Clinical and experimental neurology最新文献

Nocardial cerebral abscess, an uncommon condition, is usually secondary to a septic focus elsewhere in the body. We report a 44-year-old Chinese male patient who had primary nocardial cerebral abscesses due to Nocardia asteroides which presented with stroke-like episodes. He improved spontaneously between these episodes. The diagnosis was reached only after a contrast CT brain study and microbiological examination of specimens obtained during craniotomy. An early contrast CT study is important in avoiding any delay in diagnosis and treatment of this serious condition.

Flushing and a sensation of tightness or pain in one ear lobe was a presenting complaint of 3 patients. In one case the symptoms were confined to the ear, another was associated with sensory impairment in the distribution of the C2 and C3 segments, while the 3rd patient experienced discomfort in the area of the 1st division of the trigeminal nerve on the same side. Two out of 3 patients had evidence of hypertrophy of the ipsilateral C2-3 facet joint and the symptoms of the 3rd patient were improved by an ipsilateral C2-3 root block. A possible mechanism could be the antidromic release of vasodilator peptides from afferent nerve terminals in response to irritation of the C3 root which supplies sensory innervation to the pinna.

Motor nerve biopsy was attempted on 19 occasions in 18 patients. Nerve tissue was obtained in 16. The nerves biopsied included those to the anconeus (4 times), palmaris longus (6), flexor sublimus (1), triceps (2), extensor carpi radialis (1), quadriceps (1) and gastrocnemius (1). Attempts to biopsy the radial nerve, the nerve to plantaris and the left common peroneal nerves failed in 2 patients. The lengths of nerve obtained varied from 1 to 3 cm, and from 1-5 fasciculi were present in the specimens. Sufficient material for both electron microscopy and teasing was present in 11. No patient experienced increased weakness, but one had transient paraesthesiae in the distal forearm following biopsy of the nerve to the palmaris longus. We conclude that motor nerve biopsy as described is both feasible and safe. The nerve to the palmaris longus, where that muscle was present, provided the optimum specimen for pathological studies.

Kennedy's disease is a form of progressive spinal and bulbar muscular atrophy of adult onset. This paper describes a case of Kennedy's disease and discusses the laboratory diagnosis and the underlying genetic mechanism. Three other neurological diseases, Huntington's disease, myotonic dystrophy and fragile X syndrome, which have similar genetic defects, are also discussed.

The pathogenesis of perioperative stroke is not clear from the literature. To explore the influence of various risk factors we examined the clinical, Duplex ultrasound and computerised tomography findings of all cases suffering cerebral infarction within 24 hours of surgery in a prospective series of 358 coronary or peripheral vascular reconstructive operations. Four patients (1.1%) had cerebral infarcts within 24 hours of surgery, all associated with perioperative systolic blood pressures of less than 90 mmHg. The other significant risk factor was previous cerebral ischaemic symptoms. Haemodynamic cerebral ischaemia occurred immediately after operation in 2 of 10 cases with severe symptomatic carotid stenosis or occlusion (stroke risk 20%; 95% confidence interval 2.52%-55.61%). Two cases with mild carotid disease had cerebral infarcts in previously asymptomatic hemispheres following coronary artery bypass graft surgery. One of these had clinical and computerised tomographic evidence of cortical watershed infarction. We conclude that cerebral haemodynamics are important in perioperative stroke and that symptomatic patients with severe carotid disease may be at high risk of perioperative watershed infarction.

This paper describes patients with demyelinating motor neuropathies associated with conduction blocks, pure motor neuropathies and intermediate forms with resemblances to amyotrophic lateral sclerosis, in persons with raised titres of anti-GM1 antibodies. The specificity of the abnormal anti-GM1 antibody titres is discussed, and the possibilities of immunosuppressive therapy mentioned.

Regional cerebral blood flow was studied at rest and during a memory recognition activation task in a preliminary investigation carried out in patients with mild to moderate dementia of Alzheimer type and in 2 control groups of subjects. There were differences in the sites of activation-increased blood flows between the normal controls and the controls with major depression, while the Alzheimer's disease subjects showed more variable patterns of flow response, which differed overall from those present in the 2 control groups.

Because sensory neuropeptides improve survival of critical skin and muscle flaps in rats, skin nociceptive sensory nerve function in blister healing was examined. Sensory nerve ablation by unilateral hindlimb denervation or cutaneous axon reflex enhancement by 14 days systemic nicotine treatment (5 mg kg-1 day-1) decreased and increased, respectively, peripheral motor functions of nociceptive (peptidergic) skin nerves. Effects on nociception were measured by a radiant heat tail-flick test. Axon reflex flares were evoked by transdermal iontophoresis of acetylcholine or noxious electrical stimulation under pentobarbitone 40 mg kg-1 anaesthesia. Resultant changes in cutaneous microvascular blood flux were measured non-invasively by laser Doppler flowmetry. In nicotine-treated rats compared with placebo-treated controls, acetylcholine-evoked axon reflex flare was enhanced by 240% (p < 0.01) without enhancement of electrically evoked flare. Thus, nicotine-sensitized nociceptors show stimulus specificity in their enhancement of neurogenic flare responses. No significant changes were seen in other endothelial-dependent or smooth muscle-dependent microvascular dilator responses. Nicotine-treated rats had prolonged tail-flick withdrawal latencies to noxious radiant heat stimuli compared with placebo-treated controls (p < 0.05), suggesting an antinociceptive or analgesic effect of nicotine-treatment. Neurogenic effects on wound healing rate were assessed by measuring the dimensions of standardized blisters twice daily. The blisters were raised on hindpaw glabrous skin using a constant weight and diameter of compressed dry ice pellet applied for 30 secs at constant force. Dry-ice blisters raised on the hindpaw 14 days post-denervation were significantly slower to heal completely (42 days) than controls (30 days: P < 0.05) and the surrounding inflammation was reduced. By contrast, nicotine-treated rats showed more rapid blister healing (25 days) than controls (30 days), seen only in the later phase after day 15. Finally, resting substance P release from blisters, after direct cutaneous nerve stimulation, appears to be enhanced in nicotine-treated rats. Thus nociceptive innervation appears critical for inflammation and rapid healing of blisters in rat skin. The data signal a possible important role for neuropeptides in these processes and question the function of nicotinic receptors on sensory nerves.

Generalised ventricular dilatation with or without cerebral atrophy is common in longstanding multiple sclerosis. This has been widely assumed to be due to periventricular white matter atrophy rather than true communicating hydrocephalus although it can be difficult to distinguish between these on radiological grounds. Here we report 2 chronic MS patients who had progressive dementia, gait disturbance and urinary incontinence and in whom neuroimaging, and in one case CSF infusion studies, suggested hydrocephalus. Both significantly improved following shunting procedures. We suggest that further study is required to investigate whether a significant proportion of patients with chronic MS and dilated ventricles have shunt-responsive hydrocephalus.