Magnetic resonance imaging (MRI) studies have produced controversial results concerning the correlation of hippocampal volume loss with increasing age. The goals in this study were: 1) to test whether levels of N-acetyl aspartate (NAA, a neuron marker) change in the hippocampus during normal aging and 2) to determine the relationship between hippocampal NAA and volume changes. Proton magnetic resonance spectroscopic imaging (1H MRSI) and MRI were used to measure hippocampal metabolites and volumes in 24 healthy adults from 36 to 85 years of age. NAA/Cho decreased by 24% (r = 0.53, p = 0.01) and NAA/Cr by 26% (r = 0.61, p < 0.005) over the age range studied, whereas Cho/Cr remained stable, implying diminished NAA levels. Hippocampal volume shrank by 20% (r = 0.64, p < 0.05). In summary, aging effects must be considered in 1H MRSI brain studies. Furthermore, because NAA is considered a marker of neurons, these results provide stronger support for neuron loss in the aging hippocampus than volume measurements by MRI alone.
Purpose
Polymicrogyria (PMG) is an epileptogenic malformation of cortical development. We describe the clinical epilepsy and imaging features of a large cohort with PMG-related epilepsy.
Methods
Participants were recruited through the Epilepsy Phenome/Genome Project, a multi-center collaborative effort to collect detailed phenotypic data on individuals with epilepsy. We reviewed phenotypic data from participants with epilepsy and PMG.
Key Findings
We identified 87 participants, 43 female and 44 male, with PMG and epilepsy. Median age of seizure onset was 3 years (range <1 month-37 years). Most presented with focal epilepsy (87.4%), some in combination with seizures generalized from onset (23.0%). Focal seizures with dyscognitive features were most common (54.3%). Of those presenting with generalized seizure types, infantile spasms were most prevalent (45.2%). The most common topographic pattern was perisylvian PMG (77.0%), of which the majority was bilateral (56.7%). Generalized PMG presented with an earlier age of seizure onset (median age of 8 months) and an increased prevalence of developmental delay prior to seizure onset (57.1%). Of the focal, unilateral and asymmetric bilateral groups where PMG was more involved in one hemisphere, the majority (71.4%) of participants had seizures that lateralized to the same hemisphere as the PMG or the hemisphere with greater involvement.
Significance
Participants with PMG had both focal and generalized onset of seizures. Our data confirm the involvement of known topographic patterns of PMG and suggest that more extensive distributions of PMG present with an earlier age of seizure onset and increased prevalence of developmental delay prior to seizure onset.
Summary:Background: The introduction of IV valproic acid (VPA) has facilitated its use in situations where oral administration is not feasible. The present study was designed to evaluate the safety of administration of undiluted VPA (20 or 30 mg/kg/min) administered intravenously at rates of 6 or 10 mg/kg/min.Methods: Forty patients received a VPA loading dose (20 or 30 mg/kg) at 6 or 10 mg/kg/min. Heart rate (HR), mean arterial pressure (MAP), oxygen saturation, respiratory rate, and three lead ECG measurements were taken at baseline. Following dose administration the measurements were repeated at 2.5-min intervals for the first 20 min, then at 30, 45, 60 min, and 4 h. Local tolerance was defined as absence of irritation or phlebitis at the site of injection. Systemic tolerability was defined as absence of significant changes in vital signs and level of consciousness (LOC). Changes in vital signs and local intolerance scores were compared across time using repeated measures analysis of variance.Results: Rapid administration was well tolerated with no significant changes in HR (p = 0.9) or MAP (p = 0.7). Complaints of local irritation were transient, lasting less than 3 min in all patients with no indication of redness, irritation, or phlebitis. No patient exhibited a decline in the LOC.Conclusions: Rapid administration of undiluted valproate is safe and well tolerated at infusion rate up to 10 mg/kg/min and doses of up to 30 mg/kg. The lack of serious cardiovascular, neurological, hepatic, or local adverse effects supports the use of VPA in emergent situations.
Substantial individual heterogeneity of memory outcome exists across groups of patients undergoing ATL, with various degrees of pathologically verified HS. Patients undergoing left-sided ATL who have mild HS seem at greatest risk for broad-spectrum verbal memory decline. However, when examining outcome on a patient-by-patient basis, many patients undergoing left-sided ATL who have moderate to severe HS were also vulnerable to verbal memory loss. This risk seems selective to a retrieval-based aspect of verbal memory.
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