Question 1

A 72-year-old man is brought by his wife for progressive cognitive decline over 18 months. She reports he sees "small animals running across the floor" that are not there and describes them in vivid detail. His cognition fluctuates dramatically — some days he seems nearly normal, other days he is confused and unresponsive. He has developed a shuffling gait, resting tremor, and his wife reports he thrashes violently in his sleep, once punching her in the face. In the emergency department, he becomes increasingly agitated and the resident orders haloperidol 5 mg IM. What is the most likely diagnosis, and what is the most important immediate concern?

Accepted Answer

The tetrad of visual hallucinations (well-formed, nonthreatening), fluctuating cognition, parkinsonism (shuffling gait, resting tremor), and REM sleep behavior disorder (acting out dreams) is classic Lewy body dementia. The most critical clinical concern is the haloperidol. Patients with Lewy body dementia have severe sensitivity to dopamine-blocking agents. Typical antipsychotics can trigger a neuroleptic malignant syndrome-like reaction with severe rigidity, obtundation, and death. This is not a rare side effect — it is a predictable pharmacological catastrophe. If antipsychotic treatment is absolutely necessary, low-dose quetiapine or pimavanserin are the cautious options.

Question 2

A 79-year-old woman is brought by her daughter for progressive memory loss over the past year. Before diagnosing Alzheimer's disease, you order a workup. Labs reveal a TSH of 14.2 mIU/L (normal 0.4-4.0), and B12 of 118 pg/mL (normal >200). Brain MRI shows ventriculomegaly out of proportion to cortical atrophy. On exam, she has a wide-based, shuffling gait as though her feet are "stuck to the floor," and her daughter reports recent urinary incontinence. Which of the following is the best next step?

Accepted Answer

This patient has three potentially reversible contributors to her cognitive decline: hypothyroidism (TSH 14.2), B12 deficiency (118 pg/mL), and possible normal pressure hydrocephalus (ventriculomegaly out of proportion to atrophy, magnetic gait with feet 'stuck to the floor,' and urinary incontinence — the 'wet, wacky, and wobbly' triad). All three must be addressed before attributing the cognitive decline to an irreversible neurodegenerative disease. Hypothyroidism and B12 deficiency are treated medically. NPH is evaluated with a large-volume lumbar puncture; if gait and cognition improve after the tap, the patient is a candidate for ventriculoperitoneal shunt. Starting donepezil without ruling out reversible causes is a diagnostic failure.

Question 3

A 57-year-old woman is brought by her husband who reports two years of progressive personality change. She was previously warm and socially appropriate. She now makes cruel comments to friends without remorse, eats compulsively, shoplifts impulsively, and laughs at inappropriate times. She shows no awareness that her behavior is abnormal. Her MMSE is 27/30. She recalls 3/3 words at five minutes. A 76-year-old man is referred for progressive memory loss over three years. He cannot recall recent conversations, gets lost in familiar places, and repeats questions. His personality and social behavior are unchanged. His MMSE is 18/30 and he recalls 0/3 words at five minutes. What are the most likely diagnoses?

Accepted Answer

These two patients illustrate the fundamental difference between frontotemporal and Alzheimer's presentations. Behavioral variant FTD presents younger (50s-60s), with progressive personality change as the dominant feature: disinhibition, loss of empathy, compulsive behaviors, social inappropriateness, and often hyperorality. Memory and visuospatial skills are relatively preserved early, which is why these patients are frequently misdiagnosed with psychiatric conditions for years. Alzheimer's presents older (typically >65), with memory loss as the dominant early feature and personality relatively preserved. The first patient's near-normal MMSE with devastating behavioral changes is the classic FTD trap — clinicians who equate dementia with memory loss will miss it.

Major Neurocognitive Disorder

Red Flags & Key Clinical Considerations

Rapid Cognitive Decline

New-Onset Seizures

Focal Neurological Signs

Age Under 65

Practice With Related Cases

References & Further Reading