Cerebellar damage affects the inference of human motion.

The present study aims at the cerebellum's role in prediction mechanisms triggered by action observation. Five cerebellar patients and six age-paired control subjects were asked to estimate the occluded end point position of the shoulder's trajectories in Sit-to-Stand (STS) or Back-to-Sit (BTS) conditions, following or not biological rules. Contrarily to the control group, the prediction accuracy of the end point position in cerebellar patients did not depend on biological rules. Interestingly, both groups presented similar results when estimating the vanishing position of the target. Taken together, these results suggest that cerebellar damage affectsthe capacity of predicting upcoming actions by observation.

Neurologic manifestations of Chagas disease.

Chagas disease is endemic in Latin America and has become an emerging problem in developed countries because of international migrations. The protozoan Trypanosoma cruzi is the etiologic agent and the disease is divided into two phases. The acute phase is mostly asymptomatic or presents with unspecific symptoms. Rarely, a severe and often fatal form occurs in immunosuppressed patients or infants, characterized by meningoencephalitis (sometimes including brain tumor-like lesions) and myocarditis. The chronic phase consists of an indeterminate, asymptomatic form followed by digestive, cardiac, or neurologic symptoms in about 30% of infected patients. Autonomous nervous system dysfunction is prominent in chagasic patients and participates in the affliction of the target organs. Stroke, mainly cardioembolic, may occur in the chronic phase, but other stroke etiologies are reported. Embolic sources and inflammation are thought to play a role in stroke mechanisms. Specific treatment for Chagas disease is scarce and preventive measures are needed.

Ataxia e coreia como manifestações de síndrome paraneoplásica / Ataxia and chorea related to paraneoplasic syndrome

Relatamos um caso de ataxia subaguda e coreia em uma paciente adulta. Após extensa investigação, foi estabelecido diagnóstico de neoplasia de mama em associação com síndrome paraneoplásica (SP). SP é rara e pode ser o primeiro sintoma de uma neoplasia oculta. Ataxia é o distúrbio de movimento mais comumente relacionado à SP, no entanto a apresentação de coreia é incomum. A paciente apresentou instalação subaguda de ataxia e coreia. Assim, a SP neurológica deve ser considerada no diagnóstico diferencial de ataxia associada à coreia esporádica a despeito de tal apresentação ser rara.

We report a case of subacute ataxia and chorea in a female adult patient. After an extensive investigation breast cancer was discovered. The final diagnosis was paraneoplastic syndrome (PS). PS is rare and it could be the first symptom of an occult neoplasia. Ataxia is one of the most common movement disorder related to PS although chorea is rare. The patient presented ataxia and chorea, which is not common. Therefore, neurologic PS is important to be considered in the differential diagnosis of sporadic ataxia, as well as chorea.

Comparison between the NASCET method and subjective visual impression in the evaluation of internal carotid artery stenosis

OBJECTIVE: To evaluate the accuracy of subjective visual impression (SVI) of an experienced neuro-radiologist in the measurement of the degree of internal carotid artery (IC) stenosis evaluated by digital angiography (DGA). METHOD: Ten symptomatic patients with internal carotid stenosis greater than 70 percent in a previous duplex scan were submitted to DGA. The degree of stenosis in both sides (symptomatic and asymptomatic) were evaluated by the same neuro-radiologist who gave his SVI and applied the NASCET method immediately after. Both methods were compared using the intraclass correlation coeficient (r) and its 95 percent confidence interval (95 percent ci). For each method, the sample (20 ICs) was also divided in surgical (stenosis between 70 and 99 percent) and non surgical ICs, using kappa concordance coeficient (k) to compare the results. RESULTS: The results comparing the 20 values obtained by each method are: r = 0.90 (95 percent ci: 0.77 -- 0.96). Dividing the sample in surgical and non surgical ICs, k = 0.857, p < 0.0001; sensitivity = 100 percent (39.6 percent - 100 percent); specificity = 93.8 percent (67.7 percent - 99.7 percent); positive predictive value = 80 percent (29.9 percent - 98.9 percent); negative predictive value = 100 percent (74,7 percent - 100 percent). CONCLUSION: The SVI may be used by at least some experienced neuroradiologists as a preliminary tool to evaluate the degree of IC stenosis with DGA, but a standardised and well established method should be routinely performed

Internal carotid artery stenosis: comparison of duplex scan and magnetic resonance angiography with digital subtraction angiography

OBJECTIVE: We compare duplex scan (DS) and magnetic resonance angiography (MRA) with digital angiography (DGA) in respect to accuracy in measuring internal carotid artery (IC) stenosis in symptomatic patients. METHOD: Ten symptomatic patients with IC stenosis greater than 70 percent previously diagnosed by DS were submitted to another DS and to both MRA and DGA. Both ICs from each patient (total 20 ICs) were evaluated by physicians blinded for the results of other tests. DS and MRA were compared with DGA, using the intraclass correlation coeficient (r) and its 95 percent confidence interval (95 percent ci). For each diagnostic test, the study group (20 Ics) was also divided in surgical patients (IC stenosis between 70 and 99 percent) and non surgical patients, using kappa concordance coeficient (k) to compare the results. RESULTS: Main comparisons are: DS and DGA, r = 0.71 (0.4 - 0.87); MRA and DGA, r = 0.61 (0.25 - 0.82). After division into surgical vs. non-surgical groups, k = 0.857 (p < 0.0001) between DS and DGA; and k = 0.545 (p = 0.003) between MRA and DGA. Most DS and MRA errors occurred in IC sub-occlusions. CONCLUSION: The results suggest that when they are used together, DS and non-contrast MRA may substitute DGA in the evaluation of patients for IC stenosis surgery, except when there is discordance between their results or when the methods show sub-occlusive stenosis