Object. Neuropsychiatric changes following surgery for chronic subdural hematomas (CSDHs) were analyzed in 26 patients (21 men and five women) by using the Mini-Mental State Examination (MMSE) and the Hasegawa Dementia Scale-Revised (HDS-R) to determine factors that potentially contribute to neuropsychiatric recovery. Methods. Burr hole irrigation was performed in every patient to treat the CSDH. The patients' profiles, including age and sex, neuroimaging findings (such as hematoma volume and thickness, as well as midline shift), and preoperative and postoperative scores on the MMSE, HDS-R, and activities of daily living (ADL) scale were recorded. According to preoperative MMSE scores, eight patients (30.8%) were classified as mentally healthy and 18 (69.2%) as suffering from dementia before surgery. Nine of the 18 patients with dementia recovered to a normal psychological state following surgery. Surgery improved not only the patients' independence in ADL (p = 0.0026), but also their neuropsychiatric functions such as orientation and calculation, as estimated by scores on the MMSE (p = 0.0002) and the HDS-R (p = 0.0008). Factors affecting neuropsychiatric status on admission were midline shift (p = 0.0398) and ADL score (p = 0.0124); factors that could be used to predict neuropsychiatric recovery after surgery were patient age (p = 0.0027) and ADL score (p = 0.0193). The results of a logistic regression analysis demonstrated that significant predictors of neuropsychiatric recovery after surgery include the following: patient age (p = 0.0049, odds ratio [OR] = 0.842) and preoperative ADL (p = 0.0056, OR = 0.471), MMSE (p < 0.0001, OR = 1.895), and HDS-R (p = 0.0073, OR = 1.303) scores. Results of subgroup analyses demonstrated that patients younger than 74 years of age and those who had preoperative scores lower than 5 on the converted ADL scale, higher than 10 on the MMSE, or higher than 9 on the HDS-R on admission were found to have a significantly better recovery of neuropsychiatric functions after surgery. Conclusions. Dementia is reversible in many patients with CSDH, and surgery can improve not only independence in ADL, but also neuropsychiatric functions. Patients who are younger and/or those who have lower preoperative ADL scores and/or higher preoperative MMSE or HDS-R scores will achieve a good recovery with regard to neuropsychiatric functions after surgery. Estimations of neuropsychiatric function based on MMSE and HDS-R scores were found to be useful in predicting functional outcomes in patients with CSDH.
