Table 2

Clinical and cognitive evaluation for all cause dementia and AD

GuidelineProcedures
Step 1: criteria for ‘all cause dementia’
Interferes with the ability to function at work or with usual abilities andHistory and observation
Represents a decline from previous ability and■ Evidence of changes in functioning reported by either patient and/or informant or observed by clinician
Cannot be explained by delirium or major psychiatric disorder
Presence of cognitive impairmentHistory, observation, neuropsychological testing
■ History-taking from a knowledgeable informant
■ Objective mental status testing and/or neuropsychological testing
■ Neuropsychological testing is recommended when history and mental status testing cannot provide a confident diagnosis
The cognitive or behavioural impairment involves a minimum of two domainsHistory, observation, neuropsychological testing
■ Impaired ability to acquire/remember new information (eg, repeating questions, forgetting events or appointments, becoming lost in familiar places)
■ Impaired reasoning and handling of complex tasks, poor judgement (eg, inability to handle finances, poor decision making)
■ Impaired visuospatial abilities (eg, difficulty recognising faces or common objects)
■ Impaired language function (speaking, reading, writing; eg, difficulty thinking of common words while speaking, hesitations in speech)
■ Changes in personality, behaviour, comportment (eg, agitation, apathy, social withdrawal)
Difference between MCI and dementiaHistory and observation
■ The fundamental difference between diagnoses of dementia versus MCI depends upon whether or not there is a significant change in the ability to function at work or in daily activities. This will necessarily require clinical judgment based upon the information provided by the patient and a knowledgeable informant.
Step 2: criteria for ‘probable AD dementia’
Meets criteria for dementiaSee criteria above for dementia, step 1
Insidious onset: symptoms have a gradual onset over months or years, not sudden over hours or days.History
■ From patient and knowledgeable informant
Clear cut history of worsening of cognitionHistory, serial neuropsychological testing
■ From patient and knowledgeable informant
Initial cognitive deficits are evident and most prominent in one of the following categoriesHistory, neuropsychological testing
■ Amnestic presentation – the most common presentation
■ Non-amnestic presentations
Amnestic presentation
■ Impairment of learning and recall of recently learned information
 (1) Language presentation■ Deficit in at least one other cognitive area
Non-amnestic presentations
 (2) Visuospatial presentation■ Language: most prominent deficits are word finding, but should also be deficits in other cognitive areas
 (3) Executive dysfunction■ Visuospatial: most prominent deficits are spatial cognition, but should also be deficits in other cognitive areas
■ Executive: most prominent deficits are reasoning, judgment and problem solving, but should also be deficits in other cognitive areas
Diagnosis of AD should not be made when there is evidence of another dementing illnessHistory, neuropsychological testing, imaging studies, laboratory studies
Disorders to rule out include:
■ Vascular cognitive impairment/vascular dementia
■ Dementia with Lewy bodies
■ Frontal-temporal dementia – behavioural variant
■ Primary progressive aphasia
■ Evidence of neurological disease or non-neurological condition or medication that could have a substantial effect on cognition
Step 3: criteria for ‘probable AD dementia with increased level of certainty’
Meets criteria for AD dementiaSee criteria above for AD dementia, step 2
Probable AD dementia with documented declineHistory, serial neuropsychological testing
Evidence of progressive cognitive decline on subsequent evaluations from
■ knowledgeable informant or
■ cognitive testing (either formal neuropsychological evaluation or standardised mental status examinations)
Probable AD dementia in a carrier of a causative AD genetic mutationLaboratory studies
Presence of an early-onset familial genetic mutation
■ APP, PSEN1, or PSEN2
(Note that the apolipoprotein E ɛ4 allele was not considered specific enough to meet criteria)
Step 4: evaluate the ‘biomarker probability of AD aetiology’
Evaluate for atrophy of temporal (medial, basal, and lateral) and medial parietal cortex and other biomarkers when available and clinically usefulBiomarkers
■ Although the use of biomarkers is not recommended routinely, they are available to the clinician when desired
■ There are two categories of biomarkers, those associated with Aβ protein deposition and those associated with downstream neurodegeneration (see table 1)
■ We recommend routine review of CT and MRI patterns of atrophy, a marker of downstream neurodegeneration
■ Presence of one biomarker category makes the ‘biomarker probability of AD aetiology’ ‘intermediate;’ both categories must be positive for a ‘high’ probability. The ‘lowest’ probability is present if both categories are negative
  • Note: patients who would have met criteria under the 1984 guidelines would also meet criteria under the current guidelines.

  • Aβ, amyloid β; AD, Alzheimer's disease; APP, amyloid precursor protein; MCI, mild cognitive impairment; PSEN, presenilin.