Bedside assessment of the patient with suspected dementia: a ‘walk around the cognitive brain’
| Cognitive domain | Leading or early symptoms | Associated symptoms | Examination findings | Brain region(s) | First thoughts |
| Behaviour (social and emotional) | Loss of empathy/emotional awareness (eg, family events such as funerals, illnesses and warmth toward children/pets) and self-centredness | Disinhibition, loss of initiative, obsessionality/rituals (eg, clock watching), gluttony/sweet tooth/food faddism, altered interests/humour, loss of insight/anosognosia | Impulsive, inert, disinhibited interaction, ‘1000-yard stare’ | Frontal lobe (especially right), right temporal lobe, other | Behavioural variant frontotemporal dementia |
| Irritability, more anxious and ‘clingy’ | Quieter in social situations | Diffident/head turning | Alzheimer’s disease* | ||
| Language output (speech sounds, sentences and prosody) | Stumbling over words, especially public speaking | Mixing up ‘yes’/no’, mispronunciations, monotonous/odd accent, grammatical/spelling slips | Effortful speech, reduced articulatory agility (repeating syllable strings, eg, ‘puh-kuh-tuh’), impaired repeating single words and following complex commands | Left inferior frontal gyrus/peri-Sylvian† | Non-fluent primary progressive aphasia |
| Word-finding difficulty, losing thread of sentences | Reduced speech quantity, pauses | Reduced picture naming | Left temporoparietal junction | Logopenic aphasia | |
| Knowledge of words (vocabulary), objects and concepts | Forgetting names, circumlocutions, vague expressing thoughts and ‘going deaf’ | Asking meaning of words, keeping personal ‘dictionaries’ and decline in spelling/understanding written words | Reduced knowledge of specialist vocabulary,‡ reduced naming of objects/ability to identify pictures/define words named by examiner, surface dyslexia (irregular words, eg, ‘yacht’) | Left anteroinferior temporal lobe | Semantic primary progressive aphasia |
| Difficulty choosing groceries/tools, etc§ | Unable to describe/demonstrate use of an object§ (visual agnosia) | ||||
| Reading, spelling and calculation | Loss of pleasure reading Less numerical facility (eg, change) | Losing place reading text, difficulty resolving closely spaced text and decline in spelling ability | Difficulty reading blocked text and acalculia on simple mental arithmetic | Left parietal lobe | Posterior cortical atrophy, logopenic aphasia and Alzheimer’s disease |
| Working memory (verbal) | Poor ‘concentration’ | Difficulty holding information for example, a new phone number in mind Losing thread of conversation | Reduced forward (passive) digit span, reduced reverse (active) digit span and reduced repetition of phrases more than words | Left temporoparietal junction/frontal lobe | Logopenic aphasia and Alzheimer’s disease |
| Action (learnt/voluntary: praxis) | Difficulty learning new devices, loss of facility with do-it-yourself, etc | Difficulty using household gadgets | Ideomotor limb apraxia: impaired copying meaningless/sequential gestures (Luria), ideational limb apraxia: impaired pantomime of learnt actions (eg, tool, waving) | Left parietal lobe | Posterior cortical atrophy and corticobasal syndrome |
| Difficulty positioning self in space | Bottom apraxia (difficulty sitting on chair) | ||||
| Loss of facility whistling/singing | Difficulty swallowing | Orofacial apraxia: volitional cough/yawn/blow kiss, etc | Left frontal lobe† | Non-fluent primary progressive aphasia | |
| Object analysis (visual) | Difficulty reading large/unusual (eg, pixelated/CAPTCHA) font; not confident on escalators; often multiple optician visits | Difficulty interpreting complex scenes with patterns, overlaid objects, identifying slopes/steps, etc; difficulty recognising or misrecognising objects in suboptimal viewing conditions | Difficulty perceiving fragmented letters/pictures, distorted views | Right parietal lobe | Posterior cortical atrophy and dementia with Lewy bodies |
| Spatial awareness (visual) | Bumps/scrapes in car, difficulty parking and difficulty filling forms, etc | Unable to find items in an array, placing items too close to table edge | Difficulty drawing clockface/copying design/counting dots, finding examiner’s outstretched hand (visual disorientation) | Right parietal lobe | Posterior cortical atrophy and Alzheimer’s disease |
| Perception (early sensory–visual, auditory, somatic and interoceptive) | Difficulty driving if night-time/raining | Abnormally prolonged after-images (colour ‘washes’, often red/green), visual ‘tilt’ and other distortions | Impaired colour/shape discrimination (e.g., oblong vs square) | Sensory cortices/thalamus¶ | Posterior cortical atrophy, ‘visual’ Creutzfeldt-Jakob disease |
| ‘Double vision’, brief misperceptions | Illusions/hallucinations | Check visual acuity | Dementia with Lewy bodies | ||
| Dislikes noisy environments | Difficulty conversing in noise | Check peripheral hearing | Alzheimer’s disease and variants | ||
| Tinnitus/hyperacusis | Altered pain/temperature awareness | Check basic sensory function | Semantic primary progressive aphasia and behavioural variant frontotemporal dementia | ||
| Face recognition | Loss of facility recognising faces | ‘Blanking’ familiar people and misidentification of ‘impostors’ | Impaired famous face recognition** | Right anteroinferior temporal lobe and connections | Semantic primary progressive aphasia and right temporal lobe atrophy†† |
| Impaired perception of faces (age/gender) | Right temporal lobe/parietal lobe | Alzheimer’s disease and dementia with Lewy bodies | |||
| Executive function | Disorganised, distractible, poor planning/decision making/multitasking/prioritising, apathetic | Difficulty with inference/abstraction, choosing alternatives, envisaging/learning from consequences and dealing with novelty | Reduced/bizarre verbal fluency (category/letter–number of animals/‘S’ words in 1 min),‡‡ Stroop task errors, concrete proverb interpretation, inaccurate cognitive estimates (eg, ‘How many lions in Belgium?’)§§¶¶ | Bilateral frontal lobe and connections | May be behavioural variant frontotemporal dementia but depends on associated problems |
| Memory (episodic and topographical) | More repetitive and less facility with route finding | Vague knowledge of current affairs and getting lost | Orientation to date/time/place, details of hospital journey/stay and incidental recall of pictures from naming test | Hippocampi and connections | Alzheimer’s disease (but beware) |
| Forgetful, absent-minded | Poor concentration, disorganised | Improves on cueing/foils; ‘Did you see a…?’) | Vascular/other |
This table presents early symptoms (‘canaries’; see also table 2) that signal difficulty in each major cognitive domain, together with associated symptoms that may be elicited on history. For each domain, we suggest bedside tests (see also box 1) and features that may be used to corroborate the historical impression and indicate major neuroanatomical associations (see also figure 2) and leading diagnostic considerations.
*Refers to the clinical syndrome of typical (memory-led) Alzheimer’s disease.
†Prosody/ singing may be additionally linked to right peri-Sylvian cortical regions
‡Initial loss of knowledge of lower-frequency words reflecting patient’s interests/occupation.
§May indicate visual agnosia (the patient with apraxia recognises how an object is used).
¶Usually conjoint ‘top-down’ abnormalities in attentional/executive/semantic functions.
**Ask for other biographical details if patient cannot name.
††Refers to the syndrome associated with right temporal lobe atrophy, within the behavioural variant frontotemporal dementia spectrum.
‡‡In non-aphasic patients.
§§Dependent on education and culture.
¶¶The manner in which the patient approaches executive tests is also informative, for example, are they impulsive? do they produce odd items on fluency tasks? do they produce overprecise, incorrect estimates that they cannot revise? etc.