Aggressive outbursts and emotional lability in a 16-year-old boy
Mr. X, age 16, is having increasingly frequent aggressive outbursts that are almost always preceded by inappropriate laughing or crying. How would you help him?
The authors’ observations
Although the exact pathophysiology of PBA is unknown, multiple theories may explain the principle elements of the condition. In the absence of a neurologic insult, the cerebellum acts as an affect regulator, inhibiting laughter and crying at times in which they are considered inappropriate. Parvizi et al4 have theorized that the lesions involved in PBA disrupt the corticopontine-cerebellar circuitry, which impedes the ability of the cerebellum to function as an affect modulator.3 In addition to the dysregulation of cerebellar circuitry, altered serotonin and glutamate levels are believed to contribute to the deficient affect regulation observed in PBA; therefore, adding dextromethorphan/quinidine potentiates serotonin and glutamate levels in the synaptic cleft, resulting in a reduction in PBA episodes.4
OUTCOME Affect stability
Seven months after beginning dextromethorphan/quinidine, Mr. X has experienced resolution of his PBA episodes. His PHQ-9 score was reduced to 0 (no clinical signs of depression) within 1 month of starting this medication and his PHQ-9 scores remain below 5, representing minimal depressive severity. The CNS-LS scale is not conducted at further visits because the patient’s mother reported no further PBA episodes. Mr. X no longer exhibits episodes of aggression. These episodes seemed to have been a manifestation of his frustration and difficulty in controlling his PBA episodes. Furthermore, his dosage of diazepam was reduced, and he was weaned off risperidone. Mr. X’s parents report that he has a drastically improved affect. He continues to tolerate his medication well and no longer demonstrates any exacerbations of his psychiatric symptoms.
Bottom Line
Pseudobulbar affect (PBA) may occur secondary to various neurologic insults, including cerebral palsy and idiopathic normal pressure hydrocephalus. The condition is diagnosed by a subjective clinical evaluation and use of the Center for Neurologic Study–Lability Scale. Dextromethorphan/quinidine can significantly reduce PBA symptoms.
Acknowledgements
The authors thank Anthony S. Graziano and Rachel M. Watt, both Physician Assistant students, Daemen College, Amherst, New York.
Related Resources
- Frock B, Williams A, Caplan JP. Pseudobulbar affect: when patients laugh or cry, but don’t know why. Current Psychiatry. 2016;15(9):56-60,63.
- Crumpacker DW. Enhancing approaches to the identification and management of pseudobulbar affect. J Clin Psychiatry. 2016;77(9):e1155.
Drug Brand Names
Dextromethorphan/quinidine • Nuedexta
Diazepam • Valium
Fluoxetine • Prozac
Haloperidol • Haldol
Lorazepam • Ativan
Olanzapine • Zyprexa
Paroxetine • Paxil
Risperidone • Risperdal
