# Late-Onset Huntington’s Disease: A Case Report and Literature Review

## TL;DR

This paper reports a rare case of Huntington’s disease diagnosed in an 80-year-old man, emphasizing the importance of considering the disease in late-onset neurological symptoms.

## Contribution

The novelty lies in presenting a confirmed case of late-onset Huntington’s disease without family history, aiding in diagnostic awareness.

## Key findings

- An 80-year-old man with late-onset chorea and cognitive decline was diagnosed with Huntington’s disease via genetic testing.
- Neuroimaging showed ischemic leukoencephalopathy, complicating the diagnosis of late-onset Huntington’s disease.
- The case underscores the need to consider HD in differential diagnoses of late-onset neurological symptoms.

## Abstract

Huntington’s disease (HD) is a rare autosomal dominant neurodegenerative disorder caused by expansion of the cytosine-adenine-guanine (CAG) trinucleotide repeat in the huntingtin (HTT) gene. Although the disease typically presents in mid-adulthood, symptom onset after the age of 60, defined as late-onset Huntington’s disease (LoHD), remains uncommon and may pose diagnostic challenges. We report the case of an 80-year-old man admitted for evaluation of progressive unintentional weight loss, whose clinical assessment revealed generalized chorea and progressive cognitive decline. Genetic testing identified an expanded CAG allele with 39 repeats, confirming the diagnosis of LoHD. Neuroimaging revealed ischemic leukoencephalopathy consistent with cerebral small vessel disease (CSVD), contributing to diagnostic complexity. This case highlights the importance of considering Huntington’s disease in the differential diagnosis of late-onset chorea and cognitive impairment, even in the absence of a known family history.