Parkinson’s disease-related non-motor symptoms and risk of post-operative delirium after spinal surgery

Abstract

Background: Delirium is an acute confusional state characterized by disturbed attention and fluctuating cognition. Postoperative delirium is well known as the most frequent complication that is strongly associated with poor surgical outcomes and prolonged hospitalization of elderly patients. The clinical features of postoperative delirium are similar to the core features of alpha synuclein-related cognitive disorders, such as Parkinson’s disease dementia (PDD) or dementia with Lewy bodies (DLB). Further, previous studies suggest that underlying alpha synuclein pathologies are associated with postoperative delirium. Therefore, we hypothesized that the non-motor symptoms (NMSs) in Parkinson’s disease (PD), which precede the cardinal motor features of PD, are likely to be risk factors for developing postoperative delirium. We investigated the association between PD-related NMSs and postoperative delirium in patients aged 65 years and older undergoing elective spinal surgery.

Methods: This study was a prospective observational study at the Severance Hospital Neurosurgery Department. Participants were enrolled between September 2015 and July 2016. Eligible participants were aged 65 years and older and scheduled to undergo elective spinal surgery at the Severance Neurosurgical Department. Exclusion criteria included evidence of current or previous delirium before surgery, chemotherapy or radiotherapy for underlying cancer within the previous year, or hepatic or renal dysfunction. During the enrollment period 338 individuals were screened, of whom 42 (12.4%) did not meet the enrollment criteria. One hundred and six (31.4%) patients agreed to participate in this study. Two patients` elective operations were cancelled, leaving 104 participants. We assessed PD-related NMSs 1 day before the scheduled surgery using tests or questionnaires for each symptom. We chose eight easily-assessed PD-related NMSs: olfactory disturbance, constipation, orthostatic hypotension, insomnia, excessive daytime somnolence, rapid eye movement sleep behavior disorder (RBD), depression, and anxiety. We counted the number of positive findings for these eight PD-related NMSs to produce the prodromal symptoms score (ranging from 0 to 8) in order to analyze the predictability of postoperative delirium. We assessed the presence of delirium using the short version of the Confusion Assessment Method (Short CAM). A trained neurologist performed the delirium evaluation between 9 am and 12 midday on days 1, 2, and 3 after surgery.

Results: Fifteen (14.4%) of the 104 participants, met the Short CAM criteria for delirium at least once during the three postoperative days. Male sex and a low Mini-mental state examination (MMSE) score in the baseline measures were significantly associated with postoperative delirium (p=0.029 and p=0.023, respectively); preoperative hyposmia (p=0.021), depression (p=0.027), and RBD (p=0.002) were independent predictors of postoperative delirium. A higher prodromal symptoms score was associated with a greater risk of postoperative delirium.

Conclusion: Among PD-related NMS, RBD, hyposmia, and depression were independent risk factors for predicting postoperative delirium, and RBD was the strongest predictive factor. Furthermore, our results show that a greater number of NMSs, which may reflect the burden of alpha synuclein deposit, correlates with a higher risk of postoperative delirium. These findings suggest that postoperative delirium may be a preclinical stage of alpha synucleinopathy, and non-motor symptoms may help us to estimate the likelihood of postoperative delirium.

목적: 섬망은 주의력 손상 및 증상의 변동을 특징으로 하는 급성 혼동 상태를 말하며, 특히 수술 후 섬망은 수술의 불량한 예후와 긴 재원 기간과 직접적인 연관이 있는 흔한 수술 후 합병증이다. 수술 후 섬망의 임상양상은 파킨슨병 치매와 루이소체 치매로 대표되는 알파 시뉴클레인 (alpha synuclein) 연관 인지 장애와 비슷하다. 그리고, 최근 연구에서 기저의 알파 시뉴클레인 병리 소견이 수술 후 섬망과 연관성이 있음이 보고 되었다. 따라서 파킨슨병에서 보이는 비운동 증상이 수술 후 섬망 발생과 연관성이 있음을 가설로 세우고, 본 저자들은 65세 이상 고령의 척추 수술 환자에서 파킨슨병의 비운동 증상과 수술 후 섬망 ...