The purpose of this study is to investigate the respiratory functions of quadriplegics, particularly its mechanical and neuronal control mechanisms, using the CO₂ rebreathing method originated by Read (1966).
The amount of ventilation (V_E) and the pattern of respiration were analyzed by measuring the tidal volume (T_V), respiratory frequency (f), inspiratory time (T_I), mean inspiratory flow (V_I=V_T/T_I) and end-expiratory CO₂ tension (P_CO2) per each breath from the continuous polygraph recording.
The study was performed on 10 complete traumatic C₄-C₆ quadriplegics and on 5 healthy subjects, while they were assuming supine and sitting postures. The mouth occulusion pressure (P^O) was also measured on 3 quadriplegics to see the effective force generated by the diaphragm and to estimate the elastance of the respiratory system (Ers).
The result indicated that the CO₂ sensitivity expressed by the slope of the V_E-P_CO2 curve was low in quadriplegics (0.365 and 0.396 [L·sec/mmHg] for sitting and supine, compared to 1.214 and 1.350 for normal subjects), though it was not affected by the postural changes.
As for the respiratory pattern, quadriplegics augumented their respiration by increasing V_T when supine and by increasing f when sitting. The observation of P^O substantiated decreased force generated by the diaphragm simultaneously with increased Ers when sitting. The quadriplegics appeared to increase f when sitting to accommodate to the changes of the state of the respiratory system so as to minimize the respiratory work.
The relationship of V_T/T_I and P_CO2 revealed that the V_T/T_I at a certain P_CO2 was essentially identical in 2 postures, though T_I was markedly prolonged in supine than sitting in quadriplegics. This implied that the differences of V_T or f were attributable to the differences of T_I in each breath.
Generally speaking, T_I is determined by the activity of the medullary respiratory pacemaker which is modulated by the afferent impulses from the respiratory sensory organs, such as the lung stretch receptors via the vagal nerve, the chest wall proprioceptive receptors via the spinal nerve, and the diaphragm proprioceptive receptors via the phrenic nerve.
In quadriplegics, the proprioceptive sensory organs of the diaphragm appeared to be acting an essential role in determining the depth and the timing of the respiration, and this assumption was derived from the observation of T_I during P^O measurement.

View full abstract

We analyzed the course of motor disability in patients with Duchenne type muscular dystrophy by means of Motor Age Test. The duration of the motor age was divided into nine parts from lower motor age to higher motor age. The performance rate of each parts, which consisted of several motor tasks, was calculated in each patient. Comparative study was carried out between motor disability stage and performance rate. As motor disability stage progressed, the performance rate decreased significantly from higher motor age to lower motor age.
From these results, it was suggested that the course of motor disturbance in patients with Duchenne type muscular dystrophy is the same as, but in the opposite direction to the course of motor development in normal children.

View full abstract

Despite the importance of the psychological aspects of the patients for the completion of the rehabilitational program, little research has been done in stroke patients about the correlations between the physical disability and the psychological changes. In this study, to clarify the influences of the physical improvement to the psychological conditions of the stroke patients, physical ability and psychological scores of 82 stroke patients without dementia (51 male and 31 female 59.0±10.3yrs) were evaluated at the time of begining and after the completion of the stroke rehabilitation program. Physical activity was evaluated by scoring the ability of the upper and lower extremities to accomplish the ruled movements and actions. Psychological evaluation was done by means of Cornell Medical Index (CMI), Manifest Anxiety Scale (MAS) and Minnesota Multiphasic Personality Inventory (MMPI).
1) In male patients, physical activity scores showed high correlations to CMI and MAS scores at the time of pre- and post-rehabilitation stages.
2) Physical improvement, especially the improvement of the lower extremities, tended to produce the improvement of the abnormal psychological scores in male patients. In female patients the regaining of the upper limb abilities seemed to be more important for the improvement of the psychological scores.
3) The patients who failed to gain the stable ambulation tended to have high scores of neurosis (CMI) and anxiety (MAS) and abnormal MMPI profile even at the time of admission.
These results suggested that the differences of sex and improved lower and upper limb abilities would produce different influences to the psychological situations. Male patients socially required good physical activities was considered to show the psychological improvement by the improvement of the general and ambulatory functions. In female patients usually doing homeworks upper limb abilities would be important for the psychological stability.

View full abstract

This experiment was performed to elucidate the effect of therapeutic exercise in peripheral nerve disorders, that is, free running in acrylamide neuropathy rats.
Sixty male Wister rats were divided into three groups: running, with neuropathy; sedentary, with neuropathy; and control group, all of whose initial body weight was 85 to 92 grams at 4 weeks of age. Each rat in the running group was left all day long in its own wheeling drum, where rats with acrylamide neuropathy had made a voluntary run of 350km for 12 weeks in preliminary experiments. Each rat in the sedentary and the control group was put in its own narrow cage. Acrylamide (50mg/kg) was injected intraperitoneally into running and sedentary rats 3 times a week until 7 weeks of age and then once a week till 16 weeks old. Moderate and chronic acrylamide neuropathy was induced by this method. Ringer's saline was injected into control rats in the same way.
The evaluation of peripheral neuropathy consisted of clinical observation, motor nerve conduction velocity, and morphometric measurements of transverse sections of nerves and teased fibers. Clinical observation revealed that the running group scored lower than the sedentary group, and there was a significant difference noted between both groups at 7 to 12 and 15 to 16 weeks of age (p<0.05). Motor nerve conduction velocity of the tibial nerve was measured in 5 rats from each group every month, which were anesthetized with thiopental sodium. While motor nerve conduction velocity of running and sedentary rats was about 75% of control rats, there was no significant difference between the running and sedentory rats (p<0.05). As soon as motor nerve conduction velocity was examined, specimens from the sciatic nerve, tibial nerve, sural nerve and branches to the medial and lateral head of the gastrocnemius were taken from the rats. Some samples were embeded in Epoxyresin for transverse sections, and others were immersed in glycerin for teased fibers. Histogram of morphometric measurements of the transverse sections indicated the running group made a deviation to a smaller diameter than the sedentary group. Teased fibers showed the running group was more prominent in axonal degeneration than the sedentary group, and there was a significant difference between both groups except for the sural nerve at 12 weeks of age.
These facts suggest that free running aggravates acrylamide neuropathy in clinical and pathological evaluations. This evidence suggests that we should consider the quality and the quantity of therapeutic exercise in rehabilitation of peripheral neuropathy and avoid overwork weakness from strenuous exercise.

View full abstract

[in Japanese]

View full abstract