MEROSIN-NEGATIVE CONGENITAL MUSCULAR-DYSTROPHY, OCCIPITAL EPILEPSY WITH PERIODIC SPASMS AND FOCAL CORTICAL DYSPLASIA - REPORT OF 3 ITALIAN CASES IN 2 FAMILIES

We report clinical, EEG and neuroimaging findings of three patients in two Italian families with merosin-negative congenital muscular dystro phy (CMD), drug-resistant occipital epilepsy, diffuse persistent cereb ral white matter changes and focal cortical dysplasia. Clinical and ep ilepsy histories, EEG and neuroimaging findings were very similar in a ll patients. Seizures started in childhood and mainly consisted of per iodic spasms, a particular type of partial seizure characterized by cl usters of epileptic spasms, The motor expression of the spasms was ver y mild so that they had been frequently missed or misinterpreted as no n-convulsive generalized absence seizures. Interictal EEG showed occip ital spike-waves and bilateral synchronous slow spike-wave discharges. Ictal EEG showed prolonged periodic sequences of slow waves with asso ciated fast rhythm complexes, characteristic of periodic spasms. Two p atients had normal intelligence, one patient presented moderate mental retardation. Focal cortical dysplasia in the posterior areas of the b rain, in addition to marked diffuse white matter alterations, was dete cted in the magnetic resonance images of all patients. Findings in the se patients indicate that in merosin-negative CMD brain involvement ca n include cortical dysplasia, in addition to white matter changes. In such cases the brain damage can lead to a childhood-onset localization -related symptomatic occipital epilepsy. Epileptic seizures and cortic al dysplasia can be, however, difficult to detect in CMD, The clinical semiology of epileptic seizures may in fact be modified because of mu scular weakness. This implies that epilepsy may be misdiagnosed or eve n missed and EEG-polymyographic recordings may be necessary to identif y it. Similarly, cortical dysplasia may be very localized and visible by neuroimaging only if it is carefully investigated on the basis of e pileptological and EEG-polymyographic findings.