Changes of reflex size in upper limbs using wrist splint in hemiplegic patients.

We evaluated the effect of prolonged wrist extension on H reflex in the flexor carpi radialis (FCR) muscle and tendon jerk (T) reflex in the biceps brachii (BB) muscle of 17 chronic hemiplegic patients. H reflex of the FCR and T reflex of the BB were assessed every 5 minutes within 20 minutes during prolonged wrist extension and post-20 minutes after the extension. As a result, H reflex in the FCR was reduced by passive wrist stretch in 82% of the spastic limbs. The effect was larger in the higher spastic group. In 45% of the spastic limbs, T reflex in the BB also was reduced by passive wrist stretch. The inhibitory effects had a tendency to strengthen in accordance with the grade of muscle tone. We considered from these results, prolonged wrist extension generated inhibitory projections via probably group II afferents of the FCR in the homonym and in the transjoint in spastic limbs.

Statistical test for peri-stimulus time histograms in assessing motor neuron activity.

The peri-stimulus time histogram is a valuable tool for evaluating neural connections in humans. To detect the degree to which a conditioning stimulus to a sensory nerve modulates motor neuron activity, a histogram of motor unit spike intervals after a conditioning stimulus is measured. This histogram allows the effect of the conditioning stimulus to be visualised. By comparison with a reference histogram of motor unit spike intervals after a sham stimulus, the noise caused by spontaneous firing sway can be removed. However, no valid statistical test has yet been developed to separate the physiological effect from the spontaneous sway and statistical noise. A computational method has been proposed to detect modulation caused by a conditioning stimulus. To clarify the effect of a conditioning stimulus, this new method used reference histograms to calculate a confidence interval. A simulated experiment demonstrated that about 2000 re-samplings were sufficient to estimate a confidence interval for a histogram with 1 ms bin width constructed from 300 triggers. Testing of the experimental data, measured from the tibialis anterior muscles during the elicitation of the excitatory spinal reflex, confirmed that significant peaks were produced at 30, 34, 35 and 38ms after the conditioning stimulus. These correspond appropriately to the delay of the spinal reflex.

[Acute exacerbation of subacute interstitial pneumonia after thoracoscopic lung biopsy].

A 55-year-old woman was admitted to our hospital with progressive dyspnea that had begun one month before. Chest rentogenogram revealed groundglass appearance and reticular shadows bilaterally. Pulmonary function tests showed both decreased vital capacity and diffusing capacity. Bronchoalveolar lavage fluid had a high lymphocyte fraction with a low CD4+/CD8+ ratio. Thoracoscopic lung biopsy revealed thick, fibro-edematous interstitium and diffuse infiltration of lymphocytes. We also observed an intra-alveolar exudate with infiltration of histiocytes and lymphocytes. The clinical features and pathological findings were consistent with subacute interstitial pneumonia, which was the entity proposed by Kawabata and colleagues. The patient developed acute respiratory failure four days after lung biopsy and died despite steroid pulse therapy. Although subacute interstitial pneumonia has been reported to respond to steroid therapy, and to have a good prognosis, we believe that subacute interstitial pneumonia could fatally worsen when associated with lung biopsy, infection, or some other stimulus.