Pseudobulbar affect: prevalence and quality of life impact in movement disorders

Pseudobulbar affect (PBA) is an affective disinhibition syndrome characterized by sudden, involuntary outbursts of inappropriate crying or laughing. We have previously reported the prevalence of PBA in movement disorders using an interviewer-administered questionnaire that had not been validated. In the current study, a validated self-administered screening instrument, the Center for Neurologic Study-Lability Scale (CNS-LS), was used to study the prevalence of PBA, its association with mood symptoms, and the quality of life impact. Two hundred sixty-nine patients met inclusion criteria (consent, age > 18 years, formal diagnosis, and completion of the CNS-LS). The CNS-LS was used to assess PBA at a cutoff score of 17 (utilized from multiple sclerosis studies). The Beck Depression Inventory (BDI) scale and Parkinson's disease questionnaire (PDQ-39) were used to assess depressive symptoms and quality of life. Logistic regression analysis was used to predict associations with PBA. PBA was prevalent in 7.1% (n = 19) of movement disorder patients. No significant difference in prevalence was observed by patient diagnosis: 7.1% (12/168) in Parkinson's disease (PD), 11.4% (4/35) in essential tremor, 0% (0/13) in dystonia, 0% (0/16) in psychogenic movement disorders, and 10.7% (3/28) in patients with other movement disorders. Patients with PBA had higher BDI depression scores (p < 0.0001) and lower PDQ-39 emotional well-being subscores (p < 0.0001). Patients taking antidepressant medications had significantly higher rates of PBA (p = 0.0008). The prevalence of PBA symptoms was 7.1% in PD and all movement disorders patients. Patients with PBA tend to have more depressive symptoms and poorer quality of life.