Case 27: A woman who mistakes her reflection for her mother

01The case

A 68-year-old woman is brought to the clinic by her relatives. For the past few months she has repeatedly lost her way in her own neighbourhood. Left alone at home, she has often left the iron on and scorched clothes with it. Recently she did not recognise her grandson, who visits at weekends, and when she saw her reflection in the mirror she said it was her mother.

02Summary

Diagnosis

Dementia in Alzheimer's disease.

What points to it

• Memory loss with changes in behaviour, coming on gradually over months.
• Getting lost in a familiar place: impaired visuospatial skills.
• Failing to recognise familiar faces, and her own reflection, which she takes for someone else (the mirror sign). These point to spreading damage in the temporal and parietal cortex, and the original summary takes them to favour Alzheimer's disease over other dementias.
• Her age, and a slow, steady course.

What else it could be

Vascular dementia (stepwise course, vascular risk factors, focal signs), Lewy body dementia (fluctuations, vivid visual hallucinations, parkinsonism), frontotemporal dementia (personality and behaviour change first, often younger), depression, and reversible causes such as thyroid disease or low vitamin B12. A delirium laid on top must be excluded.

Management

• Assessment: history from the family, physical examination, cognitive testing (such as MMSE or MoCA), blood tests for reversible causes, and brain imaging.
• A care plan for supervision, safety (the iron, the cooker, going out alone), hygiene and the control of other illnesses.
• A cholinesterase inhibitor (donepezil, rivastigmine or galantamine) for mild to moderate disease, and memantine for severe disease, or for moderate disease when a cholinesterase inhibitor is not tolerated or not suitable.
• Behavioural problems: look for pain, infection or distress first, then non-drug approaches. Antipsychotics only for severe distress or danger, at the lowest dose for the shortest time.
• Support for the family, and early planning while she can take part: legal arrangements, care at home and later.

Outlook

Dementia in Alzheimer's disease is progressive: global decline over years, to full dependence. Drugs ease symptoms for a time but do not stop the disease.