The Impact of PBA on your Patients
is Substantial1
is Substantial1

Pseudobulbar affect (PBA) is not to be taken lightly. The uncontrolled laughing and/or crying episodes have a substantial impact—resulting in embarrassment for the patient and family. Because of the fear of having a PBA episode in public, patients may restrict their social interactions.
Patients with neurologic conditions including but not limited to stroke, dementia, traumatic brain injury (TBI), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), or multiple sclerosis (MS) may also be struggling with involuntary, sudden, frequent episodes of laughing and/or crying—treatable symptoms suggestive of PBA.

Patients describe PBA in their own words
These short videos of real patients discussing PBA with an interviewer shed light on how PBA affects everyday life.
PBA symptoms are prevalent in patients with various underlying neurologic conditions
37% OF PATIENTS
The prevalence of PBA in the US is approximately 2 million among patients with underlying conditions. In a multicenter registry (N=5290), a CNS-LS score ≥13, suggesting the presence of PBA symptoms, was reported in 37% of patients with any 1 of 6 neurologic conditions.3,4
Presence of PBA symptoms in select neurologic conditions4,a
Neurologic Condition (n, mean age of patients) |
CNS-LS ≥ 13
|
CNS-LS ≥ 21
|
Mean years from primary condition diagnosis to study enrollment
|
---|---|---|---|
Traumatic brain injury (n=590, 46 yrs) |
52%
|
16%
|
10.3 (n=347)
|
Multiple sclerosis (n=1215, 49 yrs) |
46%
|
12%
|
9.9 (n=785)
|
Amyotrophic lateral sclerosis (n=125, 60 yrs) |
45%
|
12%
|
2.3 (n=108)
|
Stroke (n=757, 68 yrs) |
38%
|
9%
|
4.6 (n=395)
|
Alzheimer's disease (n=1799, 79 yrs) |
29%
|
7%
|
3.7 (n=656)
|
Parkinson's disease (n=804, 73 yrs) |
26%
|
6%
|
5.3 (n=386)
|
aCenter for Neurologic Study-Lability Scale (CNS-LS) is a 7-item self-report rating scale that measures perceived frequency and control over laughing and/or crying episodes. It was validated as a PBA screening tool in ALS and MS populations. The presence of PBA symptoms (uncontrollable episodes of laughing and/or crying) was defined as a CNS-LS score ≥13. Higher CNS-LS scores are indicative of more frequent uncontrollable laughing episodes or both laughing and crying episodes. This scale does not confer a PBA diagnosis.4,6-8
PBA and the Brain
Neural damage can affect control over emotional expression9
PBA may involve a disruption of certain neurotransmitter functions1
Glutamate is thought to be one of the major neurotransmitters involved in PBA. N-methyl-D-aspartate (NMDA) is one of the main neurotransmitter receptors for glutamate.1 Glutamate receptors, including NMDA, exist throughout the brain and are also found in the neural network where PBA is thought to arise.1,11 Dextromethorphan (DM) is a sigma-1 receptor agonist and an uncompetitive NMDA receptor antagonist.2

Normal Glutamate Signaling
Glutamate receptors, such as NMDA, are responsible for facilitating many neurologic functions, including emotional expression.9,12 Glutamate exerts its signaling function by binding to and activating receptor proteins.11

Abnormal Glutamate Signaling
In a variety of neurologic conditions and brain injuries, including stroke and various neurodegenerative disorders, excess glutamate and excessive activation of glutamate receptors may lead to abnormal neurotransmission and cell dysfunction.11,12