolic rate during a seizure?
What is occurring when cytotoxic edema develops as a result of seizure activity?
What is occurring when cytotoxic edema develops as a result of seizure activity?
According to the Monroe-Kelly doctrine, what happens if one component (brain tissue, blood, or cerebrospinal fluid) increases within the cranial vault?
According to the Monroe-Kelly doctrine, what happens if one component (brain tissue, blood, or cerebrospinal fluid) increases within the cranial vault?
In addition to head tremors, what characteristics help differentiate tremors from seizures?
In addition to head tremors, what characteristics help differentiate tremors from seizures?
What is the MOST accurate way to categorize reactive seizures?
What is the MOST accurate way to categorize reactive seizures?
Which of the following would be least likely to cause a reactive seizure?
Which of the following would be least likely to cause a reactive seizure?
Structural epilepsy generally requires advanced imaging. Why is advanced imaging so important?
Structural epilepsy generally requires advanced imaging. Why is advanced imaging so important?
What is the age range in which idiopathic epilepsy is most commonly suspected?
What is the age range in which idiopathic epilepsy is most commonly suspected?
To reach level two of the IVETF tier system for diagnosing idiopathic epilepsy, what diagnostic tests must be preformed?
To reach level two of the IVETF tier system for diagnosing idiopathic epilepsy, what diagnostic tests must be preformed?
A patient is experiencing increased energy requirements and metabolic rate during a seizure. What physiological change can you expect?
A patient is experiencing increased energy requirements and metabolic rate during a seizure. What physiological change can you expect?
An owner describes their dog's seizure as involuntary, but otherwise 'normal' movements. These episodes last 10-20 minutes. What differentials should be high on your list?
An owner describes their dog's seizure as involuntary, but otherwise 'normal' movements. These episodes last 10-20 minutes. What differentials should be high on your list?
Classically, when do most epileptic events occur?
Classically, when do most epileptic events occur?
To be considered status epilepticus, a seizure must last how long?
To be considered status epilepticus, a seizure must last how long?
According to the IVETF, what is required to diagnosis a patient with epilepsy?
According to the IVETF, what is required to diagnosis a patient with epilepsy?
What can cause seizures in animals with the ABCB1 (MDR1) gene mutation?
What can cause seizures in animals with the ABCB1 (MDR1) gene mutation?
If an animal presents in status epilepticus, what concerns are present?
If an animal presents in status epilepticus, what concerns are present?
If an animal presents seizing, what is the recommendation to begin cooling?
If an animal presents seizing, what is the recommendation to begin cooling?
Which of the following clinical signs is MOST suggestive of a forebrain lesion?
Which of the following clinical signs is MOST suggestive of a forebrain lesion?
An owner mentions they think that their dog has a seizure. Who is responsible for the classification and description of the seizure?
An owner mentions they think that their dog has a seizure. Who is responsible for the classification and description of the seizure?
Which of the following parameters significantly increases the likelihood of suspecting intracranial etiologies for seizure events?
Which of the following parameters significantly increases the likelihood of suspecting intracranial etiologies for seizure events?
An animal is suspected to be experiencing hypoglycemic seizures, what diagnostic samples should be run FIRST?
An animal is suspected to be experiencing hypoglycemic seizures, what diagnostic samples should be run FIRST?
What is the recommendation for animals on long term anti-seizure medications?
What is the recommendation for animals on long term anti-seizure medications?
A 4-year-old dog has a history of seizures, but the veterinarian notes that the dog only eats from one side of its bowl. What is this called, and what does it indicate?
A 4-year-old dog has a history of seizures, but the veterinarian notes that the dog only eats from one side of its bowl. What is this called, and what does it indicate?
When ruling out idiopathic epilepsy, if a patient is over 6 at the first onset of seizures, what do most veterinarians suspect?
When ruling out idiopathic epilepsy, if a patient is over 6 at the first onset of seizures, what do most veterinarians suspect?
An owner suspects their pet is experiencing a seizure due to the rapid onset of paddling and loss of consciousness; however, the veterinarian suspects an alternative diagnosis. If the clinical signs were truly a syncopal episode, which of the following would assist in tipping the diagnostic scale?
An owner suspects their pet is experiencing a seizure due to the rapid onset of paddling and loss of consciousness; however, the veterinarian suspects an alternative diagnosis. If the clinical signs were truly a syncopal episode, which of the following would assist in tipping the diagnostic scale?
What historical/environmental consideration is important to address specifically when discussing a new onset of seizures with patients in New England?
What historical/environmental consideration is important to address specifically when discussing a new onset of seizures with patients in New England?
When attempting to differentiate narcolepsy from seizure activity, which of the following scenarios all but removes seizure probability?
When attempting to differentiate narcolepsy from seizure activity, which of the following scenarios all but removes seizure probability?
A neurologist is presented with a patient suffering from long-term tonic-clonic seizures. Over time, the neurologist notices the seizures have evolved from generalized occurrences to now only presenting on the left side of the patient. What is the MOST accurate explanation of this change?
A neurologist is presented with a patient suffering from long-term tonic-clonic seizures. Over time, the neurologist notices the seizures have evolved from generalized occurrences to now only presenting on the left side of the patient. What is the MOST accurate explanation of this change?
What is the BEST course of action regarding the order and necessity of diagnostics administered for status epilepticus?
What is the BEST course of action regarding the order and necessity of diagnostics administered for status epilepticus?
When presented with a patient displaying seizure indications, a thorough history is considered the first and most important step for moving to next steps. Which of the following historical questions are MOST crucial when evaluating this presenting complaint?
When presented with a patient displaying seizure indications, a thorough history is considered the first and most important step for moving to next steps. Which of the following historical questions are MOST crucial when evaluating this presenting complaint?
In a situation where cytotoxic edema is suspected second to seizure activity, what is the goal of initial support?
In a situation where cytotoxic edema is suspected second to seizure activity, what is the goal of initial support?
During a seizure, neurons exhibit excessive, hypersynchronous activity. Where can this dysfunction occur in the brain?
During a seizure, neurons exhibit excessive, hypersynchronous activity. Where can this dysfunction occur in the brain?
The pathophysiology of seizures primarily involves which part of the brain?
The pathophysiology of seizures primarily involves which part of the brain?
What is the effect of structural changes in the brain on neuronal communication and the balance between neuroexcitation and neuroinhibition?
What is the effect of structural changes in the brain on neuronal communication and the balance between neuroexcitation and neuroinhibition?
What cellular-level change can contribute to an increase in neuronal excitability and a predisposition to seizures?
What cellular-level change can contribute to an increase in neuronal excitability and a predisposition to seizures?
In the context of neuronal electrical activity, what characterizes the 'paroxysmal depolarizing shift' (PDS) seen in seizures?
In the context of neuronal electrical activity, what characterizes the 'paroxysmal depolarizing shift' (PDS) seen in seizures?
How do stress and estrous cycles affect the seizure threshold in animals?
How do stress and estrous cycles affect the seizure threshold in animals?
The 'kindling' effect in seizure propagation refers to what phenomenon?
The 'kindling' effect in seizure propagation refers to what phenomenon?
What does the clinical presentation of a seizure depend on?
What does the clinical presentation of a seizure depend on?
During which phase of a seizure does the actual seizure event occur?
During which phase of a seizure does the actual seizure event occur?
What is the significance of the postictal phase in recognizing seizures?
What is the significance of the postictal phase in recognizing seizures?
In the context of seizure terminology, what is the primary goal of using standardized terms instead of older, less precise terms?
In the context of seizure terminology, what is the primary goal of using standardized terms instead of older, less precise terms?
What is a key characteristic that often distinguishes focal seizures from generalized seizures?
What is a key characteristic that often distinguishes focal seizures from generalized seizures?
What is a common autonomic sign associated with focal seizures?
What is a common autonomic sign associated with focal seizures?
How do cluster seizures differ from status epilepticus?
How do cluster seizures differ from status epilepticus?
What is cytotoxic edema, which can result from prolonged seizure activity?
What is cytotoxic edema, which can result from prolonged seizure activity?
According to the Monroe-Kelly doctrine, what is the relationship between brain tissue, blood, and cerebrospinal fluid (CSF) within the cranial vault?
According to the Monroe-Kelly doctrine, what is the relationship between brain tissue, blood, and cerebrospinal fluid (CSF) within the cranial vault?
What is the minimum requirement for a diagnosis of epilepsy?
What is the minimum requirement for a diagnosis of epilepsy?
Which of the following is a common cause of reactive seizures?
Which of the following is a common cause of reactive seizures?
In cases of structural epilepsy, what diagnostic test is most crucial for identifying the underlying cause?
In cases of structural epilepsy, what diagnostic test is most crucial for identifying the underlying cause?
How does the age of onset of seizures influence the diagnostic approach to epilepsy?
How does the age of onset of seizures influence the diagnostic approach to epilepsy?
Flashcards
What is a Seizure?
What is a Seizure?
Clinical manifestation of excessive, hypersynchronous neuronal activity in the brain characterized by sudden and transient dysfunction.
Neurolocalization of Seizures
Neurolocalization of Seizures
The prosencephalon, also known as the forebrain, includes structures like the cortex, limbic system, subcortical nuclei, thalamus, and hypothalamus.
Seizure Propagation: Structural Changes
Seizure Propagation: Structural Changes
Seizure occurs if there is loss of lateral and surrounding inhibition due to outgrowth of aberrant excitatory axons, loss of inhibitory neurons and denervation hypersensitivity.
Seizure Propagation: Molecular Changes
Seizure Propagation: Molecular Changes
Signup and view all the flashcards
Seizure electrical charges
Seizure electrical charges
Signup and view all the flashcards
What is Seizure Threshold?
What is Seizure Threshold?
Signup and view all the flashcards
Seizure Propagation
Seizure Propagation
Signup and view all the flashcards
Seizure Manifestation
Seizure Manifestation
Signup and view all the flashcards
Prodrome(preictal)
Prodrome(preictal)
Signup and view all the flashcards
Ictus
Ictus
Signup and view all the flashcards
Postictal
Postictal
Signup and view all the flashcards
Focal epileptic seizure
Focal epileptic seizure
Signup and view all the flashcards
Focal epileptic seizure evolving to become generalized
Focal epileptic seizure evolving to become generalized
Signup and view all the flashcards
Generalized epileptic seizure
Generalized epileptic seizure
Signup and view all the flashcards
Cluster Seizures
Cluster Seizures
Signup and view all the flashcards
Status Epilepticus
Status Epilepticus
Signup and view all the flashcards
Effect of Seizures on the Brain
Effect of Seizures on the Brain
Signup and view all the flashcards
What is Epilepsy?
What is Epilepsy?
Signup and view all the flashcards
Reactive/Provoked Seizure
Reactive/Provoked Seizure
Signup and view all the flashcards
Structural epilepsy
Structural epilepsy
Signup and view all the flashcards
Idiopathic Epilepsy
Idiopathic Epilepsy
Signup and view all the flashcards
Vestibular Episode Indications
Vestibular Episode Indications
Signup and view all the flashcards
Neuromuscular Distress Source
Neuromuscular Distress Source
Signup and view all the flashcards
Seizure Diagnostics: History
Seizure Diagnostics: History
Signup and view all the flashcards
Seizure Diagnostics: Triage
Seizure Diagnostics: Triage
Signup and view all the flashcards
Seizure Diagnostics: Neuro Exam
Seizure Diagnostics: Neuro Exam
Signup and view all the flashcards
Full Workup Recommendation
Full Workup Recommendation
Signup and view all the flashcards
Emergency Seizures
Emergency Seizures
Signup and view all the flashcards
Maintenance AED
Maintenance AED
Signup and view all the flashcards
Choosing Medication
Choosing Medication
Signup and view all the flashcards
Paroxysmal Event
Paroxysmal Event
Signup and view all the flashcards
The Prozencephalon
The Prozencephalon
Signup and view all the flashcards
EPSP
EPSP
Signup and view all the flashcards
IPSP
IPSP
Signup and view all the flashcards
Kindling Effect
Kindling Effect
Signup and view all the flashcards
Post-Ictal Phase
Post-Ictal Phase
Signup and view all the flashcards
Generalized vs Focal Seizures
Generalized vs Focal Seizures
Signup and view all the flashcards
Tonic Seizure
Tonic Seizure
Signup and view all the flashcards
Clonic Seizure
Clonic Seizure
Signup and view all the flashcards
Cytotoxic Edema
Cytotoxic Edema
Signup and view all the flashcards
Monroe-Kelly Doctrine
Monroe-Kelly Doctrine
Signup and view all the flashcards
Movement Disorder/Paroxysmal dyskinesias,
Movement Disorder/Paroxysmal dyskinesias,
Signup and view all the flashcards
Idiopathic head tremor syndrome
Idiopathic head tremor syndrome
Signup and view all the flashcards
Narcolepsy
Narcolepsy
Signup and view all the flashcards
Ivermectin Sensitivity
Ivermectin Sensitivity
Signup and view all the flashcards
Idiopathic Epilepsy Onset: <6 years
Idiopathic Epilepsy Onset: <6 years
Signup and view all the flashcards
Cryptogenic Epilepsy: > 6 years
Cryptogenic Epilepsy: > 6 years
Signup and view all the flashcards
CBC, Chem UA and either ammonia or resting bile acids
CBC, Chem UA and either ammonia or resting bile acids
Signup and view all the flashcards
Full Evaluation Recommendation
Full Evaluation Recommendation
Signup and view all the flashcards
Emergency Drugs
Emergency Drugs
Signup and view all the flashcards
Study Notes
- Seizures and epilepsy are key topics in neurobiology.
- The following notes cover the pathophysiology of seizures, terminology, recognition, classification, diagnostics, and treatment.
Learning Objectives
- Describe the pathophysiology of seizures.
- Define terminology related to seizures and epilepsy including seizure, epilepsy, cluster seizures, and status epilepticus.
- Recognize seizures versus other causes of "episodes".
- Outline the classification of epilepsy based on underlying causes.
- Describe the diagnostics and need to initiate treatment in patients presenting with seizures.
What is a Seizure?
- A seizure is the clinical manifestation of excessive hypersynchronous neuronal activity.
- It involves dysfunction in a circumscribed part of the brain known as the seizure focus, or both cerebral hemispheres.
- Characterized by a paroxysmal event that is sudden and transient.
- Involves abnormal excessive or synchronous movements.
- A seizure is brief, roughly 1-3 minutes in length.
- Characterized by motor, autonomic, or behavioral manifestations
Seizure Pathophysiology: Anatomy
- The relevant brain anatomy includes the cortex, limbic system, and subcortical nuclei, which encompass the basal nuclei, thalamus, and hypothalamus.
- Neurolocalization is related to the prosencephalon/forebrain.
- When a pet presents with seizures, it indicates the prosencephalon is involved
- If there are other changes that can't be explained by the prosencephalon, it indicates a multifocal issue
Normal State of Neurons
- Normal brain function relies on the balance between neuroexcitation (glutamate, AcH) and neuroinhibition (GABA, glycine).
- Communication between neurons occurs via lateral and surround inhibition.
- This communication can be disrupted by structural changes that prevent the balance of neuroexcitation and neuroinhibition
Seizure Propagation: Structural Changes
- Structural changes during seizure propagation include a loss of lateral and surrounding inhibition.
- Other changes include the outgrowth of aberrant excitatory axons.
- Additionally, loss of inhibitory neurons and denervation hypersensitivity occur.
- Structural issues can result from head trauma or tumors
Seizure Propagation: Molecular Changes
- Molecular changes during seizure propagation involve an increase in the number, sensitivity, and distribution of glutamate receptors.
- Decreased GABA receptor expression and production are also present.
- Reduced potassium and glutamate uptake can occur.
- Molecular changes can be inherent in an individual with idiopathic epilepsy
Seizure Propagation: Electrical Charges
- Electrical charges during seizure propagation include excitatory postsynaptic potentials (EPSPs) and inhibatory postsynaptic potentials (IPSPs).
- Depolarization and hyperpolarization are key electrical events.
- Results in action potentials (AP) once a threshold is reached.
- Paroxysmal depolarizing shift (PDS) results in abnormal fluctuations of neuronal membrane voltage that far outlasts the depolarization of normal APs.
- Seizures are associated with a paroxysmal depolarizing shift consisting of action potentials, creating depolarization.
Seizure Threshold
- The seizure threshold is the level of neuronal inhibition, that when exceeded, leads to uncontrolled discharge of neurons causing PDS.
- The threshold is influenced by the environment.
- If the environment is altered, the threshold is lowered.
- Seizures only occur with stimulant drugs or electroconvulsant shocks under normal conditions.
- Seizures can occur with fevers, stress, or estrus.
- Patients with idiopathic epilepsy have a naturally lowered seizure threshold that can be further lowered by things like estrus or fever.
- Spontaneous seizures are associated with idiopathic epilepsy.
Seizure Propagation
- The seizure focus acts as the "pacemaker".
- Summation of PDSs occurs here.
- Synchronous paroxysmal discharges occur in a large area.
- There is a breakdown of inhibiting structures, in the neocortex, hippocampus, thalamus and basal nuclei, and cerebellum.
- Can lead to generalization and kindling.
- Kindling is the effect that the more seizures an animal has, the more likely it is to have more seizures.
Seizure Manifestation
- Clinical signs depend on the location of paroxysmal activity, brain structures involved, and degree of breakdown of inhibiting structures.
Phases of an Epileptic Seizure
- Prodrome (Preictal): Change in disposition hours to days before the seizure, often hard to recognize.
- Aura: Difficult to see.
- Ictus: The seizure itself, which varies in types.
- Postictal: Includes disorientation, repetitive vocalization, compulsive locomotion, apparent blindness, aggression, lethargy, ataxia, increased hunger/thirst, and need to urinate/defecate.
- Post-ictal signs are very important in diagnosing a seizure versus other events.
Seizure Terminology
- Many terms that have been used to describe similar seizure presentations.
- The diversity of terminology creates roadblocks on consensus between human and veterinary medicine.
- "Grand mal," "Simple partial," and "Complex partial" seizure classifications are no longer accepted.
- Standardizing terminology with the International League Against Epilepsy (ILAE) and the International Veterinary Epilepsy Task Force (IVETF).
- The veterinary hospital utilizes the International Veterinary Epilepsy Task Force tier system (IVETF).
- Cryptogenic is generally the accepted terminology.
- Petite mal is referred to as focal, grand mal is referred to as generalized.
Focal Epileptic Seizure
- Abnormal activity arises in a localized group of neurons or a network within one hemisphere.
- It may propagate to the contralateral hemisphere.
- Lateralized and/or regional signs are present.
- Clinical signs reflect the functions of the area involved.
Focal Epileptic Seizure Clinical Signs
- Motor signs include facial twitches, repeated jerking head movements, rhythmic blinking, and rhythmic jerks of one extremity.
- Autonomic signs include cardiovascular, gastrointestinal, sudomotor (sweating), vasomotor, thermoregulatory, parasympathetic, hypersalivation, and dilated pupils.
- May present with epigastric signs and vomiting.
- Behavioral signs include anxiousness, restlessness, unexplained fear reactions, and abnormal attention seeking/clingy behaviors.
- Consciousness level is variable to no impairment.
- It is recommended to avoid trying to classify consciousness during a seizure.
Generalized Epileptic Seizure
- Involves both sides of the cerebral hemisphere.
- Types include tonic only (sustained increase in muscle contraction), clonic only (excessive abnormal muscle contractions, typically bilateral), and tonic-clonic.
- Autonomic signs include salivation, mydriasis, urination, and/or defecation.
- Usually presents with loss of consciousness.
Focal Epileptic Seizure Evolving to Become Generalized
- This is the most common seizure type seen in dogs.
- The focal epileptic seizure onset is typically brief and may be difficult to detect.
Generalized vs Focal Seizure Classifications
- Classifying the type helps to confirm that it's a true seizure.
- Helps others recognize a patient's seizure (particularly if subtle physical manifestations).
- Tracking the evolution of seizure events, differentiating rank, and guiding prognosis.
- Does not dictate treatment or severity.
- Owners may falsely assume focal seizures shouldn't be treated like generalized ones.
- Focal seizures can be more difficult to treat.
Definitions
- Cluster Seizures: Two or more seizures within a 24-hour period with complete recovery in between.
- Status Epilepticus: Seizure activity lasting longer than 5 minutes, or lack of complete recovery of consciousness between events.
- Both cluster seizures and status epilepticus are medical emergencies warranting hospitalization.
Effects of Seizures on the Brain
- Metabolic rate increases.
- ATP depletion to cytotoxic edema occurs along with lactic acid accumulation.
- There is an increase in blood flow and intracranial pressure (ICP).
- Ischemia also occurs, and gray matter is more susceptible.
- Neuronal death occurs by excitotoxicity, involving glutamate and calcium influx to mitochondria, resulting in neuronal necrosis.
Effects of Seizures Systemically
- Can result in aspiration pneumonia, hyperthermia (heat stroke), hypoxemia, and metabolic acidosis (elevated lactate).
- Other effects include hyperkalemia, hyper or hypoglycemia, arrhythmias, and noncardiogenic pulmonary edema.
- In addition, the upper airway may be obstructed.
Seizure Mimics: "Abnormal Episodes"
- Movement disorders (paroxysmal dyskinesias).
- Idiopathic head tremor syndrome.
- Narcolepsy.
- Obsessive-compulsive disorder (fly catching, tail chasing).
- Vestibular episodes.
- Syncope.
- Pain.
- Neuromuscular weakness.
Epilepsy
- Epilepsy is a disease of the brain characterized by both an enduring predisposition to generate further epileptic seizures.
- Generally applied in cases with at least two unprovoked seizures >24 hours apart.
Seizure Categories
- Reactive (Provoked) Seizures
- Structural Epilepsy
- Idiopathic Epilepsy
Reactive Seizures
- Due to extracranial causes or issues outside the brain
- These are a natural response from the normal brain to a transient disturbance in function, which can be metabolic or toxic in nature.
- Typically reversible when the underlying cause or disturbance is corrected.
- Persistent seizure focus may still develop.
- Examples of causes include hypoglycemia, hepatic encephalopathy, sodium derangements, low calcium, and toxins.
Toxins that Cause Seizures
- Detergents and disinfectants like hexachlorophene.
- Caffeine/chocolate and Xylitol.
- Illicit drugs (methamphetamines, cocaine).
- Heavy metals such as Lead.
- Pesticides and rodenticides.
- Automotive products such as ethylene glycol.
- Ivermectin can cause seizures in breeds with the ABCB1 gene (previously MDR1).
Structural Epilepsy
- Provoked by intracranial/cerebral pathology.
- Commonly involves vascular diseases, infectious/inflammatory diseases, traumatic brain injury, anomalous/developmental conditions, neoplasia, and degenerative diseases.
- Commonly see inter-ictal neurologic signs or exam abnormalities like "lateralizing signs".
- Requires diagnostic imaging (MRI preferred), cerebrospinal fluid analysis, DNA testing, and/or postmortem findings for confirmation.
Idiopathic Epilepsy
- It has no demonstrable systemic or brain pathology.
- There is a rule out diagnosis, 6 month to 6 year period.
- Genetic Epilepsy: Due to causative gene or confirmed background.
- Suspected influence supported by high prevalence, genealogical analysis, and familial accumulation in epileptic individiuals.
- Likely involves multiple genes and epigenetics or unknown cause.
Terms for Idiopathic Epilepsy
- Classified as juvenile, idiopathic, or cryptogenic epilepsy based on age of onset etc.
- Juvenile epilepsy occurs before 6 months of age.
- Idiopathic epilepsy occurs between 6 months and 6 years.
- Cryptogenic epilepsy appears after 6 years of age, considered "hidden", falls into the unknown cause.
Levels of Confidence in Idiopathic Epilepsy
- Tier I requires a history of ≥2 unprovoked seizures >24 hours apart, onset between 6 months-6 years, unremarkable inter-ictal physical and neurologic exams, and no significant abnormalities on CBC/Chemistry/UA or resting bile acids.
- The addition of both fasting/post-prandial bile acids and MRI + CSF Analysis in Tier II.
- Tier III requires the Tier II qualifications.
Age of Onset and Common Differentials
- Less Than One Year Old: Encephalitis/infectious, Trauma, Hepatic shunt, Hypoglycemia, Toxins.
- 1-5 Years Old: Idiopathic epilepsy, Trauma, Neoplasia.
- Over 5 Years Old: Neoplasia, Encephalitis/inflammatory, Metabolic, Idiopathic/cryptogenic (20%).
Epidemiology of Status Epilepticus
- Causes: 23.5% had idiopathic epilepsy, 45.1% structural epilepsy.
- 31.4% reactive epilepsy.
- Seizures also have structural implications, the summary:
- IE versus non-IE cases is 30% to 70% in dogs with definitive seizures.
- Doubles risk in strucutral issues for seizures.
- Recommends more due diligence in workups.
- If the first seizure is status, there is a much higher chance of it being caused by a structural or extracranial issue.
Approach to the Seizure Patient
- History taking includes triggering factors (waking up, rest, excitement, feeding) and if they are focal versus generalized.
- Also includes the duration of ictal phase along with severity of post-ictal.
- Take note of number and frequency of events as well as any concurrent disorders.
- Possible toxin exposure, diet history, vaccinate status, and travel history.
- A diet deficient in thiamine can result in seizures.
Presentation/Triage Details
- Vital signs (Temp, HR, RR) in context of active cooling.
- Blood pressure, EKG, Pulse Ox, along with gaslytes to PCV/TS.
- Reviewing these factors of electrocytes, lactate, and the presence of "gastric tube" lavage.
- It may be necessary to empty the stomach if the patient is believed to have ingested toxins.
Complete Neurologic Exam
- Additional signs of forebrain dysfunction includes abnormal mentation, circling in one direction, head pressing, head pressing against stuck corners.
- These may occur in focal with Hemineglect, if not ignored and if an absent menace test, if there is a contraleral presence.
- If propnociceotive is able to loalize forbrain left or right suggesting a structural disease.
- Keep in mind that some disorders may be multifocal while taking tests, note the nature.
- Some tests have factors from brainstem, cerebullum, spinal cord dysfunctions.
- Seizure + Multiple cranial nerve deficits.
- Most common during post-Ital is symmtretric deficits, but in all limbs there would be bilateral ab sense of menace for prepnociceptive.
Diagnostics for Seizures
- Base testing includes for minimums such as a complete blood count, blood panels, and any urinalysis factors.
- Testing for blood pressure, bile for resting, and for felines testing for FeLV/FIV is necessary.
- Review that for under 1, 1-5, and under 5 age range.
- For over 5 years testing includes more work of metabolic samples.
- May include infectious testing as well for MRI.
Full Seizure Test
- Recommend full tests for patients to keep in mind what kind of epilepsy it may be: abnormal exams, testing if lateralizing, multiple focalities, age under 1 or 5, testing cats in general, breeds of structural tendencies, and for status or cluster testing.
Emergency Treatment
- IN HOSPITAL: Goal is to minimize excitotoxictity, while minimizing for avoid complications.
- With a diaepam or midazdam review rates.
- Also may use Phenobarbital & Ketamine and CRI's as noted from the lectures.
- AT HOME: Minimizing cluster activity for hospitalization ER.
- For rectal tests Diazepam is present.
- Clorazepate treatment and levels.
Start AED Testing Factors
- Identifiable structure, and if structural, then consider a seizure.
- At a prolonged state >6 months may have increased episodes of periods of AED.
Long Term Managements
- Some testing will show if Fist mediations should be done. First order, include:
- Phenobarbital and/or Potassium Bromide Can also do and/or also use: -Levetiracetam & Zonsiamide
How to Choose
- ACVM is recommended and to monitor effects if from an AED.
- Consider personal factors while reviewing the history while following up treatment from doctors.
- Some conditions are eased with administration.
Alternate Testing and Treatment
- Stimulators for diet.
- MCT plus ketogenci may require purina factors.
- Surgery is also present.
- Herbs and therapy may have treatment for surgery and alternative treatements.
- Adjuctive therapies do not replace traditional pharmaceutical anti-seizure medications.
Overview
- Seizures are the most common disease.
- Classifying and describing the situation for seizures is important.
- Test for history such as ages if necessary.
- Take notes of testing to determine and take note of understanding.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
