Verbal adynamia in parkinsonian syndromes: behavioral correlates and neuroanatomical substrate

ABSTRACT

Verbal adynamia (impaired language generation, as during conversation) has not been assessed systematically in parkinsonian disorders. We addressed this in patients with Parkinson’s dementia, progressive supranuclear palsy and corticobasal degeneration. All disease groups showed impaired verbal fluency and sentence generation versus healthy age-matched controls, after adjusting for general linguistic and executive factors. Dopaminergic stimulation in the Parkinson’s group selectively improved verbal generation versus other cognitive functions. Voxel-based morphometry identified left inferior frontal and posterior superior temporal cortical correlates of verbal generation performance. Verbal adynamia warrants further evaluation as an index of language network dysfunction and dopaminergic state in parkinsonian disorders.

KEYWORDS:

• Parkinson’s disease
• Lewy body disease
• progressive supranuclear palsy
• corticobasal degeneration
• dynamic aphasia

Acknowledgments

We are grateful to all patients and healthy participants for their involvement. The Dementia Research Centre is supported by Alzheimer’s Research UK, the Brain Research Trust, and the Wolfson Foundation. This work was funded by the Alzheimer’s Society, the Wellcome Trust, the UK Medical Research Council, Parkinson’s UK, the PSP Association, the Weston Trust, the Reta Lila Howard Foundation, and the NIHR UCLH Biomedical Research Centre. NKM was supported by a PSP (Europe) association and Reta Lila Weston Institute PhD Fellowship. HLG was supported by an Alzheimer Research UK PhD Fellowship. JDW was supported by a Wellcome Trust Senior Clinical Fellowship (Grant No 091673/Z/10/Z).

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplementary material can be accessed here.

Additional information

Funding

JDW was supported by a Wellcome Trust Senior Clinical Fellowship [Grant No 091673/Z/10/Z] and funded by the Alzheimer’s Society, the UK Medical Research Council, Parkinson’s UK, the PSP Association, the Weston Trust, the Reta Lila Howard Foundation, and the NIHR UCLH Biomedical Research Centre.