Generalised seizures

These are normally based on the use of either electrical stimulation or chemical convulsants. When applied generally, i.e. an electric shock to the whole brain or convulsants injected systemically, the resulting convulsions are indicative of generalised seizures. If they are applied locally to specific brain areas, the same approaches induce activity indicative of partial seizures. Also some animals can be bred in which seizures either occur spontaneously or can be induced easily by appropriate sensory stimulation. 

If a subconvulsive stimulus is applied, generally in rats, at regular intervals, e.g. daily for some two weeks to a specific brain area, especially the amygdala or hippocampus, then eventually full localised (partial) or secondary generalised seizures develop. A similar effect can be obtained by the repeated localised injection of subconvulsive doses of some convulsants. The ability of a drug to reduce the kindled seizure itself may be indicative of value in partial seizure but if it slows the actual development of kindling that may indicate some ability to retard epileptogenesis. 

Epilepsy affects 5-10 per 1000 of the general population. It is due to sudden, excessive depolarisation of some or all cerebral neurons. This may remain localised (focal seizure) or may spread to cause a secondary generalised seizure, or affect all... 

Partial and/or secondary generalised seizures Drugs of choice ... 

Uses. Carbamazepine is used for secondary generalised and partial seizures, and primary generalised seizures. Because another antiepilepsy drug (phenytoin) was sometimes beneficial in trigeminal neuralgia, carbamazepine was tried in this condition, for which it is now the drug of choice... 

Oxcarbazepine is as effective as carbamazepine, sodium valproate and phenytoin in the treatment of partial and secondary generalised seizures, for which it is used either as monotherapy or add on therapy. 

Uses. Phenytoin is used to prevent all types of partial epilepsy, whether or not the seizures thereafter become generalised, and to treat generalised seizures and status epiepticus. It is not used for absence attacks. 

Antiepilepsy members include phenobarbital (phenobarbitone) (t/ 100 h), methylphenobarbital and primidone (Mysoline), which is largely metabolised to phenobarbital, i.e. it is a prodrug. They are still used for generalised seizures sedation is usual. 

Vigabatrin is effective in partial, secondary generalised seizures which are not satisfactorily controlled by other anticonvulsants, and in infantile spasms, as monotherapy. It worsens absence and myoclonic seizures... 

Hansen HC, Drenck NE. Generalised seizures after etomidate anaesthesia. Anaesthesia 1988 43(9) 805-6. 

Based on an early possible report, the manufacturer notes that generalised seizures have been reported in patients who received ganciclovir with imipenem-cilastatin. They recommend that ganciclovir and its prodrug valganciclovir should not be used with imipenem unless the benefits outweigh the risks.No further reports of this interaction appear to have been published, or reported to the manufacturer. Note that both ganciclovir and imipenem alone may cause seizures. 

A 77-year-old man, who underwent a right internal carotid endarterectomy, developed generalised seizures after injection of 1.5 mL lidocaine into the carotid sinus. The patient was discharged 2days later in good condition. 

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