ORIGINAL ARTICLE Role of the patient comorbidity in the recurrence of chronic subdural hematomas Rafael Martinez-Perez 1,2 & Asterios Tsimpas 3 & Natalia Rayo 4 & Santiago Cepeda 1,5 & Alfonso Lagares 1 Received: 25 November 2019 /Revised: 20 January 2020 /Accepted: 17 February 2020 # Springer-Verlag GmbH Germany, part of Springer Nature 2020 Abstract Chronic subdural hematoma (CSDH) is an old blood collection between the cortical surface and the dura. Recurrence of CSDH after surgical evacuation occurs in up to a quarter of patients. The association between patient premorbid status and the rate of recurrence is not well known, and some previous results are contradictory. We aim to determine the impact of patient comor- bidities in the risk of recurrence after surgical evacuation of CSDH. Retrospective data of a single institution’ s surgically evacuated CSDH cases followed up for at least 6 months were analyzed, and univariate and multivariate analyses were performed to identify the relationships between recurrence of CSDH and factors such as age, gender, CSDH thickness, neurological impairment at admission (NIHSS score), location of the CSDH (unilateral vs bilateral), Charlson Comorbidity Index (CCI), prothrombin time (PT), hemoglobin levels, and platelet count. A total of 90 patients (71 men and 19 women), aged 41–100 years (mean age, 76.4 ± 11.2 years), were included. CSDH recurred in 17 patients (18.9%). A higher CCI correlated with higher scores in the NIHSS. In the univariate analysis, recurrence was associated with a higher CCI (2.39 vs 1.22, p = 0.002), higher NIHSS scores (6.5 vs 4, p = 0.034), and lower PT levels (9.9 vs 13.4, p = 0.007). In multivariate analysis, only PT and CCI demonstrated to be independent risk factors for CSDH recurrence after surgical evacuation (p = 0.033 and p = 0.024, respectively). Patients with more comorbidities have a higher risk of developing recurrent CSDH. CCI provides a simple way of predicting recurrence in patients with CSDH and should be incorporated into decision-making processes, when counseling patients. Keywords Recurrence . Burr hole . Effusion . Diabetes . Renal insufficiency Introduction A chronic subdural hematoma (CSDH) is an old collection of blood or blood breakdown products that has accumulated between the surface of the brain and the dura. It can be clin- ically asymptomatic. However, when a patient presents with neurologic symptoms, they are typically the result of brain compression by the CSDH and mass effect [11]. An often minor head injury has been reported as the main cause of CSDH development, yet a negative traumatic history is not uncommon [17]. The incidence of CSDH has been reported to be as high as 20 cases per 100,000 persons [3, 17]. Surgical evacuation is considered, when mass effect on the underlying brain tissue results in clinical symptoms [2]. Although CSDH evacuation is considered to be a quite simple surgical procedure, recurrence is an undesired possible out- come that increases the risk of complications and death [1]. Recurrence rates after CSDH evacuation range between 5 and 26% [6, 8, 15]. Several epidemiological, clinical, and radio- logical factors have been demonstrated to be associated with recurrence [7, 8, 10, 16]. Among the epidemiological aspects, advanced age is the most commonly reported risk factor for recurrence in CSDH [1, 7, 10]. While overall health status is declining during the aging process, and the latter is a well- This manuscript has not been previously published in whole or in part or submitted elsewhere for review. * Rafael Martinez-Perez rafa11safin@hotmail.com 1 Department of Neurosurgery, Hospital 12 de Octubre, Universidad Complutense, Avenida de Andalucia s/n., 28041 Madrid, Spain 2 Division of Neurosurgery, Institute of Neurosciences, Universidad Austral de Chile, Valdivia, Chile 3 Department of Surgery, Division of Neurosurgery, Advocate Illinois Masonic Medical Center, Chicago, IL, USA 4 Department of Biology, Western University, London, Canada 5 Department of Neurosurgery, Hospital Universitario Rio Hortega, Valladolid, Spain Neurosurgical Review https://doi.org/10.1007/s10143-020-01274-7