Gambling associated risk-taking decision in cerebellar ataxia

Abstract

Introduction: People with cerebellar ataxia (CA) can develop impulsive and compulsive behaviors that significantly affect their and their family's quality of life. To further assess the decision-making process associated with these behaviors, we used the Iowa Gambling Task (IGT) to study people with CA.

Methods: Sixty individuals with CA and thirty age-matched controls were enrolled in the study to complete the IGT. No participants had a prior or comorbid neurologic or psychiatric disorder associated with impulsivity. IGT performance in each of the five 20-trial blocks was compared between groups and the progression of participants' performance was assessed with simple linear regression models. Subgroup analyses were performed with genetic and non-genetic CA cases.

Results: CA cases obtained significantly lower IGT total scores than controls (-5.30 ± 37.53 vs. 21.30 ± 37.37, p = 0.004). In addition, those with CA made riskier decisions throughout the task compared to controls. Although both CA and controls learned to make decisions with more favorable outcomes over the course of completing the IGT, CA participants never matched the controls' performance. IGT performance did not correlate with ataxia severity or depressive symptoms.

Conclusion: The IGT may capture a unique behavioral symptom of CA. Future studies may help elucidate the mechanisms underlying impaired decision-making in CA and further the understanding of a broader spectrum of cerebellar cognitive affective syndrome.

Keywords: Cerebellar ataxia; Cerebellum; Decision making; Gambling; Impulsivity; Risk taking.

Figure 1.. Decision-making in cerebellar ataxia:

Mean ± SEM of the number of selections from the advantageous decks (C+D) minus the number of selections from the disadvantageous decks (A+B) over the course of five 20-trial blocks. Learning curves calculated through linear regression models. *p < 0.05, **p < 0.01

Figure 2.. Comparison between genetic and non-genetic ataxia:

(A) IGT total scores in controls, participants with genetic CA, and participants with non-genetic CA. (B) Mean ± SEM of IGT scores throughout the five 20-trial blocks in controls, participants with genetic CA, and participants with non-genetic CA. Learning curves calculated through linear regression models. *p < 0.05, ns: not significant.

Figure 3.. Correlation with motor and non-motor symptoms of cerebellar ataxia:

(A) The correlation between patients’ IGT total scores and their SARA scores. (B) The correlation between patients’ IGT total scores and their PHQ-9 scores.