🩺 Cognitive Decline

Cognitive decline in the UK is an increasingly common presentation due to an ageing population, often presenting as concerns about memory forgetfulness. While some decline is part of normal ageing, persistent and progressive impairment in multiple domains (memory, executive function, language, visuospatial skills) suggests dementia. Social and legal implications are profound, involving fitness to drive (DVLA notification), capacity to make decisions, and the need for long-term care planning. NICE recommends a person-centred approach including environmental modifications and, in specific cases, acetylcholinesterase inhibitors.

The history must differentiate between a gradual, insidious onset (Alzheimer's) and a step-wise progression (Vascular dementia). It is essential to obtain a collateral history from a relative to establish the impact on activities of daily living (ADLs), such as managing finances, cooking, and self-care. Enquire about personality changes, disinhibition, wandering, and 'sundowning'. A detailed medication review is needed to identify anticholinergic drugs that might worsen cognitive impairment.

The examination begins with a formal cognitive assessment using validated tools such as the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), or the Addenbrooke’s Cognitive Examination (ACE-III). A full neurological exam is necessary to look for focal signs (suggesting vascular dementia or tumours), Parkinsonian features (suggesting DLB or Parkinson's dementia), or gait abnormalities (Normal Pressure Hydrocephalus). General examination should look for signs of nutritional deficiencies or cardiovascular disease.

Alzheimer’s disease, Vascular dementia, Dementia with Lewy Bodies (DLB), Frontotemporal dementia (FTD), Depression (pseudo-dementia), Normal Pressure Hydrocephalus.

Rapidly progressive cognitive decline (over weeks or months - consider CJD or malignancy). Focal neurological deficits. Visual hallucinations or fluctuating consciousness (suggests DLB or delirium). New-onset seizures. Early-onset decline (under 65 years). Significant gait disturbance and urinary incontinence (NPH triad).

The 'Dementia Screen' blood tests include FBC, ESR/CRP, U&Es, LFTs, Calcium, Glucose, TFTs, B12, and Folate to exclude reversible causes. Syphilis and HIV testing may be indicated in high-risk groups. Structural imaging (CT or MRI head) is recommended by NICE to exclude space-occupying lesions and to identify patterns of atrophy (e.g., hippocampal atrophy in Alzheimer's or frontal/temporal lobe atrophy). Functional imaging like SPECT or PET may be used in specialist settings to differentiate subtypes.

Dementia is a clinical diagnosis; neuroimaging is mostly used to differentiate subtypes rather than 'confirm' dementia itself. Always screen for depression (the 'pseudo-dementia' mimic) and delirium, as both are reversible. In Alzheimer's, memory for recent events is lost first, whereas personality and social skills are often preserved until later. Patients with Lewy Body Dementia are extremely sensitive to the extrapyramidal side effects of antipsychotic medications, which should ideally be avoided.

Matches the 'Neurology' and 'Mental Health' modules. Understanding the legal aspects, such as Lasting Power of Attorney (LPA) and the Mental Capacity Act (MCA) 2005, is high-yield for exams. Focus on the UK requirement for a 'Dols' (Deprivation of Liberty Safeguards) assessment if a patient lacks capacity and is being restricted in a care setting.