Clinical and electrophysiological investigation of spastic muscle overactivity in patients with disorders of consciousness following severe brain injury.

OBJECTIVE: The clinical and electrophysiological profile of spastic muscle overactivity (SMO) is poorly documented in patients with disorders of consciousness (DOC) following severe cortical and subcortical injury. We aim at investigating the link between the clinical observations of SMO and the electrophysiological spastic over-reactivity in patients with prolonged DOC. METHODS: We prospectively enrolled adult patients with DOC at least 3 months post traumatic or non-traumatic brain injury. The spastic profile was investigated using the Modified Ashworth Scale and the Hmax/Mmax ratio. T1 MRI data and impact of medication were analyzed as well. RESULTS: 21 patients were included (mean age: 41 ±â€¯11 years; time since injury: 4 ±â€¯5 years; 9 women; 10 traumatic etiologies). Eighteen patients presented signs of SMO and 11 had an increased ratio. Eight patients presented signs of SMO but no increased ratio. We did not find any significant correlation between the ratio and the MAS score for each limb (all ps > 0.05). The presence of medication was not significantly associated with a reduction in MAS scores or Hmax/Mmax ratios. CONCLUSIONS: In this preliminary study, the Hmax/Mmax ratio does not seem to reflect the clinical MAS scores in patients with DOC. This supports the fact they do not only present spasticity but other forms of SMO and contracture. SIGNIFICANCE: Patients with DOC are still in need of optimized tools to evaluate their spastic profile and therapeutic approaches should be adapted accordingly.

A Double-Blind, Placebo Controlled, Randomized Trial to Assess the Impact of a Monthly Administration of 50,000 IU of Vitamin D3 for 6 Months on Serum Levels of 25-Hydroxyvitamin D in Healthy Young Adults.

In this double blind, unicentre, randomized, placebo controlled study, we evaluated the changes in 25-hydroxyvitamin D (25(OH)D) serum levels in 150 young Belgian adults (18-30 years), monthly supplemented with 50,000 IU of vitamin D (VTD) or placebo for 6 months, from November 2010 to May 2011. At T0, 30% of the population presented 25(OH)D serum levels below 20 ng/mL. In the VTD-treated group, mean serum levels increased from 21.2 ± 8.2 to 30.6 ± 8.8 ng/mL (P < 0.001) at T3mo and to 36.0 ± 9.2 ng/mL (P < 0.001) at T6mo. Despite documented VTD intake, no changes in serum levels were, however, observed in 10% of the treated group. In the placebo group, mean 25(OH)D serum levels decreased from 22.8 ± 8.5 to 14.0 ± 6.9 ng/mL at T3mo (P < 0.001) but returned to values not significantly different from those observed at T0 (23.5 ± 8.6 ng/mL) at T6mo. No difference between serum calcium levels was observed between the groups throughout the study. In conclusion, monthly supplementation with 50,000 UI of VTD in winter can warrant serum 25(OH)D levels above 20 ng/mL in 96.2% of those healthy young adults without inducing unacceptably high 25(OH)D concentration. This supplementation is safe and may be proposed without 25(OH)D testing.

Sudden dysphagia in an elderly, quadriparetic patient.

CLINICAL CASE: We report the case of a 92-year-old quadriparetic patient who suddenly presented a major swallowing disorder following trauma to the neck. A diagnosis of myasthenia gravis was suggested by single-fibre EMG of the extensor digitorum communis muscle. In view of the continued absence of dysphagia after 6 months of pyridostigmine treatment, this diagnosis was considered as definitive. DISCUSSION: We review the various characteristics of myasthenia gravis and ways of investigating dysphagia. CONCLUSION: It is important to be aware of and investigate all the direct and indirect signs of dysphagia and establish the exact aetiology in order to provide the best possible treatment.

[Thoracic outlet syndrome]. / Le syndrome du défilé cervico-thoracique.

Thoracic outlet syndrome (TOS) is due to compression/irritation of brachial plexus elements ("neurogenic TOS") and/or subclavian vessels ("vascular TOS") in their passage from the cervical area toward the axilla. The usual site of entrapment is the interscalenic triangle. TOS is a highly controversial subject in regard to its incidence, diagnostic criteria and optimal treatment. Constitutional factors--osseous or more often fibromuscular--and external factors such as trauma predispose to the development of TOS. Various clinical pictures include pain in the cervical region and arm, paresthesias, aggravated by overhead positions of the arms, hand intrinsic muscle deficit/atrophy, easy fatiguability, paleness, coldness of hand. The clinical examination may be entirely normal or show cervical and scapular muscle spasm, tenderness of supraclavicular area, radial pulse attenuation upon positional maneuvers, sensory and/or motor deficit, usually of C8/T1 distribution. The diagnosis is based on clinical evaluation and absence of other relevant pathology. Sometimes TOS can enhance symptoms consecutive to cervical or supraclavicular lesions. Cervical spine and distal peripheral nerves are investigated by radiological and electrophysiological studies. Unless there is significant motor deficit or subclavian artery compression, the treatment should be kept conservative as long as possible, by adapted physical therapy. In case of neurological deficit or symptoms unresponsive to medical treatment, the patients will--like in other nerve entrapment syndromes--be helped by decompressive surgery, nowadays preferably performed via an anterior supraclavicular approach.

Sciatic nerve regeneration through venous or nervous grafts in the rat.

This study analyses the interest of isologous venous grafts filled with saline or with Schwann cells versus nerve grafts as guides for regeneration of the sciatic nerve in 35 Wistar rats. Electrophysiological parameters (conduction velocities and distal latencies of motor responses) and the functional index of De Medinacelli were measured several times from 1 month to 1 year after surgery. An histological analysis was performed on 2 control rats and on 3 rats killed 6 or 12 months after surgery: the total number of fibers was counted on a montage photoprint of the whole nerve, and the diameters of axons and the thickness of the myelin sheath were measured on digitized images. With a portion of nerve as guide, the regeneration is faster than with a vein. However, regeneration after 6 months is at least as good with a venous graft filled with Schwann cells, as assessed by electrophysiological, functional, and histological analysis. The addition of Schwann cells in grafted veins allows the nerve to regenerate through longer gaps than previously described (25 vs 15 mm). In order to assess the quality of nerve regeneration, functional, electrophysiological, and histological analysis are complementary.

Predegenerated nerve allografts versus fresh nerve allografts in nerve repair.

This study reevaluated the possibility of using predegenerated nerves as donor nerve allografts for nerve repair and compared the results of functional recovery to those obtained after standard, fresh nerve allograft repair. Twenty donor rats underwent a ligature/ section of the left sciatic nerve 4 weeks before nerve graft harvesting. Forty recipient rats underwent severing of the left sciatic nerve leaving a 15-mm gap between the nerve stumps. Graft repair was undertaken using either the predegenerated left sciatic nerve of the 20 donor rats (predegenerated group, 20 recipient rats) or the normal right sciatic nerve of the 20 donor rats (fresh group, 20 recipient rats). Recovery of function was assessed by gait analysis, electrophysiologic testing and histologic studies. Walking tracks measurements at 2 and 3 months, electromyography parameters at 2 and 3 months, peroperative nerve conduction velocity and nerve action potential amplitude measurements at 3 months, as well as assessments of myelinated nerve fiber density and surface of myelination showed that fresh and predegenerated nerve grafts induced a comparable return of function although there was some trend in higher electrophysiologic values in the predegenerated group. The only slight but significant difference was a larger mean nerve fiber diameter in the nerve segment distal to a predegenerated nerve graft compared to a fresh nerve graft. Although our study does not show a dramatic long-term advantage for predegenerated nerve grafts compared to fresh nerve grafts, their use as prosthetic material is encouraging.