title: Ulnar F wave generation assessed within 3 days after the onset of stroke in patients with relatively preserved level of consciousness.
abstract: OBJECTIVE
  The present study aimed to detect any significant changes of F wave variables associated with acute hemiparesis in a group of stroke patients with relatively preserved consciousness (Glascow Coma Scale (GCS) score 8 or higher) and to detect the possible clinical significance of F wave recording in acute stroke patients for diagnostic purposes.
  
  
  METHODS
  Thirty-two consecutive patients with mean age 65+/-10.6 years admitted with a diagnosis of acute ischemic or primary hemorrhagic stroke were studied. A series of 40 electrical stimuli were delivered to the ulnar nerve bilaterally in order to obtain F waves. F wave studies were performed within 3 days from stroke's onset. The following variables were estimated and then compared between affected and unaffected side: F persistence, F wave latency, amplitude, duration and chronodispersion. A group of 30 healthy age-matched subjects served as control.
  
  
  RESULTS
  F persistence was significantly lower in both affected and unaffected sides as compared to controls. There was no statistical differences of latency values between control and either side of the stroke' patients. A significant decrease of maximum F wave amplitude was detected in both affected and unaffected side as opposed to controls. Separate analysis of the subgroup of 15 patients with stroke and completely normal level of consciousness (GCS score 15) did not showed any significant differences of F wave variables in the affected or unaffected side compared with controls.
  
  
  CONCLUSIONS
  The F wave persistence is not expected to be suppressed in the first few days after stroke unless the level of consciousness is reduced. The routine F wave studies are not appropriate to evaluate the severity of motor deficit, at least in the immediate period after a stroke incident.
authors.affiliation: Department of Neurology, University of Patras Medical School, Greece. echroni@yahoo.com
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Chroni
authors.forename: Andreas A
authors.initials: AA
authors.lastname: Argyriou
authors.forename: George
authors.initials: G
authors.lastname: Katsoulas
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Polychronopoulos
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D003243:Consciousness / Q000502:physiology*; D004576:Electromyography; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D010291:Paresis / Q000209:etiology / Q000503:physiopathology*; D020521:Stroke / Q000150:complications / Q000503:physiopathology* / Q000523:psychology; D013997:Time Factors; D014459:Ulnar Nerve / Q000503:physiopathology*