Chroni E, Katsoulas G, Argyriou AA, Sakellaropoulos GC, Polychronopoulos P, Nikiforidis G. Level of consciousness as a conditioning factor of F wave generation in stroke patients.
Clin Neurophysiol 2006;
117:315-9. [PMID:
16386953 DOI:
10.1016/j.clinph.2005.10.018]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2005] [Revised: 10/19/2005] [Accepted: 10/22/2005] [Indexed: 11/29/2022]
Abstract
OBJECTIVE
The current study aimed to investigate whether the level of consciousness influenced the F wave generation, as an independent factor.
METHODS
Forty three patients with acute stroke were divided according to their level of consciousness in two groups; to those with Glasgow scale (GCS) score 3-7 indicating coma (group I) and those with GCS score 8-15 (group II). A series of 40 electrical stimuli were delivered to the ulnar nerve bilaterally in order to obtain F waves. The following variables were estimated and then compared between groups: F persistence, F wave latency, amplitude and duration. All studies were performed within 3 days from the onset of the stroke symptoms.
RESULTS
The main finding to emerge was the significantly reduced F wave persistence in the group of patients with low GCS score as opposed to patients allocated in the group with GCS score 8-15. This result is referred to F waves obtained from both the affected and unaffected limb. F wave minimum latency was also prolonged in the group with low GCS score, whilst the comparison of all other F wave variables revealed no significant differences between groups I and II. F wave persistence measurements did not differ between the affected and unaffected sides. Stroke location and type (ischemic or hemorrhagic) were not associated with alterations of F wave measurements.
CONCLUSIONS
Our results on stroke patients suggest that generation of F waves, expressed by the F wave persistence is associated with the level of consciousness.
SIGNIFICANCE
F wave study may be useful as an objective measure in documenting the severity of consciousness impairment.
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