ABSTRACT
BACKGROUND: Distal ulnar nerve injury leads to impairment of hand function due to motor and sensorial changes. Stimulus electrodiagnosis (SE) is a method of assessing and monitoring the development of this type of injury. OBJECTIVE: To identify the most sensitive electrodiagnostic parameters to evaluate ulnar nerve recovery and to correlate these parameters (Rheobase, Chronaxie, and Accommodation) with motor function evaluations. METHOD: A prospective cohort study of ten patients submitted to ulnar neurorrhaphy and evaluated using electrodiagnosis and motor assessment at two moments of neural recovery. A functional evaluation using the DASH questionnaire (Disability of the Arm, Shoulder, and Hand) was conducted at the end to establish the functional status of the upper limb. RESULTS: There was significant reduction only in the Chronaxie values in relation to time of injury and side (with and without lesion), as well as significant correlation of Chronaxie with the motor domain score. CONCLUSION: Chronaxie was the most sensitive SE parameter for detecting differences in neuromuscular responses during the ulnar nerve recovery process and it was the only parameter correlated with the motor assessment.
Subject(s)
Humans , Ulnar Nerve/physiopathology , Neurosurgical Procedures/methods , Electrodiagnosis , Physical Therapy Modalities , Recovery of FunctionABSTRACT
The changes of rheobase(Rh), chronaxie(Chr), standard electrical quantity(a) and mtensity-duration curve(i. t. c) were studied for understanding the effect of aging on the excitability of sciatic and caudal nerves in Wistar rats of different age. The results show that before grown-up excitability of the peripheral nerves increases progressively with age, after that it tends to decrease. Chronaxie as an index can not reflect the change of excitability of the peripheral nerves correctly.
ABSTRACT
Standard electrical quantity (a), chronaxie (?), rheobase (Rh), "b" in Weiss' formula and intensity threshold of duration being 40 ?s and 300 ?s (T_(?) and T_(200)) were measured on peroneus nerves in rabbits. The results show that "a" is an actual index for measuring the excitability of various groups of fibers. The larger fibers, the higher excitability and the smaller "a" values. "b" does not indicate excitability. "?" , "Rh" , "T_(40)" and "T_(200)" are not actual indexes for measuring excitability because they are influenced by "b" in Weiss' formula.
ABSTRACT
Effects of temperature and anesthesia on various excitability indexes of sciatic—peronael nerve were observed in toads. The results show that standard electrical quantity(a) changes regularly with the change of excitability. The higher excitability, the less the "a" value. But "b" in Weiss's fomula, chronaxie (Chr), rheobase (Rh), and intensity-duration curve do not indicate excitability. The time constant (RC)of the cell membrane is not related to the changes of excitability. Thus, "a" is an actual index of measuring excitability.