Neuropathologic Changes in People With Essential Tremor With Dementia: A Postmortem Study

Area of Science:

• Neuropathology
• Neurodegenerative Diseases
• Cognitive Impairment

Background:

• Essential tremor (ET) is associated with an increased risk of dementia.
• The underlying neuropathological reasons for this association are not fully understood.
• This study investigates the neuropathological features in individuals with ET and dementia.

Purpose of the Study:

• To elucidate the neuropathologic features associated with dementia in patients with essential tremor.
• To determine the extent to which Alzheimer's disease pathologies contribute to cognitive impairment in ET.

Main Methods:

• A 10-year prospective cohort study involving neuropsychological testing and cognitive diagnoses.
• Post-mortem neuropathological assessment of brains, including Braak stages, amyloid scores, and neuritic plaque scores.
• Statistical analysis to compare neuropathological findings across cognitive groups (normal cognition, MCI, dementia).

Main Results:

• Participants with ET-dementia showed significantly higher odds of severe Alzheimer's disease pathologies compared to those with normal cognition.
• Individuals with ET-mild cognitive impairment (MCI) exhibited intermediate neuropathological findings.
• Other neuropathologies were comparable across the cognitive groups.

Conclusions:

• Alzheimer's disease pathology is a primary contributor to cognitive impairment and dementia in essential tremor.
• Further research is needed to understand tau aggregation in ET and its relation to Alzheimer's disease.
• Findings suggest a potential link between ET and Alzheimer's disease, opening avenues for blood-based biomarker research.