The influence of cognitive impairment on health-related quality of life in neurological disease

Background: Cognitive impairment is the most consistent neurological complication of acquired and degenerative brain disorders. Historically, most focus was on dementia but now has been broadened to include the important construct of mild cognitive impairment. Methods: Systematic search and review of articles linked quality of life (QoL) and cognitive complications of neurological disorders. We excluded QoL in dementia. Results: Our search identified 249 publications. Most research examined patients with brain tumours, stroke, epilepsy, head injury, Huntington's disease, motor neuron disease, multiple sclerosis and Parkinson's disease. Results suggested that the majority of patients with epilepsy, motor neuron disease, multiple sclerosis, Parkinson's disease, stroke and head injury have subtle cognitive deficits early in their disease course. These cognitive complaints are often overlooked by clinicians. In many cases, the cognitive impairment is progressive but it can also be relapsing-remitting and in some cases reversible. Despite the importance of severe cognitive impairment in the form of dementia, there is now increasing recognition of a broad spectrum of impairment, including those with subclinical or mild cognitive impairment. Even mild cognitive difficulties can have functional and psychiatric consequences-especially when they are persistent and untreated. Specific cognitive deficits such an inattention, dysexecutive function and processing speed may affect a number of quality of life (QoL) domains. For example, cognitive impairment influences return to work, interpersonal relationships and leisure activities. In addition, fear of future cognitive decline may also impact upon QoL. Conclusions: We recommend further development of simple tools to screen for cognitive impairments in each neurological condition. We also recommend that a thorough cognitive assessment should be a part of routine clinical practice in those caring for individuals with neurological disorders.