Summary: Beyond Alzheimer's

For two years, they treated him for Alzheimer’s disease. The diagnosis had seemed straightforward: seventy-one, retired, forgetting things. But he was not just forgetful. He was seeing people who were not there. His cognition fluctuated wildly. When they gave him an antipsychotic for the hallucinations, he became rigid, nearly catatonic. A second opinion changed the diagnosis to Lewy body dementia. The two years of wrong treatment could not be undone.

Alzheimer’s accounts for 60 to 80 percent of dementia cases. The remaining conditions are not footnotes. They have distinct characters, distinct progressions, and distinct treatment considerations. Getting the diagnosis wrong has consequences.

Vascular dementia, the second most common form, is caused by impaired blood flow to the brain and often affects executive function early rather than memory. Its risk factors overlap with cardiovascular disease, making it among the most preventable forms of cognitive decline. Lewy body dementia, the third most common, involves visual hallucinations, fluctuating cognition, and motor symptoms resembling Parkinson’s. People with Lewy body dementia have severe sensitivity to many antipsychotic drugs, a risk that is significant and known yet medications are often prescribed before the correct diagnosis is made. Frontotemporal dementia attacks personality, behavior, and language rather than memory, typically strikes between ages forty-five and sixty-five, and has no approved disease-modifying therapy.

In older adults, mixed pathologies are the norm. A brain may contain amyloid plaques alongside vascular damage, Lewy bodies, and TDP-43 deposits. LATE, identified as distinct only in 2019, mimics Alzheimer’s clinically but involves different pathology. Mixed pathology complicates treatment: clearing amyloid may help one component while leaving others untouched.

If you or someone you love has received a dementia diagnosis, the first question to ask is: what type? The type determines medication choices, including which medications to avoid. It shapes expectations about progression. It affects eligibility for new treatments and clinical trials. Ask what evidence supports the diagnosis. Ask whether a second opinion would add value. If the diagnosis is Lewy body dementia, make certain every provider knows to avoid certain antipsychotics. The risk is real.