Electrophysiological deterioration over time in patients with Huntington's disease.
In recent studies aimed at assessing the effects of original therapeutic strategies applied to patients with Huntington's disease (HD), we observed informative changes in electrophysiological results that recovered normal values in coherence with clinical improvement. However, longitudinal studies were lacking for determining whether electrophysiological test results evolve in parallel with clinical markers of the natural course of the disease and could consequently provide objective quantifiable markers of disease progression. For this purpose, electrophysiological testing was performed annually in a cohort of 20 patients with HD over a 2-year period (three examinations). The study included the recording of sympathetic skin responses and blink reflexes (BRs) to supraorbital nerve stimulation, long latency reflexes (LLRs) and somatosensory evoked potentials (SEPs) to median nerve stimulation, and cortical silent periods (CSPs) to transcranial magnetic stimulation. Clinical evaluation was based on the Total Functional Capacity scale (TFC) and the Motor part of the Unified Huntington's Disease Rating Scale (UHDRS). A significant deterioration with time was found for BR latency, LLR presence, various SEP parameters (parietal N20 peak amplitude and frontal N30 presence) and CSP duration. Attenuation of the N20 peak and CSP shortening correlated with functional decline, as assessed by the TFC score, whereas delayed BR and LLR abolition correlated with UHDRS Motor score deterioration. This study shows that several electrophysiological parameters are closely associated with dysfunction of various neural circuits in HD and could be useful markers of disease progression.
Lefaucheur
Jean-Pascal
JP
Service de Physiologie - Explorations Fonctionnelles, Hôpital Henri Mondor, AP-HP, Créteil, France. jean-pascal.lefaucheur@hmn.ap-hop-paris.fr
Ménard-Lefaucheur
Isabelle
I
Maison
Patrick
P
Baudic
Sophie
S
Cesaro
Pierre
P
Peschanski
Marc
M
Bachoud-Lévi
Anne-Catherine
AC
D000328:Adult; D001767:Blinking / Q000502:physiology*; D002540:Cerebral Cortex / Q000503:physiopathology*; D018450:Disease Progression; D042241:Early Diagnosis; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology*; D006801:Humans; D006816:Huntington Disease / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology*; D008137:Longitudinal Studies; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D009460:Neurologic Examination; D011930:Reaction Time / Q000502:physiology*; D012016:Reference Values; D013564:Sympathetic Nervous System / Q000503:physiopathology; D050781:Transcranial Magnetic Stimulation