Correlation between midline gait function performance and verbal fluency in patients with Parkinson's disease

Area of Science:

• Neuroscience
• Cognitive Science
• Movement Disorders

Background:

• Verbal fluency deficits are common early signs in Parkinson's disease (PD).
• However, group-level verbal fluency performance often doesn't differ between PD patients and controls.
• This study investigates if PD-related speech deficits are linked to midline motor control issues.

Purpose of the Study:

• To determine if phonemic verbal fluency (PVF) deficits in PD patients with poor midline motor function reflect a general cognitive-motor deficit.
• To explore the relationship between PVF and sensorimotor task performance in PD.

Main Methods:

• Thirty-one PD patients and thirteen controls were assessed.
• Participants completed the phonemic verbal fluency (PVF) test.
• The Metronome-Paced Square Step Test (MPSST), a complex sensorimotor task, was administered.

Main Results:

• While PVF scores were similar between groups, controls significantly outperformed PD patients on the MPSST.
• The odds of completing the MPSST without errors were 15 times higher for controls.
• MPSST performance explained significant PVF variability in PD patients, but not controls, even after accounting for age and disease duration.

Conclusions:

• PVF performance in PD likely indicates a PD-specific process.
• The Metronome-Paced Square Step Test (MPSST) may be more sensitive than PVF in detecting PD-specific pathology.
• Midline motor function deficits are closely related to cognitive impairments in Parkinson's disease.