Contralateral conditioning to the soleus H-reflex as a function of age and physical activity

The influence of ageing and diabetic peripheral neuropathy on posture sway, tremor, and the time to achieve balance equilibrium

BACKGROUND

It is well recognized that ageing and diabetes are associated with reduced balance and impaired gait. However, one important factor may be not just balance, but how long it takes to achieve balance equilibrium after a balance challenge. This study examined the relationship between balance, tremor, and time to achieve balance after a challenge to stability in young and old individuals without and without diabetes.

METHODS

Twenty-four of the subjects were young controls, 22 were older controls, 23 were individuals with diabetes, and 21 were young people with diabetes. Posture sway, tremor, and time to achieve stability were assessed on a force plate during 8 progressively challenging balance tasks.

RESULTS

For postural sway, tremor and time to reach postural stability, there was a significant difference in all groups with the increased balance challenge of the 8 tests (P<0.01). However, ageing and diabetes made balance, tremor and time to reach stability worse. In general, the young group with diabetes, for example, had similar responses to the old group without diabetes.

CONCLUSIONS

In the subjects with diabetes, balance was poorer than the non-diabetes groups. The young subjects with diabetes showed similar results to the older subjects without diabetes. Diabetes subjects had more muscle tremor and a slower response time of the body to a balance challenge. This may account for increased falls in individuals with diabetes.

Assessment of the corticospinal fiber integrity in mirror movement disorder

Mirror movements are unintended movements occurring on one side of the body that mirror the contralateral voluntary ones. It has been proposed that mirror movements occur due to abnormal decussation of the corticospinal pathways. Using detailed multidisciplinary approach, we aimed to enlighten the detailed mechanism underlying the mirror movements in a case subject who is diagnosed with mirror movements of the hands and we compared the findings with the unaffected control subjects. To evaluate the characteristics of mirror movements, we used several techniques including whole exome sequencing, computed tomography, diffusion tensor imaging and transcranial magnetic stimulation. Computed tomography showed the absence of a spinous process of C5, fusion of the body of C5-C6 vertebrae, hypoplastic dens and platybasia of the posterior cranial fossa. A syrinx cavity was present between levels C3-C4 of the spinal cord. Diffusion tensor imaging of the corticospinal fibers showed disorganization and minimal decussations at the lower medulla oblongata. Transcranial magnetic stimulation showed that motor commands were distributed to the motor neuron pools on the left and right sides of the spinal cord via fast-conducting corticospinal tract fibers. Moreover, a heterozygous missense variation in the deleted in colorectal carcinoma gene has been observed. Developmental absence of the axonal guidance molecules or their receptors may result in abnormalities in the leading of the corticospinal fibers. Clinical evaluations and basic neuroscience techniques, in this case, provide information for this rare disease and contribute to our understanding of the normal physiology of bimanual coordination.