A comparison of methods to assess the excitability of lower motoneurones.
The purpose of this investigation was to compare three methods of assessing the excitability of lower motoneurones--TA-reflex, H-reflex and F-wave--in 120 patients with spastic hemiparesis following a stroke. The H-reflex was recorded from the soleus muscle after submaximal electrostimulation of the tibial nerve. The T-Achilles (TA) reflex was recorded from the soleus muscle after percussion of the Achilles tendon. The F-wave was recorded in the distal limb muscles after supramaximal electrostimulation of the median, ulnar, fibular and tibial nerves. The patient's healthy side was used as a control. The TA-reflex, H-reflex and F-wave showed increased amplitudes on the spastic side. All amplitude ratios: TA/M, H/M, Fmax/M and Fmean/M were increased. The H-reflex thresholds were decreased. The F-wave duration, persistence and number of phases were also increased on the spastic side. Despite clinically decreased muscle tone, there were no changes in TA or H-reflex parameters after treatment. On the other hand, F-wave parameters tended to normalize after treatment in all groups. In conclusion, the F-wave is a more sensitive method than the TA and H-reflexes in assessing the excitability of the lower motoneurone.
Milanov
I G
IG
Institute of Neurology, Psychiatry and Neurosurgery, Bulgarian Medical Academy, Sofia.
D000125:Achilles Tendon / Q000502:physiology; D000328:Adult; D000368:Aged; D002561:Cerebrovascular Disorders / Q000150:complications / Q000503:physiopathology; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006181:H-Reflex / Q000502:physiology; D006429:Hemiplegia / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009132:Muscles / Q000502:physiology; D009460:Neurologic Examination / Q000379:methods; D012026:Reflex, Stretch / Q000502:physiology