Evaluation of a Fully Automated Method for Ventricular Volume Segmentation Before and After Shunt Surgery in Idiopathic Normal Pressure Hydrocephalus.

BACKGROUND: Determination of the ventricle size in idiopathic normal pressure hydrocephalus (iNPH) is essential for diagnosis and follow-up of shunt results. Fully automated segmentation methods are anticipated to optimize the accuracy and time efficiency of ventricular volume measurements. We evaluated the accuracy of preoperative and postoperative ventricular volume measurements in iNPH by a magnetic resonance imaging (MRI)-based licensed software for fully automated quantitative assessment. METHODS: Forty-eight patients diagnosed with iNPH were retrospectively analyzed. All patients received a ventriculoperitoneal shunt and had symptom grading and routine MRI preoperatively and 3-6 months postoperatively. Ventricular volumes, generated by fully automated T1-weighted imaging volume sequence segmentation, were compared with semiautomatic measurements and routine radiologic reports. The relation of postoperative ventricular size change to clinical response was evaluated. RESULTS: Fully automated segmentation was achieved in 95% of the MRIs, but showed various rates of 8 minor segmentation errors. The correlation between both segmentation methods was very strong (r >0.9) and the agreement very good using Bland-Altman analyses. The ventricular volumes differed significantly between semiautomated and fully automated segmentations and between preoperative and postoperative MRI. The fully automated method systematically overestimated the ventricles by a median 15 mL preoperatively and 14 mL postoperatively; hence, the magnitudes of volume changes were equivalent. Routine radiologic reports of ventricular size changes were inaccurate in 51% and lacked association with treatment response. Objectively measured ventricular volume changes correlated moderately with postoperative clinical improvement. CONCLUSIONS: A fully automated volumetric method permits reliable evaluation of preoperative ventriculomegaly and postoperative ventricular volume change in idiopathic normal pressure hydrocephalus.

MRI diffusion and perfusion alterations in the mesencephalon and pons as markers of disease and symptom reversibility in idiopathic normal pressure hydrocephalus.

INTRODUCTION: Core symptomatology in idiopathic normal pressure hydrocephalus (iNPH) points at dysfunction in the mesencephalon and pons indicating pathological changes in these regions, but only a few studies have addressed the issue. The aim of this study was to investigate diffusion (ADC) and perfusion patterns pre- and postoperatively in these areas in iNPH. METHODS: Twenty iNPH patients and 15 healthy controls were included. Patients underwent a clinical examination and brain MRI pre- and 3-6 months postoperatively. The MRI-scan included diffusion and dynamic susceptibility contrast perfusion weighted sequences. Regions of interest in the mesencephalon and pons were drawn on a FLAIR sequence and co-registered to ADC maps and perfusion data. RESULTS: There were no significant differences in pre or postoperative ADC compared to the control group, however postoperative ADC increased by 10% (p = 0.026) in the mesencephalon and 6% (p = 0.016) in the pons in all patients and also in the subgroup of shunt responders by 11% (p = 0.021) and 4% (p = 0.020), respectively. Preoperative relative cerebral blood flow (rCBF) was similar in iNPH patients and controls. Postoperatively, rCBF increased in shunt responders by 6% (p = 0.02) in the mesencephalon and 11% (p = 0.004) in the pons. This increase correlated with the degree of clinical improvement (rs = 0.80, p = 0.031 and rs = 0.66, p = 0.021, respectively). CONCLUSION: The postoperative increase in ADC and the correlation between postoperative increase in rCBF and clinical improvement in the mesencephalon and pons shown in this study point at an involvement of these areas in the core pathophysiology and its reversibility in iNPH.

Survival in treated idiopathic normal pressure hydrocephalus.

OBJECTIVE: To describe survival and causes of death in 979 treated iNPH patients from the Swedish Hydrocephalus Quality Registry (SHQR), and to examine the influence of comorbidities, symptom severity and postoperative outcome. METHODS: All 979 patients operated for iNPH 2004-2011 and registered in the SHQR were included. A matched control group of 4890 persons from the general population was selected by Statistics Sweden. Data from the Swedish Cause of Death Registry was obtained for patients and controls. RESULTS: At a median 5.9 (IQR 4.2-8.1) year follow-up, 37% of the iNPH patients and 23% of the controls had died. Mortality was increased in iNPH patients by a hazard ratio of 1.81, 95% CI 1.61-2.04, p < 0.001. More pronounced symptoms in the preoperative ordinal gait scale and the Mini-mental State Examination were the most important independent predictors of mortality along with the prevalence of heart disease. Patients who improved in both the gait scale and in the modified Rankin Scale postoperatively (n = 144) had a similar survival as the general population (p = 0.391). Deaths due to cerebrovascular disease or dementia were more common in iNPH patients, while more controls died because of neoplasms or disorders of the circulatory system. CONCLUSIONS: Mortality in operated iNPH patients is 1.8 times increased compared to the general population, a lower figure than previously reported. The survival of iNPH patients who improve in gait and functional independence is similar to that of the general population, indicating that shunt surgery for iNPH, besides improving symptoms and signs, can normalize survival.

Predictive factors of complications in revisional gastric bypass surgery: results from the Scandinavian Obesity Surgery Registry.

BACKGROUND: Roux-en-Y gastric bypass is the most common procedure for revisional bariatric surgery. This study is an analysis of revisional gastric bypass operations (rGBP) compared with primary gastric bypass (pGBP) performed in Sweden between 2007 and 2016. OBJECTIVE: The aim was to compare the incidence of adverse events in primary and revisional gastric bypass surgery and to identify predictive factors of intraoperative, early, and late complications in revisional gastric bypass surgery. SETTING: Forty-four hospitals. METHODS: Registered study from the Scandinavian Obesity Surgery Registry. The study group (rGBP) comprised 1795 patients, and the control group (pGBP) comprised 46,055 patients. RESULTS: Median follow-up time was 28 months. The rate of open procedures was significantly higher in the rGBP group (39.1% versus 2.4%; P < .001) decreasing from 70.8% in 2007 to 8.5% in 2016. Intraoperative complications (15.5% versus 3.0%, P < .001), early complications (24.6% versus 8.7%; P < .001), and late complications (17.7% versus 8.7%; P < .001) occurred more often in the rGBP group. Open access in revisional surgery was an independent risk factor for intraoperative complications (odds ratio 3.87; 95% confidence interval: 2.69-5.57, P < .001), early complications (odds ratio 2.08; 95% confidence interval: 1.53-2.83, P < .001), and late complications (odds ratio 1.91; 95% confidence interval: 1.31-2.78, P = .001). Indication for revision or type of index operation were not associated with complications. CONCLUSION: RGBP was associated with a higher incidence of intraoperative, early, and late complications compared with pGBP. Open access in revisional surgery was predictive of complications regardless of the index operation or indication for revision.

The phenotype of idiopathic normal pressure hydrocephalus-a single center study of 429 patients.

INTRODUCTION: Idiopathic Normal Pressure Hydrocephlaus (iNPH) is, despite a vastly improved knowledge of the disorder since its first description still underdiagnosed and undertreated. Because of this, there is a need for further large studies describing the typical symptomatology and reversibility of symptoms in iNPH, which was the aim of this study. METHODS: In all, 429 patients (mean age 71 years) were included. Detailed pre- and postoperative examinations of symptoms and signs were analyzed. A composite outcome measure was constructed. RESULTS: Sixty-eight % improved after surgery. Preoperatively, 72% exhibited symptoms from three or four of the assessed domains (gait, balance, neuropsychology and continence) while 41% had symptoms from all four domains. Ninety % had gait disturbances, of which 75% had broad-based gait, 65% shuffling gait and 30% freezing of gait. These disturbances coexisted in most patients preoperatively, but were more likely to appear as isolated findings after surgery. Impaired balance was seen in 53% and retropulsion in 46%. MMSE <25 was seen in 53% and impaired continence in 86%. Improvements were seen in all symptom domains postoperatively. CONCLUSIONS: The iNPH phenotype is characterized by a disturbance in at least 3/4 symptom domains in most patients, with improvements in all domains after shunt surgery. Most patients present with a broad-based and shuffling gait as well as paratonia. Present symptoms in all domains and a shuffling gait at the time of diagnosis seem to predict a favorable postoperative outcome, whereas symptom severity does not.

Long-term effects of complications and vascular comorbidity in idiopathic normal pressure hydrocephalus: a quality registry study.

BACKGROUND: There is little knowledge about the factors influencing the long-term outcome after surgery for idiopathic normal pressure hydrocephalus (iNPH). OBJECTIVE: To evaluate the effects of reoperation due to complications and of vascular comorbidity (hypertension, diabetes, stroke and heart disease) on the outcome in iNPH patients, 2-6 years after shunt surgery. METHODS: We included 979 patients from the Swedish Hydrocephalus Quality Registry (SHQR), operated on for iNPH during 2004-2011. The patients were followed yearly by mailed questionnaires, including a self-assessed modified Rankin Scale (smRS) and a subjective comparison between their present and their preoperative health condition. The replies were grouped according to the length of follow-up after surgery. Data on clinical evaluations, vascular comorbidity, and reoperations were extracted from the SHQR. RESULTS: On the smRS, 40% (38-41) of the patients were improved 2-6 years after surgery and around 60% reported their general health condition to be better than preoperatively. Reoperation did not influence the outcome after 2-6 years. The presence of vascular comorbidity had no negative impact on the outcome after 2-6 years, assessed as improvement on the smRS or subjective improvement of the health condition, except after 6 years when patients with hypertension and a history of stroke showed a less favorable development on the smRS. CONCLUSION: This registry-based study shows no negative impact of complications and only minor effects of vascular comorbidity on the long-term outcome in iNPH.

Vascular factors in suspected normal pressure hydrocephalus: A population-based study.

OBJECTIVE: We examined clinical and imaging findings of suspected idiopathic normal pressure hydrocephalus (iNPH) in relation to vascular risk factors and white matter lesions (WMLs), using a nested case-control design in a representative, population-based sample. METHODS: From a population-based sample, 1,235 persons aged 70 years or older were examined with CT of the brain between 1986 and 2000. We identified 55 persons with hydrocephalic ventricular enlargement, i.e., radiologic findings consistent with iNPH. Among these, 26 had clinical signs that fulfilled international guideline criteria for probable iNPH. These cases were labeled suspected iNPH. Each case was matched to 5 controls from the same sample, based on age, sex, and study cohort. Data on risk factors were obtained from clinical examinations and the Swedish Hospital Discharge Register. History of hypertension, diabetes mellitus (DM), smoking, overweight, history of coronary artery disease, stroke/TIA, and WMLs on CT were examined. Risk factors associated with iNPH with a p value <0.1 in χ2 tests were included in conditional logistic regression models. RESULTS: In the regression analyses, suspected iNPH was related to moderate to severe WMLs (odds ratio [OR] 5.2; 95% confidence interval [CI]: 1.5-17.6), while hydrocephalic ventricular enlargement was related to hypertension (OR 2.7; 95% CI: 1.1-6.8), moderate to severe WMLs (OR 6.5; 95% CI: 2.1-20.3), and DM (OR 4.3; 95% CI: 1.1-16.3). CONCLUSIONS: Hypertension, WMLs, and DM were related to clinical and imaging features of iNPH, suggesting that vascular mechanisms are involved in the pathophysiology. These findings might have implications for understanding disease mechanisms in iNPH and possibly prevention.