Neurology News: Alzheimer Disease, MS, and More

Early-onset Alzheimer disease linked with circulating cholesterol and gene variants. Novel findings suggested that circulating low-density lipoprotein cholesterol (LDL-C) levels may play a role in the pathogenesis of early-onset Alzheimer disease (EOAD). In a case series of plasma samples from patients with EAOD, researchers found an association between EAOD and higher levels of LDL-C independent of the effects of the apolipoprotein E ε4 (APOE E4) allele and enrichment of rare coding variants of the apolipoprotein B (APOB) gene. They noted that the findings highlight the importance of LDL-C in EOAD pathogenesis and suggest a direct link between APOB variants and AD risk.

Obesity adds to multiple sclerosis severity. Obesity and altered lipid profile were associated with exacerbated central inflammation and higher clinical disability in patients with relapsing-remitting multiple sclerosis in a cross-sectional study. A positive correlation was seen between body mass index and Expanded Disability Status Scale score. Obese patients had higher clinical disability, increased cerebrospinal fluid (CSF) levels of the proinflammatory molecules IL-6 and leptin, and reduced concentrations of the anti-inflammatory cytokine IL-13. The serum levels of triglycerides and TC/HDL-C ratio showed a positive correlation with IL-6 CSF concentrations. The authors suggested that increased adipocytokines and lipids can mediate the negative impact of high adiposity.

Patients with mild traumatic brain injury not always quick to recover. Most patients with mild traumatic brain injury (mTBI) who presented to US level I trauma centers reported persistent, injury-related life difficulties at 1 year postinjury. In a cohort study that used data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, 53% of patients with mTBI reported impairment 12 months postinjury vs 38% of patients with orthopedic trauma. Impairment was reported by more patients with mTBI who had acute intracranial findings than those who did not. The authors suggested that more systematic follow-up is needed to provide treatments and reduce the risk of chronic problems after mTBI.

Antihypertensives decrease dementia incidence. In a retrospective study conducted to investigate the relationship between antihypertensive drug use and dementia in patients aged ≥60 years, the most frequent comorbidities were hyperlipidemia, diabetes mellitus, and coronary heart disease. The use of angiotensin II receptor blockers, angiotensin-converting enzyme inhibitors, calcium channel blockers, and beta blockers was associated with a decrease in dementia incidence. The authors suggested that the finding of the negative association highlights the importance of the prescription of antihypertensive drugs in the context of preventing hypertension-associated cognitive decline.

More Parkinson disease with bipolar disorder. In a study that investigated the risk of Parkinson disease among patients who have bipolar disorder, the incidence of Parkinson disease was higher in patients with bipolar disorder during follow-up than in controls. Sensitivity analyses after exclusion of the first year or first 3 years of observation showed consistent findings. In addition, high frequency of psychiatric admission for manic/mixed and depressive episodes was associated with an increased risk of Parkinson disease. The authors suggested more studies to investigate the underlying pathophysiology.