Clinical significance of the F wave area in diabetic polyneuropathy.
OBJECTIVE
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).


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Toyokura
M
M
Department of Rehabilitation Medicine, Tokai University, Oiso Hospital, Kanagawa, Japan.
Ishida
A
A
D003929:Diabetic Neuropathies / Q000503:physiopathology*; D004576:Electromyography; D006801:Humans; D008875:Middle Aged; D009132:Muscles / Q000503:physiopathology*; D009431:Neural Conduction / Q000502:physiology; D010543:Peroneal Nerve / Q000503:physiopathology; D011930:Reaction Time / Q000502:physiology; D013979:Tibial Nerve / Q000503:physiopathology