Irreversible damage to the spinal cord following spinal anesthesia.

The authors report five patients with damage to the distal spinal cord following spinal anesthesia. The patients developed leg weakness and sensory disturbance. MRI of the lumbosacral spine showed an abnormal area of high signal within the conus medullaris in all patients. Symptoms and signs persisted at 1- to 2.5-year follow-ups. Incorrect needle placement and type of needle used are possible factors leading to spinal cord injury.

Evidence for interactive locomotor and oculomotor deficits in cerebellar patients during visually guided stepping.

Eight patients suffering from primary cerebellar degenerative diseases undertook a walkway task, demanding precise foot placement at each step, and a visual fixation task, requiring only eye movements. Step cycle and horizontal eye movements were recorded throughout the tasks and compared to those of healthy adults (including age- and sex-matched controls). Cerebellar patients displayed both locomotor and oculomotor deficits. Increases in duration of the stance, swing and double support phases of the step cycle were all shown to contribute to ataxic gait. Dysmetric saccades to fixate the footfall targets were seen more frequently in patients than in controls. These hypometric saccades were followed by one or more corrective saccades (patients: >45% accompanied by one or more corrective saccades; controls: <10% accompanied by a single corrective saccade). Similarities between the oculomotor deficits displayed by patients during the visual fixation task and when walking indicate that the latter are not merely a consequence of ataxic gait. The existence of several links between these locomotor and oculomotor deficits provides evidence for considerable interaction between the two control systems in the production of patterned eye and stepping movements. These results also suggest that the cerebellum plays an active role in the co-ordination of visually guided eye and limb movements during visually guided stepping.

Parkinsonism associated with obstructive hydrocephalus due to idiopathic aqueductal stenosis.

Two cases of parkinsonism after recurrent obstructive hydrocephalus due to idiopathic aqueductal stenosis are reported. In both patients an extrapyramidal syndrome was noted in the absence of contemporaneous evidence of hydrocephalus or shunt failure. One of the patients underwent a shunt operation, but showed no clinical improvement. However, both patients improved after the administration of dopaminergic therapy. The seven previously reported cases of this syndrome were reviewed and it is concluded that the prognosis of the parkinsonism is good, usually with total, or near total, resolution. It is recommended that if a patient with idiopathic aqueduct stenosis develops hydrocephalus or evidence of shunt malfunction in association with acute parkinsonism their shunt should be replaced. If there is no evidence of hydrocephalus or shunt malfunction they should initially be treated with domaminergic medication.

Nerve injury after posterior and direct lateral approaches for hip replacement. A clinical and electrophysiological study.

Nerve injury is a rare complication of total hip replacement which may be related to the exposure used for the operation. The posterior approach is traditionally associated with injury to the sciatic nerve. We have compared the incidence of nerve injury after primary total hip replacement (THR) using either a posterior or a direct lateral approach. We studied 42 consecutive patients undergoing primary total hip replacement. The surgeons used a posterior (22 patients) or direct lateral (20 patients) approach in accordance with their normal practice. The obturator, femoral, posterior tibial and common peroneal nerves were assessed clinically and electrophysiologically by electromyography (EMG) and measurement of the velocity of nerve conduction before operation and at four weeks after. All patients were free from symptoms of nerve injury after operation but five lesions were identified in four patients by the electrophysiological studies; the obturator nerve was involved in two, the femoral in one, the common peroneal in one and the posterior tibial in one. All these injuries occurred using the lateral approach. Clinical assessment alone underestimates the incidence of nerve injury complicating THR. Our study does not confirm the association of nerve injury with the posterior approach which had been described previously.

Focal upper limb demyelinating neuropathy.

Observations are presented on nine selected patients with chronic upper limb demyelinating neuropathy to illustrate the range of manifestations that may be observed. In three, the involvement was purely motor, in five, mixed motor and sensory and, in one, virtually purely sensory; in seven the symptoms were unilateral and in two bilateral. The presence of reduced nerve conduction velocity and conduction block and the response to treatment in seven of the cases indicate that they represented examples of chronic inflammatory demyelinating polyneuropathy (CIDP) with focal involvement. This was confirmed by nerve biopsy in two cases. The presentation in one patient was accompanied by forearm swelling initially suspected of being a tumour but shown to be due to muscle hypertrophy. This was probably the consequence of recurrent muscle cramps and fasciculation and possibly neuromyotonia. The patient with predominant sensory involvement restricted to the upper limbs demonstrates that sensory CIDP can present focally. In one patient with monomelic motor and sensory involvement, nerve biopsy showed multifocal areas of hypertrophic demyelinating neuropathy distally in the ulnar nerve without inflammatory infiltration. This patient failed to respond to therapy. Response in the others was satisfactory, although one patient with a monomelic motor neuropathy showed a severe deterioration after being given corticosteroids; he subsequently improved with intravenous human immunoglobulin therapy.

Plasma exchange in the treatment of Guillain-Barré syndrome: experience in a sub-regional referral centre.

Plasma exchange became popular in the treatment of Guillain-Barré syndrome with the publication in 1985 of results by the Guillain-Barré Study Group. Since then we have treated 24 patients referred for plasma exchange. We have audited their outcome and compared this with the results of patients in the treatment arm of the USA Study. Our patients were of comparable age and clinical severity and had similar duration of illness before starting plasma exchange. Nine of our patients required ventilation for a median of 24 days. The median time to improve one clinical grade was 19 days which compared well with the Study Group results. We have shown that plasma exchange may be safely performed in a district general hospital in a setting appropriate to the patient's clinical condition. We concur with the central conclusion of the Study, that if treatment is started early in the disease, the patient's outcome is improved.

Mononeuritis multiplex and occipital infarction complicating giant cell arteritis.

A 67-year-old lady with giant cell arteritis presented with a normal erythrocyte sedimentation rate (ESR) and developed occipital infarction and mononeuritis multiplex shortly after being started on high dose steroids.

Stretch and vibration reflexes of wrist flexor muscles in spasticity.

The surface electromyographic (EMG) reflex responses of the voluntarily contracting flexor carpi radialis evoked by 'stretch' and by tendon vibration have been compared in patients with spasticity of the upper limb, arising from upper motor neuron lesions, and normal subjects. Reflex responses to 'stretch' comprised increases in EMG activity lasting up to 100 ms which were often divided into 'short' and 'long'-latency peaks. The short-latency responses of spastic patients were increased in size compared with those of normal subjects whereas later activity was commonly reduced or absent. In both groups vibration elicited short-latency, essentially phasic responses with activity falling back to or below the background level within 50 ms despite continuing stimulation. These initial reflex responses were exaggerated in the spastics as compared with the normals. In the relaxed state 'stretch' and vibration either failed to elicit reflex responses in normal subjects or reflexes were of small amplitude; in spastic patients both modes of stimulation regularly evoked well developed responses. These findings with 'stretch' and vibration, both of which forms of stimulation powerfully excite primary endings of muscle spindles, support the view that group Ia afferent-mediated reflex action is enhanced in spasticity. The observation that the normal long-latency responses evoked by stretch, which have been attributed to the action of spindle group II afferents (Matthews, 1984a) additionally excited with this stimulus, are depressed in many spastic patients is consistent with reduced group II effects. Observed abnormalities of stretch reflex behaviour did not readily explain the severity of accompanying spasticity of individual patients.

Brain stem auditory evoked potentials and blink reflexes in multiple sclerosis.

Brain stem auditory evoked potentials (BAEP) and the blink reflex (BR) were recorded from 50 patients with a wide spectrum of multiple sclerosis, to determine whether the combination of the two tests of brain stem function would yield a higher rate of abnormality than each test performed alone. Sixty-four per cent of patients had a BAEP abnormality and fifty-two per cent had an abnormal BR, but when the results were combined, seventy-six per cent were abnormal. The blink reflex was abnormal in all patients with symptoms suggestive of trigemino-facial pathology.

An adult case of Andersen's disease--Type IV glycogenosis. A clinical, histochemical, ultrastructural and biochemical study.

A middle-aged man presented with a thirty-year history of progressive, asymmetrical limb-girdle weakness. The muscle biopsy revealed a vacuolar myopathy. The vacuoles which did not disrupt the fibre outline, lay in a subsarcolemmal position. They were PAS-positive and the material was partially resistant to diastase digestion. Electron microscopy showed the vacuoles to contain free unbound glycogen with filamentous material. Leucocyte brancher enzyme activity was normal but the muscle activity was less than half the control value. Histochemical and ultrastructural characteristics of the storage material resemble the amylopectin polysaccharide deposits seen in childhood Type IV glycogenosis.

Facial nerve preservation during surgery for removal of acoustic nerve tumors.

A series of 33 patients with 35 acoustic nerve tumors is reviewed. Tumor size was estimated from computerized tomography (CT) scans, and its influence on anatomical and functional preservation of the facial nerve was assessed. Six tumors (one invading the petrous bone, three medium and two large tumors) were not detected on CT scans. The translabyrinthine approach was used in seven instances (one small and six medium tumors) and the suboccipital transmeatal approach for 28 tumors (seven medium and 21 large tumors). Anatomical preservation of the facial nerve was achieved in 83% of operations for tumor removal, two of which were subtotal. A further two patients underwent subtotal removal, but the facial nerve was destroyed. Large tumors carried an increased risk of damage to the facial nerve, but even in this group the nerve was preserved anatomically intact in 70% of cases. Damage to the facial nerve occurred more frequently in patients with preoperative evidence of facial weakness; however, this factor did not appear to influence functional recovery of the facial nerve, provided that the nerve was intact at the end of the operation. A simple grading system for facial nerve function is described. Ony 76% of anatomically intact facial nerves showed any evidence of function 1 month after surgery. Postoperatively, facial function improved with time. At the latest review, 45% of these patients had normal facial function or mild facial weakness (Grades I and II).

Ventilatory failure in myasthenia gravis.

This retrospective study over the decade 1969-1978 examines the precipitating factors and outcome in thirty-one patients with myasthenia gravis who developed ventilatory failure. An unusual example of chronic alveolar hypoventilation is discussed in detail. The most favourable outcome occurred in younger patients with a hyperplastic thymus, in contrast to a poorer outlook for older patients with an atrophic gland. Eleven patients died during the period of follow up: three deaths were unrelated to myasthenia but the remaining eight were attributed directly or indirectly to it. The mortality of 36% represents a marked improvement on a 70% mortality in a similar group of patients, reported from this hospital for the years 1960-1968.