Summary
Highlights
Epilepsy is defined as a tendency for spontaneous, recurrent seizures due to abnormal electrical discharges in the central nervous system. It can be classified into partial and generalized epilepsy, with some cases being unclassifiable.
Partial epilepsy involves localized areas of the brain. The reticular formation and thalamus play a crucial role in maintaining consciousness. Altered consciousness during a seizure indicates involvement of the diencephalon.
Normal brain function relies on a balance between stimulatory (cholinergic, glutaminergic, aspartate) and inhibitory (GABAergic) systems. Epilepsy can result from an overactive stimulatory system or an underactive inhibitory (GABAergic) system causing abnormal electrical spread.
Partial seizures originate in one hemisphere, while generalized seizures involve both. Altered consciousness indicates diencephalon involvement. Simple partial seizures maintain consciousness; complex partial seizures involve altered consciousness.
It's crucial to differentiate between true seizures (epilepsy) and pseudo-seizures (psychological). Tongue biting, especially on the side, is highly suggestive of a true seizure. Investigations are warranted even after only one seizure.
Distinguishing between partial and generalized epilepsy is important because the first-line drugs differ. Carbamazepine is a first-line drug for partial epilepsy, while valproic acid is broad spectrum.
Valproic acid is a broad-spectrum anti-epileptic drug effective for various seizure types including partial, generalized tonic-clonic, absence, and myoclonic epilepsy. Other drugs are Ethosuximide and Clonazepam
Status epilepticus, a medical emergency, requires aggressive treatment to prevent brain damage or death. Initial treatment involves benzodiazepines (lorazepam or diazepam), followed by phenytoin or fosphenytoin, with general anesthesia (propofol or thiopental) as a last resort.
Securing the airway and administering oxygen come first. Phenytoin has significant side effects in females (ataxia, coarsening of facial features, hirsutism, gingival hyperplasia, osteomalacia, teratogenic effects) and should be avoided when possible. Fosphenytoin is preferred due to lower risk of thrombophlebitis and circular roses.
Anti-epileptic drugs work by either reducing cation loading (sodium or calcium influx) or increasing anion loading (chloride influx) or enhance cation deloading (potassium efflux). Examples include phenytoin, carbamazepine, valproic acid (sodium channel blockers), and ethosuximide (calcium channel blocker).