Electroclinical and genetic findings in a family with cortical tremor, myoclonus, and epilepsy.

We report a five-generation family showing cortical tremor, myoclonus, and epilepsy, originating from Naples, Italy. Eleven members, aged 24-56 years (mean: 39.2 years), suffered from hand tremor and myoclonus, whereas generalized seizures occurred in six. Electrophysiological study confirmed the presence of cortical reflex myoclonus in all affected members. In addition, giant somatosensory-evoked potential components and enhanced long loop reflex I were found also in three presymptomatic members who manifested hand tremor and myoclonus at upper limbs after 1.5 years of follow-up. Genetic study of the pedigree revealed a significant linkage on chromosome 2p (maximum lod score = 5.9). Further observations are needed to clarify the pathophysiology of this condition.