Impaired activation of somatosensory cortex as FMRI correlate of reduced dexterity in PD

Abstract

WCN 2013 No: 1278 Topic: 2 — Movement Disorders Impaired activation of somatosensory cortex as FMRI correlate of reduced dexterity in PD T. Foki, W. Pirker, A. Geissler, D. Haubenberger, M. Hilbert, I. Hoellinger, M. Wurnig, J. Rath, J. Lehrner, S. Trattnig, E. Auff, R. Beisteiner. Department of Neurology, Medical University of Vienna, Vienna, Austria; MR Center of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria; Department of Radiology, Medical University of Vienna, Vienna, Austria Background: Previously (1ab), the DOPA-resistant component of decreased dexterity in PD was called limb-kinetic apraxia (LkA). Our recent fMRI pilot study (2) investigating PD patients OFF medication suggested impaired activation of primary somatosensory cortex (SSC) as closely related to LkA. Both in the behavioral (1ab) and FMRI studies (2), coin rotation (CR, LkA task, target condition) was contrasted with simple finger tapping (FT, bradykinesia task, reference condition). FMRI signal changes were hence corrected for basic motor skills and represented activation particularly associated with dexterity. Based on the DOPA resistance of CR performance in (1ab), we hypothesized a reproducibility of impaired activation of the SSC ON medication. Objective: The objective of this study is to confirm dysfunction of SSC as closely related to DOPA-resistant dexterity deficits in PD. Patients and methods: According to the experimental setup (CR vs. FT) mentioned above, 10 PD patients performed the FMRI experiment in the ON as well as the OFF condition. 14 healthy controls performed the same experiment. Patients were compared to controls (SPM8). Results: Confirming our pilot study, we assessed decreased activation of the SSC in patients OFF medication compared to controls. In line with our study hypothesis, this finding was reproducible in patients ON medication compared to controls (p b 0.01, uncorr., k = 25 vox.). Comparing FMRI signals in the SSC between ON and OFF conditions, no differences could be assessed (lowering even to p b 0.05). Conclusions: Dexterity deficits in PD are linked to a dysfunction of the SSC. (1a) Gebhardt-et-al._MovDisord 2008;23 :1701-6. (1b) Quencer-et-al._Neurology 2007;68:150-1. (2) Foki-et-al._ExpNeurol 2010;225:416-22. doi:10.1016/j.jns.2013.07.405 Abstract — WCN 2013 No: 1269 Topic: 2 — Movement Disorders Subjective and objective alcohol responsiveness in different tremor disorders WCN 2013 No: 1269 Topic: 2 — Movement Disorders Subjective and objective alcohol responsiveness in different tremor disorders P. Schwingenschuh, M. Koegl-Wallner, U. Werner, T. Pendl, C. Ghadery, S. Seiler, K. Wenzel, R. Schmidt, P. Katschnig-Winter. Department of Neurology, Medical University of Graz, Graz, Austria Background: A few studies exist on the effect of alcohol in essential tremor (ET) and Parkinson s disease (IPD), but so far no systematic studies have been performed in other tremor syndromes. Nevertheless, a positive response to alcohol – commonly simply inquired by history – is used as supportive diagnostic criterion for ET. Objective: The objective of this study is to investigate if subjective/ objective alcohol responses distinguish a broad range of tremor disorders. Methods: (1) We assessed drinking habits and response of tremor to alcohol intake in 100 consecutive patients with arm tremor. (2) For a double-blind placebo-controlled oral alcohol test we recruited 12 patients with ET, 10 IPD, and 7 dystonic tremor (DT). The effect to alcohol/placebo was assessed at baseline and after 30/ 60/120 min by clinical rating scales and accelerometry. Results: (1) We investigated 44 patients with IPD, 22 ET, 20 DT, and 14 others. Of 77 patients drinking alcohol, 23 had no response, 26 had improvement, and 28 never paid attention. None of the evaluated parameters differed between the groups. (2) ET, IPD, and DT had a significant tremor improvement with placebo and alcohol. There were no significant between group differences. However, in the ET group there was a stronger objective effect of alcohol compared to placebo. Conclusions: Subjective alcohol response inquired by history may not be suitable as supportive diagnostic criterion for ET. Objectively, all investigated patients improved with alcohol. This effect seems to be truly alcohol related in ET only. doi:10.1016/j.jns.2013.07.406 Abstract — WCN 2013 No: 1258 Topic: 2 — Movement Disorders Exome sequencing analysis in familial progressive supranuclear palsy WCN 2013 No: 1258 Topic: 2 — Movement Disorders Exome sequencing analysis in familial progressive supranuclear palsy C. Bettencourt, A. Tucci, R. Ros, J. Lopez-Sendon, J. Hardy, J. Garcia deYebenes,H.Houlden. Department ofMolecularNeuroscience, UCL Institute of Neurology, London, UK; Department of Neurology, Hospital Ramon y Cajal, Madrid, Spain Background: Progressive supranuclear palsy (PSP) is a clinicopathological syndrome characterized by akinesia, supranuclear gaze palsy, Abstracts / Journal of the Neurological Sciences 333 (2013) e109–e151 e121