R. Dattola

Local steroid treatment in idiopathic carpal tunnel syndrome: short- and long-term efficacy.

A clinical and electrophysiological study evaluated the usefulness of local steroid therapy for carpal tunnel syndrome (CTS). To evaluate the efficacy of local steroid therapy 32 patients (53 nerves) were randomly assigned to one of two groups: one (27 nerves) received 15 mg methylprednisolone acetate injected locally and the other (26 nerves) received the same amount of saline solution. The injections were repeated after a week. Clinical and electrophysiological findings were evaluated, double blind, at regular intervals. A clear-cut efficacy of steroid treatment was found. Only 8% of nerves were not benefitted while a marked early improvement was observed in most of the nerves. In order to appraise the long-term effect of local steroid treatment on CTS, 53 patients (91 nerves) were studied and followed up by means of clinical and electrophysiological examinations performed every 2 months for 2 years. The benefit of steroid treatment was transient. About 50% of the nerves became worse within 6 months and 90% within 18 months. Only a small percentage (8%) of the nerves remained improved at the 2-years follow-up. The clinical features were not useful in foretelling the duration of the improvement, which appeared to be related to the antidromic SAP latency.

Muscle Rearrangement in Patients with Hemiparesis after Stroke: An Electrophysiological and Morphological Study

Skeletal muscle changes were evaluated in patients suffering from hemiparesis after stroke. Concentric needle EMG and single fiber EMG of the paretic gastrocnemius medialis muscle were performed. Maximal amplitude of H, T and M responses in calf muscles of both the affected and the unaffected sides were determined by usual electrophysiological techniques. Muscle biopsy of the lateral gastrocnemius muscle of the affected side was performed to determine the distribution of fiber types and fiber sizes. Fibrillation activity and positive sharp waves occurred in paretic muscles in patients with more recent hemiparesis while the duration of motor unit potentials was prolonged in patients with long-lasting disease. The H/M ratio was increased on the paretic side. The percentage of type 1 fibers was augmented in most patients with normal mean diameter and low atrophy factor. The percentage of type 2 fibers was reduced with decreased mean diameters and with a high atrophy factor. Such changes may be related to inactivity or transsynaptic degeneration of type 2 motoneurons as a consequence of the interruption of the corticospinal tract. Increased percentage of type 1 fibers may be due to a collateral reinnervation process or a motor unit type transformation.

Unilateral cerebellar stroke disrupts movement preparation and motor imagery

OBJECTIVE To assess motor cortex excitability, motor preparation and imagery in patients with unilateral cerebellar stroke with damage of the dentate nucleus by using transcranial magnetic stimulation (TMS). METHOD Eight patients with unilateral cerebellar lesions due to tromboembolic stroke and 10 age matched healthy subjects were enrolled. Resting (RMT) and active (AMT) motor threshold, cortical and peripheral silent period, evaluation of motor imagery, reaction time and premovement facilitation of motor evoked potential (MEP) were tested bilaterally using TMS. RESULTS The RMT and AMT were found to be increased contra lateral to the affected cerebellar hemisphere while the cortical silent period was prolonged. In addition the amount of MEP facilitation during motor imagery and the pre-movement facilitation were reduced in the motor cortex contra lateral to the affected cerebellar hemisphere. The reaction time, performed with the symptomatic hand, was slower. CONCLUSIONS On the whole, our data confirm a role for the cerebellum in maintaining the excitability of primary motor area. Furthermore, patients with unilateral cerebellar stroke exhibit lateralized deficit of motor preparation and motor imagery. SIGNIFICANCE Our results add to evidence that cerebellum contributes to specific aspects of motor preparation and motor imagery.

Effects of steroid hormones on muscle reinnervation after nerve crush in rabbit

The ability of an association of three steroid hormones to influence the reinnervation process and the trophism of rabbit muscles denervated by crush of the sciatic nerve was investigated. The beginning of reinnervation was established with electromyographic recordings from the tibialis anterior muscle. The distance from the site of crushing to the point where the motor nerve enters the tibialis anterior muscle was then measured in each animal, and the nerve regeneration velocity (mm/day) was calculated: a slightly but significantly higher (P less than 0.001) mean value was found in treated animals compared with untreated ones. When soleus and extensor digitorum longus (EDL) muscles were histochemically examined 50 days after lesion, a larger mean diameter of type 2c fibers was found in treated than in untreated animals, pointing out a possible useful effect of the treatment. On the contrary, the size reduction of EDL type 2b fibers was more pronounced in treated rabbits, indicating a catabolic influence of the drugs on this fiber type.

Effect of electrotherapy on denervated muscles in rabbits: An electrophysiological and morphological study

Abstract The effects of electrotherapy on muscles denervated by crushing the sciatic nerve were studied in rabbits using electrophysiologic and morphologic techniques. The sciatic nerve was crushed in the thigh, just above its division into the lateral and medial popliteal nerves and the completeness of denervation was ascertained by EMG tests. Electrotherapy was carried out in six animals and six others were denervated controls; the contralateral leg of each animal was used as the normal control. The first appearance of signs of reinnervation was detected by means of EMG tests and the “reinnervation time” established. The animals were killed at the 50th day after nerve crush; the length of nerves below the crushed point was measured; soleus and extensor digitorum longus (EDL) muscles were removed and weighed. The percentages and the mean diameter of different muscle-fiber types in normal, control-denervated, and treated soleus and EDL muscles were calculated. No statistically significant difference was observed between electrophysiologic findings in control-denervated and treated rabbits. Electrotherapy was found to antagonize the weight loss of EDL muscles and the reduction of type 2b fiber diameters induced by denervation, but significantly accentuated the reduction of the mean diameter of type 1 fibers in EDL and soleus and increased the weight loss of denervated soleus muscles. The results obtained raise further doubts about the clinical utility of electrotherapy.

Single fibre EMG in 6 cases of botulism

ABSTRACT‐ In 6 cases of mild botulinum intoxication, conventional EMG and single fibre EMG (SFEMG) were performed on admission to our ward (about 15 days after ingestion of the toxin) and 4, 8 and 14 weeks after admission.

Experimental hyperthyroidism fails to expedite reinnervation of muscles denervated by crushing sciatic nerves in rabbits.

Abstract The time for initial reinnervation of tibialis anterior muscle after sciatic nerve crushing was measured in rabbits treated with intraperitoneal injections of 3,3′,5-triiodothyronine, 1 μg/kg body weight/day. The sciatic nerve was crushed in the thigh, just above its division into lateral and medial popliteal nerves. The method used to determine the beginning of reinnervation consisted of EMG recordings of (a) muscular potentials evoked by electrical stimulation of the sciatic nerve, below the crushed point, and (b) spontaneous action potentials during activity; the muscle tested was the tibialis anterior. The time for initial reinnervation averaged 43.6 ± 1.15 days in treated rabbits, and 43.2 ± 1.78 days in vehicle-injected animals. The distance from the site of crushing to the point where the anterior tibial nerve enters the tibialis anterior muscle was measured in each animal and the regeneration rate was calculated; this parameter averaged 1.48 ± 0.05 mm/day in treated rabbits, and 1.50 ± 0.04 mm/day in control animals. Therefore, no effect of 3,3′,5-triiodothyronine at the dosage used on the reinnervation process of muscles denervated by a crushed sciatic nerve could be demonstrated.

Familial oculopharyngeal muscular dystrophy with distal spread

SummaryAn Italian male aged 50 years with oculopharyngeal muscular dystrophy is reported. Eleven of his relatives, over a period of three generations, had ptosis, dysphagia, nasal voice and difficulty in walking.The distribution of muscle weakness in the propositus and in one of his sisters was proximal in the upper, but distal in the lower limbs, confirming the existence of a relationship between oculopharyngeal dystrophy and distal myopathy. The first muscle biopsy appeared normal except for some round-cell collections, whereas the second one, 5 years later, showed marked dystrophic changes. Some patients with oculopharyngeal dystrophy may apparently pass through a secondary muscular inflammatory stage.ZusammenfassungEs wird über einen 50jährigen Italiener mit einer oculopharyngealen Muskeldystrophie berichtet. Es zeigte sich, daß in der Familie 11 drei verschiedenen Generationen angehörige Individuen eine Ptosis, Dysphagie, eine näselnde Sprache und Schwierigkeiten beim Gehen aufwiesen.Die Verteilung der Muskelschwäche beim Propositus und einer ebenfalls untersuchten Schwester war an den oberen Extremitäten proximal, an den unteren jedoch distal, wodurch eine Beziehung der oculopharyngealen Dystrophie und einer distalen Myopathie bestätigt wurde. Eine erste Muskelbiopsie zeigte lediglich einige Ansammlungen von Rundzellen, während eine zweite Biopsie, die fünf Jahre später durchgeführt wurde, ausgeprägte Zeichen eines dystrophischen Prozesses ergab. Diese Befunde sprechen dafür, daß vereinzelte Patienten mit oculopharyngealer Dystrophie sekundäre entzündliche Muskelsymptome aufweisen könnten.

Effect of ACTH4-10 on nerve fiber regeneration after sciatic nerve crush in rabbits: an electrophysiological and morphological study.

Crush of sciatic nerve in rabbits supported by morphologic and electrophysiologic data was used to evaluate the effects of ACTH4-10 on nerve fiber regeneration. Treated animals showed a statistically significant higher regeneration rate than did control rabbits. Fiber density and mean diameters of myelinated nerve fibers were measured in semithin nerve sections at 1 and 3 cm distal from the crushed point at three different time points. Nerve fiber density results were higher in ACTH4-10-than in vehicle-treated rabbits. This difference showed an unequivocal trend and attained a statistically significant level in the sections 3 cm distal from the crush. ACTH4-10 seemed therefore to have a beneficial effect on nerve fiber regeneration.

Blink reflex in hemiplegia.

Data about the influence of hemispheric lesions on the blink reflex are conflicting. 21 hemiplegic patients and 11 control subjects were investigated. The duration, latency and electric area of electrically evoked blink reflex responses were evaluated by common electromyographic techniques. A depression of the ipsilateral and the consensual late response after stimulation of the paretic side was the most evident finding. However, also a certain increase of the early response and a depression of the late response of the paretic side independent of the side of stimulation emerged. Concerning the parameters taken into account, the evaluation of the latency period seems to be the most significant and reliable. Determination of the electric area provides additional useful data which, however, may easily lead to mistakes.