Brain : a journal of neurology
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Multiple system atrophy (MSA) has varying clinical (MSA-P versus MSA-C) and pathological [striatonigral degeneration (SND) versus olivopontocerebellar atrophy (OPCA)] phenotypes. To investigate the spectrum of clinicopathological correlations, we performed a semi-quantitative pathological analysis of 100 MSA cases with well-characterized clinical phenotypes. In 24 areas, chosen from both the striatonigral (StrN) and olivopontocerebellar (OPC) regions, the severity of neuronal cell loss and gliosis as well as the frequency of glial (oligodendroglial) cytoplasmic inclusions (GCIs) and neuronal cytoplasmic inclusions (NCIs) were determined. ⋯ As might be expected, there was a significant difference in the severity of bradykinesia and the presence of cerebellar signs between the pathological phenotypes: the SND phenotype demonstrates the most severe bradykinesia and the OPCA phenotype the more frequent occurrence of cerebellar signs, confirming that the clinical phenotype is dependent on the distribution of pathology within the basal ganglia and cerebellum. Putaminal involvement correlated with a poor levodopa response in MSA. Our finding that relatively mild involvement of the substantia nigra is associated clinically with manifest parkinsonism, while more advanced cerebellar pathology is required for ataxia, may explain why the parkinsonian presentation is predominant over ataxia in MSA.
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The purpose of this study was to assess whether the histological subtype of focal cortical dysplasia and dual pathology affect surgical outcome in patients with medically intractable epilepsy due to focal cortical dysplasia (FCD). We retrospectively analysed the outcome of 67 patients from 2 to 66 years of age at follow-up periods of 6 to 48 months after epilepsy surgery. Histological subtypes were classified according to Palmini and included a few cases with mild histological abnormalities corresponding to the definition of mild malformations of cortical development. ⋯ We conclude that patients with FCD type 1 and mMCD had a better outcome compared with those with more severe forms of cortical dysplasia. A higher incidence of FCD type 1 in temporal localization did not allow the effects of histological subtype and localization to be separated. A subanalysis of extratemporal FCDs, however, revealed a similar tendency for a better outcome with FCD type 1, suggesting that the histological subtype itself seems to be at least a relevant cofactor influencing postsurgical outcome.
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The excitability of the cerebral cortex in the interictal state of migraine appears to be fundamental in the brain's susceptibility to migraine attacks. Subpopulations of cortical neurons are reported to have different physiological response properties to different interstimulus intervals (ISIs) and, hence, may be differentially altered or modulated in migraine. The aim of this study therefore was to evaluate response characteristics of temporally and spatially defined neuronal subpopulations in the cortex of migraineurs. ⋯ This hyperexcitability appears not to be related to habituation since habituation was not found in the control subjects. In contrast, the magnitude of P35m is not pathophysiologically linked to the interictal state of migraine. Furthermore, the cellular mechanisms causing ISI-dependent depression of N20m and P35m are not altered in migraine.
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To determine the usefulness of [18F]fluorodeoxyglucose (FDG) whole body FDG-PET in the diagnosis of tumours in patients with paraneoplastic neurological syndromes (PNS), we prospectively studied 20 patients with paraneoplastic antibodies in whom conventional imaging gave negative or inconclusive results for the presence of tumour. All 20 patients had neurological manifestations compatible with PNS and well-characterized paraneoplastic antibodies (12 anti-Hu, one anti-Hu and anti-CV2, one anti-CV2, four anti-Yo, one anti-Ri and one anti-amphiphysin). The mean delay between the onset of neurological symptoms and FDG-PET was 10 months (range 1-54). ⋯ Over the study period, we saw 73 other patients with PNS and paraneoplastic antibodies. A tumour was demonstrated in 71 out of 73 by conventional techniques. Since false-positive and false-negative results are possible with FDG-PET and in most patients with PNS, the tumour is demonstrated by conventional techniques, we believe that FDG-PET should be reserved, at the moment, for patients with well-defined PNS antibodies when conventional imaging fails to identify a tumour or when lesions are difficult to biopsy.
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Limb movement imparts a perturbation to the body. The impact of that perturbation is limited via anticipatory postural adjustments. The strategy by which the CNS controls anticipatory postural adjustments of the trunk muscles during limb movement is altered during acute back pain and in people with recurrent back pain, even when they are pain free. ⋯ In both instances, the changes were consistent with adoption of an altered strategy for postural control and were similar to those observed in patients with recurrent back pain. We conclude that anticipation of experimental back pain evokes a protective postural strategy that stiffens the spine. This protective strategy is associated with compressive cost and is thought to predispose to spinal injury if maintained long term.