Photosensitive and other specific reflex epilepsies: neuropsychological findings

Purpose. To study the neuropsychological status of an epileptic patient presenting with epileptic activity triggered by eye closure in a 14 years follow-up period. Methods. The patient was studied at 12 and 26 years of age; during this period he underwent periodical clinical evaluations and EEG investigations; brain MRI was performed at 12 years of age. A neuropsychological assessment was carried out both at 12 years of age (T0) and at 26 years of age. At T0 and T1, neuropsychological tests (digits and words span, graphoestesia, reactions time to auditory stimuli, sentences repetition, words repetition, digital gnosis, backward counting (i.e.100-0)) were performed during video-EEG monitoring either with eyes closed or with eyes open, to evaluate possible transitory effects related to ongoing epileptic activity. Morevor, at T0 the patient underwent Wechsler Intelligence Scale for Children-Revised, and at T1 to Wechsler Adult Intelligence Scale-Revised. Results. EEG recordings showed continuous epileptic activity triggered by eye closure, disappearing only with eyes opening, both at T0 and T1 (in this latter case, anteriorly predominant). The results of neuropsychological assessment during eyes closed as compared to performances with eyes open did not show significant differences, at T0 as well as at T1. Wechsler Intelligence scales showed a deterioration of performances at T1 respect to T0; in addition, at T1, attention and short term memory abnormalities, impairment in facial recognition and block design, and defective results in Continuous Performance Test and Wisconsin Card Sorting Test were observed. Conclusions. Lack of differences between the results of neuropsychological tests performed with eyes closed as compared to the eyes open condition suggests that in our patient epileptic activity did not cause transitory cognitive abnormalities. Deterioration of Wechsler Intelligence Scales in the follow up period might be interpreted as the result of a disruption of cognitive processes possibly related to the persistence of a continuous epileptic activity during eye closure over the years. We speculate whether a dysfunction in posterior cortical areas involved in visual processing might be related to the impairment in face recognition and block design tests as well to eye closure sensitivity.