PRISM Registry: A Novel Tool to Assess the Prevalence of Pseudobulbar Affect Symptoms in People with Alzheimer's Disease

Pseudobulbar affect (PBA) is a neurologicalcondition characterized by uncontrollable, disruptive outbursts of laughingand/or crying; PBA occurs secondary to a variety of neurological conditions, including Alzheimer's disease (AD). However, few studies have estimated prevalence of PBAsymptoms in patients with AD, and it is thought to be under-recognized in thisand other populations. The PBA Registry Series (PRISM) was established to provide additional prevalence datafrom a “real world” clinic sample, including patients with AD. Following Institutional Review Board approval, participating sites wereasked to enroll ≥20 patients with any of 6 neurological conditions, includingAD. Patients (or their caregivers) completed the Center for NeurologicStudy-Lability Scale (CNS-LS) to screen for PBA symptoms; patients were notscreened for other psychiatric disorders. The CNS-LS is validated ascorresponding to physician diagnosis of PBA in patients with amyotrophiclateral sclerosis and multiple sclerosis at scores of ≥13 and ≥17, respectively; it has not yet been validated in patients with AD. For PRISM, presence of PBA symptomswas defined as a CNS-LS score ≥13. Additionally, patients (or their caregivers) rated the impact of their neurological condition on quality of life (QOL) usingan 11-point scale (0–10). Demographic data and current use ofantidepressant/antipsychotic medications were also recorded. PRISM enrolled 5290 participants, of whom 1799(34%) had AD as a primary neurological condition, making it the registry'slargest disease group. The mean age of patients with AD was 79.2 years (SD9.75, median 81.0), 1124 (62.5%) were female, and 527 (29.3%) had PBA symptoms (CNS-LS score ≥13). AD patients with CNS-LS ≥13 vs <13 reported greaterimpact of their neurological condition on QOL (6.4 vs 4.3; P<0.0001), and greater use of antipsychotics (8.7% vs 3.1%; P<0.0001), tricyclic (30.9% vs 15.5%;P<0.0001) and other antidepressants(38.3% vs 30.7%; P =0.002). PRISM is currently the largest clinic-based study to assess PBA symptom prevalence. PBA symptoms were common in AD and were associated with impaired QOL and greater use of antipsychotic/antidepressant medications. These data underscore a need for greater recognition and assessment of PBA in patients with AD and other at-risk neurological conditions.