Abstracts

Rationale: Video EEG monitoring (vEEG) is a valuable tool in diagnosis of spells and evaluation for epilepsy surgery. Provocative measures are generally used to induce epileptic seizures (ES) including tapering antiepileptic drugs (AED). vEEG has potential risks including status epilepticus (SE), seizure related trauma, and post-ictal psychosis. However the frequency of complications is not well described. Methods: This was a retrospective chart review of adults with epilepsy who had scalp vEEG at Mayo Clinic Arizona in 2005-6 for spell classification or presurgical evaluation. Standard safety precautions included 24 hour monitoring of video and EEG by trained technicians, protocols for treatment of seizure clusters (SC), safety belts, bed padding and direct supervision when out of bed. The number, type and timing of ES was noted. The following adverse outcomes were evaluated: SC, SE, post-ictal psychosis, falls, orthopedic or dental injury, aspiration pneumonia, pulmonary edema, cardiac arrest, intensive care transfer. SC were defined as 3 or more partial complex (PCS) or generalized (GTC) ES in a 4 or 24 hour period. Results: 149/423 vEEG admissions met inclusion criteria. Mean age was 44.2 years (range 18 to 88 yrs). 50% were women. 40% were admitted for spell classification and 60% for presurgical evaluation. 124 (83%) had partial epilepsy, 12 generalized epilepsy, and 12 mixed ES and psychogenic seizures. Average length of stay was 5 days (range 2-18 days). A total of 752 ES were recorded, with 73% of patients having 1 or more ES and a mean of 5 ES per person (range 0-150). There were 258 simple partial seizures in 21 patients (14% of admits), 424 PCS in 74 patients (50% of admits), and 70 GTC in 36 patients (24% of admits). The mean time to first seizure was 2 days. 24 and 4 hour SC occurred in 23.5% and 9% of admissions respectively. 25% of SC required treatment with intravenous benzodiazepine or AED. Only 1 seizure lasting 5-30 minutes and 1 episode of partial SE occurred; both responded to intravenous medication. There were no deaths, ICU transfers, falls, dental injuries, or pulmonary complications. 3 patients had cardiac complications: 1 ictal asystole treated with pacemaker, 1 ictal arrhythmia, 1 ictal ST segment elevation. 2 patients had post-ictal psychosis. 4 had vertebral compression fractures from GTC (2.7% of all admits, 11% of patients with GTC). The overall complication rate was 32%, however only 15% had complications requiring intervention. There was no difference in length of stay for those with vs without complication. Conclusions: vEEG is a generally safe procedure. Complications occur but rarely require intervention. SC were present in only 25% of patients as compared to earlier reports of 50-60% and rarely needed treatment. While it is important to be alert for SC and SE during vEEG, they do not necessarily result in significant morbidity or increased length of hospitalization. Of noted adverse outcomes, only vertebral fractures required treatment beyond discharge. Clinicians should be alert to potential fractures with GTC during vEEG.