Salvage of the PWI/DWI mismatch up to 48 h from stroke onset leads to favorable clinical outcome.

BACKGROUND AND PURPOSE: In acute ischemic stroke perfusion/diffusion-weighted image, mismatch using magnetic resonance imaging approximates the ischemic penumbra. For early time windows, mismatch salvage improves clinical outcomes, but uncertainty exists at later time epochs. We hypothesized that (a) mismatch may exist up to 48 h; (b) the proportion of mismatch salvage is time independent; and (c) when salvaged, it improves clinical outcomes. METHODS: Magnetic resonance imaging was performed within 48 h of ischemic stroke. Perfusion-weighted image was defined by relative Tmax two-second delay. Perfusion/diffusion-weighted image mismatch was the perfusion-weighted image not overlapped by the diffusion-weighted image when coregistered. Infarct volume and disability (modified Rankin Score) were assessed at three-months. Mismatch salvage was the region not overlapped by final infarction. Favorable outcome was defined as modified Rankin Score 0-1. RESULTS: Sixty-six patients were studied [mean age 69.9 years (standard deviation 13.1), initial median National Institute of Health Stroke Scale 9.0 (interquartile range 6.0, 18.3)]. There was no relationship between time of stroke onset and the proportion of mismatch salvaged (P = 0.73). Age (adjusted odds ratio = 0.92, 95% confidence interval 0.86-0.98, P = 0.01), initial National Institute of Health Stroke Scale (adjusted odds ratio = 0.80, 95% confidence interval 0.70-0.92, P < 0.01), mismatch volume (adjusted odds ratio = 0.98, 95% confidence interval 0.968-0.1, P = 0.05), and percentage of mismatch salvage (adjusted odds ratio = 1.04, 95% confidence interval 0.99-1.07, P = 0.05) were independently associated with favorable outcome. CONCLUSION: Using coregistered perfusion/diffusion-weighted image criteria, mismatch persists up to 48 h post stroke. For the whole group, the proportion of mismatch salvage remains independent of time and, although the effect is small, its salvage is independently associated with improved clinical outcomes at three-months. Larger sample sizes are needed to determine the time limit for mismatch salvage.

Millimeter-scale resolution of trace metal distributions in microbial mats from a hypersaline environment in Baja California, Mexico.

Microbial mats from two ponds with different salinities from the saltern of Guerrero Negro (Mexico) points toward millimeter-scale coherent variations in trace metal (Me) concentrations (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn). Total, HCl-leachable and pyrite-associated Me showed a trend of increasing concentrations with increasing depth suggesting gradual addition of reactive Me probably as a result of metal sulfide precipitation at depth. The trends in Me profiles can be ascribed to the establishment and maintenance of microzones that promote geochemical processes, bacterial population distributions, and differential mass transport within the mats. Degrees of trace metal pyritization (1 ± 1% for Zn to 24 ± 7% for Cd) as well as metals associated with the pyrite fraction (<1.4-36 ± 18 nmol g(-1) for Zn and Mn, respectively) were low, as expected from a reactive Fe-limited system like Guerrero Negro. Calculated enrichment factors showed that Ni (2.6 ± 2.1), Co (5.5 ± 4.0), Pb (9.4 ± 7.4), and Cd (57 ± 39) were, on average, enriched in the microbial mats of Guerrero Negro. Natural enrichments of Cd, Pb, and Co in sediments along the coast of Baja California and metabolical requirements of Co and Ni by the predominant cyanobacteria in the Guerrero Negro mats may explain these enrichments. Metal characteristics in microbial mats could be advantageously used as biosignatures to identify their presence in the geological record or in other planetary systems.

Relationship between metal enrichments and a biological adverse effects index in sediments from Todos Santos Bay, northwest coast of Baja California, México.

In 1992 and 2004, heavy metals concentrations were measured in surficial sediments from Todos Santos Bay, located in Ensenada, Baja California, Mexico. The aim was to search for relationships between metal enrichment factors and a biological adverse effects index. Unlike Ni, the elements Cd, Cu and Zn showed significant correlations (p<0.05) between enrichment factors and the biological adverse effects index. Cu showed a 0.74:1 relationship, which means that any enrichment above 0.74 could represent biological adverse effects. On the other hand, Cd and Zn enrichments must be >5.5 and >1.5, respectively, in order for the sediments to be considered toxic. In general, data showed that most of the metal concentrations in Todos Santos Bay sediments could not cause adverse effects to biota. Only Ensenada's harbor and the zone next to a dredging dumping site showed metal enrichments that could be toxic.

Symptom onset of spinocerebellar ataxia type 10 in pregnancy and puerperium.

Spinocerebellar ataxia type 10 is an autosomal dominant neurodegenerative disorder. It was initially described in Mexican families presenting with ataxia and epilepsy, with or without polyneuropathy, pyramidal signs and cognitive symptoms. The authors report three patients from the same family who were asymptomatic until gestation and puerperium, when they developed symptoms and signs suggestive of the syndrome. Genetic diagnosis was made in the three patients. The authors hypothesize that hormonal changes are likely to influence the manifestation of the condition.

11C-PIB binding is increased in patients with cerebral amyloid angiopathy-related hemorrhage.

BACKGROUND: The in vivo diagnosis of cerebral amyloid angiopathy (CAA) is inferred from clinical and structural imaging features. (11)C-Pittsburgh compound B (PIB) is a PET ligand that binds to beta-amyloid in extracellular plaques and vessel walls. We hypothesized that patients with a clinical diagnosis of CAA-related hemorrhage (CAAH) have increased (11)C-PIB uptake and that the pattern differs from Alzheimer disease (AD). METHODOLOGY: Patients with CAAH based on established clinical criteria were studied using (11)C-PIB PET and were compared with age-matched controls and patients with AD. Distribution volume ratio (DVR) parametric maps were created using the cerebellar cortex as a reference region. RESULTS: Twelve patients with CAAH of mean age 73.9 (range 58-93) years were compared with 22 normal controls and 13 patients with AD of mean age 71.8 (59-83) and 73.8 (56-90) years, respectively. CAAH PIB median DVR binding was higher in cortical regions (1.69, interquartile range 1.44-1.97) compared with controls (1.32, 1.21-1.44, p = 0.002) but lower than AD (2.04, 1.93-2.26, p = 0.004). The occipital-global uptake ratio was lower among patients with AD than among patients with CAAH (p = 0.008), and the frontal-global uptake ratio was higher (p = 0.012). CONCLUSION: (11)C-Pittsburgh compound B (PIB) binding is moderately increased in most patients with probable cerebral amyloid angiopathy (CAA)-related intracerebral hemorrhage. The distribution may differ from that seen in Alzheimer disease. (11)C-PIB PET may assist in the in vivo diagnosis of CAA and serve as a surrogate marker for future therapeutic studies.

Penumbral mismatch is underestimated using standard volumetric methods and this is exacerbated with time.

BACKGROUND AND AIMS: The mismatch between perfusion weighted images (PWI) and diffusion weighted images (DWI) using MR is increasingly being applied in patient selection for therapeutic trials. Two approaches to the calculation of the mismatch volume exist--the commonly used volumetric and the more precise co-registration method, the latter of which considers lesion topography. That there are differences in the mismatch volume analysed by each method and that these are time dependent was hypothesised. METHODS: Patients within 48 h of ischaemic stroke onset had baseline MR PWI/DWI mismatch and T2 outcome volumes at 3 months. Volumetric mismatch volume was defined as PWI minus DWI lesion. Co-registration mismatch volume was defined as the PWI defect lesion not overlapped by the co-registered DWI lesion. RESULTS: 72 patients of median age 74.0 years were studied. Median baseline MR was at 5.9 h (IQR 3.0, 20.4 h) after stroke onset. Consistent underestimation of the mismatch volume occurred using the volumetric method (volumetric median 9.3 ml, IQR 0, 63 ml; co-registration median 20.1 ml, IQR 3.2, 69.8 ml; p<0.0001). This difference increased with time from stroke onset (p = 0.006). CONCLUSIONS: Volumetric analysis consistently underestimates the PWI/DWI mismatch volume compared with the more precise co-registration method. This effect increases with time.

Distribution of mercury in surficial sediments from Todos Santos Bay, Baja California, México.

During 2004 the spatial distribution of total Hg in sediments from Todos Santos Bay, Baja California, México was studied to evaluate the degree of environmental impact in this bay. The results showed low concentrations and no Hg enrichment at any site. These findings suggest natural levels of Hg in the water of Todos Santos Bay. The regional distribution of Hg/Fe shows lower values in the East and higher in the West of the bay. No significant correlations (p<0.05) were found between Hg and organic matter or particle size, suggesting that the distribution of Hg is not controlled by these variables.

Generalized dystonia and striatal calcifications with lipoid proteinosis.

Lipoid proteinosis (LP) is an autosomal recessive disease that typically presents with papular, verrucous, poxlike, or acneiform scars and lesions and hoarseness. LP was recently mapped to the 1q21 locus and shown to result from mutations in the extracellular matrix protein 1 gene (ECM1). Epilepsy, mental retardation, and hippocampal calcifications can occur. The authors describe a patient with generalized dystonia caused by striatal calcifications.

[Acute cerebellitis caused by Epstein-Barr virus: case report]. / Cerebelite aguda causada por vírus Epstein-Barr: relato de caso.

Acute cerebellitis can occur in association with varicella-zoster virus, enterovirus, mumps, mycoplasma, and other infective organisms. Acute cerebellitis is a rare complication of Epstein-Barr virus (EBV) infection. We report the case of a 21-year-old woman with a 12-day history of nausea and vomiting, gait and limbs ataxia, myoclonus, tremor of head and all four limbs, opsoclonus and cutaneous rash. Anti-EBV IgG and IgM antibodies against antiviral capsid were positive and anti-EBV against virus-associated nuclear antigen was also positive. EBV infection in association with neurological findings can occur without the classic signs and symptoms of infectious mononucleosis.

[Contributions of Charcot and Marsden to the development of movement disorders in the 19th and 20th centuries]. / As contribuições de Charcot e de Marsden para o desenvolvimento dos distúrbios do movimento nos séculos XIX e XX.

Charcot described many neurological diseases in the 19th century, particularly in movement disorders. Charcot contributed in the clinical description of Parkinson's disease, and introduced its first pharmacological treatment. He also studied the hyperkinesias, e.g. of Tourette syndrome, differential diagnosis of tremors, dystonias, choreas and startle disease. Marsden, who died recently, was an exponent in the study of Movement Disorders, with many publications in this field in the 20th century. His most important contributions are definitions and classifications of movement disorders, such as Parkinson's disease, dystonia, myoclonus, essential tremor, the description of the syndromes "Painful Legs Moving Toes", "Gait Ignition Failure" and "Primary Writing Tremor". The contributions of Charcot in the 19th century and Marsden in the 20th century to the movement disorders allow us to conclude that both of them were the most representative icons in this field in the past two centuries.