The Correlation between Modified Ashworth Scale and Biceps T-reflex and Inter-rater and Intra-rater Reliability of Biceps T-reflex

OBJECTIVE: To establish a correlation between the modified Ashworth scale (MAS) and amplitude and latency of T-reflex and to demonstrate inter-rater and intra-rater reliability of the T-reflex of the biceps muscle for assessing spasticity after stroke. METHOD: A total of 21 patients with hemiplegia and spasticity after ischemic stroke were enrolled for this study. The spasticity of biceps muscle was evaluated by an occupational therapist using the MAS. The mean value of manual muscle test of biceps muscles was 2.3+/-0.79. Latency and amplitude of T-reflex were recorded from biceps muscles by two physicians. The onset latency and peak to peak amplitude of the mean of 5 big T-reflex were measured. The examinations were carried out by two physicians at the same time to evaluate the inter-rater reliability. Further, one of the physicians performed the examination again after one week to evaluate the intra-rater reliability. The correlations between MAS and T-reflex, and the intra- and inter-rater reliability of biceps T-reflex were established by calculating the Spearman correlation coefficients and the intra-class correlation coefficients (ICCs). RESULTS: Amplitude of the biceps T-reflex increased with increasing level of MAS (rs=0.464 and 0.573, respectively, p<0.01). ICCs of latency and amplitude of biceps T-reflex were 0.914 and 0.822. The Spearman correlation coefficients of latency and amplitude of biceps T-reflex were 0.937 and 0.635, respectively (p<0.01). CONCLUSION: Biceps T-reflex demonstrates a good quantitative measurement and correlation tool with MAS for spasticity, and also shows acceptable inter- and intra-rater reliability, which can be used for patients with spasticity after stroke.

Electrophysiological Changes after Botulinum Toxin Type A in Children with Cerebral Palsy

OBJECTIVE: To investigate the electrophysiological changes after botulinum toxin type A injection in children with cerebral palsy. METHOD: Sixteen children with spastic cerebral palsy enrolled in the study. Botulinum toxin type A (Dysport(R)) was injected into gastrocnemius muscles. Electrophysiological assessments included the compound motor action potential of the tibial nerve, the sensory nerve action potential of the sural nerve, the H-reflex and the T-reflex before injection, and at 2 weeks and 4 weeks after the injection. Modified Ashworth scale was used to evaluate spasticity before, 2 weeks and 4 weeks after the injection. RESULTS: Modified Ashworth scale of the ankle decreased at 2 weeks and 4 weeks after injection. The amplitude of the H-reflex and H(max)/M(max) ratio decreased significantly at 4 weeks. The amplitude of the T-reflex decreased at 2 weeks and 4 weeks. The correlation between changes in modified Ashworth scale of the ankle and the changes in electrophysiological parameters at 4 weeks after injection were not significant. CONCLUSION: The change in T-reflex is faster than the change of H-reflex and H(max)/M(max) ratio after botulinum toxin A injection in children with cerebral palsy. Electrophysiological tests could quantify the change in spasticity after botulinum toxin injection.

The Effects of Jendrassik Maneuver on the T-reflex and the H-reflex of Soleus Muscle

OBJECTIVE: To investigate the effects of Jendrassik maneuver on latency and amplitude of the T-reflex and H-reflex of the soleus muscle in normal adults. METHOD: The T-reflex and H-reflex tests were performed on sixty normal adults with standardized technique using the soleus muscle. The shortest latency and the largest peak-to-peak amplitude were chosen for representative values. RESULTS: The results were as follows: 1) There was a significant difference in latency of the T-reflex between with and without Jendrassik maneuver. 2) The increment ratio of the amplitude with Jendrassik maneuver was 88% in the T-reflex and 18% in the H-reflex. There were a significant difference in the amplitude of both reflexes between with and without Jendrassik maneuver. 3) A high correlation was present between the latency of H- & T-reflex and the length. CONCLUSION: According to these results, we suggest that Jendrassik maneuver primarily increases the sensitivity of muscle spindles and decreases the presynaptic inhibition of the Ia terminals at cortical, subcortical and spinal levels. Jendrassik maneuver can be a useful tool in cases of clinically decreased or absent deep tendon reflex.

T-reflex Changes in Asymptomatic Diabetics

BACKGROUND: The loss or depression of ankle jerk has been considered one of the earliest physical findings of diabetic polyneuropathy, even in asymptomatic cases. Therefore, the electronic ankle T-reflex test (ATR) could be a sensitive, objective test for the early detection of polyneuropathy among diabetics. METHOD: In order to verify the sensitivity and usefulness of the ATR, the ankle jerk and ATR were studied in 99 legs of 50 patients with diabetes who did not have any symptoms related to neuropathy or peripheral vascular disease at the time of the study. A sensory nerve conduction study (SNCS) of sural and superficial peroneal nerves was also performed and the results were compared with the ATR. RESULTS: The ATR response was abnormal in 42.4% of the legs tested and was more sensitive than the sural SNCS (18.2%) or superficial peroneal SNCS (30.3%) in revealing subclinical abnormalities. Our results confirm that ATR abnormalities in asymptomatic diabetics are more frequent than conventional SNCS abnormalities and are a reliable indicator of peripheral nerve dysfunction in diabetic patients. CONCLUSIONS: The ATR seems to be a sensitive test in detecting subclinical abnormalities in diabetics and would be useful especially in early or equivocal cases of