Introduction

Cognitive impairment, sometimes amounting to dementia, may accompany many neurological disorders1; thus, any neurological sign2 might, in theory, be associated with a cognitive deficit. However, in practice, only a few are relevant because of the limited number of conditions that typically present to cognitive disorders clinics. In addition to these textbook (canonical) neurological signs, a number of others that are easily observed and categorised may help in deciding whether there is cognitive impairment or not. These signs, therefore, also merit inclusion here; indeed, they are discussed first, since in practice, the differentiation of cognitively healthy and cognitively impaired individuals should precede any further investigations.

This article does not presume to be exhaustive, but focuses on those signs that I have found useful in practice. Clearly, any neurological examination must follow a detailed history in order to contextualise any examination findings.

The pattern of neuropsychological deficits evident on cognitive testing, either performed by the neurologist3 or more formally by a neuropsychologist, may help more than neurological signs in establishing an aetiological diagnosis.