MRI volumetric findings were correlated with seizure patterns and EEGs in 14 patients with intractable seizures, porencephaly and hippocampal sclerosis (HS) in a study at the University of Alabama, Birmingham, AL. Psychoparetic complex partial seizures (CPS) occurred in 10, simple partial seizures in 3, and generalized TC seizures in 1. EEGs showed ictal or interictal temporal localization in 9 (64%) patients with CPS. Porencephaly was distant from the temporal area and in the middle cerebral artery distribution in 8; it was related to the posterior cerebral in only 3. Hippocampal formation atrophy in 13 (93%) patients was concordant with CPS and EEG temporal localization in 70% cases. Ten had amygdala atrophy, concurrent with HS in 57%. Two with HS were seizure free after temporal lobectomy. A common ischemic pathogenesis is proposed for the dual pathology involving both porencephaly and mesial temporal sclerosis. HS is the most likely origin for CPS in patients with EEG temporal localization. [1]

COMMENT. Patients presenting with intractable complex partial seizures and congenital porencephaly should be evaluated with MRI for coexistent mesial temporal sclerosis. Hippocampal formation atrophy is the more likely origin for the seizures in patients with dual pathologies, particularly when the EEG shows localization to the temporal lobe.

Quantitative MRI of the hippocampus [2], and Proton magnetic resonance spectroscopic imaging [3] were used in the presurgical evaluation of temporal lobe epilepsy at the National Hospital, London, UK, and Montreal Neurological Institute, Canada.