Neuropsychological and Related Clinical Features Associated with Complex Regional Pain Syndrome: A Latent Class Analysis

Aim: The current research examined neuropsychological and key features related to Geschwind-Behan-Galaburda (GBG) model (i.e., non-right handedness, learning problems, autoimmune disease) in patients with Chronic Regional Pain Syndrome (CRPS).

Methods: A large sample of patients with CRPS (n=509) were evaluated with a neuropsychological protocol that assessed executive control, language/ lexical retrieval, and declarative memory. A portion of our sample was assessed with the modified Oldfield-Edinburgh questionnaire (n= 262) surveyed handedness, learning problems, and autoimmune disease was obtained on a portion of patients.

Results: Latent Class Analysis identified four neuropsychological classes: patients with moderate cognitive impairment (n= 44), patients with elements of an amnestic syndrome (n= 93), patients with intact but low average/ average neuropsychological test performance (n= 191), and patients with average/ high average neuropsychological test performance (n= 181). Elements of dysexecutive impairment were obtained in some groups. A minority, but statistically significant number of patients presented with mixed/ non-right handedness (26.30%); learning disabilities/ related problems (18.40%); and autoimmune disease (23.50; P< .001, all analyses). While intact neuropsychological performance was generally found in this large sample of patients with CRPS patients, elements of mild dysexecutive and amnestic impairment were observed in a portion of patients.

Conclusion: Neuropsychological impairment is present in a minority number of patients. The statistically significant incidence of non-right handedness, learning problems, and autoimmune medical disorders among a subset of patients is consistent with elements of the GBG model.

Summary: These data suggest the presence of mild neuropsychological deficits in some patients along with the possibility for anomalous brain development, suggesting a possible predisposition for CRPS in some patients.