Pseudobulbar laughter as a levodopa off phenomenon exacerbated by subthalamic deep brain stimulation

Area of Science:

• Neurology
• Neuroscience
• Movement Disorders

Background:

• Pseudobulbar affect (PBA) is a neurological symptom common in neurodegenerative diseases.
• PBA can manifest as emotional lability, such as crying without subjective emotional experience.
• In Parkinson's disease (PD), PBA may occur during medication 'wearing-off' periods.

Observation:

• A case study involving a Parkinson's disease patient presenting with inappropriate laughter lacking mirth.
• This laughter was identified as a levodopa OFF phenomenon.
• The patient's laughter also worsened with subthalamic nucleus deep brain stimulation (STN-DBS) when not on medication.

Findings:

• The patient's pseudobulbar laughter was a levodopa OFF phenomenon.
• STN-DBS exacerbated the pseudobulbar laughter in the non-medicated state.
• Levodopa administration effectively ameliorated the PBA, both with and without STN-DBS.

Implications:

• This case highlights pseudobulbar laughter as a distinct levodopa OFF phenomenon in PD.
• It suggests STN-DBS can exacerbate PBA, particularly in a non-medicated state.
• Levodopa remains a key therapeutic option for managing PBA in PD patients, even with concurrent DBS.