Cognitive subtypes in individuals with essential tremor seeking deep brain stimulation

Area of Science:

• Neurology
• Neuroscience
• Cognitive Science

Background:

• Essential tremor (ET) is a common neurological disorder associated with an increased risk of dementia.
• Deep brain stimulation (DBS) is a surgical intervention for advanced ET symptoms.
• Cognitive decline is a significant concern in the ET population.

Purpose of the Study:

• To identify distinct cognitive subgroups among ET patients undergoing pre-surgical evaluation for DBS.
• To determine how these empirically derived cognitive subgroups align with criteria for mild cognitive impairment (MCI).

Main Methods:

• A cohort of 201 ET patients (mean age 68.9 years) completed a comprehensive neurocognitive assessment.
• Cluster analysis (K-means, hierarchical) was used to classify cognitive patterns based on memory, executive function, visuospatial skills, language, and processing speed.
• Demographics, clinical data, and MCI criteria were analyzed across identified clusters.

Main Results:

• Three distinct cognitive subgroups were identified: Low Executive (N=64), Low Memory Multi-Domain (N=41), and Cognitively Normal (N=96).
• Overall, 27.4% of participants met criteria for MCI.
• The Low Memory Multi-Domain group exhibited the highest proportion of MCI cases (65.9%), followed by the Low Executive group (35.9%).

Conclusions:

• This study reveals three distinct cognitive subtypes in ET patients evaluated for DBS surgery.
• The Low Memory Multi-Domain subgroup appears to be at a higher risk for cognitive impairment and potential progression to dementia.
• Further research is warranted to track cognitive changes within these identified subgroups.