Memory for Faces in Essential Tremor

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Memory for Faces in Essential Tremor Abstract Introduction: Historically, essential tremor (ET) has been conceptualized as kinetic tremor without any other neurologic signs or symptoms. However, the difficulties of individuals with ET apparently transcend the motor domain and implicate cognition. One interesting finding is that individuals with ET exhibit poor immediate recognition of faces similar to that seen in Parkinson’s disease (PD). This deficit could reflect a deficit in visual memory, but it might also be related to poor visual attention, visuoperception, processing speed, and nonverbal reasoning. The purpose of the current study was to determine the neurocognitive correlates of facial recognition in an ET sample to shed light on which elements of cognition might contribute to this deficit. Analyses were repeated on a sample of individuals with PD and normal controls for comparison.

Methods: The ET group consisted of 24 individuals evaluated at a movement disorders neurosurgical service. Patients with PD were selected from the same clinic and individually matched with each ET patient based on age, education, gender, and presence or absence of a depression diagnosis. Twenty-one healthy adults similar in age, and gender ratio but slightly more educated were recruited from the community. Participants were administered neuropsychological measures of visual attention (Spatial Span), visuoperception (Block Design), processing speed (Symbol Search), nonverbal reasoning (Matrix Reasoning), and immediate facial recognition memory (Faces I). Pearson correlation coefficients were calculated to determine the linear relationship between facial recognition and the other cognitive measures for each group.

Results: In the ET group, Faces I significantly correlated with only Symbol Search, r = .43, p = .018. In the PD group, Faces I significantly correlated with Spatial Span r = .36, p = .047, and Matrix Reasoning, r = .46, p = .014. In the control group, Faces I did not significantly correlate with any of the other cognitive variables, but the correlation with Spatial Span approached significance, r = .36, p = .054.

Discussion: Our results indicate that immediate recognition memory of faces is related to processing speed in ET but not PD or similar but healthy adults, and suggest that deficient recognition of faces in ET may be due to slowed processing speed. This seems reasonable since the stimuli are only presented for a few seconds in the memory task used and because processing speed deficits have been observed in ET.