TENS is harmful in primary writing tremor

OBJECTIVE

It is unclear whether primary writing tremor (PWT) is a tremulous form of dystonia or a tremor per se. Transcutaneous electrical nerve stimulation (TENS) at 50 Hz applied for 2 weeks was reported to improve the writing capabilities of patients with writer's cramp (WC). We explored whether such a beneficial effect can be obtained in patients with a PWT.

METHODS

In a cross-over, double-blinded randomized study we tested whether 2-week periods of 5, 25 or 50 Hz TENS applied to wrist flexor muscles, improved the score of the Fahn-Tolosa-Marin scale of nine patients with PWT. Excitability of neurons and of various intracortical circuits in the motor cortex were also tested before and after TENS by using transcranial magnetic stimulation.

RESULTS

TENS at 5 and 25 Hz did not have any effect while TENS at 50 Hz worsened the clinical condition and the cortical excitability.

CONCLUSIONS

TENS is not a new treatment alternative for PWT.

SIGNIFICANCE

The beneficial effect in WC and the harmful one in PWT of TENS stresses that the two disorders are likely different nosological entities.

Structural abnormalities in the cerebellum and sensorimotor circuit in writer's cramp

BACKGROUND

Structural abnormalities were detected in bilateral primary sensorimotor areas in writer's cramp. Evidence in other primary dystonia, including blepharospasm and cervical dystonia, suggest that structural abnormalities may be observed in other brain areas such as the cerebellum in writer's cramp.

OBJECTIVE

To test the hypothesis that structural abnormalities are present along the sensorimotor and cerebellar circuits in patients with writer's cramp.

METHODS

Using voxel-based morphometry, the authors compared the brain structure of 30 right-handed patients with writer's cramp with that of 30 healthy control subjects matched for gender, age, and handedness.

RESULTS

Gray matter decrease was found in the hand area of the left primary sensorimotor cortex, bilateral thalamus, and cerebellum (height threshold p < 0.01, cluster significant at p < 0.05 corrected for multiple comparisons).

CONCLUSIONS

These results demonstrate in writer's cramp the presence of structural abnormalities in brain structures interconnected within the sensorimotor network including the cerebellum and the cortical representation of the affected hand. These abnormalities may be related to the pathophysiology of writer's cramp, questioning the role of the cerebellum, or to maladaptive plasticity in a task-related dystonia.

[Role of rehabilitation Parkinson's disease, by disease severity and disability pattern]

Physical therapy is recognized as one of the most helpful means of improving the disabling side-effects of Parkinson's disease. Techniques which reduce stiffness, and improve muscle contracture and respiratory function are well established in different fields of rehabilitation including rheumatology and orthopedics. Parkinson's disease patients derive an obvious benefit from such treatments, suitably adapted to each stage of the disease course. New avenues for rehabilitation care include the cognitive approach for learning strategies or mental preparation for a given action in an attempt to reduce the akinesia, one of the main features of parkinsonism. Attractive as this new approach may be, its effectiveness remains to be proven.