Age-Related Changes in the Response of Finger Skin Blood Flow during a Braille Character Discrimination Task.

We hypothesized that age-related changes in sensory function might be reflected by a modulation of the blood flow response associated with tactile sensation. The aim of the present study was to clarify how the blood flow response of the fingers during concentrated finger perception is affected by aging. We measured the tactile-pressure threshold of the distal palmar pad of the index finger and skin blood flow in the finger (SBF) during Braille reading performed under blind conditions in young (n = 27) and older (n = 37) subjects. As a result, the tactile-pressure threshold was higher in older subjects (2.99 ± 0.37 log10 0.1 mg) than in young subjects (2.76 ± 0.24 log10 0.1 mg) (p < 0.01). On the other hand, the SBF response was markedly smaller in older subjects (-4.9 ± 7.0%) than in young subjects (-25.8 ± 15.4%) (p < 0.01). Moreover, the peak response arrival times to Braille reading in older and young subjects were 12.5 ± 3.1 s and 8.8 ± 3.6 s, respectively (p < 0.01). A decline in tactile sensitivity occurs with aging. Blood flow responses associated with tactile sensation are also affected by aging, as represented by a decrease in blood flow and a delay in the reaction time.

The attenuating effect of a dynamic cushion on the development of leg edema in wheelchair users with spinal cord injuries.

BACKGROUND: Prolonged wheelchair sitting is known to lead to venous stasis and results in leg edema. OBJECTIVE: To clarify how a dynamic cushion affects leg edema in people with spinal cord injuries (SCI) evoked by wheelchair sitting, we measured the changes in leg volume induced during wheelchair sitting with a dynamic air cushion or a static cushion. METHODS: Seven wheelchair users with SCI participated in this study. Leg edema during wheelchair sitting was evaluated with strain gauge plethysmography (the gauge was placed 10 cm proximally from the medial malleolus). Following a period of rest, the subjects sat on a reclining wheelchair containing a dynamic cushion for 15 min. Then, the protocol was repeated with a static cushion. The above two procedures were performed in a random order. These data were statistically compared between the two procedures. RESULTS: The change in leg volume observed during sitting on the dynamic cushion (-0.02 ± 0.21 ml/100 ml) was smaller than that observed during sitting on the static cushion (0.18 ± 0.28 ml/100 ml) (P< 0.05). CONCLUSIONS: These results suggested that the dynamic air cushion relieved leg edema induced by wheelchair sitting in individuals with SCI.

Effects of Training for Finger Perception on Functional Recovery of Hemiplegic Upper Limbs in Acute Stroke Patients.

BACKGROUND: Stroke causes severe disability, including motor and sensory impairments. We hypothesized that upper limb functional recovery after stroke may be augmented by combining treatments for motor and sensory functions. In order to examine this hypothesis, we conducted a controlled trial on rehabilitation for sensory function to the plegic hand. METHODS: The sensory training program consisted of several types of discrimination tasks performed under blind conditions. The sensory training program was performed for 20 min per day, 5 days a week. An experimental group of 31 patients followed this sensory program, while a control group of 25 patients underwent standard rehabilitation. The efficacy of the intervention was evaluated by the tactile-pressure threshold, handgrip strength, and the completion time of manipulating objects. A two-way repeated measures analysis of variance was used to assess interactions between group and time. Moreover, to provide a meaningful analysis for comparisons, effect sizes were calculated using Cohen's d. RESULTS: The mean change in the tactile pressure threshold was significantly larger in the experimental group than in the control group (p < 0.05, d = 0.59). Moreover, the completion times to manipulate a middle-sized ball (d = 0.53) and small ball (d = 0.80) and a small metal disc (d = 0.81) in the experimental group were significantly different from those in the control group (p < 0.05). CONCLUSION: The present results suggest that the sensory training program to enhance finger discrimination ability contributes to improvements in not only sensory function but also manual function in stroke patients. The trial is registered with the UMIN Clinical Trials Registry (UMIN000032025).