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Questions and Answers
Which of the following is NOT a cause of Generalized Tonic-Clonic Seizures (GTCS)?
Which of the following is NOT a cause of Generalized Tonic-Clonic Seizures (GTCS)?
Electrolyte imbalances can lead to Generalized Tonic-Clonic Seizures.
Electrolyte imbalances can lead to Generalized Tonic-Clonic Seizures.
True
What is the recommended treatment for HSV-1 encephalitis?
What is the recommended treatment for HSV-1 encephalitis?
Acyclovir
Withdrawal seizures can occur from substances such as _____ and barbiturates.
Withdrawal seizures can occur from substances such as _____ and barbiturates.
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Match the following causes of syncope with their types:
Match the following causes of syncope with their types:
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Which nerve fiber type is associated with proprioception and position sense?
Which nerve fiber type is associated with proprioception and position sense?
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Small fiber neuropathy affects pain and temperature sensations.
Small fiber neuropathy affects pain and temperature sensations.
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Name one condition that causes pure motor neuropathy.
Name one condition that causes pure motor neuropathy.
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Which of the following is a common cause of Small Fibre Neuropathy?
Which of the following is a common cause of Small Fibre Neuropathy?
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The type of touch sensation carried by the $A_eta$ fibers is called blank touch.
The type of touch sensation carried by the $A_eta$ fibers is called blank touch.
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Large Fibre Neuropathy can cause burning pain as a primary symptom.
Large Fibre Neuropathy can cause burning pain as a primary symptom.
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What is the characteristic sensory symptom of Large Fibre Neuropathy that indicates sensory ataxia?
What is the characteristic sensory symptom of Large Fibre Neuropathy that indicates sensory ataxia?
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Match the following sensations with their corresponding nerve fiber types:
Match the following sensations with their corresponding nerve fiber types:
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Small Fibre Neuropathy can lead to loss of ______ sense.
Small Fibre Neuropathy can lead to loss of ______ sense.
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Match the following conditions with their associated type of neuropathy:
Match the following conditions with their associated type of neuropathy:
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What is the most common cause of compressive radiculopathy?
What is the most common cause of compressive radiculopathy?
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Asymmetrical pain is a characteristic feature of radiculopathy.
Asymmetrical pain is a characteristic feature of radiculopathy.
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What type of pathology is associated with pure motor effects at the anterior horn cells?
What type of pathology is associated with pure motor effects at the anterior horn cells?
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The loss of deep tendon reflex (DTR) is associated with weakness along the ______.
The loss of deep tendon reflex (DTR) is associated with weakness along the ______.
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Match the root values with their corresponding actions and DTR:
Match the root values with their corresponding actions and DTR:
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Which of the following lesions are characterized by hypotonia?
Which of the following lesions are characterized by hypotonia?
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Fasciculations are present in LMN lesions and absent in UMN lesions.
Fasciculations are present in LMN lesions and absent in UMN lesions.
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Name the two main tracts associated with lower motor neurons.
Name the two main tracts associated with lower motor neurons.
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The site of LMN lesion includes the ___________ and peripheral nerves.
The site of LMN lesion includes the ___________ and peripheral nerves.
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Match the cranial nerve structures with their corresponding cranial nerves:
Match the cranial nerve structures with their corresponding cranial nerves:
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What is the primary severity associated with bacterial meningitis?
What is the primary severity associated with bacterial meningitis?
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Viral meningitis has a higher mortality rate than bacterial meningitis.
Viral meningitis has a higher mortality rate than bacterial meningitis.
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List two clinical features of viral encephalitis.
List two clinical features of viral encephalitis.
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Which of the following is a common clinical feature of ganglionopathy?
Which of the following is a common clinical feature of ganglionopathy?
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The onset of symptoms for viral meningitis typically occurs within ____ days.
The onset of symptoms for viral meningitis typically occurs within ____ days.
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Sjogren's syndrome is a potential cause of ganglionopathy.
Sjogren's syndrome is a potential cause of ganglionopathy.
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What is the most common causative organism for viral meningitis?
What is the most common causative organism for viral meningitis?
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Name a drug that is known to cause ganglionopathy.
Name a drug that is known to cause ganglionopathy.
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Match the condition with its primary clinical feature:
Match the condition with its primary clinical feature:
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CSF analysis for bacterial meningitis typically shows a normal sugar level.
CSF analysis for bacterial meningitis typically shows a normal sugar level.
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In ganglionopathy, the deep tendon reflex (DTR) may be _____ due to certain causes.
In ganglionopathy, the deep tendon reflex (DTR) may be _____ due to certain causes.
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Match the following causes of ganglionopathy with their respective characteristics:
Match the following causes of ganglionopathy with their respective characteristics:
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What is the maximum cell count range seen in CSF for bacterial meningitis?
What is the maximum cell count range seen in CSF for bacterial meningitis?
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What symptom is commonly associated with a lesion of the Common Peroneal Nerve?
What symptom is commonly associated with a lesion of the Common Peroneal Nerve?
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Plexopathy typically causes sharp pain.
Plexopathy typically causes sharp pain.
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Name one common cause of Mononeuritis Multiplex.
Name one common cause of Mononeuritis Multiplex.
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The biceps jerk reflex is associated with the root value ___.
The biceps jerk reflex is associated with the root value ___.
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Match the following neuropathy types with their descriptions:
Match the following neuropathy types with their descriptions:
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Which of the following is a sign of impending herniation?
Which of the following is a sign of impending herniation?
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CSF protein levels are elevated in bacterial infections.
CSF protein levels are elevated in bacterial infections.
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What is the normal range for CSF pressure in mm H₂O?
What is the normal range for CSF pressure in mm H₂O?
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In cases of viral CNS infections, the CSF glucose level is typically _____ compared to blood glucose.
In cases of viral CNS infections, the CSF glucose level is typically _____ compared to blood glucose.
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Match the following conditions with their CSF findings:
Match the following conditions with their CSF findings:
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What is a hallmark feature of axonal neuropathy?
What is a hallmark feature of axonal neuropathy?
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In demyelinating radiculoneuropathy, all reflexes are preserved early in the disease.
In demyelinating radiculoneuropathy, all reflexes are preserved early in the disease.
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Name one condition that is classified under inherited causes of demyelinating radiculoneuropathies.
Name one condition that is classified under inherited causes of demyelinating radiculoneuropathies.
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In axonal neuropathy, the ankle jerk reflex is typically ______ early in the course of the disease.
In axonal neuropathy, the ankle jerk reflex is typically ______ early in the course of the disease.
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Match the following features with the type of neuropathy:
Match the following features with the type of neuropathy:
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Study Notes
Generalized Tonic-Clonic Seizures (GTCS) and Syncope
- GTCS can be caused by metabolic imbalances like hypoglycemia, electrolyte abnormalities, and encephalopathy
- Electrolyte imbalances include low sodium, high sodium (rare), low calcium, low calcium and high phosphate, low magnesium, high magnesium (rare)
- Encephalopathy can stem from liver or kidney failure
- GTCS can be triggered by encephalitis, including viral encephalitis like HSV-1 encephalitis, autoimmune encephalitis with anti-NMDA antibodies, and paraneoplastic encephalitis
- Brain injury, post-stroke seizures, drug non-adherence or discontinuation can all contribute to GTCS
- Certain medications like theophylline, imipenem, cefepime, quinolones, lithium, and tricyclic antidepressants are known to trigger seizures
- Withdrawal seizures can occur from alcohol, barbiturates, and benzodiazepine withdrawal
- Syncope can manifest in various forms including vasovagal, cardiac, orthostatic hypotension, and situational syncope
CNS Infections: Bacterial Meningitis, Viral Meningitis, and Viral Encephalitis
- Bacterial meningitis is a serious condition characterized by a rapid onset, typically within 24-48 hours, with high fever, neck stiffness, vomiting, severe headache, photophobia, and altered mental status
- Viral meningitis has a more benign presentation, usually onset within 3- 5 days, with initial fever and headache peaking within 1-2 days, followed by nausea, vomiting, photophobia, neck stiffness, discomfort, distraction, confusion, lethargy
- Viral encephalitis is a severe condition affecting the brain parenchyma, with an onset of 1-2 days, and complications like refractory status epilepticus, complete behavioral/personality changes, confusion, speech defects, and focal neurological deficits.
- Common causative organisms for each infection:
- Enterovirus type 7 is the most common cause of viral meningitis
- HSV-1 is the most common cause of viral encephalitis followed by Japanese encephalitis virus in India
- Nipah virus is a rare cause of encephalitis
- CSF analysis is a vital tool for diagnosis, with specific patterns observed for each infection
- Bacterial meningitis typically shows low sugar, high protein, high cell count, and no red blood cells
- Viral meningitis presents with normal sugar, slightly elevated protein, and normal to slightly elevated cell count
- Viral encephalitis shows normal sugar, slight protein elevation, and normal cell count
- MRI can reveal hyperintensity in specific brain regions, suggesting encephalitis caused by HSV or Japanese encephalitis virus
- Untreated bacterial meningitis has a 100% mortality rate
Large vs Small Fibre Neuropathy
- Large fibre neuropathy affects the large nerve fibres responsible for proprioception, fine touch, vibration, joint sense, and can be caused by Friedrich ataxia, vitamin B12 deficiency, pyridoxine toxicity, and Taxanes
- Small fibre neuropathy is more common, affects small nerve fibres associated with pain and temperature sensation, and can result from various causes such as lepromatous leprosy, amyloidosis, diabetes, uremic neuropathy, vasculitis, autoimmune diseases like SLE and RA, HIV, Fabry's disease with severe pain, and Tangier's disease
- Large fibre neuropathy leads to tingling, paraesthesia, numbness, sensory ataxia, and loss of DTR (deep tendon reflexes)
- Small fibre neuropathy presents with burning pain, distal to proximal evolution of symptoms, burns, non-healing ulcers, and loss of temperature sense
- Large fibre neuropathy demonstrates loss of DTR, often with ankle jerk loss
- Small fibre neuropathy can lead to ANS (Autonomic Nervous System) complications like orthostatic hypotension, erectile dysfunction, excessive sweating, and tachycardia/bradycardia syndrome
- Vitamin B12 deficiency can be associated with copper and vitamin A deficiency
LMN Approach: Part 1
- Lower motor neuron (LMN) lesions can be categorized into sensorimotor, pure sensory and pure motor types
- Sensorimotor LMN lesions are the most common and are further divided into large fibre neuropathy, affecting the posterior column responsible for proprioception and fine touch, and small fibre neuropathy, impacting the spinothalamic tract responsible for pain and cruide touch, as well as the autonomic nervous system.
- Pure sensory LMN lesions manifest as ganglionopathy
- Pure motor LMN lesions can be caused by lead poisoning, drugs like Dapsone, and MMN-CB (multifocal motor neuropathy with conduction block)
- The posterior column functions in proprioception, position sense, fine touch, vibration, and joint sense via Aα fibres, pain via Aδ fibres, temperature via C fibres, and crude touch and pressure via Aβ fibres
- The spinothalamic tract carries pain, temperature, and crude touch and pressure via Aβ, C fibres, and is affected by small fibre neuropathy
- Motor and sensory pathways involve different fibre types:
- Motor pathways: primarily thick myelinated Aα fibres
- Sensory pathways: involve a mix of Aα/β fibres for myelinated fibres and thinly myelinated and unmyelinated C fibres
- Autonomic pathways: primarily thinly myelinated and unmyelinated C fibres
- Large fibres are responsible for muscle control, touch, vibration, and position perception
- Small fibres govern cold perception, pain, warm perception, pain, heart rate, blood pressure, sweating, GIT, and GUT function
Site of Lesion and Pathology
- Pure motor lesions suggest a problem at the anterior horn cell, neuromuscular junction or nerve root
- Sensorimotor lesions point to a problem with the plexus
- Pure sensory lesions often indicate a nerve or ganglion issue
Radiculopathy
- Compressive radiculopathy, most commonly caused by intervertebral disc prolapse (IVDP), is a form of nerve root compression
- Non-compressive radiculopathy can also be caused by Guillain-Barré syndrome
- Radiculopathy is characterized by asymmetrical pain, often sharp and brief, along the root distribution, worsened by coughing or movement
- It can also lead to weakness in the myotomal distribution and loss of DTR (deep tendon reflexes)
Root Values for Lower Limb Actions
- L1 root is responsible for hip flexion and adduction
- L2, L3, and L4 roots contribute to knee extension, dorsiflexion of the foot (tibialis anterior), and eversion of the foot
- L5 root governs knee flexion, hip extension, plantar flexion, and hip abduction
- S1 root controls plantar flexion and foot inversion
LMN Approach: Part 1 (Continued)
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The spinal cord is comprised of gray matter (horns) and white matter (tracts), with ventral horn containing α and γ motor neurons
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The LMN tract includes the anterior horn cell (AHC), cranial nerve nuclei, corticobulbar tract, and corticospinal tract
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Understanding the differences between Upper Motor Neuron (UMN) and LMN lesions is crucial for diagnosis
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UMN lesions affect motor functions, causing paralysis and a stiff, rigid muscle tone in the extremities
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LMN lesions result in weakness, hypotonia, fasciculations (twitching), and decreased reflexes in the affected areas
Ganglionopathy
- Ganglionopathy is a form of pure sensory neuropathy affecting the large fibres, primarily affecting the trunk, leading to severe asymmetrical truncal ataxia
- The arms are typically more affected than the legs
- DTR can be variable
Radiculopathy vs Plexopathy
- Radiculopathy, primarily resulting from IVDP, presents with asymmetric sensory and motor symptoms, characterized by sharp pain
- Plexopathy, often caused by tumors, displays asymmetric sensory and motor involvement, with dull aching, continuous, deep-seated pain and both proximal and distal features
- Nerve conduction study can help differentiate between the two, with anterior and posterior root involvement in radiculopathy, but intact paraspinal supply in plexopathy
Neurology
- A foot drop can be caused by various conditions: common peroneal nerve injury, sciatic nerve injury, and L5 radiculopathy
- L5 radiculopathy specifically produces foot drop, loss of inversion, and impaired hip abduction and eversion
- DTR and their corresponding root values are:
- Biceps jerk: C5-C6
- Triceps jerk: C6-C7
- Finger flexion: C8-T1
Mononeuropathy & Polyneuropathy
- Mononeuropathy involves a single nerve, such as carpal tunnel syndrome often associated with Amyloidosis
- Mononeuritis multiplex involves multiple single nerves and can be caused by various conditions like leprosy, HIV, amyloidosis, sarcoidosis, neurofibromatosis, vasculitis (including Polyarteritis nodosa), and cryoglobulinemia
- Polyneuropathy affects both sides of the body and involves multiple peripheral nerves
Demyelinating RadiculoNeuropathies - Causes
- Demyelinating radiculopathies are characterized by nerve root involvement, leading to widespread myelin loss
- Acute demyelinating radiculopathies:
- AIDP (Acute inflammatory demyelinating polyneuropathy) within 8 weeks
- POEMS (Polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes)
- Myeloma
- HIV
- CTS (Carpal Tunnel syndrome) - a form of mononeuropathy
- Inherited demyelinating radiculopathies:
- CMTD (Charcot-Marie-Tooth disease)
- Refsum's disease
CNS Infections (Continued)
- Imaging studies like CT or MRI should be avoided in certain situations including papilledema, space occupying lesion (SOL), abscess, impending herniation, Cushing reflex, recent onset seizure, impaired consciousness, and focal neurological signs
- CSF analysis is a valuable tool for diagnosing CNS infections
CSF Analysis: Comparing Different Infections
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Bacterial meningitis: Increased CSF pressure (180-350 mmH₂O), low CSF glucose (< 0.4), high CSF protein (> 100 mg/dL), high cell count
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Viral meningitis: Normal to slightly elevated CSF pressure, normal CSF glucose, normal to slightly elevated CSF protein, normal to slightly elevated cell count
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TB meningitis: High CSF pressure, CSF glucose between 0.4- 0.6, high CSF protein, and high cell count
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Fungal meningitis: Normal or elevated CSF pressure, normal CSF glucose, low CSF protein (<100 mg/dL), and normal to slightly elevated cell count
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The document emphasizes that the provided information is general and specific cases may differ.
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The document is version 1.0, Marrow 8.0, 2024
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Description
This quiz explores the causes and triggers of Generalized Tonic-Clonic Seizures (GTCS) and syncope. It covers metabolic imbalances, various medical conditions, and specific medications that can lead to these episodes. Test your understanding of the factors involved in GTCS and syncope.
