Progressive supranuclear palsy presenting with dynamic aphasia

Area of Science:

• Neurology
• Neuropsychology

Background:

• Progressive supranuclear palsy (PSP) is a neurodegenerative disorder characterized by motor deficits like unsteadiness and bradykinesia.
• While dysarthria is common, significant language disorders are less recognized in PSP.

Observation:

• This study reports on three patients with PSP where initial symptoms included pronounced difficulties with language output.
• Pathological confirmation was obtained in two of the three reported cases.

Findings:

• Neuropsychological assessments revealed significant impairments in tasks requiring active language initiation and retrieval, such as verbal fluency and narrative production.
• Conversely, tasks like picture naming, verbal description comprehension, and sentence comprehension remained largely intact.
• Semantic memory impairment was minimal in these patients.

Implications:

• These findings suggest that some PSP patients may experience selective cognitive deficits affecting language planning and initiation.
• This presentation mimics 'verbal adynamia' or 'dynamic aphasia' typically associated with frontal lobe damage.
• The observed neuropsychological deficits likely stem from functional frontal deafferentation due to disrupted frontostriatal pathways.