Author/Editor		Podnar, S; Mrkaić, M; Vodušek, DB
Title		Reinnervation of anal sphincter muscle by low and high-threshold motor neurones
Type		članek
Source		Neurophysiol Clin
Vol. and No.		Letnik 31
Publication year		2001
Volume		str. 293-9
Language		eng
Abstract		The external anal sphincter (EAS) has continuously active low-threshold and recruftable high-threshold motor units (MUs), the latter being 'larger'. On performing concentric needle electromyography (EMG) of the EAS, the high-threshold MUs seemed to reveal mare neuropathic changes than the low-threshold MUs. To verify this hypothesis, low- and high-threshold motor unit potentials (MUPs) were compared in patients with neuropathic EAS and controls. Fifteen subjects without pelvic disorders and 29 patients with sequela after cauda equina lesions were studied. In patients, only muscles ipsilateral to severe perianal sensory loss were included. MUPs were sampled using mufti-MUP analysis during relaxation ('low-threshold'), and on activation (žhigh-threshold' MUs). MUP parameters of low- and high-threshold MUs from controls and patients were compared, as was the sensitivity and specificity with which MUPs were classified as normal or pathological (using discriminant analysis). MUP changes due to reinnenration, and the sensitivity and specificity in classifying MUPs as normal or pathological were not significantly different between the lowand high-threshold MUPs. Stronger activation of EAS does not improve discrimination between neuropathic and normal MUPs. New EMG techniques for sampling sphincter MUPs at higher activation levels would seem not to yield additional information.
Descriptors		ELECTROMYOGRAPHY ANUS CAUDA EQUINA MOTOR NEURONS MUSCLE DENERVATION