What are the steps to diagnose early onset dementia?

From the Guidelines

Diagnosing early onset dementia requires a comprehensive approach, starting with a thorough medical history, physical examination, and cognitive testing, and may involve blood biomarker tests, such as those detecting amyloid pathology, as recommended by the Global CEO Initiative on Alzheimer's Disease 1. The diagnostic process for early onset dementia involves multiple steps, including:

• A thorough medical history and physical examination to identify cognitive changes, behavioral symptoms, and functional abilities
• Cognitive testing using standardized assessments like the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), or neuropsychological testing to evaluate memory, language, problem-solving, and other cognitive domains
• Laboratory tests, including complete blood count, thyroid function, vitamin B12 levels, and metabolic panels, to rule out reversible causes of cognitive decline
• Brain imaging studies, such as MRI or CT scans, to identify structural abnormalities, vascular issues, or patterns of brain atrophy characteristic of specific dementias
• Blood biomarker tests, such as those detecting amyloid pathology, which have been shown to have acceptable performance and are recommended for clinical use by the Global CEO Initiative on Alzheimer's Disease 1
• In some cases, more specialized tests like PET scans may be used to detect abnormal protein deposits in the brain
• Lumbar puncture might be recommended to analyze cerebrospinal fluid for biomarkers of Alzheimer's disease or other conditions
• Genetic testing may be particularly relevant for early onset cases, as some forms have strong genetic components The diagnostic process typically involves multiple healthcare professionals, including neurologists, psychiatrists, and neuropsychologists, working together to establish an accurate diagnosis and rule out other conditions that might mimic dementia symptoms. Early diagnosis is crucial as it allows for appropriate treatment planning, access to support services, and participation in clinical trials when appropriate, and may involve the use of disease-modifying treatments, such as amyloid-β antibodies, which have been shown to be effective in early symptomatic AD 1. It is also important to note that the concept of preclinical AD and the role of biomarkers in the detection and tracking of this stage of the disease have important implications for the development of effective treatments, and that researchers are working to establish a link between biomarker effects and the onset of clinical symptoms of AD 1.

From the Research

Steps to Diagnose Early Onset Dementia

To diagnose early onset dementia, the following steps can be taken:

• A two-step process for the assessment of dementia can be used, which includes a screening performed by a family physician and a diagnostic procedure performed by specialists 2
• The screening can consist of taking a medical history, gathering information from relatives and friends of the patient, and administering the combined Mini-Mental State Examination (MMSE) and Clock Drawing Test (CDT) 2
• Specialists can examine patients with suspected dementia to confirm the diagnosis of dementia and provide recommendations for treatment 2
• The diagnosis can also involve neurological and psychiatric examinations, imaging (computer-assisted tomography [CT], magnetic resonance imaging [MRI]), and laboratory work-up 2
• The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) core neuropsychological battery can be used as a minimal data set that is internationally compatible 2
• The Nurses' Observation Scale for Geriatric Patients (NOSGER) can be used as a standard tool for functional assessment 2

Cognitive Tests for Detecting Dementia

Several cognitive tests can be used to detect dementia, including:

• The Mini-Mental State Examination (MMSE) 3
• The Mini-Cog test 3
• The Addenbrooke's Cognitive Examination-Revised (ACE-R) 3
• The Montreal Cognitive Assessment 3
• These tests have been shown to have good diagnostic performance for detecting dementia, with sensitivities and specificities ranging from 0.81 to 0.92 and 0.86 to 0.89, respectively 3

Diagnostic Approach

A practical diagnostic approach can be used to diagnose dementia, which includes:

• A two-step investigation procedure, with the first step including basic blood tests and brain neuroimaging, and the second step including specific second-line investigation based on the results of the first step 4
• The use of a diagnostic flow-chart to help clinicians through the differential diagnosis of dementia 4
• The consideration of metabolic, infectious, autoimmune, inflammatory, and genetic dementias, which can represent a significant number of disorders, especially in younger subjects 4

Role of MMSE in Diagnosing Dementia

The Mini-Mental State Examination (MMSE) can be used to diagnose dementia, but its accuracy can vary:

• The MMSE has been shown to have a sensitivity of 23% to 76% and a specificity of 40% to 94% for converting from mild cognitive impairment (MCI) to dementia 5
• The MMSE may not be sufficient as a stand-alone test for diagnosing dementia, and additional tests may be needed to confirm the diagnosis 5
• The use of MMSE changes over time, rather than single measurements, may be more successful in predicting conversion from MCI to dementia 5

New Developments in Diagnosing Dementia

New developments in diagnosing dementia include:

• The use of simple screening tests such as the mini mental state examination, clock drawing tests, and DemTect to detect early clinical manifestations of a dementing illness 6
• The use of biomarkers such as Abeta-peptide and (phospho-)tau in the cerebrospinal fluid to suggest the presence of Alzheimer's disease 6
• The use of new types of morphological magnetic resonance imaging (MRI) and automated analysis of the images obtained to improve the consistency of radiological assessment 6