Cognitive deficits in patients with essential tremor

Area of Science:

• Neuroscience
• Neurology
• Cognitive Psychology

Background:

• Essential tremor (ET) is traditionally viewed as isolated, lacking associated neurological or cognitive abnormalities.
• Emerging evidence indicates gait disturbances and bradykinesia in ET patients, suggesting broader neurological involvement.
• Cognitive functioning in ET has not been extensively investigated.

Purpose of the Study:

• To evaluate the cognitive and affective functioning in patients diagnosed with essential tremor (ET).
• To compare cognitive and affective profiles of ET patients with Parkinson's disease (PD) patients.

Main Methods:

• Neuropsychological tests assessing cognitive performance were administered to 18 ET patients and 18 PD patients.
• Mood assessments were conducted concurrently with cognitive evaluations.
• Patients were recruited from a neurosurgical clinic for symptom management.

Main Results:

• ET patients exhibited deficits in verbal fluency, naming, set-shifting, verbal memory, and working memory, alongside elevated depression levels.
• Despite specific deficits, ET patients outperformed normative samples in certain verbal and nonverbal conceptualization and reasoning tasks.
• PD patients showed impairments in similar cognitive domains as ET patients, plus visuospatial deficits; ET patients had greater verbal fluency and working memory deficits compared to PD patients.

Conclusions:

• Patients with ET demonstrate specific neuropsychological deficits, particularly in functions associated with the prefrontal cortex.
• Findings suggest the involvement of frontocerebellar circuits in the pathophysiology of essential tremor.
• Cognitive and affective assessments are crucial for a comprehensive understanding of ET's impact.