Italian journal of neurological sciences最新文献

Proton magnetic resonance spectroscopy (MRS) allows accurate and noninvasive biochemical assay of living tissues. In vivo measurements provided by MRS have greatly enhanced our understanding of the pathophysiology of dementia. Increases in choline and myo-inositol (markers of membrane turnover) have been demonstrated in several studies on patients with Alzheimer's disease (AD), suggesting the presence of a significant cellular membrane (and glial) pathology in this disorder. Large decreases in brain N-acetylaspartate (NAA) (a marker of neuroaxonal integrity) are commonly seen in AD as well as in other forms of dementia in cerebral gray and white matter, indicating the presence of significant axonal damage. Since greater NAA decreases have been demonstrated in brains of patients with clinically more severe disease, NAA could provide an index relevant to patients' clinical status. Brain metabolic changes can be independent of abnormalities detected by conventional magnetic resonance imaging (MRI), since proton MRS may show a normal metabolic pattern in patients with mild neurological impairment and severe MRI abnormalities. However, quantitative measurements of regional brain volumes can be useful in the diagnosis of dementia. Thus, proton MRS, alone or combined with new quantitative magnetic resonance techniques, can provide sensitive indices able to monitor disease progresson or effects of drug therapy.

Magnetization transfer imaging (MTI) is a magnetic resonance imaging (MRI) technique that is now used in multiple sclerosis (MS) studies, and is thought to have a higher pathological specificity than conventional T2-weighted imaging. This review outlines the major contributions given by MTI for the understanding of MS evolution.MTI studies of individual MS lesions confirm the pathological heterogeneity of T2-weighted MRI abnormalities and the potential role of unenhanced T1-weighted hypointensities as specific markers of localized severe white matter disruption. Correlative cross-sectional and longitudinal studies using MIT and gadolinium (Gd)-enhanced MRI reveal that MTI findings may vary in lesions with different patterns of enhancement, and that MTI abnormalities are closely related to the onset and recovery of blood-brain barrier disruption in new MS plaques. MTI lesion load (LL) is highly correlated with T2-weighted MRI lesion load, but it has a limited reliability as a measure of MS lesion burden. On the other hand, measures obtained from MT scans using whole-brain histogram analysis are highly correlated with the extent of MS abnormalities on conventional MRI scans, and predict patients' clinical disability well, since they are sensitive to both macro- and microscopic MS lesion burden in the whole brain and in specific regions. These data suggest that (a) MTI is sensitive to different stages of lesion pathology and pathological evolution in MS patients; and (b) MT histogram analysis can provide a more global assessment of MS lesion burden, since it encompasses both macro- and microscopic MS pathology.

Diffusion-weighted imaging (DWI) provides a unique form of magnetic resonance (MR) contrast that enables the diffusional motion of water molecules to be quantitatively measured. As a consequence, DWI provides information about the orientation, size and geometry of brain structures. Cellular structures in the central nervous system restrict water molecular motion, and the apparent diffusion coefficient (ADC) is reduced compared to diffusion in bulk water. Pathological processes that modify tissue integrity, thus removing some of the "restricting" barriers, can result in increased ADC. Preliminary studies in multiple sclerosis (MS) using DWI showed that the ADC is higher in macroscopic lesions than in the normal appearing white matter (NAWM). The ADC is also dependent on the direction in which diffusion is measured, thus making comparison of ADC values meaningless without taking into account the measurement direction. One measurement of diffusion that is independent of the orientation of structures is provided by measuring the ADC in three orthogonal directions, and then averaging the results to form the mean diffusivity, D. We obtained DW scans from 35 patients with relapsing-remitting MS and 24 healthy volunteers. D was measured inside T2-visible lesions and regions located in different areas of the NAWM. D histograms from a large portion of the brain were created. MS lesions had a significantly higher D than NAWM. T1-hypointense lesions had the highest diffusion values, consistent with more severe tissue disruption. D was higher in the NAWM from patients than in the white matter from healthy controls. We also found significant differences between D histogram-derived measures from patients and controls, confirming the presence of diffuse damage in the brain of patients with MS.

Regional cerebral blood flow (rCBF) was measured by 133-xenon inhalation in 24 amateur and 20 professional boxers, and in 10 judoka. Results were compared with those from age- and sex-matched healthy controls. Eighteen boxers (9 amateurs and 9 professionals) and all judoka also underwent electroencephalography (EEG). Mean rCBF values did not differ between either amateur boxers orjudoka and controls, whereas in professional boxers rCBF was significantly (p<.001) reduced in the whole brain, especially in the frontocentral regions. Healthy subjects, judoka, and amateur boxers showed a similar distribution of global CBF (gCBF, the mean of 32 probes) values, although 12.5% of amateurs had a significantly lower gCBF than controls. Among professional boxers, 25% showed a significantly low gCBF value; in the remaining 75%, gCBF was below the mean value of controls but did not reach statistical significance. Regional hypoperfusion, mainly in the frontocentral regions of both sides, was found in 35% of professional and in 29% of amateur boxers. A correlation between gCBF values and number of official matches was not found in boxers. EEG was normal in all judoka and amateur boxers, but it was abnormal in 3 professionals. This study shows the relevance of the neurophysiological assessment of athletes engaged in violent sports which can cause brain impairment. In fact, while professional boxers may show brain functional impairment in comparison to normal subjects, judoka do not. The lack of correlation between CBF values in boxers and the number of official matches points to the difficulty of taking into account variables, such as the number and the severity of matches during training.

The authors report two patients with isolated unilateral tongue atrophy. Magnetic resonance imaging (MRI) of the brain stem and angio-MRI demonstrated a dolichovertebral artery with an abnormal course compressing the medulla oblongata at the emergence of the hypoglossal rootlets. The semeiological observation of a sectorial and not uniform distribution of atrophy in the half-affected tongue is discussed in relation to the lesional site.

We investigated the incidence of first-ever stroke in three Sicilian municipalities over the years 1984-1987. Case ascertainment involved two approaches: a door-to-door two-phase prevalence survey and a study of death certificates. Only first-ever strokes occurring within the study time interval were included, and diagnoses were based on specified criteria. We found 138 subjects who had experienced a first stroke over 73 488 person-years; the average incidence rate (new cases per 1000 population per year) was 1.9 overall, 1.7 in men, and 2.1 in women. Incidence increased steeply with age and was similar in men and women. Incidence was similar in the three study municipalities. The overall case-fatality rate was 35% at 30 days and 22% at one week. Survival after stroke was similar in men and women but better in younger compared to older stroke patients. Comparisons with previous studies suggest the absence of major geographic variations in stroke incidence within Italy.

Infantile Huntington's disease (HD) shows a wide clinical heterogeneity. Here we describe the case of a child affected by HD who showed unusual neurological features consistent with tourettism. The absence of family history and persisting normal magnetic resonance imaging (MRI) results long after the onset of symptoms delayed the diagnosis of the disease. An MRI exam performed 26 months after disease onset disclosed bilateral atrophy in the putamen, suggesting HD. The diagnosis was confirmed by genetic analysis. The present report underlines the need to consider HD in childhood cases of unusual and even unfamiliar progressive movement disorders.

The present study set out to define the possible effect of reduced glutathione (GSH), the substrate of glutathione peroxidase (GSH-Px), a free radical inactivating enzyme, in amyotrophic lateral sclerosis (ALS). Thirty-two patients affected by definite ALS seen in our institution between August 1993 and July 1994 were admitted to the study. The effect of GSH was studied in an open, crossover, randomized study. GSH was given at the dose of 600 mg each day intramuscularly for 12 weeks. The patients, taken sequentially, were randomly assigned to two groups. The first group received the drug while the second received only symptomatic therapies for 12 weeks. After a week of washout, the second group received GSH and the first only symptomatic therapies for 12 weeks. The rate of progression of the diseases was compared in the two groups. Clinical evaluation included manual test for muscle strength, Norris scale, bulbar scale, and forced vital capacity (FVC) percent. No significant difference was found in the progression of ALS in the two periods, although a slight slowing of the disease progression rate was found during the period of treatment, probably related to the open design of the study. Our data do not show any significant effect of reduced glutathione in modifying the progression of ALS.

Although many studies on carpal tunnel syndrome (CTS) have been reported, few data on the natural history of CTS are available. Knowledge of the natural course of the disease has significant clinical and therapeutic value. We prospectively followed up 80 cases of untreated CTS. The evaluation was based on self-administered questionnaires and on neurophysiological investigation. According to the neurophysiological classification, cases of CTS were divided into six groups on the basis of impairment severity: negative, minimal, mild, moderate, severe, and extreme. Disease worsening was inversely related to severity of nerve entrapment. On the contrary, improvement was proportionally related to nerve function impairment (except for extreme cases that never improved), and about one-third of mild and moderate cases improved. Most minimally cases remained neurophysiologically unchanged. We hypothesize that in a good percentage of CTS cases, nerve impairment is self-limited. Our data suggest the utility of further studies on the natural course of this common disease.