A 74-year-old woman is brought to the clinic by her daughter because of progressive memory loss over the past year. The daughter reports that her mother often misplaces household items, forgets recent conversations, and occasionally gets lost in familiar surroundings. She has also had increasing difficulty managing her finances and preparing meals. The patient denies any hallucinations, delusions, or depressive symptoms. There is no history of seizures, head trauma, or substance use. She denies urinary incontinence. Medical history includes hypertension and hyperlipidemia. Her medications include lisinopril and atorvastatin. Family history is notable for her mother having had “senile dementia.” She is a retired schoolteacher and does not smoke cigarettes or drink alcohol. Vital signs are within normal limits. On mental status examination, she is alert but disoriented to date. She is unable to recall 3 out of 3 objects after 5 minutes, even with cues. Her speech is fluent, and there are no motor or sensory deficits. Her score on the Mini-Mental State Examination (MMSE) is 21/30, with impairments in recall and orientation.
A) Alzheimer dementia
This elderly woman presents with insidious, progressive memory impairment and difficulty performing instrumental activities of daily living (e.g., finances, cooking), which are characteristic of Alzheimer disease. Her deficits in orientation and recall, as well as her MMSE score (21/30), indicate mild-to-moderate cognitive impairment. Alzheimer disease typically begins with early anterograde memory loss, followed by impairments in executive function and language. Risk factors include advanced age, family history, and cardiovascular comorbidities.
Answer choice B: Frontotemporal dementia, is incorrect. Frontotemporal dementia often presents earlier (in the 50s–60s) and is characterized by prominent behavioral changes or language deficits (e.g., apathy, disinhibition, compulsive behaviors), with relative preservation of memory in the early stages. This patient’s presentation of early memory impairment with no personality change argues against this diagnosis.
Answer choice C: Lewy body dementia, is incorrect. Lewy body dementia is characterized by visual hallucinations, fluctuating cognition, REM sleep behavior disorder, and Parkinsonism. Although it may overlap with Alzheimer dementia, the absence of hallucinations and extrapyramidal signs makes this less likely.
Answer choice D: Normal pressure hydrocephalus, is incorrect. Normal pressure hydrocephalus presents with the classic triad of gait disturbance, urinary incontinence, and dementia (“wet, wobbly, and wacky”). This patient’s predominant symptom is memory loss, without any incontinence or mention of gait instability, making NPH unlikely.
Answer choice E: Vascular dementia, is incorrect. Vascular dementia typically follows a stepwise progression associated with cerebrovascular events and may present with focal neurologic findings. Risk factors include hypertension and stroke history. This patient has cardiac risk factors but lacks evidence of a stepwise decline or focal deficits, making Alzheimer dementia more likely.
Key Learning Point
Alzheimer dementia is the most common cause of dementia and presents with gradual, progressive memory loss, particularly affecting recent memory and executive function. Early diagnosis is based on clinical features and exclusion of other causes. Risk factors include advanced age and family history.
