Seizure and Epilepsy PDF

Seizure and Epilepsy Tadele Mesfin (M.D.) DBU, AWHSC December 2024. Outline  Definition  Classification  Seizure Mimics  Approach to Patient  Status epilepticus  References  Objectives  Define seizure and epilepsy  Underst...

Seizure and Epilepsy Tadele Mesfin (M.D.) DBU, AWHSC December 2024. Outline  Definition  Classification  Seizure Mimics  Approach to Patient  Status epilepticus  References  Objectives  Define seizure and epilepsy  Understand the classification of seizure  Know presenting features of seizure disorders  Know how to approach a patient presented with seizure 3 Introduction Seizure  Is a sudden behavior change caused by electrical hyper-synchronization of neuronal networks in the cerebral cortex.  Can be provoked or unprovoked Epilepsy:  Refers to a clinical phenomenon rather than a single disease entity that is defined as a disorder of the brain characterized by an enduring predisposition to epileptic seizures  ILAE …..2014 definition  Epilepsy is a disease of the brain defined by any of the following conditions:  At least two unprovoked (or reflex) seizures occurring >24hrs apart………..Why?  One unprovoked (or reflex) seizure and a probability of further seizures similar to the general recurrence risk of 2 unprovoked seizures, occurring over the next ten years /at least 60%/  Diagnosis of an epilepsy syndrome Epidemiology  ~5–10% of the population will have at least one seizure, with the highest incidence occurring in early childhood and late adulthood  The incidence of epilepsy is ~0.3–0.5% in different populations throughout the world, and the prevalence of epilepsy has been estimated at 5–30 persons per 1000  CLASSIFICATION OF SEIZURES  Why do we classify seizures? 1. For proper diagnostic approach 2. Identifying particular etiologies, triggers 3. Selecting the appropriate therapy, 4. Providing potentially vital information regarding the prognosis 5. To inform the risk of comorbidities and mortality  Cont’d  The International League Against Epilepsy, is based on the; 1, Clinical features of seizures and 2, Associated electroencephalographic findings  Etiology or cellular substrate are not considered in this classification system (for now) 10 Focal Onset Seizures  Focal seizures arise from a neuronal network either discretely localized within one brain region or more broadly distributed but still within a cerebral hemisphere  Classified based on  Awareness (intact or impaired) and  Nature of the onset (motor or nonmotor).  Focal seizures can also evolve into generalized seizures.  Focal Seizures with Intact Awareness  Focal seizures can have motor manifestations (such as tonic, clonic, or myoclonic movements) or  nonmotor manifestations (such as sensory, autonomic, or emotional symptoms) without impairment of awareness.  Three additional features of focal motor seizures are worth noting.  Jacksonian march- represents the spread of seizure activity over a progressively larger region of motor cortex.  Todd’s paralysis  epilepsia partialis continua  Focal Seizures with Impaired Awareness  The patient is unable to respond appropriately to visual or verbal commands during the seizure and has impaired recollection or awareness of the ictal phase  The seizures; 1. Frequently begin with an aura 2. Are usually accompanied by automatisms: 3. Postictal confusion ( seconds to hours) 4. Anterograde amnesia and transient postictal neurologic deficit following the seizure (caused by postictal inhibition of the cortical regions most involved in the seizure itself)  GENERALIZED ONSET SEIZURES  Generalized seizures arise at some point in the brain but immediately and rapidly engage neuronal networks in both cerebral hemispheres.  Absence Seizures (Typical vs Atypical)  Generalized, Tonic-Clonic Seizures  Atonic Seizures  Myoclonic Seizures  Generalized Absence Seizures  Typical absence seizures are characterized by a sudden blank stare with motor arrest, usually lasting less than 15 seconds.  The individual is usually unresponsive and unaware.  The seizure ends as abruptly as it starts, and the patient returns immediately to a baseline level of function with no postictal confusion but may have missed conversation and seems confused as a result. Generalized Absence Seizures Typical Atypical Absence Absence Seizures Seizures  Longer duration and less abrupt in onset and cessation  Sudden, brief lapses of consciousness without loss of  more obvious motor signs postural control   Usually associated with diffuse or Usually accompanied by subtle, bilateral motor signs multifocal structural abnormalities of the brain  generalized 2.5- to 4-Hz spike- and-wave activity with a normal interictal background  Less responsive to anticonvulsants Generalized Tonic-Clonic Seizures  The main seizure type in ∼10% of all persons with epilepsy  Themost common seizure type resulting from metabolic derangements  The seizure usually begins abruptly without warning, aura is not common 19 Tonic phase (10 to 20 seconds Clonic phase (30 to 90 seconds)  Sudden loss of consciousness  Loss of posture with high risk of self Brief, violent, generalized flexor injury depending on activity contractions alternating with  Brief flexion of arms, eyes deviated progressively longer muscle upward relaxation  Extension of back, neck, arms, and -cyanosis legs -possible cheek or tongue biting  Involuntary crying out from -foamy salivation contraction of respiratory muscles -possible loss of bowel or bladder  Shallow respiration, cyanosis may control occur -ends with deep inspiration, sustained muscle relaxation  Ends with tremors that gradually slow and merge with clonic phase 20  Cont’d  Postictal phase (Minutes to several hours) Headache, mild confusion Muscles sore Fatigue, patient may sleep and awake refreshed  Other features Fast heart rate Elevated blood pressure Respiratory and metabolic acidosis Dilated pupils Risk of aspiration pneumonia Atonic Seizures  Characterized by sudden loss of postural muscle tone lasting 1–2 s.  Consciousness is briefly impaired, but there is usually no postictal confusion.  A very brief seizure may cause only a quick head drop or nodding movement,  Whereas a longer seizure will cause the patient to collapse 22 Myoclonic Seizures  Myoclonus is a sudden and brief muscle contraction that may involve one part of the body or the entire body.  Pathologic myoclonus is most commonly seen in association with  Metabolic disorders,  Degenerative CNS diseases,  Anoxic brain injury 23  Epilepsy Syndromes An epilepsy syndrome represents a complex of clinical features, signs, and symptoms that together define a distinctive, recognizable clinical seizure disorder. Some syndromes are highly correlated with a single specific etiology (eg, severe loss of function SCN1A variants in Dravet syndrome). In contrast, others may be due to a broad range of causes (eg, infantile epileptic spasms syndrome or Lennox-Gastaut syndrome). Epilepsy Syndromes JUVENILE MYOCLONIC LENNOX-GASTAUT EPILEPSY SYNDROME  Characterized by bilateral defined by the following triad: myoclonic jerks that may be 1) multiple seizure types single or repetitive. 2) EEG showing slow ( 5 minutes Elevation in prolactin Frequent Rare Elevation in ck Frequent Rare  Management Principles  Ensure that the patient has a seizure disorder and not a condition that mimics epilepsy  Confirm weather the seizure is provoked or unprovoked  First time seizure or Recurrent seizure  Iffirst time unprovoked seizure, assess risk of recurrence 42 Cont’d Acute symptomatic seizure  Focused on correction of the acute provoking illness and preventing its recurrence Some indications for antiseizure medications  Severe electrolyte disturbances with dehydration  Seizures due to meningitis or encephalitis  Severe traumatic brain injury requiring intensive care 43  Cont’d First unprovoked seizure  Immediate AED initiation Vs Deferring till second seizure  Seizure recurrence and long-term outcomes Factors influencing the decision  The risk for recurrent seizures  The relative risk reduction with initiation  The risks of not treating  The risks of chronic antiseizure medication therapy 44 Cont’d Risk factors associated with recurrent seizures include the following:  Abnormal neurologic examination (focal findings, ID)  Prior brain insult such as a stroke or trauma,  EEG with epileptiform abnormalities,  A significant brain imaging abnormality  A nocturnal seizure. 45  Cont’d Initiation of anti-seizure medication  Seizure classification is an important element in designing the treatment plan  Start with 10-20 % of the maintenance dose of single drug  Gradually escalate the dose till seizure controlled or adverse effects develop  Add additional drug if not controlled with the first drug of choice Follow-up and monitoring  Utility of serum drug levels  Monitoring for specific drugs  Monitoring for adverse events 46  Cont’d  Treatment of underlying conditions that cause or contribute to the seizures,  Avoidance of precipitating factors,  Suppression of recurrent seizures by prophylactic therapy with antiepileptic medications or surgery, and  Addressing a variety of psychological and social issues When to Discontinue Therapy The following patient profile yields the greatest chance of remaining seizure free after drug withdrawal:  Complete medical control of seizures for 1–5 years;  Single seizure type  Normal neurologic examination  No family history of epilepsy;  Normal EEG. 48  Pregnancy and epilepsy  Seizure frequency during pregnancy will remain unchanged in ~50% of women, increase in ~30%, and decrease in ~20%.  Always consider eclampsia in new onset seizure during pregnancy and post partum period  Incidence of fetal abnormalities is 5-6% (CVS & MSS)  Valproic acid is Category X drug;  Except Topiramate, newer drugs are safer than valproate 49 Cont’d  Pregnant women should be maintained on effective AED therapy.  Put on monotherapy at the lowest effective dose, especially during the first trimester  Give folate (1-4mg/day)  Treat all pregnant mothers with oral vitamin K  The infant should receive intramuscular vitamin K at birth 50 Status Epilepticus  Refers to continuous seizures or repetitive, discrete seizures with impaired consciousness in the interictal period  Status epilepticus has numerous subtypes, including  Generalized convulsive status epilepticus (GCSE) (e.g., persistent, generalized electrographic seizures, coma, and tonic-clonic movements) and  Nonconvulsive status epilepticus (e.g., persistent absence seizures or focal seizures with confusion or partially impaired consciousness, and minimal motor abnormalities)  Management  The first steps in the management of a patient in GCSE are to attend to any:  ABCDs  Manageor Rule out Causes (hypoglycemia, Ethanol, Eclampsia, Poisoning….)  Anticonvulsant therapy should then begin without delay  Search for underlying cause  Other Management Issues  EPILEPSY COMORBIDITIES 1. Psychiatric Problems 2. Psychosocial Issues 3. Driving 4. Employment  Mortality of Epilepsy  Risk of death 2-3x greater than expected in a matched population without epilepsy.  Most of the increased mortality is due to the underlying etiology of epilepsy (e.g., tumors or strokes)  A significant number of patients die from accidents, status epilepticus, and a syndrome known as sudden unexpected death in epilepsy (SUDEP), which usually affects young people with convulsive seizures and tends to occur at night). Questions? Thanks!!