PhD student 4BRAIN, Department of Head and Skin, Ghent University, Ghent, Belgium, Belgium
Rationale: Intracerebral hemorrhage (ICH) is a known risk factor for the development of acute symptomatic seizures and late unprovoked seizures ( > 7 days post-stroke). An animal model to study these post-ICH seizures is currently lacking. The aim of this study was to investigate the occurrence of seizures in the rat collagenase model using long-term video-EEG monitoring (VEM). Methods: Male Sprague-Dawley rats (n=16) were implanted with four scalp electrodes (4 AP ±2 ML and -4.5 AP ±3 ML) and a craniotomy (0.5 AP 3.5 ML) for later injection of collagenase was made and filled with bone wax. After one week of baseline VEM, 0.6 U of collagenase was injected (6 DV) in left striatum via the earlier performed craniotomy. Immediately following ICH-induction, the rats were reconnected to the VEM for 180 days to assess the occurrence of clinical and electrographic seizures. Severity of clinical seizures was scored following the Racine scale. Results: Acute symptomatic seizures occurred in 6/16 animals (38 %), with the first seizure starting between six and 80 hours after ICH induction. Behavioral changes could be observed in all acute symptomatic seizures. Mean seizure duration was 122±19 s. One animal had a status epilepticus (SE) after 56 hours which lasted for more than 24 hours. After 180 days of VEM, late unprovoked seizures were present in 5/16 animals (31%), of which two animals also had acute symptomatic seizures (including the SE animal). The late unprovoked seizures started between 13 and 172 days post-ICH and had a mean seizure duration of 60±17 s. These late unprovoked seizures were all clinical and more severe than the acute symptomatic seizures (Racine scale 4.7±0.1 vs 3.9±0.2, Mann-Whitney U test p< 0.0001). Conclusions: Both acute symptomatic and late unprovoked seizures were frequently seen in the rat collagenase model. Therefore this model seems suitable to study post-ICH seizures and post-ICH epilepsy. Funding: Please list any funding that was received in support of this abstract.: C.G. is supported by a grant of Research Foundation Flanders (FWO, grant 1181719N) and is laureate of the Helaers Research Prize for Stroke.