Evidence of memory impairment in asymptomatic individuals with hippocampal atrophy

Our objective was to investigate if MRI-determined hippocampal atrophy (HA) is associated with memory deficits independent of seizure frequency. We studied three groups of individuals: (1) 10 asymptomatic first-degree relatives of patients with familial mesial temporal lobe epilepsy (FMTLE), all of them with HA; (2) 14 patients with benign FMTLE, 9 with HA, and 5 with normal hippocampal volumes; and (3) 16 patients with refractory FMTLE, all but one with HA. HA was associated with lower scores on general memory (P=0.015), verbal memory (P=0.020), and delayed recall (P=0.028), even in those with no or few seizures in life. General linear model analyses showed that the interaction between seizure outcome and HA was associated with worse verbal memory (P=0.029), visual memory (P=0.022), and delayed recall (P=0.039) as compared with each of these factors independently. Our findings suggest that seizures and HA are independently associated with memory impairment.