Past appendectomy may be related to early cognitive dysfunction in Parkinson's disease.

Introduction: The vermiform appendix is a potential site of initiation of Parkinson's disease (PD) pathology. We hypothesized that the appendectomy earlier in life may alter the clinical expression of PD.

Objective: To explore the effects of appendectomy prior to onset of PD motor symptoms on patients' symptoms, in particular on cognitive dysfunction.

Methods: Two hundred and sixty-two consecutive PD patients were asked about past history of appendectomy and underwent an evaluation, which included the Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn & Yahr scale (H&Y), Schwab & England Independence Scale (S&E), Dementia Rating Scale-2 (DRS-2), Apathy Evaluation Scale, Hospital Anxiety and Depression Scale, and Brief Smell Identification Test. Motor symptoms were evaluated in OFF and ON states. Non-parametric group comparisons and logistic regressions were used for data analyses.

Results: Thirty-one patients (11.8%) had history of appendectomy prior to PD onset. These patients had more severe motor symptoms (UPDRS-III and H&Y) and lower functional independence (S&E) in ON and had higher frequency of cognitive dysfunction (DRS-2 Initiation/Perseveration, Conceptualization, and Memory subscales) (p < 0.05). The association between history of appendectomy and cognitive dysfunction was evident only in patients with late onset PD (≥ 55 years) and with disease duration ≤ 5 years. History of appendectomy remained statistically associated with impairment on DRS-2 Conceptualization and Memory subscales, when demographic and clinical variables were considered.

Conclusion: History of appendectomy appears to alter the clinical expression of late onset PD, with early cognitive impairment, more severe motor symptoms in ON, and poorer functional independence under anti-parkinsonian medication.