Abstracts

Behavioral modification is expected during the intracarotid sodium amytal testing (ISAT). It may happen either shortly after the injections or along the recovery period, being generally subtle and easily manageable. On occasion, inappropriateness, extreme agitation and even aggression may be observed. Although rare, those reactions are potentially misleading, promoting testing delay, inaccurate data or testing abortion. We report a series of such cases, along with a literature review, seeking for features that might be of help in predicting their occurrence.
We reviewed 129 patients with refractory epilepsy who underwent a comprehensive non-invasive surgical evaluation at our institution between 1997 and 2002. Eighty-one patients were subjected to the ISAT. Our protocol is an authorized and modified version (adapted to language and culture) of the Minnesota Epilepsy Group ISAT Protocol. A pre-injection cerebral angiography and continuous EEG monitoring were performed in all patients.We use a 125mg bolus injection of Sodium Amytal in each side, with injections being 30 minutes apart. Patients presenting with bizarre behaviors were reviewed for seizure history, video-EEG/imaging data, psychiatric profile and ISAT performance.
Five (5.1%) patients (2 male, 3 female, ages 13-38 years) presented with bizarre reactions during the ISAT. Four patients had temporal lobe epilepsy (all with unilateral hippocampal atrophy, unilateral interictal/ictal epileptiform discharges, and pathology proven mesial temporal sclerosis).One patient had a parietal glioma (with a lateralized ictal EEG and confirmatory pathology).Bizarre reactions included 2 patients with extreme agitation (screaming, violent aggressive behavior), 2 patients with inappropriate behavior (an elaborated seductive proposal to a team member and a report on sexual abuse accompanied by copious crying and cursing) and 1 adult patient presented with an infantile behavior (childish voice, giggling,uncooperative). Four patients had a prior diagnosis of mild mood disorder (depression). An early EEG crossover phenomenon ([lt]10 seconds) was noted in 5/9 injections, being 4/5 in the dominant hemisphere (p=0.047). Additional analysis of 93 injections on our own ISAT patients presenting with no bizarre behaviors, showed an early crossover phenomenon in 40 injections (24 in the dominant hemisphere)(p=0.048). Thus, neither side of injection, nor the latency to crossover were considered valid predictores.
Bizarre reactions during the ISAT are uncommon, occurring in about 5% of the procedures. Our series matches the literature for both the frequency and main features of such behaviors. Like others, we did not identify clinical or laboratorial predictors of bizarre reactions. Thorought explanations plus test simulations should be encouraged on ISAT candidates, aiming to reduce anxiety and minimize test complications.