Prevalence of Schizophrenia in Idiopathic Normal Pressure Hydrocephalus

Neurosurgery 84:883–889, 2019

Idiopathic normal pressure hydrocephalus (iNPH) is a progressive and potentially treatable neurodegenerative disease affecting elderly people, characterized by gait impairment and ventricular enlargement in brain imaging. Similar findings are seen in some patients with schizophrenia (SCZ).

OBJECTIVE: To determine the prevalence of SCZ among patients suffering from probable or possible iNPH and the specific effects of comorbid SCZ on the outcome of the cerebrospinal fluid (CSF) shunting.

METHODS: All medical records of the 521 iNPH patients in the NPH registry were retrospectively analyzed from 1991 until 2017. The prevalence of comorbidity of SCZ was determined and compared to that of general aged (≥65 yr) population in Finland.

RESULTS: We identified a total of 16 (3.1%) iNPH patients suffering from comorbid SCZ. The prevalence of SCZ among the iNPH patients was significantly higher compared to the general population (3.1% vs 0.9%, P < .001). All iNPH patients with comorbid SCZ were CSF shunted and 12 (75%) had a clinically verified shunt response 3 to 12mo after the procedure. The CSF shunt response rate did not differ between patients with and without comorbid SCZ.

CONCLUSION: SCZ seems to occur 3 times more frequently among iNPH patients compared to the general aged population in Finland. The outcome of the treatment was not affected by comorbid SCZ and therefore iNPH patients suffering from comorbid SCZ should not be left untreated. These results merit validation in other populations. In addition, further research towards the potential connection between these chronic conditions is warranted.

Microsurgery for Spetzler-Ponce Class A and B arteriovenous malformations utilizing an outcome score adopted from Gamma Knife radiosurgery

J Neurosurg 127:1105–1116, 2017

The purpose of this study was to adapt and apply the extended definition of favorable outcome established for Gamma Knife radiosurgery (GKRS) to surgery for brain arteriovenous malformations (bAVMs). The aim was to derive both an error around the point estimate and a model incorporating angioarchitectural features in order to facilitate comparison among different treatments.

METHODS A prospective microsurgical cohort was analyzed. This cohort included patients undergoing embolization who did not proceed to microsurgery and patients denied surgery because of perceived risk of treatment. Data on bAVM residual and recurrence during long-term follow-up as well as complications of surgery and preoperative embolization were analyzed. Patients with Spetzler-Ponce Class C bAVMs were excluded because of extreme selection bias. First, patients with a favorable outcome were identified for both Class A and Class B lesions. Patients were considered to have a favorable outcome if they were free of bAVM recurrence or residual at last follow-up, with no complication of surgery or preoperative embolization, and a modified Rankin Scale score of more than 1 at 12 months after treatment. Patients who were denied surgery because of perceived risk, but would otherwise have been candidates for surgery, were included as not having a favorable outcome. Second, the authors analyzed favorable outcome from microsurgery by means of regression analysis, using as predictors characteristics previously identified to be associated with complications. Third, they created a prediction model of favorable outcome for microsurgery dependent upon angioarchitectural variables derived from the regression analysis.

RESULTS From a cohort of 675 patients who were either treated or denied surgery because of perceived risk of surgery, 562 had Spetzler-Ponce Class A or B bAVMs and were included in the analysis. Logistic regression for favorable outcome found decreasing maximum diameter (continuous, OR 0.62, 95% CI 0.51–0.76), the absence of eloquent location (OR 0.23, 95% CI 0.12–0.43), and the absence of deep venous drainage (OR 0.19, 95% CI 0.10–0.36) to be significant predictors of favorable outcome. These variables are in agreement with previous analyses of microsurgery leading to complications, and the findings support the use of favorable outcome for microsurgery. The model developed for angioarchitectural features predicts a range of favorable outcome at 8 years following microsurgery for Class A bAVMs to be 88%–99%. The same model for Class B bAVMs predicts a range of favorable outcome of 62%–90%.

CONCLUSIONS Favorable outcome, derived from GKRS, can be successfully used for microsurgical cohort series to assist in treatment recommendations. A favorable outcome can be achieved by microsurgery in at least 90% of cases at 8 years following microsurgery for patients with bAVMs smaller than 2.5 cm in maximum diameter and, in the absence of either deep venous drainage or eloquent location, patients with Spetzler-Ponce Class A bAVMs of all diameters. For patients with Class B bAVMs, this rate of favorable outcome can only be approached for lesions with a maximum diameter just above 6 cm or smaller and without deep venous drainage or eloquent location.

 

Complication-Effectiveness Analysis for Unruptured Intracranial Aneurysm Surgery

Aneurysm surgery

Neurosurgery 78:648–659, 2016

The aim of intervention for unruptured intracranial aneurysms (UIAs) is safe, effective treatment.

OBJECTIVE: To analyze a prospective database for variables influencing the risk of surgery to produce a risk model adjusting this risk for effectively treated aneurysms.

METHODS: First, we identified variables to create a model from multiple logistic regression for complications of surgery leading to a 12-month modified Rankin Scale score .1. Second, we established the long-term cumulative incidence of freedom from retreatment or rupture (treated aneurysm) from Kaplan-Meier analysis. Third, we combined these analyses to establish a model of risk of surgery per effective treatment.

RESULTS: One thousand twelve patients with 1440 UIA underwent 1080 craniotomies. We found that 10.1% (95% confidence interval [CI], 8.4-12.0) of craniotomies resulted in a complication leading to a modified Rankin Scale score .1 at 12 months. Logistic regression found age (odds ratio, 1.04; 95% CI, 1.02-1.06), size (odds ratio, 1.12; 95% CI, 1.09-1.15), and posterior circulation location (odds ratio, 2.95; 95% CI, 1.82-4.78) to be significant. Cumulative 10-year risk of retreatment or rupture was 3.0% (95% CI, 1.3-7.0). The complication-effectiveness model was derived by dividing the complication risk by the 10-year cumulative freedom from retreatment or rupture proportion. Risk per effective treatment ranged from 1% for a 5-mm anterior circulation UIA in a 20-year-old patient to 70% for a giant posterior circulation UIA in a 70-year-old patient.

CONCLUSION: Complication-effectiveness analyses increase the information available with regard to outcome for the management of UIAs.