Journal of neurology
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Journal of neurology · Jan 2005
Memory evaluation with a new cued recall test in patients with mild cognitive impairment and Alzheimer's disease.
Free delayed recall is considered the memory measure with the greatest sensitivity for the early diagnosis of dementia. However, its specificity for dementia could be lower, as deficits other than those of pure memory might account for poor performance in this difficult and effortful task. Cued recall is supposed to allow a better distinction between poor memory due to concurrent factors and impairments related to the neurodegenerative process. ⋯ The RI48 Test classified correctly 88% of the MCI and SMC participants and was the best predictor of the status of MCI and mild AD as well as the outcome of the MCI patients. Poor visual memory was the second best predictor of those MCI patients who evolved to AD. A cued recall test which avoids the ceiling effect is at least as good as the delayed free recall tests in the early detection of AD.
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The pathophysiology of human narcolepsy is still poorly understood. The hypoactivity of some neurotransmitter systems has been hypothesised on the basis of the canine model. To determine whether narcolepsy is associated with changes in excitability of the cerebral cortex, we assessed the excitability of the motor cortex with transcranial magnetic stimulation (TMS) in 13 patients with narcolepsy and in 12 control subjects. ⋯ These results are consistent with an impaired balance between excitatory and inhibitory intracortical circuits in narcolepsy that leads to cortical hypoexcitability. We hypothesise that the deficiency of the excitatory hypocretin/orexin-neurotransmitter-system in narcolepsy is reflected in changes of cortical excitability since circuits originating in the lateral hypothalamus and in the basal forebrain project widely to the neocortex, including motor cortex. This abnormal excitability of cortical networks could be the physiological correlate of excessive daytime sleepiness and it could be the substrate for allowing dissociated states of wakefulness and sleep to emerge suddenly while patients are awake, which constitute the symptoms of narcolepsy.
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Journal of neurology · Dec 2004
Long-term prognosis of ischemic stroke in young adults. Study of 272 cases.
There have been few studies of the long-term prognosis of young adults with ischemic stroke. The present study aimed to evaluate the long-term clinical outcome in a large series of young adults with ischemic stroke admitted to a tertiary medical center over the last 27 years, and to identify possible predictors for mortality, stroke recurrence and poor functional recovery. ⋯ The long-term prognosis for the ischemic stroke in the young is better than in the elderly, but the risk of mortality in young adults with ischemic stroke is much higher than in the general population of the same age. A bad prognosis is associated with an atherosclerotic risk profile, with a higher mortality and recurrent stroke rates and poorer functional recovery. The main functional limitation in the young survivors of their initial ischemic stroke occurs in work activity, since most patients are independent but almost half of them do not return to work.
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Journal of neurology · Oct 2004
Comparative StudyCombined MR spectroscopic imaging and diffusion tensor MRI visualizes corticospinal tract degeneration in amyotrophic lateral sclerosis.
Motor neuron damage and cortical spinal tract (CST) degeneration are pathological features of amyotrophic lateral sclerosis (ALS). We combined whole-brain diffusion tensor imaging (DTI) and three-dimensional magnetic resonance spectroscopic imaging (MRSI) to study the CST at different locations. Eight ALS patients were compared with normal controls. ⋯ NAA/Cr ratios were also decreased in ALS patients compared with normal controls, with significant differences in the SWM and PV but not in PIC. Combined whole-brain DTI and MRSI can detect axonal degeneration in ALS. Measurements of FA obtained in the SWM, CS, PV and PIC, and NAA/Cr ratios in the SWM and PV yield the most robust results.