PMID- 16904126 OWN - NLM STAT- MEDLINE DCOM- 20070123 LR - 20061107 IS - 0022-510X (Print) IS - 0022-510X (Linking) VI - 250 IP - 1-2 DP - 2006 Dec 1 TI - Reduction in the motor unit number estimate (MUNE) after cerebral infarction. PG - 27-32 AB - BACKGROUND: The mechanism of the decrease in motor unit number estimates (MUNEs) after cerebral infarction has not been studied systematically. We examined the relationship between the degree to which MUNEs decreased and the other clinical features of patients with the infarction. METHODS: Using a multiple point stimulation technique, we obtained the MUNE of the hypothenar muscle group in 13 age-matched control subjects and 30 patients with cerebral infarction. In all patients, we obtained the Japan Stroke Scale (JSS) and head MR images. In eight patients with acute cerebral infarction, admitted within 24 h after onset, we also obtained head MR angiograms and single-photon emission CT. FINDINGS: There was a decrease in the MUNE of the hypothenar muscle group on the affected side of 24 patients with cerebral infarction and hand weakness. The decrease in the MUNE started from 4 to 30 h after the infarction, when T1-weighted MR images of the brain involved were normal. The degree to which the MUNE decreased correlated with the part of the JSS showing the upper extremity weakness. INTERPRETATIONS: A decrease in the MUNE of the hypothenar muscle group within 30 h after cerebral infarction may be due to trans-synaptic inhibition of the spinal alpha motor neurons innervating this muscle. FAU - Arasaki, Keisuke AU - Arasaki K AD - Stroke Care Unit, Department of Neurology, NTT East Kanto Medical Center, Tokyo, Japan. arasaki@aikawanaika.or.jp FAU - Igarashi, Osamu AU - Igarashi O FAU - Ichikawa, Yasumitsu AU - Ichikawa Y FAU - Machida, Toru AU - Machida T FAU - Shirozu, Ichiro AU - Shirozu I FAU - Hyodo, Akira AU - Hyodo A FAU - Ushijima, Ryosuke AU - Ushijima R LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20060809 PL - Netherlands TA - J Neurol Sci JT - Journal of the neurological sciences JID - 0375403 SB - IM MH - Action Potentials/physiology MH - Aged MH - Aged, 80 and over MH - Cerebral Infarction/pathology/*physiopathology MH - Electric Stimulation MH - Electromyography MH - Excitatory Postsynaptic Potentials/physiology MH - Hand/innervation/*physiopathology MH - Humans MH - Magnetic Resonance Imaging MH - Middle Aged MH - Motor Cortex/pathology/*physiopathology MH - Motor Neurons/*physiology MH - Muscle, Skeletal/innervation/*physiopathology MH - Nerve Degeneration/etiology/physiopathology MH - Neural Conduction/physiology MH - Paresis/etiology/physiopathology MH - Peripheral Nerves/physiopathology MH - Predictive Value of Tests MH - Pyramidal Tracts/pathology/*physiopathology MH - Synaptic Transmission/physiology MH - Time Factors MH - Tomography, X-Ray Computed EDAT- 2006/08/15 09:00 MHDA- 2007/01/24 09:00 CRDT- 2006/08/15 09:00 PHST- 2006/03/16 00:00 [received] PHST- 2006/06/12 00:00 [revised] PHST- 2006/06/19 00:00 [accepted] PHST- 2006/08/15 09:00 [pubmed] PHST- 2007/01/24 09:00 [medline] PHST- 2006/08/15 09:00 [entrez] AID - S0022-510X(06)00305-4 [pii] AID - 10.1016/j.jns.2006.06.024 [doi] PST - ppublish SO - J Neurol Sci. 2006 Dec 1;250(1-2):27-32. doi: 10.1016/j.jns.2006.06.024. Epub 2006 Aug 9.