1,721,039 research outputs found
Temporal processing of visuotactile and tactile stimuli in writer's cramp
No full textNeurophysiological studies in animals show that basal ganglia are involved not only in motor and nonmotor timing functions but also in integrating tactile and visual signals delivered in the peripersonal space. We tested temporal discrimination of cross-modal and unimodal stimuli in 13 controls and 14 patients with writer's cramp, a disorder supposedly linked to dysfunction of basal ganglia. Subjects were asked to discriminate whether pairs of visual, tactile, or visuotactile stimuli were simultaneous or sequential (temporal discrimination threshold) and which stimulus preceded the other (temporal order judgment). Patients were impaired in temporal processing of tactile and cross-modal stimuli. A significant positive correlation between temporal deficits and the severity of disability was detected for both affected and unaffected sides. Findings suggest that multimodal and not only modality-specific temporal processing is defective in focal hand dystonia. Deficits of temporal processing of stimuli delivered to the unaffected side may represent a behavioral index of the susceptibility to develop dystonia and thus have remarkable practical and theoretical implications
Timing of tactile and visuo-tactile stimuli is impaired in patients with cervical dystonia
No full textPsychophysical studies show alterations of cross-modal integration and timing processes in patients with generalized and focal hand dystonia. Here we assess the capability of 10 cervical dystonia patients, 5 patients with cervical pain but no dystonia, and 10 healthy controls to determine whether pairs of visual, tactile or visuo-tactile stimuli were simultaneous or sequential (TD threshold) and which stimulus preceded the other (temporal order judgement, TOJ). Visual stimuli consisted of light emitting diodes and tactile stimuli of non-noxious electrical shocks delivered to the hands. Intervals between stimuli were increased from 0 to 400 ms in steps of 10 ms. Cervical dystonia patients had a clear impairment of tactile and visuo-tactile temporal discrimination compared with patients with cervical pain but no dystonia who performed as well as healthy subjects. This suggests that deficits of temporal discrimination in cervical dystonia patients are not due to the possible distracting effect of unpleasant sensations or pain. Comparisons with previous studies show that deficits in cervical dystonia were more severe than in focal hand dystonia and less severe than in generalized dystonia. Thus, impairment of sensory timing may be a marker of disease, which varies along a continuum in the different forms of dystonia
Impaired heteronymous somatosensory motor cortical inhibition in dystonia
No full textA typical pathophysiological abnormality in dystonia is cocontraction of antagonist muscles, with impaired reciprocal inhibitory mechanisms in the spinal cord. Recent experimental data have shown that inhibitory interactions between antagonist muscles have also a parallel control at the level of the sensorimotor cortex. The aim of this work was to study heteronymous effects of a median nerve stimulus on the corticospinal projections to forearm muscles in dystonia. We used the technique of antagonist cortical inhibition, which assesses the conditioning effect of median nerve afferent input on motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (TMS) in ipsilateral forearm extensor muscles at rest. Nine healthy subjects and 10 patients with torsion dystonia participated in the study. MEPs and somatosensory evoked potentials were normal in patients. In healthy subjects, median nerve stimulation at 15- to 18-msec intervals inhibited the test MEPs in forearm extensors. In dystonic patients, median nerve stimulation delivered at the same conditioning-test intervals elicited significantly less inhibition of the test MEP. On the whole, these data suggest an impaired sensory-motor integration in dystonia and, more specifically, the decreased antagonistic cortical inhibition could suggest that functional interactions between antagonist muscles are primarily impaired at the cortical level. © 2003 Movement Disorder Society
Acetylcholine receptor-antibody-positive myasthenia gravis presenting with early atrophy and nonfluctuating weakness of proximal limb muscles
No full text[no abstract available
Hemiparkinsonism-hemiatrophy syndrome: neuroradiological and neurophysiological findings
No full textA rare form of secondary parkinsonism has been recently described as 'hemiparkinsonism-hemiatrophy syndrome'. We report a case with such clinical features. A neurophysiological study of the evoked potentials, somatosensory and motor, has been conducted. We stress the neuroradiological findings at nuclear magnetic resonance, which documented the presence of an area of altered signal in the mesencephalon, between the cerebral pedunculus and the red nucleus on the right side. The etiopathogenetic considerations and diagnostic criteria are discussed. Moreover we evaluate the efficacy of levodopa therapy
Genital and sexual pain in women
No full textThis chapter discusses the all too common problem of sex-related pain in women. Pain is a complex perceptive experience, involving biologic as well as psychologic and relational meanings. They become increasingly important with the chronicity of pain. Neurologists are quite aware of the painful aspect of many neurologic disorders, but lifelong and acquired genital and sexual pain is still neglected in a consistent percentage of women. One reason is the view - still held by many - that psychologic factors play the most important role in sex-related pain complaints. The consequences of diagnostic delay can be dramatic. Persisting tissue inflammation induces pain to change from acute and "nociceptive," which indicates a "friendly signal," alerting one to ongoing tissue damage, to chronic and "neuropathic," a disease per se. Whilst the primary disease is progressing and neuroinflammation becomes a prominent feature, affected women have to bear years of pain and distress, huge quantifiable and non-quantifiable costs, and a progressive deterioration of personal and relational health and happiness. The scenario is even more dramatic when pain complicates an already disabling disease. The main aspects considered in this chapter include neuroinflammation as a key feature of pain; genital and sexual pain as part of neurologic diseases; and genital and sexual pain syndrome (dyspareunia and vaginismus) as primary problems, and their pelvic comorbidities (bladder pain syndrome, endometriosis, irritable bowel syndrome, provoked vestibulodynia/vulvodynia). Finally, we discuss iatrogenic pain, i.e., genital and sexual pain caused by ill-conceived medical, surgical, pharmacologic or radiologic therapeutic interventions
Natural history of motor neuron disease in adult onset GM2-gangliosidosis: A case report with 25 years of follow-up
No full textAn adult with Sandhoff disease presented with pure lower motor neuron phenotype. Twenty years later, he showed signs of upper motor neuron involvement. 25 years from the onset, his muscle weakness slightly worsened but he was fully independent in activities of daily living.
GM2-gangliosidosis can manifest as a motor neuron disease with a slowly progressive course. The correct knowledge of the natural history can be really important to achieve the diagnosis, design new therapies and evaluate clinical trials
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