Semantic fluency deficits and associated brain activity in Parkinson’s disease with mild cognitive impairment

Abstract

People living with Parkinson’s disease (PD) with poor verbal fluency have an increased risk of developing dementia. This study examines the neural mechanisms underpinning semantic fluency deficits in patients with PD with mild cognitive impairment (PD-MCI) compared to those without MCI (PD-NC) and control participants without PD (non-PD). Thirty-seven (37) participants with PD completed a cognitive assessment battery to identify MCI (13 PD-MCI). Twenty sex- and age-matched non-PD patients also participated. Participants were scanned (3T Siemens PRISMA) while performing semantic fluency, semantic switching, and automatic speech tasks. The number of responses and fMRI data for semantic generation and semantic switching were analyzed. Participants also completed a series of verbal fluency tests outside the scanner, including letter fluency. Participants with PD-MCI performed significantly worse than PD-NC and non-PD participants during semantic fluency and semantic switching tasks. PD-MCI patients showed greater activity in the right angular gyrus than PD-NC and non-PD patients during semantic switching. Increased right angular activity correlated with worse verbal fluency performance outside the scanner. Our study showed that the PD-MCI group performed worse on semantic fluency than either the PD-NC or non-PD groups. Increased right angular gyrus activity in participants with PD-MCI during semantic switching suggests early compensatory mechanisms, predicting the risk of future dementia in PD.

Hippocampal resting‐state connectivity is associated with posterior‐cortical cognitive impairment in Parkinson's disease

“…In the PD literature, Mak et al (2015) found increased right fusiform gyrus activity during an fMRI facial perception task compared to HCs, potentially compensating for left hemispheric dysfunction (Cardoso et al, 2010). Our previous work also revealed increased right angular gyrus activity in people with PD-MCI compared to HCs and cognitively intact people with PD during an alternating category fluency task, indicating additional recruitment of the contralateral hemisphere in PD with cognitive impairment (Yang et al, 2022). While increased activity in the right hemisphere during category fluency has been reported with respect to normal ageing (Meinzer et al, 2009), the aforementioned studies highlight PD-specific compensatory activity over and above that of age-matched controls.…”

Smaller and Denser Speech Graphs in Nondemented Patients with Progressive Supranuclear Palsy

“…Semantic disfluency is a common problem in progressive supranuclear palsy (PSP) and Parkinson's disease (PD). Patients with PSP or PD tended to generate fewer correct words than age-matched healthy adults in the semantic fluency test [ 1 , 2 ].…”

Clustering and Switching in Semantic Verbal Fluency: Their Development and Relationship with Word Productivity in Typically Developing Greek-Speaking Children and Adolescents

“…For that reason, they have proven valuable in identifying cognitive deficits associated with neurological and psychiatric disorders, monitoring disease progression, and evaluating the effectiveness of relevant interventions (e.g., da Silva et al 2004). Alterations in verbal fluency performance have been observed in conditions such as aphasia, schizophrenia, epilepsy, Alzheimer's, or Parkinson's disease in adults (Bose et al 2022;Carpenter et al 2021;Chrobak et al 2022;Robert et al 1998;Tallberg et al 2010;Yang et al 2022), and attention deficit hyperactivity disorder (ADHD), Down syndrome, autism spectrum disorder (ASD), developmental language disorder (DLD), or dyslexia in children (e.g., Begeer et al 2013;Koren et al 2005;Mengisidou et al 2020;Raboutet et al 2010;Ralli et al 2021;Troyer et al 1997).…”