Freeze Lesion-Induced Focal Cortical Dysplasia Predisposes to Atypical Hyperthermic Seizures in the Immature Rat

Autor: Morris H. Scantlebury, Pierre-Luc Ouellet, Caterina Psarropoulou, Lionel Carmant
Rok vydání: 2004
Předmět:
Zdroj: Epilepsia. 45:592-600
ISSN: 1528-1167
0013-9580
DOI: 10.1111/j.0013-9580.2004.51503.x
Popis: Summary: Purpose: To determine the effects of focal corti- cal dysplasia on the behavioral and electrographic features of hyperthermia-induced seizures (HSs) in rats. Methods: A right sensorimotor cortex freeze lesion was in- duced in postnatal day 1 (P1) rat pups, and HSs were provoked at P10 under continuous monitoring of core temperature; EEGs were recorded from the right amygdala during and after hyper- thermia. Controls included both sham-operated at P1 and na¨ ive rats. Results: HSs began with jaw myoclonus, followed by hindlimb clonus and generalized convulsions (GCs), and termi- nated by a period of posthyperthermia depression. The threshold temperature and latency of jaw myoclonus were similar across the groups. However, both the threshold temperature and latency of GCs were significantly lower in lesioned pups than in controls (40.5 ± 0.5 ◦ C, n = 24, vs. 42.0 ± 0.2 ◦ C, n = 21; p < 0.001; 6.7 ± 0.6 min, n = 20, vs. 8.4 ± 0.6 min, n = 22; p < 0.05). In lesioned pups, the threshold and latencies for jaw myoclonus and hindlimb clonus were similar, whereas in controls, the pro- gression from one to the other was marked by significant dif- ferences in both parameters. Posthyperthermia depression was longer in lesioned (13.3 ± 1.2 min, n = 21) than in control (8.0 ± 0.8 min, n = 20; p < 0.0001) pups. Ictal EEG activity was recorded during both behavioral seizures and posthyperthermia depression. Conclusions: An HS in rats with a localized freeze lesion results in lower threshold GC and prolonged ictal manifestations, thus supporting a pathophysiologic link between focal cortical dysplasia and atypical febrile seizures, conditions that have a high prevalence in children with mesial temporal lobe epilepsy.
Databáze: OpenAIRE
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