The Neurological Examination in Aging, Dementia and Cerebrovascular Disease

Part 1: Introduction, Head and Neck, and Cranial Nerves

David J. Gladstone, BSc, MD, Fellow, Cognitive Neurology and Stroke Research Unit, Sunnybrook and Women's College Health Sciences Centre and Division of Neurology, University of Toronto, Toronto, ON.

Sandra E. Black, MD, FRCPC, Professor of Medicine (Neurology), University of Toronto; Head, Division of Neurology and Director, Cognitive Neurology Unit, Sunnybrook and Women's College Health Sciences Centre, Toronto, ON.

Abstract
This four-part series of articles provides an overview of the neurological examination of the elderly patient, particularly as it applies to patients with cognitive impairment, dementia or cerebrovascular disease. The focus is on the method and interpretation of the bedside physical examination; the mental state and cognitive examinations are not covered in this review. Part 1 begins with an approach to the neurological examination in normal aging and in disease, and reviews components of the general physical, head and neck, neurovascular and cranial nerve examinations relevant to aging and dementia. Part 2 covers the motor examination with an emphasis on upper motor neuron signs and movement disorders. Part 3 reviews the assessment of coordination, balance and gait. Part 4 discusses the muscle stretch reflexes, pathological and primitive reflexes, sensory examination and concluding remarks. Throughout this series, special emphasis is placed on the evaluation and interpretation of neurological signs in light of findings considered normal in the elderly.

Introduction
Maximizing diagnostic accuracy in dementia is important given the increasing availability of treatment options for Alzheimer disease (AD), stroke, vascular dementia (VaD), other neurodegenerative disorders such as Parkinson's disease (PD) and depression.^1-3 Despite increasingly sophisticated diagnostic neuroimaging technologies, the clinical examination remains essential to the proper evaluation of a patient with neurological disease.⁴ Together with a thorough medical and neurological history, the diagnostic examination aims to identify the presence or absence of neurological disease, refine the differential diagnosis of dementia type and etiology, and screen for medical comorbidities and functional limitations (Table 1). Physical examination is especially important in the geriatric population where an accurate history may be difficult to obtain, atypical presentations of disease are common, and multiple coexisting diseases, disabilities and polypharmacy are the rule.⁵ Indeed, the standard neurological examination often needs to be expanded in the elderly to include functional assessments and other components of a "comprehensive geriatric assessment", where appropriate.^6,7 As the saying goes, "you won't find what you don't look for." Many excellent references on the technique of neurological examination and principles of neurological diagnosis are available for the interested reader.^8-13

Neurological examination should be guided by hypotheses generated from the patient's history. Just as a radiologist's interpretation of imaging studies is improved by prior knowledge of the clinical history, the neurological examination is most reliable when it aims to confirm findings that are suspected from the history.^14,15 Neurological assessment is based on principles of anatomical localization that aim to identify lateralized or focal neurological findings suggestive of local pathology, multifocal disease or bilateral cerebral dysfunction. Determination of the site of nervous system dysfunction (e.g., cortical, subcortical, peripheral nervous system) and which systems are involved (e.g., pyramidal, extrapyramidal, cerebellar, sensory, autonomic) can guide diagnosis toward specific neurodegenerative, vascular or multi-system disorders.

Stroke is suggested by focal neurological signs.¹⁶ Thus, finding evidence of stroke on examination can help support a clinical diagnosis of VaD or mixed AD-VaD.^17,18 Non-neurologists are able to make a correct clinical diagnosis of stroke in the majority of cases.¹⁹ In a study of 1,701 patients assessed in a tertiary referral dementia clinic setting, the clinical examination features that best distinguished patients with mixed