Diagnosis and Treatment of Pseudobulbar Affect in MS

Outbursts of Crying and Laughter as a Symptom of MS

Woman laughing in restaurant
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Pseudobulbar affect, or PBA, is a syndrome characterized by outbursts of crying or laughter, which are inappropriate or exaggerated within the person's social setting. This syndrome can significantly affect a person and their loved one's quality of life, causing feelings of anxiety, embarrassment, and social isolation. 

The good news is that this disorder is becoming more widely recognized, and there is effective treatment available. 

Who is Affected by PBA?

Besides MS, there are a number of other neurological disorders associated with the development of pseudobulbar affect. These include:

  • Alzheimer's disease
  • Traumatic brain injury
  • Stroke
  • Brain Tumor
  • Amyotrophic lateral sclerosis (ALS)
  • Parkinson's disease

For people with MS, PBA tends to affect those in the later stages, meaning people who have had several MS relapses or have a progressive, disabling disease course.

What are Other Terms Used to Describe PBA?

The variability of terms used to describe this syndrome has created some confusion among people who suffer from it, as well as within the medical field. Some others terms used to describe pseudobulbar affect include:

  • involuntary emotional expression disorder
  • emotional lability or dysregulation or incontinence
  • pathological laughing and crying
  • emotionalism

What Causes PBA?

Scientists believe that people with pseudobulbar affect have disrupted nerve signaling withing their cerebellum. While we know that the cerebellum controls coordination and how the body moves, scientists believe that it may also help control the body's expression of emotion based on input from other parts of the brain. While the precise involvement of the cerebellum in pseudobulbar affect is unclear, the main neurotransmitters believed to play a vital role in PBA are serotonin and glutamate. 

Differentiating Between PBA and Depression in MS

Pseudobulbar affect can be missed by doctors because they attribute the crying episodes to depression, which is common in multiple sclerosis. But there are some key differences that can help distinguish between these two conditions.

One key difference is that in depression, an episode of crying coincides with a low mood. In pseudobulbar affect though, a person's episode of crying is inconsistent, exaggerated, or even contradictory with how they really feel. Also, in pseudobulbar affect, a person can switch from crying to laughing within a single outburst.

Another clue is duration. The outbursts of pseudobulbar of crying, or laughing, tend to come on abruptly and end abruptly, lasting seconds to minutes. An episode of depression, on the other hand, lasts at least two weeks. In addition, depression is associated with other symptoms like a change in sleep habits and appetite, feelings of guilt, and a loss of interest in activities.

How Will My Doctor Treat my PBA?

If your doctor diagnoses you with PBA, you may be prescribed an antidepressant, like:

  • tricyclic antidepressants, like Elavil (amitriptyline) or nortriptyline
  • selective serotonin reuptake inhibitors (SSRIs), like Celexa (citalopram)

More likely, you may be prescribed Nuedexta (dextromethorphan hydrobromide/quinidine sulfate), which was approved by the FDA in 2010 for the treatment of PBA. In scientific studies, it has shown to be effective for alleviating symptoms of PBA in patients with MS, in addition to patients with ALS.

Potential side effects of Nuedexta

  • diarrhea
  • dizziness
  • cough
  • vomiting
  • weakness
  • swelling
  • urinary tract infections
  • influenza
  • flatulence

While taking this medication, follow-up is important, especially for monitoring of potassium and magnesium levels in the body, which can be reduced with Nuedexta. More monitoring may be needed for people who are at risk for certain rhythm disturbances of the heart. 

Telling Others About Your PBA

Just like forgetting where you left your sunglasses, taking a little longer to walk (or roll) to your destination, or not being able to see as well as you used to, PBA is a symptom of MS. Just like any symptom, you may need to explain a little bit about PBA to your loved ones or people that you work with — if you choose. 

One tip is to prepare a little speech about PBA explaining what it is, and how it relates to your MS. This way, when you do find yourself laughing or crying, you will have something ready to say that is not clouded by embarrassment, frustration or anger. This can greatly reduce stress.

DISCLAIMER: The information in this site is for educational purposes only. It should not be used as a substitute for personal care by a licensed physician. Please see your doctor for diagnosis and treatment of any concerning symptoms or medical condition. 

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Article Sources
  • Ahmed A & Simmons Z. Pseudobulbar affect: prevalence and management. Ther Clin Risk Manag. 2013;9:483-89. 
  • Cruz MP. Nuedexta for the Treatment of Pseudobulbar Affect. A Condition of Involuntary Crying or Laughing. PT. 2013 Jun;38(6):325-28. 
  • Cummings J et al. Defining and diagnosing involuntary emotional expression disorder. CNS Spectr. 2006 Jun;11(6):1-7.