Volume 11 Issue 3, March 2015

Type 2 diabetes mellitus (T2DM) has been linked with cognitive impairment and dementia. A new cross-sectional study reports that T2DM is also associated with dementia in Parkinson disease, and another study describes the long-term clinical course of diabetes-associated cognitive dysfunction; however, the mechanisms through which T2DM affects the brain are not completely understood.

Traumatic brain injury (TBI) is increasingly recognized as a risk factor for dementia. New data provide further support for this association and demonstrate the influence of age at injury and injury severity on dementia risk after TBI, revealing that even mild TBI increases dementia risk in those aged ≥65 years.

Approximately 60% of people diagnosed with childhood-onset epilepsy are known to be in 5-year remission and off medication, or in complete remission. A new report confirms and consolidates these findings and gives further evidence of the long-term stability of remission in epilepsy. A future risk of relapse is suggested, which might be an overestimate.

Stroke has a heavy socioeconomic burden. A subset of patients with transient or nondisabling cerebral ischaemic events will experience recurrent stroke, leading to permanent deficits. Two new studies tackle the challenge of identifying the patients most at risk for recurrent stroke via examination of radiological and serum biomarkers.

The past 20 years have seen remarkable progress in research into multiple sclerosis (MS), resulting in a veritable armamentarium of treatment options. Ransohoff and colleagues reflect on three major eras of drug development to date. The authors also offer guidance on how best to select between various therapeutics, and look to the future of MS research.

Mounting evidence suggests that autoantibodies contribute to the pathogenesis of demyelination in the PNS and CNS, and that such autoantibodies might impair saltatory conduction mediated by the node of Ranvier. In this Review, the authors provide a detailed description of the molecular anatomy of the node of Ranvier, discuss nodal, paranodal and juxtaparanodal proteins as likely autoantigens, and examine the role of autoantibodies in the pathogenesis of demyelinating disease.

White matter hyperintensities (WMHs) are frequently seen on brain MRI in older people, and are thought to result from chronic ischaemia associated with cerebral small vessel disease. Prins and Scheltens provide a timely Review on WMHs, including their relationship with cognitive decline and dementia. The authors also discuss how WMHs might provide a therapeutic target to prevent the onset and progression of dementia.

Age related hearing impairment (ARHI, also known as presbycusis) is an important frailty marker, and could be a reversible risk factor for dementia and Alzheimer disease. Poor verbal communication and depletion of cognitive reserve might causally link ARHI to cognitive decline and frailty; hearing aids and cognitive training might, thus, provide a strategy to delay or prevent cognitive deterioration. In this Review, Panza and colleagues discuss the interplay between cognitive impairment, ARHI and frailty in older age.

The short-term safety and efficacy of IFN-β in patients with multiple sclerosis are well established, but less is known about this drug when taken over years and decades. Sormani and Bruzzi discuss the difficulties associated with designing studies of the long-term treatment effects of IFN-β. They then present techniques that have been employed to minimize potential sources of bias. The authors conclude that long-term use of IFN-β reduces clinical progression, but important questions relating to mortality warrant further investigation.