July 11, 2016: Localization of pseudobulbar affect

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July 11, 2016

Localization of pseudobulbar affect

Pseudobulbar affect (PBA) is defined as involuntary crying, laughing or both, inconsistent with the patient's subjective mood state. There are two hypotheses regarding the etiology and anatomical localization of PBA: Dysmetria of emotions due to loss of cerebellar modulation secondary to lesions of cortico-ponto-cerebellar pathways1 versus disinhibition of laughing and crying centers in the brainstem, resulting from lesions of corticobulbar volitional pathways2. A recent diffusion tensor imaging study of patients with PBA showed some loss of cortico-ponto-cerebellar inputs in affected subjects, lending support to the emotional dysmetria hypothesis3. Dextromethorphan acts as an agonist on brainstem and cerebellar sigma-1 receptors to alleviate PBA symptoms4.

  1. Parvizi J, Anderson SW, Martin CO, Damasio H, Damasio AR. Pathological laughter and crying: a link to the cerebellum. Brain 2001; 124: 1708-1719.
  2. Wilson SAK. Some problems in neurology II: Pathological laughing and crying. J Neurol Psychopathol 1924; 4: 299-333.
  3. Floeter, MK, Katipally R, Kim MP, et al. Impaired corticopontocerebellar tracts underlie pseudobulbar affect in motor neuron disorders. Neurology 2014; 83: 620-627.
  4. Yang LP and Deeks ED. Dextromethorphan/quinidine: a review of its use in adults with pseudobulbar affect. Drugs (2014); 75: 83-90.

Emily Kunkel, BS, Medical Student Lewis Katz School of Medicine at Temple University and Kandan Kulandaivel, MD, Department of Neurosciences, Abington Hospital

Emily Kunkel and Dr. Kulandaivel report no disclosures.

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