title: [Electrophysiological signs of structural changes in motor units after ischaemic stroke].
abstract: BACKGROUND
  While it is several decades ago that electrophysiological studies in the early stages after an ischaemic stroke revealed spontaneous activity in the affected muscles, today few data are available on the peripheral changes in later stages after a cerebrovascular event. The aim of this study was to detect electrophysiological signs that could indicate changes at the motor unit level occurring within a longer post-stroke period.
  
  
  METHODS
  Forty-four patients who had developed hemiparesis after an ischaemic stroke in the area of the middle cerebral artery were involved in the study. Motor and sensory nerve conduction studies and electromyography were carried out on each side on six nerves and in five muscles respectively. Values between the affected and unaffected side were compared by statistical methods.
  
  
  RESULTS
  In patients with hemiparesis present for less then nine months, low M wave amplitudes, fibrillation potentials and an increased number of complex motor unit potentials were found on the affected side; in patients with symptoms present for more then nine months the mean duration and size index of the motor unit potentials in the paretic abductor digiti minimi muscle were increased. These data suggest a process of neurogenic type. The signs of distal axonal damage observed in the early period after stroke have been replaced later by chronic neurogenic changes. These changes could be the consequence of spinal motor neuron damage and axonal transport disturbance due to the loss of supraspinal trophic inputs.
  
  
  CONCLUSIONS
  The correlation between the extent of electrophysiological changes and of the central motor deficit of the patient indicates the importance of delaying this process by appropriate rehabilitation procedures.
authors.affiliation: Diósgyori Kórház, Neurológiai Osztály, Miskolc. mikluk33@hotmail.com
authors.forename: Lukács
authors.initials: L
authors.lastname: Miklós
mesh_terms: D000328:Adult; D002545:Brain Ischemia / Q000150:complications; D004576:Electromyography; D004594:Electrophysiology; D005260:Female; D006801:Humans; D020244:Infarction, Middle Cerebral Artery / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000503:physiopathology; D009431:Neural Conduction; D009469:Neuromuscular Junction / Q000473:pathology* / Q000503:physiopathology*; D010291:Paresis / Q000209:etiology / Q000473:pathology / Q000503:physiopathology