Role of social factors on cell death, cerebral plasticity and recovery after stroke

Abstract

Stroke is a serious global health care problem. It is now is the fourth leading cause of death and the primary cause of adult disability in the United States. Substantial evidence from both experimental and clinical studies has demonstrated that social isolation (SI) can increase stroke incidence and impair recovery. Epidemiological studies demonstrate that an increasing number of patients are living alone, and as the aging population increases, loneliness will only increase in prevalence. SI is increasingly identified as an independent risk factor for all-cause mortality. In contrast, individuals with high levels of social support exhibit more rapid and extensive functional and cognitive recovery after a wide variety of pathological insults, including stroke. Clinical data suggests that SI is an important risk factor for increased mortality and delayed functional recovery following ischemic stroke. Attesting to the importance of mortality and behavioral factors in stroke outcome is that these same effects can be reproduced in animal models of experimental stroke. This has allowed researchers to identify several mechanistic changes that occur with affiliative interactions. These include decreased systemic inflammation, elaboration of growth factors including brain derived neurotropic factor (BDNF), enhanced neurogenesis, and improved neuroimmune responsiveness in group housed animals. These may mediate the beneficial effects of social interaction on improving stroke recovery and reducing neuronal death. In this review we provide an overview of the effects of SI on ischemic injury and recovery and discuss their clinical and therapeutic implications.

Social networks and neurological illness

“…Language itself might have evolved as a vehicle to facilitate social demands 17 . Pathologically, the socially isolated brain has been shown to have higher baseline vascular resistance, lower inflammatory control, and decreased neurogenesis after injury 21–23 . These effects of social isolation on the brain are accompanied by a host of systemic physiological changes, including an elevated stress response, inflammation, and hypertension 24 .…”

Functional Status and Disability in Patients After Acute Stroke: A Longitudinal Study

“…Some studies 27,32,42 have indicated that social isolation and social support most likely influence recovery in stroke patients. Our findings also show that social risk is associated with worse recovery.…”

Social Network Structure in Young Stroke Survivors with Aphasia: A Case Series Report

“…2 Similarly, Venna et al found that clinical data from group-housed animals with stroke showed decreased systemic inflammation, elaboration of BDNFs, enhanced neurogenesis, and improved neuroimmune responsiveness which differed significantly from isolated animals. 3 Studies of stroke survivors have reported similar findings. Boden-Albala et al found that individuals experiencing social isolation experienced worse poststroke outcomes such as death, recurrent stroke, or myocardial infarction.…”

“…5 The exact mechanism by which social networks influence stroke recovery is not clearly understood, as it is unclear if it is the type, function, density, or frequency of contacts within the social network structure that is most critical to stroke recovery. 3 Aphasia is a poststroke condition where social networks appear critical to recovery. Recent estimates suggest that approximately 18% of individuals with a diagnosis of stroke are discharged from U.S. hospitals with aphasia 6 and there are believed to be more than 2.5 million Americans currently living with aphasia.…”