Midbrain catecholaminergic neurons co-express α-synuclein and tau in progressive supranuclear palsy.

OBJECTIVE: To analyze the frequency and distribution of α-synuclein deposits in progressive supranuclear palsy (PSP). METHODS: The brains of 25 cases of pathologically confirmed PSP were evaluated with immunohistochemistry for α-synuclein and tau. Multiple immunofluorescent stains were applied to analyze the expression of tau and α-synuclein aggregates in catecholaminergic neurons. Patients' clinical symptoms were retrospectively recorded. RESULTS: Deposits α-synuclein in the form of typical Lewy bodies (LBs) were only found in two PSP cases (8%) that fulfilled the clinical subtype of PSP known as Richardson's syndrome (RS). LBs were present in the locus ceruleus (LC), substantia nigra pars compacta (SNc), basal forebrain, amygdala and cingulated cortex in a distribution mimicking that of Parkinson's disease (PD). Triple-immunolabeling revealed co-expression of α-synuclein and tau proteins in some tyrosine hydroxilase (TH)-positive neurons of the LC and SNc. CONCLUSIONS: There is no apparent clinical correlation between the presence of LBs in PSP. Tau protein co-aggregate with α-synuclein in catecholaminergic neurons of PSP brains suggesting a synergistic interaction between the two proteins. This is in keeping with the current view of neurodegenerative disorders as "misfolded protein diseases".

Myasthenia gravis: sleep quality, quality of life, and disease severity.

INTRODUCTION: There is much research on quality of life in myasthenia gravis (MG), and its relationship to disease severity is well-established. However, evidence regarding sleep disturbance in MG is inconclusive. METHODS: To evaluate sleep and quality of life among clinically stable MG patients, 54 subjects were investigated by means of the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and 15-Item-Quality-Of-Life Instrument for MG (MG-QOL15). RESULTS: A pathological PSQI score, which was observed in 59% of patients, was increased in subjects with active disease compared with patients in clinical remission [odds ratio = 4.3; confidence interval 95% (1.0-17.6); P = 0.04]. We found a relationship between PSQI and MG-QOL15 scores in patients with clinically active disease (r = 0.62; P < 0.001). CONCLUSIONS: Our study highlights the high prevalence of sleep disturbance among MG patients. Disease severity may be considered to be a MG-specific risk factor for patient-reported sleep disturbance. The MG-QOL15 and PSQI should be used to estimate the impact of the disease on sleep and quality of life.

Basilar branch occlusion.

OPINION STATEMENT: During the past few years, the branch syndromes have been ascribed to pontine lesions, and the development of neuroimaging techniques has renewed the interest in exploring their clinical-radiological correlation. Brain imaging via MRI has helped in the diagnosis and accurate localization of lesions. From classic studies it is now accepted that the pathogenic mechanism of lacunar pontine infarction (LPI) is perforating small arterial disease or microangiopathy caused by lipohyalinosis, whereas paramedian pontine infarction (PPI) are caused by paramedian or circumferential basilar branch disease due to atheromatous branch occlusion. The importance of basilar artery disease not only in severe posterior circulation infarcts but also in minor brainstem strokes is known from previous reports. The mechanism of PPI is probably local occlusion of the mouths of paramedian perforators through the atheromatous basilar artery (basilar branch occlusion). Infrequent basilar artery diseases such as dissection, aneurysm and hypoplasia, dolichoectatic basilar artery, embolism, or vasospasms are known to block the orifices of penetrating branch arteries and cause an infarct in the territory of the obstructed branches. An association between basilar artery branch disease and isolated pontine infarction exists; moreover, the enlargement of pontine lesion seems to be associated with neurologic worsening and fluctuating symptoms, but we know little about stroke mechanisms in patients with fluctuating symptoms and about the role of branch atherosclerotic disease. The treatment remains controversial, even in acute cases. Implementation of new neuroimaging techniques, such as high-resolution MRI, could be helpful in identifying pathogenetic mechanisms of isolated pontine infarction, thus improving therapeutic strategy and secondary prevention.

Síndromes paraneoplásicos neurológicos / Paraneoplasic neurologic syndromes

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