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This study explored structural correlates of immediate and delayed face recognition in 22 nonsurgical patients with nonlesional, unilateral mesial temporal lobe epilepsy (TLE, 10 left/12 right). We measured T2 relaxation time bilaterally in the hippocampus, the amygdala, and the fusiform gyrus. Apart from raised T2 values in the ipsilateral hippocampus, we found increased T2 values in the ipsilateral amygdala. Patients with right TLE exhibited impaired face recognition as a result of a decrease from immediate to delayed recognition. Higher T2 values in the right than left fusiform gyrus or hippocampus were related to worse immediate face recognition, but did not correlate with 24-hour face recognition. These preliminary results indicate that structural changes in the fusiform gyrus and hippocampus may influence immediate face recognition deficits, but have no linear influence on long-term face recognition in TLE. We suggest that long-term face recognition depends on a right hemispheric network encompassing structures outside the temporal lobe.

A 67-year-old, right-handed woman became unable to recognize familiar faces following a period of nonconvulsive status epilepticus. Neuropsychological assessment revealed a relatively selective impairment of familiar face recognition in the absence of low-level visual deficits or widespread cognitive impairment. MRI scanning demonstrated an isolated lesion, probably a venous angioma, involving the left fusiform gyrus, mirror-symmetrical to the site typically linked to prosopagnosia. Potential explanations for the patient's prosopagnosia include seizure-related damage to a left fusiform region required for fully competent face recognition and damage to the contralateral fusiform gyrus via interhemispheric connections. Focal neuropsychological deficits in patients with refractory partial epilepsy who develop nonconvulsive status epilepticus may be underdiagnosed.

A 23-year-old right-handed woman developed isolated transient prosopagnosia following surgical resection of a right posterior temporal seizure focus. At 18 years of age she had developed secondarily generalized tonic-clonic seizures. Preoperative neuropsychological evaluation was normal, and neurological examination revealed only a left superior quadrant achromatopsia. MRI revealed a circumscribed lesion in the right inferolateral temporo-occipital junction. Following surgery she was agitated for 36 hours, and afterward, when her attention and orientation improved, she was unable to recognize familiar faces. She could, however, recognize familiar voices. Her prosopagnosia resolved over the next 6-7 days. This case demonstrates that isolated prosopagnosia can occur in patients with lesions restricted to the right inferior posterior temporal-anterior occipital region. The temporary nature of the prosopagnosia may result from postsurgical tissue injury, including focal cerebral edema, with compensation by ipsilateral or contralateral areas.