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.

Physiotherapy of focal dystonia: a physiotherapist's personal experience.

The approach of the physiotherapist to each form of dystonia is individual and has to be specific. There is not one single method but several strategies related to the different clinical forms. Although there is no standard programme applicable to all forms of cervical dystonia, we can distinguish a number of guidelines for the different clinical forms. In the myoclonic form, emphasis is placed on seeking to immobilize the head, and for the tonic form, on rehabilitating corrector muscles. Physiotherapy and botulinum toxin injections mutually interact in order to reduce the symptoms. Recent studies have shown the clinical benefits of physiotherapy. The physiotherapy of writer's cramp is designed as a re-learning process. The first step is to perform exercises to improve independence and precision of fingers and wrist movements. Then, the muscles involved in the correction of dystonic postures are trained by drawing loops, curves and arabesques. The aim of rehabilitation is not to enable patients with writer's cramp to write as they used to, but to help their dysgraphia evolve towards a fast, fluid and effortless handwriting. A reshaping of the sensory cortical hand representation appears to be associated with clinical improvement in patients with dystonia after rehabilitation.

Case-control study of writer's cramp.

Task-specific focal dystonias are thought to be due to a combination of individual vulnerability and environmental factors. There are no case-control studies of risk factors for writer's cramp. We undertook a case-control study of 104 consecutive patients and matched controls to identify risk factors for the condition. We collected detailed data on medical history and writing history as part of hobbies or occupation. Cases had a college or university degree more frequently than controls [OR = 4.6 (1.3-20.5), P = 0.01]. The risk of writer's cramp increased with the time spent writing each day (P-trend = 0.001) and was also associated with an abrupt increase in the writing time during the year before onset (OR = 5.7, 95% CI = 1.3-33.9, P = 0.02). Head trauma with loss of consciousness [OR = 3.5 (1.0-15.7), P = 0.05] and myopia [OR = 4.1 (1.7-12.0), P = 0.0009] were both associated with the condition but it was not significantly associated with peripheral trauma, left-handedness, constrained writing, writing in stressful situations or the choice of writing tool. The dose-effect relationship between writer's cramp and the time spent handwriting each day, and the additional burden of acute triggers such as an abrupt increase in the writing time in the year before onset, point to a disruptive phenomenon in predisposed subjects. Homeostatic regulation of cortical plasticity may be overwhelmed, resulting in dystonia.

Abnormal spinal interactions from hand afferents to forearm muscles in writer's cramp.

OBJECTIVE: Spinal reflexes from hand to wrist muscles were investigated in writer's cramp. METHODS: Stimulus-triggered rectified EMG averages after ulnar nerve and cutaneous stimulation, in wrist flexors and extensors during tonic contraction, were compared in 18 controls and 19 patients. RESULTS: On the patient dystonic side, ulnar-induced EMG suppression was decreased in wrist extensors, and facilitation in wrist flexors modified dependent on the dystonic wrist posture during writing. No change was found on the patient non-dystonic side. Cutaneous stimulation increased wrist flexor EMG on both sides of the patients with normal wrist posture during writing, but had no effect in controls and patients with abnormal wrist posture. CONCLUSIONS: Comparison between cutaneous and mixed nerve stimuli suggests that spindle afferents from intrinsic hand muscles may mediate patients' ulnar-induced EMG modulations. Abnormal proprioceptive control was only observed on dystonic side, while bilateral unusual cutaneous control was found in patients. Changes in spinal transmission were partly related to the dystonic wrist posture, suggesting that systems involved in sensory processing can be differentially altered in writer's cramp. SIGNIFICANCE: Changes in spinal transmission, probably related to peripheral and/or cortical inputs, might either take part in primary or adaptive mechanisms underlying writer's cramp.

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]. / La reeducation de la maladie de Parkinson en fonction des differents stades evolutifs et du profil de handicap.

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.

[Clinical, electrophysiologic and endocrine effects of the perfusion of high doses of TRH in amyotrophic lateral sclerosis]. / Effets cliniques, électrophysiologiques et endocriniens de la TRH en perfusion à doses élevées dans la sclérose latérale amyotrophique.

Eight patients with amyotrophic lateral sclerosis received 500 mg TRH by IV infusion, at a progressive rate during 3 hours. Only 3 patients noted subjective improvement of strength. Clinical muscular testing and H response study failed to show any change. Moreover modifications of the prolactin, growth hormone, TSH and T3 serum levels raise a question concerning the tolerance with long term utilization of TRH.