Clinical significance of the F wave area in diabetic polyneuropathy
Toyokura, M.; Ishida, A.
Electromyography and Clinical Neurophysiology 39(2): 93-99
1999
ISSN/ISBN: 0301-150X PMID: 10207678 Document Number: 511814
To investigate the electrophysiological significance of the abnormal F wave are (Farea) and its ratio (F/Marea) (%) to the corresponding M wave area (Marea) in patients with diabetic polyneuropathy (DP). For tibial and peroneal nerves, the F/Marea and other F wave parameters (duration [Fdur], minimum latency [Fmin], amplitude [Famp]) were compared in 34 patients and age-matched controls. For controls, the Farea correlated with the Marea, but this was not found for DP patients. The peroneal F/Marea for DP patients was significantly larger than that for controls. For the both nerves, however, the F/Marea for DP patients was larger in nerves with a decreased Marea than those in nerves with a normal Marea and in the controls. An increased F/Marea was accompanied by prolonged Fdur. A decreased F/Marea was uncommon. The incidence of abnormal F/Marea was somewhat larger than that of abnormal F/Mamp, but smaller than the values for MCV and Fmin. The relationship between Farea and the Marea for DP patients differed from that of controls. An increased F/Marea was considered to reflect a denervation-reinnervation process or some central modification in firing of the anterior horn cells. Whereas amplitude of the F wave also reflect these electrophysiological conditions, the F/Marea is a little more sensitive than F/Mamp in detecting the abnormality.