“Pseudobulbar affect is a syndrome of emotion that comprises disinhibition, characterised by uncontrollable, exaggerated, and often inappropriate emotional outbursts, which may cause severe distress, embarrassment, and social dysfunction. MS is a common cause of a pseudobulbar affect and typically occurs in MSers with progressive disease that are disabled. The presence of pseudobulbar affect occurs when MS lesions involve the frontal lobes or a region in the brain stem called the pons. In a large online survey ~10% of MSers had pseudobulbar affect; this high figure indicates that the condition is under-recognised. This is important as there are effective treatments that can reduce the frequency and intensity of these emotional outbursts. If this affects you and has not been recognised, you may want to bring it to the attention of your neurologist or specialist nurse.”
METHODS: An online survey was conducted to estimate the prevalence of PBA in the six most commonly associated conditions: Alzheimer’s disease, amyotrophic lateral sclerosis, multiple sclerosis, Parkinson’s disease, stroke, and traumatic brain injury. 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.
“Since this study was published a new drug called Nuedexta, which is a combination of dextromethorphan and quinidine has been approved in the US and has been given provisional approval in the EU. Whether or not we will be allowed to prescribe Nuedexta in the UK will be another story. PBA is known to respond to tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs); I assume NICE will want to see comparative cost-effectiveness data before green-lighting Nuedexta. In other words Nuedexta is going to have to be cost-effective; this is a high bar for symptomatic therapies, which is why we are unable to prescribe fampridine and Sativex to our MSers at Barts Health.”
“To get a handle on PBA will you be willing to complete this short questionnaire? Thanks.”
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