Spasmodic cough preceding CANVAS phenotype in a family with biallelic repeat expansions in RFC1.

Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a late-onset, multisystem ataxia that remained only clinically defined, until recently, when the discovery of biallelic repeat expansion in the RFC1 gene allowed the genetic link. We describe the first Portuguese familial CANVAS harboring the pathogenic RFC1 expansion. Detail clinical features and course of four affected members are provided. Phenotype characterizations are important as the novel RFC1 mutation is expected to be a major cause of idiopathic late-onset ataxia.

Electrooculogram and submandibular montage to distinguish different eye, eyelid, and tongue movements in electroencephalographic studies.

OBJECTIVE: We propose an electrooculogram and submandibular montage that helps to discriminate eye/eyelid/tongue movements and to differentiate them from epileptiform activity or slowing on electroencephalography (EEG). METHODS: We analyzed different eye/eyelid and tongue movements in 6 and 4 patients, respectively. Six peri-orbitally and one submandibular electrodes were placed. We referred these electrodes to an indifferent reference (Cz/Pz) and we recorded eye/eyelid and tongue movements simultaneously with the 10-20 system EEG. Additionally, we analyzed 2 seizures with the electrooculogram montage. RESULTS: The electrooculogram deflections always showed an opposite phase direction when eye/eyelid movements occurred. Conversely, epileptiform activity produced deflections in the same phase direction in all electrooculogram electrodes. The electrooculogram montage was able to distinguish eye ictal semiology. Vertical tongue movements showed opposite phase deflections between the submandibular and the inferior ocular electrodes. Horizontal tongue movements revealed opposite phase reversal deflections between both inferior ocular electrodes. CONCLUSIONS: The proposed montage accurately defines different eye/eyelid and tongue movements from brainwave activity. Additionally, it is useful to differentiate eye/eyelid movements from epileptiform activity and to characterize ictal ocular semiology, which can help localize or lateralize the epileptogenic zone. SIGNIFICANCE: We propose this new montage to provide added value to prolonged video-EEG studies.