Abstracts

RATIONALE: Tiagabine is an effective drug for adjunctive therapy of partial onset seizures. It has been reported to cause absence status epilepticus in a few patients with primary generalized epilepsies.
We report a case of status epilepticus of the complex partial type in a patient with refractory partial onset seizures treated with tiagabine, with EEG/videotape documentation of resolution with discontinuation of tiagabine.
METHODS: A 66-year old man was admitted to the hospital for evaluation of a confusional state. Eighteen years earlier, a subfrontal meningioma had been partially resected, after which he developed epilepsy. Complex partial seizures, some secondarily generalized, occurred weekly despite trials of multiple medications. Eighteen months earlier, tiagabine had been added to his regimen of valproate and gabapentin, and the dose slowly increased. Although some sleepiness and lethargy were reported, seizure frequency improved. Nine days before admission, the tiagabine dosage was increased from 48 to 52mg daily. His wife noted him to be confused and partially responsive three days later, without any observed seizures. He was admitted and placed on continuous EEG/video monitoring.
RESULTS: The EEG revealed diffuse arrhythmic delta activities. There were also sharp-and-slow wave complexes in the right frontal and central regions occurring in long trains of 5 to 60 seconds, with pauses of 5-20 seconds., He was disoriented, mumbling brief replies, and refusing to eat or follow commands. A diagnosis of the continuous form of complex partial status epilepticus was made, and tiagabine was increased to 60mg daily. The following day, he was more confused and the sharp-and-slow wave complexes were continuous. Tiagabine was then abruptly discontinued. Within 12 hours of the last dose, he became responsive and oriented, and the EEG displayed alpha and beta rhythms with some focal theta slowing in the right frontal region, his baseline EEG pattern for many years. No other changes in his antiepileptic medications had been made, and no benzodiazepines or other acute treatments administered.
CONCLUSIONS: This patient may have developed complex partial status epilepticus as a dose-related adverse effect of tiagabine. Although this phenomenon has been reported for absence and other generalized forms of nonconvulsive status epilepticus, frontal lobe status of this type precipitated by tiagabine has not been described, nor has the dramatic resolution of the EEG abnormality with drug discontinuation. In rare cases, worsening of seizures with high doses of other antiepileptic drugs has been seen; this effect may not be unique to tiagabine. Physicians should be aware that sometimes less, not more, medication is needed for resolution of complex partial status epilepticus.
Disclosure: Grant - Abbott Laboratories; Consulting - Abbott Laboratories Honoraria - Abott Laboratories