Abstracts

RATIONALE: Continuous EEG monitoring (cEEG) in the ICU setting has documented frequent non-convulsive seizures in patients with acute brain injury such as head trauma. However, the incidence of non-convulsive seizures in patients with spontaneous (non-traumatic) intraparenchymal cerebral hemorrhage (ICH) is unknown. The purpose of this study was to review the utility of cEEG in these patients.
METHODS: Medical charts of neurological ICU patients from 1998 to 2002 were reviewed. Patients were included in this study if they had spontaneous ICH and were monitored by cEEG. Patients were excluded if they had ICH resulting from trauma, hemorrhagic infarct, prior epilepsy, or primary subarachnoid hemorrhage. 34 patients met these criteria.
RESULTS: All 34 patients had abnormal mental status at some point. Seizures occurred in 7/34 (21%) patients. 4/34 (12%) had non-convulsive seizures, which were diagnosed on the basis of cEEG monitoring alone. In all 4 patients, the seizures occurred despite initiation of prophylactic phenytoin on admission. 3/14 (21%) patients with lobar ICH had non-convulsive seizures on cEEG vs. 1/20 (5%) patients with non-lobar (i.e. basal ganglia, cerebellar) ICH. Extension of ICH to the ventricles (IVH) was not associated with increased frequency of non-convulsive seizures (2/20 with IVH vs. 2/14 without IVH). 2/7 (29%) patients who underwent surgical evacuation had non-convulsive seizures, whereas 2/27 (7%) patients who did not have surgical evacuation developed non-convulsive seizures. None of the above differences was statistically significant.
CONCLUSIONS: Non-convulsive seizures are not uncommon in patients with spontaneous ICH and abnormal mental status, especially lobar ICH. Continuous EEG monitoring may be indicated in these patients.