Apolipoprotein E genotype moderates the association between dietary polyunsaturated fat and brain function: an exploration of cerebral glutamate and cognitive performance.

Objective: To investigate the effect of Apolipoprotein E (APOE) genotype on the association between dietary polyunsaturated fat (PUFA), cognitive function, and cerebral glutamate. Methods: A participant sample of 122 middle-aged adults were grouped according to APOE genotype (ϵ4 carrier or ϵ4 non-carrier) and asked to record dietary intake for three consecutive days. All participants also underwent neuropsychological testing and a proton magnetic resonance spectroscopy (1H MRS) scan to assess glutamate in the posterior cingulate cortex. Results: Multiple regression analyses revealed a significant interaction between APOE genotype and PUFA intake on memory performance, F(1,113) = 6.749, p = .016. Greater PUFA intake was associated with better memory performance in healthy middle-aged adults who were APOE ϵ4 non-carriers, but not for ϵ4 carriers. Furthermore, there was a significant interaction between APOE genotype and PUFA intake on cerebral glutamate, in that dietary PUFA was associated with greater cerebral glutamate in APOE ϵ4 carriers, but not for ϵ4 non-carriers, F(1,114) = 5.173, p = .025. Conclusions: The findings suggest that PUFA action on the brain differs according to APOE polymorphism and points towards cerebral glutamate as a potential marker of genetic risk for Alzheimer's disease (AD). Early treatment consisting of PUFA supplementation that is tailored to APOE genotype may be an important intervention for the prevention of cognitive decline.

Perineural spread of basosquamous carcinoma to the orbit, cavernous sinus, and infratemporal fossa.

Basosquamous carcinoma is a rare, highly aggressive variant of basal cell carcinoma with elevated rates of recurrence, perineural invasion, and metastasis. We describe a patient who presented with unilateral complete ophthalmoplegia, ptosis, optic neuropathy, and trigeminal neuropathy due to perineural intracranial invasion of nasal basosquamous carcinoma via the sphenopalatine fossa to the cavernous sinus, orbit, and infratemporal fossa. To our knowledge, this is the first reported case of basosquamous carcinoma with perineural invasion involving the cavernous sinus in the English language ophthalmic literature. Physicians should be aware of the diagnostic features, clinical challenges and aggressive nature of basosquamous carcinoma, a rare diagnosis that can lead to significant morbidity/mortality when left unrecognized.