Blink reflex excitability abnormalities in multiple sclerosis

Abstract

WCN 2013 No: 1729 Topic: 36 — Other topic Blink reflex excitability abnormalities in multiple sclerosis C. Cabib, E. Martinez-Heras, S. Llufriu, J. Casanova-Molla, Y. Blanco, A. Saiz, J. Valls-Sole. EMG Unit, Neurology Department, Hospital Clinic, University of Barcelona, Spain; Center for Neuroinmunology, Neurology Service, Hospital Clinic Barcelona and Institut d'Investigacions Biomediques August Pi i Sunyer (IDIBAPS), Barcelona, Spain Background: Brainstem dysfunctions in multiple sclerosis (MS) may be caused by either local brainstem lesions or changes in excitability modulation from supranuclear inputs. We hypothesized that while brainstem lesions lead to abnormalities in latency of BR (AbLat), supranuclear lesions lead to abnormalities in excitability measures (AbExc). Objective: To assess abnormalities in BR excitability in MS patients and their correlation with MRI-supranuclear lesions. Patients and methods: In 20 patients and 10 control subjects, we measured latencies and area of R1, R2 and R2c to single unilateral supraorbital stimulation of either side. We calculated the R2c/R2 ratio as a measure of asymmetric excitability enhancement. Patients were classified as having AbLat or AbExc when the values were above the mean + 2SD of our control group reference data. Brainstem and hemispheres (hLL) MRI-lesion load were measured with computer-assisted software (FSL). T-test and Spearman's test were used for statistics. Results:AbLatwere found in 8 patients (7 of them had pontomedullary lesions). AbExc were found in 7 out of the remaining 12 patients. In these patients, a significantly larger R2c/R2 ratio (p = 0.03 with respect to controls) coincided with a significant enhancement of R1 amplitude (p = .0001 with respect to the contralateral side). They also showed a positive correlation between R2c/R2 ratio and ipsilateral hLL (r = 0.357), but only one had a lesion that compromised the trigeminal-facial circuit. Conclusion: Asymmetric BR excitability enhancement correlates with unilateral brain lesions in MS. These tests add information for the functional evaluation of the effects of brain LL on brainstem circuits. doi:10.1016/j.jns.2013.07.2280 Abstract — WCN 2013 No: 2141 Topic: 36 — Other topic Homozygosity for P.Cys183ser mutation in Notch3 gene may influence the severity of clinical presentation? Report of an Italian family S. Bianchi, A. Rufa, C. Vinciguerra, G.N. Gallus, M.T. Dotti, A. Federico. Department of Medical, Surgical and Neurological Sciences, University of