Epilepsy: Cellular Mechanisms and Classification

Cellular Mechanisms of Seizure Generation

• Cellular mechanisms of seizure generation not specified in the text.

Clinical Classification of Epilepsy

• Acute symptomatic causes of epilepsy: fluid and electrolyte imbalance (Na+, Ca+, Mg+), metabolic disorders (diabetic coma, hypoglycemic coma, uremia, hypothyroidism, alkalosis, B6 deficiency), drugs and toxins, stroke, head injury, CNS infection.

Etiology of Epilepsy

• Remote symptomatic causes of epilepsy not specified in the text.

Drugs That May Cause Seizures

• Antimicrobials: penicillins, cephalosporins, quinolones, Amphotericin, fluconazole, isoniazid, zidovudine.
• Cardiovascular drugs: lignocaine (intravenous), procaine.
• Antidepressants: tricyclic antidepressants, lithium, phenothiazines, baclofen, clozapine.
• Antipsychotic drugs: cocaine, Amantadine, antimuscarinics.
• Stimulants: aminophylline, caffeine, theophylline.
• Other CNS drugs: methylphenidate.

Precipitating Factors

• Reflexly induced seizures (photosensitive epilepsy).
• Non-specific factors: sleep deprivation, psychological stress, before menstruation, estrogen medication, hypoglycemia, B6 deficiency, psychotropic drugs, electrolyte imbalance.

Predictors of Poor Outcome (Intractability)

• Not specified in the text.

Clinical Features of Epilepsy

• Partial seizures:
• Simple partial seizures: motor, autonomic, psychic, somatosensory, special sensory.
• Complex partial seizure (TLE, psychomotor).
• Partial seizure 2ry generalized.
• Generalized seizures:
• Petit mal.
• Grand mal.
• Tonic seizure.
• Clonic seizure.
• Tonic clonic seizure.
• Atonic seizure.
• Myoclonic seizure.
• Special seizure syndromes:
• Febrile convulsions.
• Infantile spasm (West syndrome).

Strategy for Medical Treatment of Epilepsy

• Starting therapy: when two or more unprovoked seizures have occurred in a short period (6 months up to 1 year).
• How to start antiepileptic drugs: use a first-line drug for the seizure type, start at a low dose and introduce slowly, add additional drugs if the first drug is pushed to its maximum tolerated dose and seizure still not controlled.
• Adjuvant therapy: B6, folic acid.

Status Epilepticus

• Definition: continuous seizures with no recovery of consciousness lasting for longer than 30 minutes.
• Clinical data: hyperpyrexia, hypotension, acidosis, hypoglycemia, cardiac dysrhythmia, shock, reflex pulmonary edema, aspiration pneumonia, neuronal damage which may be irreversible.
• Causes: usually organic (metabolic, infection, stroke, trauma, tumors, sudden withdrawal of AED).
• Management:
• On admission: care of vital functions; BP, temp, respiration, heart rate, intubations may be required and low flow O2 inhalation.
• Start an IV infusion of glucose 5% and 0.9 saline 500ml, 100mg thiamine.
• Draw blood sample for antiepileptic serum level, glucose level, electrolytes, renal and hepatic function tests, blood gases.

This quiz covers the basics of epilepsy, including cellular mechanisms of seizure generation, clinical classification, etiology, and acute symptomatic causes. It's a great resource for neurology students and practitioners.