It has been postulated that sensorimotor integration is abnormal in dystonia. We investigated changes in motor cortical excitability induced by peripheral stimulation in patients with focal hand dystonia (12 patients with hand cramps) and with cervical dystonia (nine with spasmodic torticollis) compared with 16 age-matched normal controls. Motor evoked potentials (MEP) to focal (figure-of-eight coil) transcranial magnetic stimulation of the hand area were recorded from the right abductor pollicis brevis (APB), first dorsal interosseus (FDI), flexor carpi radialis and extensor carpi radialis muscles. Changes of test MEP size following conditioning stimulation of the right median nerve (or of the index finger) at conditioning-test (C-T) intervals of 50, 200, 600 and 1000 ms were analysed. Peripheral stimulation significantly reduced test MEP size in the APB and FDI muscles of normal control and spasmodic torticollis patients. The inhibitory effect was larger upon median nerve stimulation and reached a maximum at the C-T interval of 200 ms. On the contrary, hand cramp patients showed a significant facilitation of test MEP size. This study suggests that MEP suppression following peripheral stimulation is defective in patients with focal hand dystonia. Central processing of sensory input is abnormal in dystonia and may contribute to increased motor cortical excitability.
Reliable, simple and safe criteria are needed for the early prediction of short-term outcome in patients with acute ischemic stroke. The aim of our study was to evaluate, in terms of their individual and combined power, the prognostic value of a few widely available clinical and instrumental variables obtained during the acute phase. The study involved 351 consecutive patients who were examined within 48 hours of their first ischemic stroke. Eight variables were chosen: age, initial level of consciousness, limb paresis, arterial blood pressure, glycemia, the results of electrocardiography and electroencephalography, and the infarct size revealed by computed tomography. Mortality and disability were evaluated on Day 30, when the variables that significantly correlated with disability were the severity of limb paresis, electroencephalographic abnormalities, infarct size and (less significantly) the level of consciousness and hyperglycemia. There was no statistical correlation with blood pressure. Logistic analysis confirmed only infarct size, the severity of limb paresis and electroencephalographic abnormalities as independent variables. The variables that significantly correlated with early death were the severity of limb paresis, infarct size, electrocardiographic abnormalities, the level of consciousness, electroencephalographic abnormalities and hyperglycemia. More intriguingly, logistic analysis confirmed only the electroencephalographic and electrocardiographic abnormalities as independent variables. The predictive prognostic value of limb paresis, infarct size, the level of consciousness and hyperglycemia is well known, but we would like to stress the fact that only a few independent variables are predictive of early death (electroencephalographic and electrocardiographic abnormalities) and poor recovery (infarct size, the severity of limb paresis, electroencephalographic abnormalities). The prognostic value of electroencephalography may express the potential involvement of dynamic non-structural phenomena, such as penumbra ischemica and diaschisis.
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