Clinical, neuropsychological, neurophysiologic, and genetic features of a new Italian pedigree with familial cortical myoclonic tremor with epilepsy

Abstract

SUMMARYWe studied the clinical, neuropsychological, neurophysiologic, and genetic features of an Italian family with familial cortical myoclonic tremor with epilepsy (FCMTE). Clinically affected members of the family had limb and voice tremor, seizures, and myoclonus involving the eyelids during blinking. Neuropsychological testing disclosed visuospatial impairment, possibly due to temporal lobe dysfunction. Neurophysiologic findings suggested increased primary motor cortex excitability with normal sensorimotor integration. Linkage analysis excluded the 8q24 locus, where patients shared a common haplotype spanning 14.5 Mb in the pericentromeric region of chromosome 2.

Altered intrinsic brain activity in patients with familial cortical myoclonic tremor and epilepsy: An amplitude of low-frequency fluctuation study

“…These anti-epileptic drugs (AEDs) could raise the inhibitory neurotransmitter (e.g., GABA) concentrations by increasing GABA synthesis and decreasing GABA degradation, thus reducing the excitability of neurons and inhibiting seizures [28]. Here, this result is in line with the view that some AEDs (especially VBA and clonazepam) could improve the tremulous movements and lessen the number of seizures [4,7,8].…”

“…The fusiform gyrus plays major roles in the visual system; altered connection might indicate a reorganization of the visual system. A visuospatial impairment has been reported in a single FCMTE family [7]. In addition, visual impairment was also observed in two of the seven subjects in this study.…”

“…2a, b, and df). FCMTE studies including several genealogies have presented evidence of a sensorimotor origin for tremulous movements [1,[3][4][5][6][7]. Meanwhile, electromyography (EMG)-fMRI and neurophysiological studies have demonstrated that the tremulous movements in FCMTE patients may be correlated with the activity in the sensorimotor cortex [14,26].…”

“…However, only one candidate causative gene, CNTN2, has been identified in autosomal recessive FCMTE [2]. No causative gene has been identified in autosomal dominant FCMTE [3][4][5][6][7]. Thus far, the pathophysiology of this condition remains speculative.…”

“…Thus far, the pathophysiology of this condition remains speculative. FCMTE patients demonstrated abnormalities in the cortical and subcortical areas, such as the frontoparietal lobe, and the cortical deficits may lead to complex partial seizures, intractable seizures, and mental retardation [4,5,7]. In addition, routine electroencephalography (EEG) and 24 h-video EEG show irregular bursts, slow waves and spikes predominantly in the centrotemporal regions [4,8].…”