PRISM: a novel research tool to assess the prevalence of pseudobulbar affect symptoms across neurological conditions.

BACKGROUND: Pseudobulbar affect (PBA) is a neurological condition characterized by involuntary, sudden, and frequent episodes of laughing and/or crying, which can be socially disabling. Although PBA occurs secondary to many neurological conditions, with an estimated United States (US) prevalence of up to 2 million persons, it is thought to be under-recognized and undertreated. The PBA Registry Series (PRISM) was established to provide additional PBA symptom prevalence data in a large, representative US sample of patients with neurological conditions known to be associated with PBA. METHODS: Participating clinicians were asked to enroll ≥20 consenting patients with any of 6 conditions: Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), Parkinson's disease (PD), stroke, or traumatic brain injury (TBI). Patients (or their caregivers) completed the Center for Neurologic Study-Lability Scale (CNS-LS) and an 11-point scale measuring impact of the neurological condition on the patient's quality of life (QOL). Presence of PBA symptoms was defined as a CNS-LS score ≥13. Demographic data and current use of antidepressant or antipsychotic medications were also recorded. RESULTS: PRISM enrolled 5290 patients. More than one third of patients (n = 1944; 36.7%) had a CNS-LS score ≥13, suggesting PBA symptoms. The mean (SD) score measuring impact of neurological condition on QOL was significantly higher (worse) in patients with CNS-LS ≥13 vs <13 (6.7 [2.5] vs. 4.7 [3.1], respectively; P<0.0001 two-sample t-test). A greater percentage of patients with CNS-LS ≥13 versus <13 were using antidepressant/antipsychotic medications (53.0% vs 35.4%, respectively; P<0.0001, chi-square test). CONCLUSIONS: Data from PRISM, the largest clinic-based study to assess PBA symptom prevalence, showed that PBA symptoms were common among patients with diverse neurological conditions. Higher CNS-LS scores were associated with impaired QOL and greater use of antipsychotic/antidepressant medications. These data underscore a need for greater awareness, recognition, and diagnosis of PBA.

Pseudobulbar affect: an under-recognized and under-treated neurological disorder.

INTRODUCTION: Pseudobulbar affect (PBA) is a neurologic syndrome of emotional affect disinhibition, characterized by uncontrollable, exaggerated, and often inappropriate emotional outbursts, which may cause severe distress, embarrassment, and social dysfunction. However, the US prevalence of PBA remains unknown. METHODS: An online survey was conducted primarily to estimate the US prevalence of PBA in patients with the six most commonly associated conditions: Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, Parkinson's disease, stroke, and traumatic brain injury. Invitations to participate were randomly sent online to adults (aged ≥ 18 years) registered in the Harris Poll Online Panel who were patients or belonged to a household with a patient diagnosed with one of the six conditions (identified through previous screening by Harris Interactive). Participants were screened for PBA using the Pathological Laughing and Crying Scale (PLACS) and the Center for Neurologic Study-Lability Scale (CNS-LS). PBA estimates were made using a cut-off score of ≥ 13 on the PLACS and two different cut-off thresholds on the CNS-LS, a lower one of ≥ 13 and a more rigorous one of ≥ 21. Existing US prevalence data for the six underlying conditions were used to estimate US prevalence of PBA. RESULTS: Of 38,000 individuals invited to participate, 8876 responded (23%) and 2318 (26%) completed the questionnaire. Mean prevalence of PBA across all six conditions was 10.1%, 9.4%, and 37.5% with the PLACS ≥ 13, CNS-LS ≥ 21, and CNS-LS ≥ 13 thresholds, respectively. Using disease population estimates from government agencies and professional organizations, the estimated US population with PBA ranged from 1.8 to 7.1 million. Among patients who discussed their laughing and/or crying episodes with a physician, 41% were diagnosed, and about half received a medication for their episodes. CONCLUSIONS: The overall prevalence of PBA was estimated to be about 10% across these commonly associated underlying neurological conditions and appears to be under-recognized.