Pavis Laengvejkal

White Matter Deterioration May Foreshadow Impairment of Emotional Valence Determination in Early-Stage Dementia of the Alzheimer Type

In Alzheimer Disease (AD), non-verbal skills often remain intact for far longer than verbally mediated processes. Four (1 female, 3 males) participants with early-stage Clinically Diagnosed Dementia of the Alzheimer Type (CDDAT) and eight neurotypicals (NTs; 4 females, 4 males) completed the emotional valence determination test (EVDT) while undergoing BOLD functional magnetic resonance imaging (fMRI). We expected CDDAT participants to perform just as well as NTs on the EVDT, and to display increased activity within the bilateral amygdala and right anterior cingulate cortex (r-ACC). We hypothesized that such activity would reflect an increased reliance on these structures to compensate for on-going neuronal loss in frontoparietal regions due to the disease. We used diffusion tensor imaging (DTI) to determine if white matter (WM) damage had occurred in frontoparietal regions as well. CDDAT participants had similar behavioral performance and no differences were observed in brain activity or connectivity patterns within the amygdalae or r-ACC. Decreased fractional anisotropy (FA) values were noted, however, for the bilateral superior longitudinal fasciculi and posterior cingulate cortex (PCC). We interpret these findings to suggest that emotional valence determination and non-verbal skill sets are largely intact at this stage of the disease, but signs foreshadowing future decline were revealed by possible WM deterioration. Understanding how non-verbal skill sets are altered, while remaining largely intact, offers new insights into how non-verbal communication may be more successfully implemented in the care of AD patients and highlights the potential role of DTI as a presymptomatic biomarker.

The Association of Alpha-Blockers and 5-Alpha Reductase Inhibitors in Benign Prostatic Hyperplasia With Fractures

Background:Alpha-blockers and 5-alpha reductase inhibitors are common drugs used to treat benign prostatic hyperplasia (BPH), a prevalent problem in older men associated with significant morbidity and cost. Data regarding how these medications affect skeletal health and fracture risk remain scarce. Methods:Studies were identified by searching PubMed, EMBASE, the Cochrane library and Thomson Reuters Web of Knowledge. Studies involving BPH patients that reported odds ratio (OR) estimates with 95% confidence intervals (CIs) for the association between fractures and exposure to 5-alpha reductase inhibitors or alpha-blockers were included. Pooled ORs were calculated using the random-effects model. Results:Three studies addressed fracture risk in patients exposed to 5-alpha reductase inhibitors (21,366 fracture cases). Four studies addressed fracture risk in patients exposed to alpha-blockers (22,051 fracture cases). The pooled OR for fractures with 5-alpha reductase inhibitor use was 0.9 (95% CI = 0.7–1.1). For hip/femur fractures with 5-alpha reductase inhibitor use, the pooled OR was 0.8 (95% CI = 0.7–1.0). The pooled OR for fractures with alpha-blockers was 1.1 (95% CI = 0.9–1.3). There was significant statistical heterogeneity among studies for alpha-blockers. Conclusions:In patients with BPH, exposure to 5-alpha reductase inhibitors was not associated with change in fracture risk. The 5-alpha reductase inhibitors may have a small protective effect against hip/femur fractures although this was not statistically significant. Although alpha-blockers were not associated with change in fracture risk, caution is required when interpreting the results as significant heterogeneity was present.

Meningitis-Retention Syndrome as a Presentation of West Nile Virus Meningitis

A 26-year-old previously healthy man presented with fever, urinary retention, nuchal rigidity, and hyperreflexia but with a clear sensorium. His initial spinal fluid results were consistent with aseptic meningitis from West Nile virus infection, and this was confirmed by serological studies on blood and cerebrospinal fluid. Computed tomography and magnetic resonance imaging studies were unremarkable. He received supportive care and urinary catheterization to prevent bladder injury from overdistension. He was discharged home without recurrence of urinary retention after five days of hospitalization. Therefore, this case report describes the first case of West Nile virus meningitis in a patient with the meningitis-retention syndrome.

Topiramate-induced hyperammonemic encephalopathy in a patient with mental retardation: A case report and review of the literature

Hyperammonemia is an uncommon side effect of topiramate (TPM) that has only been reported when it is used as an adjunct to valproate. We report a patient with mental retardation who developed reversible encephalopathy from TPM. Ammonia level was monitored during the course of TPM treatment. This patient had recurring, reversible elevations in serum ammonia levels that coincided with the administration of TPM. To our knowledge, symptomatic hyperammonemia has not been reported to occur with TPM monotherapy.

Lower activation in frontal cortex and posterior cingulate cortex observed during sex determination test in early-stage dementia of the Alzheimer type

Face-labeling refers to the ability to classify faces into social categories. This plays a critical role in human interaction as it serves to define concepts of socially acceptable interpersonal behavior. The purpose of the current study was to characterize, what, if any, impairments in face-labeling are detectable in participants with early-stage clinically diagnosed dementia of the Alzheimer type (CDDAT) through the use of the sex determination test (SDT). In the current study, four (1 female, 3 males) CDDAT and nine (4 females, 5 males) age-matched neurotypicals (NT) completed the SDT using chimeric faces while undergoing BOLD fMRI. It was expected that CDDAT participants would have poor verbal fluency, which would correspond to poor performance on the SDT. This could be explained by decreased activation and connectivity patterns within the fusiform face area (FFA) and anterior cingulate cortex (ACC). DTI was also performed to test the association of pathological deterioration of connectivity in the uncinate fasciculus (UF) and verbally-mediated performance. CDDAT showed lower verbal fluency test (VFT) performance, but VFT was not significantly correlated to SDT and no significant difference was seen between CDDAT and NT for SDT performance as half of the CDDAT performed substantially worse than NT while the other half performed similarly. BOLD fMRI of SDT displayed differences in the left superior frontal gyrus and posterior cingulate cortex (PCC), but not the FFA or ACC. Furthermore, although DTI showed deterioration of the right inferior and superior longitudinal fasciculi, as well as the PCC, it did not demonstrate significant deterioration of UF tracts. Taken together, early-stage CDDAT may represent a common emerging point for the loss of face labeling ability.