Mediterranean diet adherence, gut microbiota, and Alzheimer's or Parkinson's disease risk: A systematic review.

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most prevalent neurodegenerative diseases, both without prevention or cure. The Mediterranean diet (MeDi) may be neuroprotective by modulating gut microbiota. We aimed to assess the effects of adherence to MeDi on the gut microbiota in relation to AD or PD risk. A search from inception to November 2020 was conducted in PubMed, CINAHL, EMBASE, Web of Science, Global Health, Biological Abstracts, and Grey Literature Report databases. Two searches were conducted: 1) (MeDi or Microbiota) and (PD or AD) and 2) MeDi and microbiota. Inclusion criteria for papers were specified prior to review. Of 4672 studies identified, 64 were eligible for inclusion. These studies were divided into five groups: MeDi and AD risk (n = 4), MeDi and PD risk (n = 2), MeDi and microbial composition or metabolomics (n = 21), AD and microbial composition or metabolomics (n = 7), and PD and microbial composition or metabolomics (n = 30). Adherence to the MeDi was associated with a lower risk of AD and PD development. Eight genera and two species of bacteria had an inverse relationship with MeDi and AD, and one family, eight genera and three species of bacteria had an inverse relationship with MeDi and PD. More studies are needed to investigate if MeDi, gut microbiota, and neurodegeneration are causally related.

Acute disseminated encephalomyelitis presenting as a brainstem encephalitis.

Acute disseminated encephalomyelitis (ADEM) is a disease characterized by inflammation and destruction of myelin. Acute hemorrhagic leukoencephalitis (AHLE) is a severe form of ADEM known for its particularly poor outcome. We present a case of a young Caucasian female who presented with drowsiness and slurred speech followed by rapid brainstem involvement resembling rhomboencephalitis. Despite multiple diagnostic tests and empiric therapy with immunosuppressants, immunoglobulins, and antimicrobials, she lost most brainstem reflexes within a few weeks and ultimately passed away. Magnetic resonance imaging (MRI) showed progression of lesions from the brainstem to eventually involve bilateral cerebral hemispheres. Autopsy and microscopic examination of the brain revealed several hemorrhagic lesions throughout the brain and rendered a diagnosis of AHLE. AHLE was initially described in 1941 and is thought to be autoimmune related, possibly related to cross reactivity between the immune system and CNS tissues like myelin. While a definitive inciting pathogen was not discovered, this case emphasizes the importance of considering AHLE in the differential diagnosis of patients with rapid loss of neurologic function and highlights an atypical presentation of ADEM/AHLE.