Brain : a journal of neurology
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Complex regional pain syndrome type I (CRPS I, formerly known as reflex sympathetic dystrophy) is a painful neuropathic disorder that develops after trauma affecting the limbs without overt nerve injury. Clinical features are spontaneous pain, hyperalgesia, impairment of motor function, swelling, changes in sweating, and vascular abnormalities. In this study, the pathophysiological mechanisms of vascular abnormalities were investigated. ⋯ Secondary changes in neurovascular transmission may lead to vasoconstriction and cold skin in chronic CRPS I, whereas sympathetic activity is still depressed. Vascular abnormalities are dynamic. The maximal skin temperature difference that occurs during the thermoregulatory cycle distinguishes CRPS I from other extremity pain syndromes with high sensitivity and specificity.
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Comparative Study Clinical Trial Controlled Clinical Trial
Delayed onset mixed involuntary movements after thalamic stroke: clinical, radiological and pathophysiological findings.
Although occurrence of involuntary movements after thalamic stroke has occasionally been reported, studies using a sufficiently large number of patients and a control population are not available. Between 1995 and 1999, the author prospectively identified 35 patients with post-thalamic stroke delayed-onset involuntary movements, which included all or some degree of dystonia-athetosis-chorea-action tremor, occasionally associated with jerky, myoclonic components. A control group included 58 patients examined by the author during the same period who had lateral thalamic stroke but no involuntary movements. ⋯ Further analysis showed that dystonia-athetosis-chorea was closely associated with position sensory loss, whereas the tremor/myoclonic movements were related to cerebellar ataxia. Recovery of severe limb weakness seemed to augment the instability of the involuntary movements. Persistent failure of the proprioceptive sensory and cerebellar inputs in addition to successful, but unbalanced, recovery of the motor dysfunction seemed to result in a pathological motor integrative system and consequent involuntary movements in patients with relatively severe lateral-posterior thalamic strokes simultaneously damaging the lemniscal sensory pathway, the cerebellar-rubrothalamic tract and, relatively less severely, the pyramidal tract.
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Clinical Trial Controlled Clinical Trial
A dissociation between subjective and objective unsteadiness in primary orthostatic tremor.
Patients with primary orthostatic tremor (OT) experience a disabling sense of unsteadiness but rarely fall. In order to study the relationship between the development of subjective unsteadiness, objective unsteadiness and tremor, we recorded standing under four conditions (eyes open or closed, feet together or apart) in six patients with OT. Subjective unsteadiness was indicated by the patients on a four-point scale using a hand-held slider. ⋯ We postulate that the sensation of unsteadiness arises from a tremulous disruption of proprioceptive afferent activity from the legs. This disturbance gives rise to increased co-contracting drive to the leg muscles in order to stiffen the joints and increase stability. Since muscle activity remains tremor-locked, the tremulous proprioceptive feedback is increased, which then further increases the sensation of unsteadiness, and so on in a vicious circle of escalating activity.
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The incidence of subarachnoid haemorrhage (SAH) is stable, at around six cases per 100 000 patient years. Any apparent decrease is attributable to a higher rate of CT scanning, by which other haemorrhagic conditions are excluded. Most patients are <60 years of age. ⋯ Antifibrinolytic drugs reduce the risk of rebleeding, but do not improve overall outcome. Measures of proven value in decreasing the risk of delayed cerebral ischaemia are a liberal supply of fluids, avoidance of antihypertensive drugs and administration of nimodipine. Once ischaemia has occurred, treatment regimens such as a combination of induced hypertension and hypervolaemia, or transluminal angioplasty, are plausible, but of unproven benefit.
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Investigation of human ano-rectal physiology has concentrated largely on understanding the motor control of defecation and continence mechanisms. However, little is known of the physiology of ano-rectal sensation. There are important differences in the afferent innervation and sensory perception between the rectum and anal canal. ⋯ In conclusion, anal and rectal sensation resulted in a similar pattern of cortical activation, including areas involved with spatial discrimination, attention and affect. The differences in sensory perception from these two regions can be explained by their different representation in the primary somatosensory cortex. The anterior cingulate cortex was only activated by rectal stimulation, suggesting that the viscera have a greater representation on the limbic cortex than somatic structures, and this explains the greater autonomic responses evoked by visceral sensation in comparison with somatic sensation.