People living with Alzheimer’s disease frequently have additional neurodegenerative conditions, one of which is the less well-understood frontotemporal lobar degeneration (FTLD). Traditionally, FTLD could only be definitively identified through post-mortem examination. However, emerging research suggests that clinicians may be able to recognise individuals affected by both Alzheimer’s disease and FTLD during life by carefully assessing patterns of neuropsychiatric symptoms.
A study published in Neurology found that individuals with both conditions are more likely to exhibit a broader and more pronounced range of neuropsychiatric symptoms compared with those who have either Alzheimer’s disease or FTLD alone. In other words, the coexistence of these disorders appears to shape a distinct clinical profile that reflects features of both conditions.
These findings carry important implications for patients and their care partners. Individuals affected by both Alzheimer’s disease and FTLD may experience a more complex progression of illness, potentially including a faster decline or different responses to available treatments. Recognising this overlap earlier could therefore support more tailored care planning and better preparation for the challenges ahead.
Lead author Daliah Ross, a postdoctoral fellow in clinical neuropsychology at Brown University Warren Alpert Medical School, noted that the presence of both pathologies is associated with distinct neuropsychiatric patterns. These differences may help guide both diagnosis and treatment strategies. She emphasised that such symptoms can significantly affect the quality of life for patients and their families, as well as the level of support and resources required.
Ross has long focused on improving how neurodegenerative conditions are understood and diagnosed. Through her review of research on neuropathology and clinical presentation, she observed that many individuals with neurodegenerative disease have more than one underlying condition. Despite this, research and clinical approaches have often treated disorders like Alzheimer’s disease in isolation, which does not reflect the reality of many patients’ experiences.
In the case of FTLD, symptoms such as disinhibition and marked personality changes are not typically associated with Alzheimer’s disease, making the overlap between the two conditions particularly complex. To explore this further, researchers analysed data from 29 Alzheimer’s Disease Research Centres funded by the National Institutes of Health, examining 919 individuals whose diagnoses were confirmed at autopsy and who had intermediate to high levels of Alzheimer’s disease and/or FTLD pathology.
The analysis revealed clear differences in symptom patterns. Compared with individuals who had FTLD alone, those with both Alzheimer’s disease and FTLD were more likely to have experienced anxiety, delusions, and irritability before death. Conversely, compared with those who had only Alzheimer’s disease, the combined group showed higher rates of personality change and disinhibition. Co-author Edward Huey noted that while treatments exist for Alzheimer’s disease, none currently modify FTLD, underscoring the importance of improved diagnosis and the need for further research into mixed forms of dementia.
More information: Daliah Ross et al, Neuropsychiatric Symptoms in Patients With Pathologically Confirmed Comorbid Alzheimer Disease and Frontotemporal Lobar Degeneration, Neurology. DOI: 10.1212/WNL.0000000000214750
Journal information: Neurology Provided by Brown University
