Studying The H-reflex Of Hemiplegic Upper Limbs In Patients With Cerebral Infarction

Objective:To discuss the application of the upper H reflex in hemiplegic upper extremity of patients with cerebral infarction by studying the difference of the maximum amplitude of H reflex (Hmax), the ratio of the maximum amplitude of H reflex and maximum M amplitude (H/ M) in normal human's upper limb, upper extremity hemiplegia of patients with acute cerebral infarction and upper extremity hemiplegia of patients with cerebral infarction which is in the stage of recovery, and analysing the relationship between Hmax, H/M of hemiplegic upper extremity in patients with cerebral infarction and their muscle force, muscle tone.Methods:We collected 22 healthy subjects and 42 patients with cerebral infarction (one group of 19 acute patients, another group of 23 recoveries),who met the inclusion criteria, and then respectively tested H reflex of two muscles (the abductor pollicis brevis and the abductor digiti minimi) dominated by two upper extremity peripheral nerves (median nerve and ulnar nerve). We measured the maximum amplitude of H reflex (Hmax), the ratio of the maximum amplitude of H reflex and maximum M amplitude (H/M), which were compared among the three groups by One way ANOVA.The muscle force of hemiplegic upper extremity of patients with cerebral infarction in the two groups was assessed by Lovett grading score, and the muscle tone was assessed by modified Ashworth grading score. We analysed the relationships between muscle force, muscle tone and Hmax, H/M of each group by statistical test analysis of Spearman rank correlation coefficientResults:①The Hmax and H/M were higher in the patients' hemiplegic upper limbs with acute cerebral infarction than in the upper limbs of healthy people, but the difference was not statistically significant (P> 0.05).②The Hmax and H/M in hemiplegic upper limbs of convalescent patients with cerebral infarction were significantly higher than in the upper limbs of healthy people(P<0.05).③The Hmax and H/M in hemiplegic upper limbs of convalescent patients with cerebral infarction were significantly higher than in hemiplegic upper limbs of patients with acute cerebral infarction(P<0.05).④The scores of muscle force assessed by Lovett grading score and the scores of muscle tone assessed by modified Ashworth grading score were not correlate with the Hmax and H/M in patients'hemiplegic upper limbs with acute cerebral infarction.⑤In the convalescent patients'hemiplegic upper limbs, the correlation between the Hmax and H/M and muscle force was poor,but the Hmax and H/M had a strong positive correlation with the scores of muscle tone assessed by modified Ashworth grading score, and more higher the scores of muscle tone were, more larger Hmax and H/M were.Conclusion:①The Hmax and H/M in hemiplegic upper limbs of patients with acute cerebral infarction had no significant differences with that of heathy upper limbs, and were not correlate with the muscle force scores or muscle tension scores.②The Hmax and H/M in hemiplegic upper limbs of convalescent patients with cerebral infarction were much more higher than the heathy upper extremities, and they correlated poorly with the musle force Lovett grading scores, but correlated positively with the modified Ashworth grading muscle tone scores.