Pure alexia without visual or language accompanying deficits (isolated pure alexia), represents an infrequent finding in clinical practice. It has been linked to lesions involving the splenium of the ...callosal corpus in classical descriptions; however, it has also been reported after occipito-temporal cortex damage in the absence of white matter implication. In this regard, a functional region called the visual word form area has been recently related to the posterior aspect of the occipitotemporal gyrus. We report two new cases of cortical hematomas leading to this rare condition and we discuss the neuroanatomical evolution of this syndrome. Finally, we propose a new classification of pure alexia based on the neuroanatomical location of the lesion, namely: (1) disconnection alexia, after posterior and dorsal lesions involving the splenium of the callosal corpus or the paraventricular white matter, often associated with visual deficits, and (2) cortical alexia, after more anterior and ventral lesions in the occipito-temporal cortex with damage of the visual word form area, that usually manifests as isolated pure alexia.
Background
Glutamate (Glu) and glutamine (Gln) are strongly compartmentalized (in neurons for Glu and in astrocytes for Gln). The visual cortex is the brain region with a higher neuron/astrocyte ...ratio (the highest neuronal density and the relatively lowest density of astrocytes). Elevations in extracellular Glu or potassium above certain thresholds are likely candidates to be the final common steps in the multiple distinct processes that can lead to cortical spreading depression. Astrocytes play a key role in this phenomenon, by acting as a sink for extracellular Glu and potassium, as well as generally acting as a buffer for the ionic and neurochemical changes that initiate and propagate cortical spreading depression.
Objective
The purpose of this study was to quantify Glu and Gln to generate Glu/Gln ratios in women with migraine during the interictal state compared with healthy control women.
Methods
Twenty‐seven patients with migraine (8 with aura and 19 without aura) and 19 matched healthy controls were included in the study. We performed proton magnetic resonance spectroscopy in the anterior paracingulate cortex and occipital cortex (OC). Spectral analysis was performed by LCModel, allowing a separation of Glu and Gln using a 3T machine.
Results
The main result was a significantly higher Glu/Gln ratio in the OC of migraine patients compared with healthy control subjects (4.87 for migraineurs standard deviation (SD) = 2.74 and 3.42 for controls SD = 1.52, P = .042). We also observed higher Glu levels (6.98 for migraineurs SD = 0.85 and 6.22 for controls SD = 0.97, P = .007) and Glu/creatine + phosphocreatine ratio (1.18 for migraineurs SD = 0.18 and 1.00 for controls SD = 0.16, P = .001) in anterior paracingulate cortex in migraine patients but saw no differences in Glu/Gln ratio (2.79 for migraineurs SD = 1.11 and 2.63 for controls SD = 1.61, P = .68).
Conclusion
These findings are consistent with glutamatergic differences in migraine patients during the interictal period compared with healthy controls. We hypothesize that an increased Glu/Gln ratio could arise from neuronal–glial coupling of glutamatergic metabolism differences or an increased neuron/astrocyte ratio in the OC.
Abstract Mutation in the protocadherin 19 (PCDH19) gene is an increasingly recognized cause of epilepsy in females. This disorder is frequently associated with mental retardation and psychiatric ...features. We describe two unrelated females with novel PCDH19 missense mutations. One was de novo , and the other was inherited from her unaffected father. Both had mild mental impairment but had remarkable behavioral problems. We reviewed the cognitive and behavioral profiles of previously reported PCDH19-positive cases. Intellectual disability appeared in 75% of patients, ranging from borderline to severe. More than half of the individuals presented behavioral disturbances, which could be divided into two different groups: autistic and non-autistic. The majority of patients with autism already had some degree of cognitive impairment. It appears that seizures tend to diminish or even stop in adolescence, so non-epileptic problems can become the most important and disabling issue in adult patients with PCDH19 mutation.
Tenecteplase (TNK) is a fibrinolytic drug that is administrated in a single bolus, recommended in eligible patients with acute ischemic stroke prior to mechanical thrombectomy. This study explores ...its usefulness in adverse situations, such as the SARS-CoV-2 pandemic. We conducted a retrospective study involving consecutive patients with suspected acute ischemic stroke treated either with intravenous fibrinolysis with alteplase during 2019 or with TNK (.25 mg/kg) between March 2020 and February 2021. A comparative analysis was made to compare patient treatment times and prognosis. A total of 117 patients treated with alteplase and 92 with TNK were included. No significant differences were observed in age, main vascular risk factors or previous treatments. The median National Institutes of Health Stroke Scale was 8 in the alteplase group and 10 in those treated with TNK (P = .13). Combined treatment with mechanical thrombectomy was performed in 47% in the alteplase group and 46.7% in the TNK group; Thrombolysis In Cerebral Infarction scale 2b-3 recanalization was achieved in 83% and 90.7%, respectively (P = .30). There was a decrease in onset-to-needle median time (165 min vs 140 min, P < .01) and no significant variations in door-needle median time. There was no significant difference in the incidence of symptomatic hemorrhagic transformation in mortality or functional independence at 3 months. The easier administration of TNK has improved the accessibility of fibrinolytic therapy, even in adverse circumstances, such as the COVID-19 pandemic. Its use appears to be safe and effective, even in patients who are not candidates for mechanical thrombectomy.
Cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL) is an autosomal recessive vascular disorder caused by biallellic variants in HTRA1. Recently, it ...has been reported that several heterozygous mutations in HTRA1 are responsible for a milder late-onset cerebral small vessel disease (CSVD) with an autosomal dominant pattern of inheritance. The majority of them are missense that affects the Htr1A protease activity due to a dominant-negative effect caused by defective trimerization or monomer activation. The molecular mechanism related to the structural destabilization of the protein supports the practical utility of integrating computational stability predictors to prioritize candidate variants in this gene. In this work, we report a family with several members diagnosed with subcortical ischemic events and progressive cognitive impairment caused by the novel c.820C > G, p.(Arg274Gly) heterozygous variant in HTRA1 segregating in an autosomal dominant manner and propose its molecular mechanism by a three-dimensional model of the protein's structure.
