Lesser-Known Types of Dementia

Continuing my series on insights from my doctoral research, which focused on personalizing learning for care partners of people living with dementia, I’m highlighting more lesser-known types of dementia that families and caregivers may not be aware of.

In Part 1, I talked about Traumatic Brain Injury (TBI) and Wernicke-Korsakoff Syndrome. Still, there are even more causes of dementia that are just as life-altering and often misunderstood or misdiagnosed. Here’s a high-level overview of a further five lesser-known causes of dementia to help care partners better understand the spectrum of needs they may encounter:

🔹 LATE (Limbic-Predominant Age-Related TDP-43 Encephalopathy)
A recently recognized condition that can look a lot like Alzheimer’s, especially in adults over 80, but involves a different protein (TDP-43). Early changes often center on memory and language, and standard Alzheimer’s biomarker tests may be negative. (Care partner note: if symptoms look “Alzheimer’s-like” but testing doesn’t align, ask clinicians whether LATE is being considered.)

🔹 Posterior Cortical Atrophy (PCA)
Often linked to Alzheimer’s pathology, PCA begins with visual processing problems rather than memory loss; difficulty reading, judging distance, or recognizing objects are common early signs. People may seem “clumsy” or avoid driving because the world suddenly feels hard to navigate. (Care partner note: lighting, large labels, high-contrast cues, and simplified spaces in the home environment can make a big difference.)

🔹 CADASIL (a genetic small-vessel disease)
An inherited condition (NOTCH3 gene) that can cause migraines with aura, early strokes, mood changes, and cognitive decline that may resemble vascular dementia, even without typical risk factors. (Care partner note: a family pattern of early stroke plus migraines is a red flag; discuss genetic evaluation and proactive vascular risk management with your primary care provider.)

🔹 Hashimoto’s Encephalopathy (SREAT)
A rare autoimmune brain inflammation associated with thyroid antibodies that can mimic rapidly progressive dementia and may improve with appropriate treatment. People can show fluctuating confusion, attention problems, tremor, or seizures. (Care partner note: in sudden or rapidly worsening cognitive changes, ask whether reversible autoimmune causes have been ruled out in sudden or rapidly worsening cognitive changes.)

🔹 Niemann–Pick Disease Type C (adult-onset)
A rare lipid-storage disorder that can present in adulthood with executive dysfunction, psychiatric symptoms, balance/coordination issues, and a characteristic difficulty moving the eyes up and down (vertical gaze palsy). (Care partner note: when cognition changes occur alongside unusual neurological signs, specialist evaluation can help identify targeted next steps.)

🧠 Why This Matters:
These diagnoses may not be as common, but they are no less profound for the individuals and families experiencing them. Understanding the cause of cognitive changes is essential for caregivers to avoid inappropriate treatment or stigma, and to increase compassion and flexibility in interpreting symptoms.

As with all forms of dementia, knowledge is power. And personalized learning, tailored to the specific diagnosis, is a critical tool for anyone navigating life as a caregiver.

Medical disclaimer: This article is for educational purposes only. It is not medical advice and does not replace care from your clinician. If you have a medical concern, contact your healthcare professional. If this is an emergency, call 911 (or your local emergency number).