Congenital porencephaly and hippocampal sclerosis

Abstract

We studied clinical features and seizure localization in 14 patients with porencephaly and intractable seizures. Perinatal complications were present in nine patients, childhood febrile convulsions in two, congenital hemiparesis in 12, and intellectual impairment in seven. Ten patients had psychoparetic complex partial seizures (CPS), three had sensorimotor simple partial seizures, and one had generalized tonic-clonic seizures. Surface EEG showed temporal onset in nine patients (one bitemporal) and extratemporal onset in four. MRI showed porencephaly in the distribution of the middle cerebral artery in eight patients, posterior cerebral in three, internal carotid in one, and multiple vessels in two. MR-based volumetry revealed hippocampal formation atrophy in 13 patients (eight unilateral and five bilateral) and amygdalar atrophy in 10 patients (nine unilateral and one bilateral). Hippocampal formation atrophy was concordant with CPS semiology in 10 patients (71%) and with EEG temporal localization in nine patients. Two patients had pathologic confirmation of mesial temporal sclerosis and were seizure free after temporal lobectomy. We conclude that mesial temporal sclerosis often coexists with porencephaly and is the likely seizure focus in the presence of concordant electroclinical data. This recognition implies that effective surgical intervention can be offered to certain patients with porencephaly-related seizure disorders. The dual pathology and association with perinatal cerebral vascular occlusion suggest a common ischemic pathogenesis.

Congenital destructive hemispheric lesions and epilepsy: clinical features and relevance of associated hippocampal atrophy

“…We identified CPS in 71% and 57% of the patients with associated HA in the cystic and atrophic groups respectively, similar to previous studies that showed a concordance of 77% between porencephaly associated HA and CPS 6,7 .…”

“…In a series of porencephaly, that represents a different patient population from the "pure" TLE, HA was concordant with interictal EEG localization to the ipsilateral temporal region in 69.2% of the patients 6 . In the present study we found EEG localization concordant with HA in 85.7% of patients with cystic lesions and in 71.4% of patients with atrophic lesions.…”

“…These insults result either in cystic or atrophic lesions commonly within a particular vascular distribution. The advances in neuroimaging techniques, particularly magnetic resonance imaging (MRI), turned it possible to re-evaluate the spectrum of structural brain abnormalities associated with the more obvious lesion (cystic or atroph) [3][4][5][6][7] . A striking association has been found between these lesions and atrophy of medial temporal structures, suggesting that they share a common pathogenic mechanism in these cases [5][6][7] .…”

Congenital porencephaly with cerebellar hypoplasia in a Holstein calf: a case report

“…The extent of porencephaly does not correlate with the severity of clinical signs in people (Ho et al, 1998). In a previous report of porencephaly in a calf, a unifocal defect was located in the frontoparietal region (Lee et al, 2009) and in the present case the defect was located in the same area suggesting an anatomic predilection for unifocal porencephaly in this region of the brain.…”

“…Hydrocephalus (Ho et al, 1998;Lee et al, 2009), intracranial arachnoid cysts (Lee et al, 2009), vascular anomalies (Stewart et al, 1978), intracranial haemorrhage (Moinuddin et al, 2003), optic chiasm agenesis (Lee et al, 2009), optic nerve hypoplasia (Lee et al, 2009) and corpus callosum agenesis (Lee et al, 2009) have been seen in association with porencephaly in humans and animals. In the calf presented here, a porencephalic defect was identified along with hydrocephalus and cerebellar hypoplasia.…”