White matter integrity in adolescents with histories of marijuana use and binge drinking

Structural brain abnormalities have been observed in adolescents with alcohol use disorders but less is known about neuropathological brain characteristics of teens with sub-diagnostic binge drinking or the common pattern of binge drinking combined with marijuana use. The goal of this study was to examine white matter integrity in adolescents with histories of binge drinking and marijuana use.Diffusion tensor imaging (DTI) was conducted with 42 adolescents (ages 16–19) classified as controls, binge drinkers, or binge drinkers who are also heavy marijuana users. Tract based spatial analysis identified shared fiber structure across individuals and facilitated voxelwise comparisons of fractional anisotropy (FA) and mean diffusivity (MD) between groups.Significant between group differences were found in FA in eight white matter regions (ps ≤ .016) between the binge drink-only group and controls, including superior corona radiata, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, and superior longitudinal fasciculus. Interestingly, in 4 of these same regions, binge drinkers who are also heavy marijuana users had higher FA than binge drinkers who did not use marijuana (ps < .05). MD did not differ between groups.Findings are largely consistent with research suggesting less neuropathology in adolescents without histories of substance use. However, binge drinkers who also use marijuana did not show as consistent a divergence from non-users as did the binge drink-only group. Detection of white matter alterations may have implications in identifying early cognitive dysfunction in substance using adolescents.     

Short- and long-term limbic abnormalities after experimental febrile seizures

Experimental febrile seizures (FS) are known to promote hyperexcitability of the limbic system and increase the risk for eventual temporal lobe epilepsy (TLE). Early markers of accompanying microstructural and metabolic changes may be provided by in vivo serial MRI. FS were induced in 9-day old rats by hyperthermia. Quantitative multimodal MRI was applied 24 h and 8 weeks later, in rats with FS and age-matched controls, and comprised hippocampal volumetry and proton spectroscopy, and cerebral T2 relaxometry and diffusion tensor imaging (DTI). At 9 weeks histology was performed. Hippocampal T2 relaxation time elevations appeared to be transient. DTI abnormalities detected in the amygdala persisted up to 8 weeks. Hippocampal volumes were not affected. Histology showed increased fiber density and anisotropy in the hippocampus, and reduced neuronal surface area in the amygdala. Quantitative serial MRI is able to detect transient, and most importantly, long-term FS-induced changes that reflect microstructural alterations.     

Subtypes of learning and memory on the California Verbal Learning Test-Second Edition (CVLT-II) in the standardization sample

The purpose of this study was to determine representative, core profile subtypes of learning and memory, based on four variables representing different latent constructs, in the standardization sample of the California Verbal Learning Test-Second Edition (CVLT-II; Delis, Kramer, Kaplan, & Ober, 2000). Two-stage cluster analysis identified six reliable subtypes. Variability in both level and pattern of performance contributed to the differentiation of these subtypes. Level of education was meaningfully related to variability in overall performance of the subtypes. Implications for the interpretation of CVLT-II findings obtained in clinical practice are discussed.     

Adherence to HAART therapy measured by electronic monitoring in newly diagnosed HIV patients in Botswana

Aims

This pilot study was designed to evaluate the feasibility and benefits of electronic adherence monitoring of antiretroviral medications in HIV patients who recently started Highly Active Anti Retroviral Therapy (HAART) in Francistown, Botswana and to compare this with self-reporting.

Methods

Dosing histories were compiled electronically using Micro Electro Mechanical Systems (MEMS) monitors to evaluate adherence to prescribed therapies. Thirty patients enrolled in the antiretroviral treatment program were monitored over 6 weeks. These patients were all antiretroviral (ARV) naïve. After each visit (mean three times) to the pharmacy, the data compiled by the monitors were downloaded. Electronic monitoring of adherence was compared to patient self-reports of adherence.

Results

The mean individual medication adherence level measured with the electronic device was 85% (range 21–100%). The mean adherence level measured by means of self-reporting was 98% (range 70–100%). Medication prescribed on a once-a-day dose base was associated with a higher adherence level (97.9% for efavirenz) compared with a twice-a-day regimen (88.4% for Lamivudine/Zidovudine).

Conclusions

It is feasible to assess treatment adherence of patients living in a low resource setting on HAART by using electronic monitors. Adherence, even in the early stages of treatment, appears to be insufficient in some patients and may be below the level required for continuous inhibition of viral replication. This approach may lead to improved targeting of counselling about their medication intake of such patients in order to prevent occurrence of resistant viral strains due to inadequate inhibition of viral replication. In this pilot study a significant difference between the data recorded through the electronic monitors and those provided by self-reporting was observed.

     

Nonmuscular involvement in merosin-negative congenital muscular dystrophy

The spectrum of nonmuscular involvement in six children with merosin-negative congenital muscular dystrophy is described. In all children, biochemical, neuroradiologic, cardiac, and neurophysiologic studies were performed. Cerebral structures that were myelinated at gestation, including internal capsule, corpus callosum, brainstem, and cerebellar white matter, demonstrated no abnormalities, whereas the periventricular and subcortical white matter, which were myelinated in the first postnatal year, demonstrated signs of leukoencephalopathy. Cerebrospinal fluid analysis revealed an elevated albumin cerebrospinal fluid to serum ratio in the younger children. Electroencephalogram results were abnormal in the two elder children. One child suffered from congestive cardiomyopathy. The increase in nerve conduction velocity in these children over the years lagged behind those of healthy patients, pointing to a demyelinating neuropathy. We conclude that in merosin-negative congenital muscular dystrophy patients, nonmuscular involvement includes the central and peripheral nervous system and the heart. The pattern of myelination of the brain and nerve conduction slowing suggests a myelination arrest. Merosin deficiency can give rise to a congestive cardiomyopathy, which is of no clinical relevance in the majority of children.     

Nighttime sleep problems and daytime sleepiness in Parkinson's disease

Our objective is to evaluate nighttime sleep problems (NSP) and daytime sleepiness (DS) in patients with Parkinson's disease (PD) compared to controls, and to assess relations with demographic, disease‐related, and clinical characteristics in patients. NSP and DS were evaluated with the SCOPA‐SLEEP questionnaire in PD patients and controls. In patients, other disease‐related and clinical characteristics were also evaluated. Four hundred twenty PD patients [mean (SD) age 61.1 (11.5) years] and 150 controls [mean (SD) age 60.9 (9.9) years] participated in the study. Compared to controls, a significantly greater proportion of patients had excessive DS (EDS) (43 vs. 10%), excessive NSP (ENSP) (27 vs. 9%), or used sleep medication (17 vs. 12%). Difficulties with falling asleep were similar in both groups. In both patients and controls, women experienced more NSP than men. In patients, depressive symptoms accounted for 21% of NSP variance and was the major contributor to the total explained variance (30%). Furthermore, NSP were related to dopamine‐agonist and levodopa dose, whereas DS was related to age, dopamine‐agonist dose, and disease severity. NSP and DS occur frequently in PD, with EDS being reported more commonly than ENSP. No strong relations were found between DS and demographic or clinical variables. The strong relation between NSP and depressive symptoms in PD calls for future studies to explore the nature of this relation. © 2007 Movement Disorder Society