Meta-Analysis of White Matter Hyperintensity Volume Differences Between APOE ε4 Carriers and Noncarriers.

Several studies have suggested that white matter hyperintensity volume (WMHV) is increased among apolipoprotein E (APOE) ε4 carriers while others have reported contradictory findings. Although APOE ε4 carriage is associated with greater AD pathology, it remains unclear whether cerebrovascular damage is also associated with APOE ε4 carriage. The aim of this meta-analysis was to determine whether WMHV is associated with APOE ε4 carrier status. 12 studies that were included yielded a total sample size of 16,738 adult subjects (ε4 carrier n = 4,721; ε4 noncarrier n = 12,017). There were no significant differences in WMHV between ε4 carriers and noncarriers (Hedge's g = 0.07; 95% CI (-0.01 to 0.15), P = 0.09). Subgroup analysis of community-based studies (n = 8) indicated a small effect size where ε4 carriers had greater WMHV relative to noncarriers (Hedge's g = 0.09 95% CI (0.02 to 0.16), P = 0.008). Among clinic-based studies (n = 3) there was no significant difference in WMHV by APOE ε4 carrier status (Hedge's g = -0.09, 95% CI (-0.60 to 0.41), P = 0.70). Observed APOE ε4-associated WMHV differences may be context-dependent and may also be confounded by a lack of standardization for WMHV segmentation.

Infratemporal abscess: a rare complication of a common procedure.

The infratemporal fossa (ITF) is an anatomically complex cavity that houses a variety of muscular and neurovascular structures at the base of the skull. Infections involving the ITF, though uncommon, can be fatal due to the difficulties of accessing this anatomical space and its proclivity to evolve into a cavernous venous thrombosis (CVT). As a result, a multi-disciplinary approach involving several surgical and medical subspecialists is often warranted. We present a case of an infratemporal fossa abscess (IFA) after wisdom teeth extraction with a very complicated clinical course and a distinct microbiologic profile.

Pathologically Confirmed Alzheimer's Disease in APOE ɛ2 Homozygotes is Rare but Does Occur.

BACKGROUND: Homozygous APOEɛ4 status is a well-known risk factor in the development of Alzheimer's disease (AD). However, other genotypes of APOE have not yet been found to have equal clinical significance. There is a paucity of reports regarding clinically or pathologically described AD in APOEɛ2 homozygotes compared to the other alleles. OBJECTIVE: To notify clinicians that patients with homozygous APOEɛ2 are also at risk of developing AD based on results from the largest prospectively gathered registry of brain samples to date. METHODS: We queried the National Alzheimer's Coordinating Center (NACC) database for autopsy-confirmed AD cases. Of the Uniform Data Set (UDS) participants who are deceased, 5,779 were diagnosed with dementia at their last UDS visit prior to death, and autopsy data is available for 3,518. RESULTS: Of the brains in the NACC database with pathologically confirmed dementia, seven were found to be homozygous for APOEɛ2, which represents only 0.2% of the autopsy-confirmed sample. Furthermore, pathology-confirmed AD represents 29% (2/7) of the APOEɛ2/ɛ2 patients diagnosed with dementia. CONCLUSIONS: Although rare, autopsy-confirmed AD can be present in APOEɛ2/ɛ2 carriers.