Multiple point electrical stimulation of ulnar and median nerves.
A computer-assisted method of isolating single motor units (MUs) by multiple point stimulation (MPS) of peripheral nerves is described. MPS was used to isolate 10-30 single MUs from thenar and hypothenar muscles of normal subjects and patients with entrapment neuropathies, with the original purpose of obtaining a more representative mean motor unit potential for estimating the number of MUs in a muscle. The two important results that evolved from MPS however, were: (1) in the absence of 'alternation' MUs were recruited in an orderly pattern from small to large, and from longer to shorter latencies by graded electrical stimulation in both normal and pathological cases, (2) a comparison of the sizes of MUs recruited by stimulation proximal and distal to the elbow suggested that axonal branching can occur in the forearm 200 mm or more proximal to the motor point in intrinsic hand muscles. (+info)
Cyclic compression of the intracranial optic nerve: patterns of visual failure and recovery.
A patient with a cystic craniopharyngioma below the right optic nerve had several recurrences requiring surgery. Finally the cyst was connected with a subcutaneous reservoir by means of a fine catheter. Symptoms of optic nerve compression recurred more than 50 times during the following year, and were relieved within seconds upon drainage of the reservoir. In each cycle, a drop in visual acuity preceded a measurable change in the visual field. The pattern of field changes was an increasingly severe, uniform depression. Optic nerve ischaemia induced by compression was probably the most important factor causing visual failure in this case. (+info)
Common peroneal nerve palsy: a clinical and electrophysiological review.
In a series of 70 patients (75 cases of common peroneal nerve palsy) the common causes were trauma about the knee or about the hip, compression, and underlying neuropathy. A few palsies occurred spontaneously for no apparent reason. The prognosis was uniformly good in the compression group; recovery was delayed but usually satisfactory in patients who had suffered stretch injuries. In the acute stage, when clinical paralysis appears to be complete, electrophysiological studies are a useful guide to prognosis. They may also indicate an underlying neuropathy and they detect early evidence of recovery. The anatomical peculiarities of the common peroneal nerve are noted and aspects of the clinical picture, management, and prognosis of palsy are discussed. (+info)
Lumbar spinal subdural hematoma following craniotomy--case report.
A 52-year-old female complained of lumbago and weakness in the lower extremities 6 days after craniotomy for clipping an aneurysm. Neurological examination revealed symptoms consistent with lumbosacral cauda equina compression. The symptoms affecting the lower extremities spontaneously disappeared within 3 days. Magnetic resonance (MR) imaging 10 days after the operation demonstrated a lumbar spinal subdural hematoma (SSH). She had no risk factor for bleeding at this site, the symptoms appeared after she began to walk, and MR imaging suggested the SSH was subacute. Therefore, the SSH was probably due to downward movement of blood from the cranial subdural space under the influence of gravity. SSH as a complication of cranial surgery is rare, but should be considered if a patient develops symptoms consistent with a lumbar SSH after craniotomy. (+info)
Removal of petrous apex meningioma and microvascular decompression for trigeminal neuralgia through the anterior petrosal approach. Case report.
A 64-year-old female presented with right trigeminal neuralgia. Computed tomography and magnetic resonance (MR) imaging demonstrated a tumor attached to the right petrous apex. MR imaging also revealed that the trigeminal nerve was compressed and distorted by the tumor. Tumor removal and microvascular decompression (MVD) were performed via the anterior petrosal approach. The trigeminal nerve was distorted by the tumor and the superior cerebellar artery compressed the medial part of the root entry zone of the trigeminal nerve. The surgery resulted in complete relief of the trigeminal neuralgia. Posterior fossa tumors causing ipsilateral trigeminal neuralgia are not rare, and are often removed via the suboccipital retromastoid approach, as MVD for trigeminal neuralgia is usually performed through the retromastoid approach. The advantages of the anterior petrosal approach are shorter access to the lesion and direct exposure without interference from the cranial nerves, and that bleeding from the tumors is easily controlled as the feeding arteries can be managed in the early stage of the surgery. We conclude that the anterior petrosal approach is safe and advantageous for the removal of petrous apex tumor associated with trigeminal neuralgia. (+info)
The wrist of the formula 1 driver.
OBJECTIVES: During formula 1 driving, repetitive cumulative trauma may provoke nerve disorders such as nerve compression syndrome as well as osteoligament injuries. A study based on interrogatory and clinical examination of 22 drivers was carried out during the 1998 formula 1 World Championship in order to better define the type and frequency of these lesions. METHODS: The questions investigated nervous symptoms, such as paraesthesia and diminishment of sensitivity, and osteoligamentous symptoms, such as pain, specifying the localisation (ulnar side, dorsal aspect of the wrist, snuff box) and the effect of the wrist position on the intensity of the pain. Clinical examination was carried out bilaterally and symmetrically. RESULTS: Fourteen of the 22 drivers reported symptoms. One suffered cramp in his hands at the end of each race and one described a typical forearm effort compartment syndrome. Six drivers had effort "osteoligamentous" symptoms: three scapholunate pain; one medial hypercompression of the wrist; two sequellae of a distal radius fracture. Seven reported nerve disorders: two effort carpal tunnel syndromes; one typical carpal tunnel syndrome; one effort cubital tunnel syndrome; three paraesthesia in all fingers at the end of a race, without any objective signs. CONCLUSIONS: This appears to be the first report of upper extremity disorders in competition drivers. The use of a wrist pad to reduce the effects of vibration may help to prevent trauma to the wrist in formula 1 drivers. (+info)
Predictors of outcome in cauda equina syndrome.
This retrospective review examined the cause, level of pathology, onset of symptoms, time taken to treatment, and outcome of 19 patients with cauda equina syndrome (CES). The minimum time to follow up was 22 months. Logistical regression analysis was used to determine how these factors influenced the eventual outcome. Out of 19 patients, 14 had satisfactory recovery at 2 years post-decompression; 5 patients were left with some residual dysfunction. The mean time to decompression in the group with a satisfactory outcome was 14 h (range 6-24 h) whilst that of the group with the poor outcome was 30 h (range 20-72 h). There was a clear correlation between delayed decompression and a poor outcome (P = 0.023). Saddle hypoaesthesia was evident in all patients. In addition complete perineal anaesthesia was evident in 7/19 patients, 5 of whom developed a poor outcome. Bladder dysfunction was observed in 19/19 patients, with 12/19 regarded as having significant impairment. Of the five patients identified as having a poor overall outcome, all five presented with a significant sphincter disturbance and 4/5 were left with residual sphincter dysfunction. There was a clear correlation between the presence of complete perineal anaesthesia and significant sphincter dysfunction as both univariate and multivariate predictors of a poor overall outcome. The association between a slower onset of CES and a more favourable outcome did not reach statistical significance (P = 0.052). No correlation could be found between initial motor function loss, bilateral sciatica, level or cause of injury as predictors of a poor outcome (P>0.05). CES can be diagnosed early by judicious physical examination, with particular attention to perineal sensation and a history of urinary dysfunction. The most important factors identified in this series as predictors of a favourable outcome in CES were early diagnosis and early decompression. (+info)
Sonographic detection of radial nerve entrapment within a humerus fracture.
Radial neuropathy is frequently associated with fracture of the middle third of the humerus owing to the course of the nerve adjacent to the humeral shaft. The prevalence varies from 2 to 18% of humeral fractures. The therapeutic management is still controversial. Some authors recommend initial surgical exploration, whereas others prefer observation and intervention only if the injured nerve failed to recover after a period of more than 4 months. According to the literature, verification of an entrapped radial nerve in a fracture gap requires surgical exploration, but diagnostic tools to verify the existence of a pathologic condition are limited. We describe the sonographic findings of an entrapped radial nerve and review the literature regarding diagnosis and treatment of entrapped radial nerve in cases of humeral fracture. (+info)