Health Care Expenditures of Medicare Beneficiaries with Normal Pressure Hydrocephalus.

BACKGROUND: Normal pressure hydrocephalus (NPH) is an underdiagnosed and undertreated condition affecting the elderly population and with costs associated with its surgical management reported to be less than those associated with conservative management. OBJECTIVE: To determine if the rate of diagnosis of NPH has improved over the last decade, the rate of treatment has increased, and if surgical treatment costs and socioeconomic factors related to receipt of treatment have changed over time compared with conservative therapy. METHODS: A retrospective study based on data from a nationally representative random sample of 2,378,637 Medicare beneficiaries (2006-2010) was performed. Shunt surgery, shunt revision, replacement, and removal were analyzed as independent variables. RESULTS: A total of 2321 patients with NPH were included, with 580 (24.99%) receiving a first shunt procedure. The adjusted effect of the procedure is that total 5-year expenditures are $11,676 more per patient (P < 0.001) than expenditures associated with nonsurgical management. Shunt revision ($22,715, P < 0.01) and/or replacement ($46,607, P < 0.001) add significantly to 5-year expenditures. Socioeconomic factors including African American race (P = 0.006); age 75-79 years (P = 0.024), 80-84 years (P < 0.001), and ≥85 years (P < 0.001); and Medicaid (P < 0.001) have significant negative associations with shunt surgery. CONCLUSIONS: There was a 1.66-fold increase in the rate of diagnosis of NPH, from 0.12% in 1999 to 0.2% in 2008. The total costs per surgical patient rose by approximately 145% to 160% comparing 2001 and 2010. This increase was mainly due to hospital (by 167% to 168%) and home health costs (by 118% to 148%). Providing appropriate care across the socioeconomic spectrum warrants further study and requires identifying the factors that limit access to care.

Ultrasound for the assessment of distal shunt malfunction in adults with internal ventricular shunts.

Shunts that are used for the treatment of hydrocephalus have a propensity towards malfunction, however, diagnosing a shunt malfunction can sometimes be a challenge. The purpose of this study was to investigate whether ultrasound technology can be safely and effectively used to assess for distal shunt malfunction. This was a prospective cohort study at a single institution. Eighteen adult patients that received a radionuclide shunt patency study also underwent an ultrasound shunt patency study. Ultrasound with Doppler technology was used to visualize flow through the shunt tubing following manual compression of the shunt reservoir. A peak flow speed was recorded and the results were compared to the results of the radionuclide shunt patency study. A Receiver Operating Characteristic (ROC) curve comparing the ultrasound to the radionuclide shunt patency study was generated, revealing an Area Under the Curve (AUC) of 0.95 (95% CI: 0.84-1.00). The ultrasound test performed maximally with a cutoff speed of ≤10cm/s as the criteria for malfunction, with a sensitivity of 100.00%, specificity of 90.91%, accuracy of 94.44%, positive likelihood ratio of 11.000 and negative likelihood ratio of 0.000 using the radionuclide study results as criteria for comparison. Overall, ultrasound has the potential to be a safe, quick, available and cost-effective screening test for patients with suspected distal shunt malfunction. The high sensitivity of the test makes it an attractive option for use as a screening method that could potentially reduce the number of cases requiring radionuclide shunt patency study.

Alzheimer's disease pathology and shunt surgery outcome in normal pressure hydrocephalus.

We aimed to determine whether presence of AD neuropathology predicted cognitive, gait and balance measures in patients with idiopathic normal pressure hydrocephalus (iNPH) after shunt surgery. This is a prospective study of gait and balance measured by Timed Up and Go (TUG) and Tinetti tests, and cognitive function measured by Mini Mental Status Exam (MMSE), before and after shunt surgery in participants 65 years and older with iNPH at the Johns Hopkins University. Random effects models were used and adjusted for confounders. 88 participants were included in the analysis with a median (IQR) time of 104 (57-213) days between surgery and follow-up. 23 (25%) participants had neuritic plaques present (NP+) and were significantly older [76.4 (6.0) years], but were otherwise similar in all demographics and outcome measures, when compared to the group without neuritic plaques (NP-). NP- and NP+ participants equally improved on measures of TUG (ß = -3.27, 95% CI -6.24, -0.30, p = 0.03; ß = -2.37, 95% CI -3.90, -0.86, p = 0.02, respectively), Tinetti-total (ß = 1.95, 95% CI 1.11, 2.78, p<0.001; ß = 1.72, 95% CI 0.90, 2.53, p<0.001, respectively), -balance (ß = 0.81, 95% CI 0.23, 1.38, p = 0.006; ß = 0.87, 95% CI 0.40, 1.34, p<0.001, respectively) and -gait (ß = 1.03, 95% CI 0.61, 1.45, p<0.001; ß = 0.84, 95% CI 0.16, 1.53, p = 0.02, respectively), while neither NP- nor NP+ showed significant improvement on MMSE (ß = 0.10, 95% CI -0.27, 0.46, p = 0.61, ß = 0.41, 95% CI -0.27, 1.09, p = 0.24, respectively). In summary, 26% of participants with iNPH had coexisting AD pathology, which does not significantly influence the clinical response to shunt surgery.

NPH Log: Validation of a New Assessment Tool Leading to Earlier Diagnosis of Normal Pressure Hydrocephalus.

INTRODUCTION: Early treatment of normal pressure hydrocephalus (NPH) yields better postoperative outcomes. Our current tests often fail to detect significant changes at early stages. We developed a new scoring system (LP log score) to determine if this tool is more sensitive in detecting clinical differences than current tests. MATERIAL AND METHODS: Sixty-two consecutive new patients with suspected idiopathic NPH were studied. Secondary, previously treated and obstructive cases were not included. We collected age, pre- and post-lumbar puncture (LP) Tinetti, Timed Up and Go (TUG) Test, European NPH scale, and LP log scores. The LP log score is recorded at baseline and for seven consecutive days after removing 40 cc of cerebrospinal fluid (CSF) via LP. We studied the diagnostic accuracy of the tests for surgical indication. RESULTS: The post-LP log showed improvement in 90% of people with good baseline gait tests and in 93% of people who did not show any pre-LP and post-LP change in gait tests. Sensitivity, specificity, and accuracy to detect intention to treat when positive post-LP improvements were 4%, 100%, and 24%, respectively, for TUG, 21%, 86%, and 34%, respectively, for the Tinetti Mobility Test, 66%, 29%, and 58%, respectively, for Medical College of Virginia (MCV) grade, and 98%, 33%, and 85%, respectively, for LP log score. Pre-LP and post-LP TUG improvement and pre-LP and post-LP Tinetti improvement were not associated with a surgical indication (p > 0.05). LP log improvement was associated with surgical indication odds ratio (OR): 24.5 95% CI (2.4-248.12) (p = 0.007). CONCLUSIONS: LP log showed better sensitivity, diagnostic accuracy, and association with surgical indication than the current diagnostic approach. An LP log may be useful detecting NPH patients at earlier stages and, therefore, yield better surgical outcomes.

Clinical outcomes after ventriculoatrial shunting for idiopathic normal pressure hydrocephalus.

INTRODUCTION: Idiopathic normal pressure hydrocephalus (iNPH) is a neurological disorder that classically presents with a triad of progressive gait impairment, urinary incontinence, and cognitive deterioration. Treatment predominantly involves ventriculoperitoneal (VP) shunting, but one alternative is ventriculoatrial (VA) shunting. This study sought to describe and evaluate the clinical outcomes of patients with iNPH primarily treated with VA shunting. MATERIALS AND METHODS: A retrospective review of patients with iNPH who were treated with VA shunting at a single institution, from 2003 to 2013, was performed. RESULTS: 58 patients with iNPH underwent primary VA shunting at a median age of 74 (IQR: 70-80) years. The most common comorbidities included hypertension (n=39, 67%) and diabetes mellitus (n=11, 19%). Median duration of symptoms prior to VA shunting was 24 (IQR: 12-36) months. All patients had gait impairment, 52 (90%) had cognitive decline, and 43 (74%) had urinary incontinence. Forty-three (74%) patients had all three symptoms. At a median last follow-up of 16 (IQR: 7-26) months, median iNPH score improved from 6 to 3 (p<0.0001), mini mental status exam (MMSE) tended to increase from 26 to 29 (p=0.082), timed up-and-go (TUG) improved from 18 to 13s (p<0.0001), and Tinetti score improved from 19 to 25 (p<0.0001) after VA shunting. 78% of patients had improvement in at least one of their symptoms with 66% of patients having improvement in gait, 53% having improvement in their cognition, and 52% having improved urinary incontinence. A total of 21 patients (36%) had improvement in all 3 symptoms. CONCLUSIONS: There were significant improvements in functional outcomes as evaluated via the iNPH score, TUG, and Tinetti score, while improvement in MMSE trended toward significance. Patients also had improvement of clinical symptoms related to gait, urinary function and cognition. These results suggest that VA shunting can be an effective primary treatment alternative to VP shunting for iNPH.

Lower rates of symptom recurrence and surgical revision after primary compared with secondary endoscopic third ventriculostomy for obstructive hydrocephalus secondary to aqueductal stenosis in adults.

OBJECT Endoscopic third ventriculostomy (ETV) is the treatment of choice for obstructive hydrocephalus; however, the success of ETV in patients who have previously undergone shunt placement remains unclear. The present study analyzed 103 adult patients with aqueductal stenosis who underwent ETV for obstructive hydrocephalus and evaluated the effect of previous shunt placement on post-ETV outcomes. METHODS This study was a retrospective review of 151 consecutive patients who were treated between 2007 and 2013 with ETV for hydrocephalus. One hundred three (68.2%) patients with aqueductal stenosis causing obstructive hydrocephalus were included in the analysis. Postoperative ETV patency and aqueductal and cisternal flow were assessed by high-resolution, gradient-echo MRI. Post-ETV Mini-Mental State Examination, Timed Up and Go, and Tinetti scores were compared with preoperative values. Univariate and multivariate analyses were performed comparing the post-ETV outcomes in patients who underwent a primary (no previous shunt) ETV (n = 64) versus secondary (previous shunt) ETV (n = 39). RESULTS The majority of patients showed significant improvement in symptoms after ETV; however, no significant differences were seen in any of the quantitative tests performed during follow-up. Symptom recurrence occurred in 29 (28.2%) patients after ETV, after a median of 3.0 (interquartile range 0.8-8.0) months post-ETV failure. Twenty-seven (26.2%) patients required surgical revision after their initial ETV. Patients who received a secondary ETV had higher rates of symptom recurrence (p = 0.003) and surgical revision (p = 0.003), particularly in regard to additional shunt placement/revision post-ETV (p = 0.005). These differences remained significant after multivariate analysis for both symptom recurrence (p = 0.030) and surgical revision (p = 0.043). CONCLUSIONS Patients with obstructive hydrocephalus due to aqueductal stenosis exhibit symptomatic improvement after ETV, with a relatively low failure rate. Patients with a primary history of shunt placement who undergo ETV as a secondary intervention are at increased risk of symptom recurrence and need for surgical revision post-ETV.

Functional gait outcomes for idiopathic normal pressure hydrocephalus after primary endoscopic third ventriculostomy.

We evaluated if patients with idiopathic normal pressure hydrocephalus (iNPH) showed functional improvement after primary endoscopic third ventriculostomy (ETV). The efficacy of ETV for iNPH remains controversial. We retrospectively reviewed 10 consecutive patients treated between 2009 and 2011 with ETV for iNPH. Seven patients with a median age of 73 years (range: 60-80) who underwent a primary ETV for iNPH were included for analysis. Median follow-up was 39 months (range: 26-46). Post-ETV stoma and aqueductal and cisternal flows were confirmed via high resolution, gradient echo and phase contrast MRI. Post-ETV timed up and go (TUG) and Tinetti performance oriented mobility assessment scores were compared to pre- and post-lumbar puncture (LP) values. A second LP was performed if ETV failed to sustain the observed improvement after initial LP. Patients who demonstrated ETV failure were subsequently shunted. Compared to pre-LP TUG and Tinetti values of 14.00 seconds (range: 12.00-23.00) and 22 (range: 16-24), post-LP scores improved to 11.00 seconds (range: 8.64-15.00; p=0.06) and 25 (range: 24-28; p=0.02), respectively. ETV failed to sustain this improvement with slight worsening between pre-LP and post-ETV TUG and Tinetti scores. Improvement from pre-LP assessment was regained after shunting and at last follow-up with TUG and Tinetti scores of 12.97 seconds (range: 9.00-18.00; p=0.250) and 25 (range: 18-27; p=0.07), and 11.87 seconds (range: 8.27-18.50; p=0.152) and 23 (range: 18-26; p=0.382), respectively. Despite stoma patency, ETV failed to sustain functional improvement seen after LP, however, improvement was regained after subsequent shunting suggesting that shunt placement remains the preferred treatment for iNPH.

Does CT wand guidance improve shunt placement in patients with hydrocephalus?

OBJECT: To evaluate the effectiveness of stereotactic navigation in enhancing the accuracy of ventricular shunt placement in patients with hydrocephalus. METHODS: A retrospective cohort study at a single institution by a single surgeon was performed. Consecutive patients who underwent implantation of a ventricular shunt for the management of hydrocephalus between July 2001 and December 2011 were included in the study, totaling 535 patients. Patients were classified as either having optimal or sub-optimal placement of the shunt into the ventricle. Multiple logistic regression analysis was used. RESULTS: Overall, 93.8% of patients were found to have optimal shunt placement. On multivariate analysis, navigation use was not significantly associated with improved accuracy of shunt placement (odds ratio [OR] = 0.54; 95% confidence interval [CI] = 0.19-1.54; p = 0.25). Pseudotumor cerebri diagnosis was significantly associated with increased odds of sub-optimal shunt placement (OR = 6.41; 95% CI = 1.90-21.59; p=0.003). CONCLUSIONS: CT guided navigation did not significantly improve the accuracy of ventricular shunt placement in adults with hydrocephalus for an experienced surgeon. Further studies are required to assess the utility of CT guided navigation for less experienced surgeons and patients with small or dysmorphic ventricles.

The Use of an Aspirating/Resecting Device to Reduce Stoma Closure Following Endoscopic Third Ventriculostomy for Aqueductal Stenosis.

BACKGROUND: Endoscopic third ventriculostomy (ETV) is commonly used to treat obstructive hydrocephalus. Closure of the stoma can be associated with symptom recurrence and need for further surgical intervention. OBJECTIVE: To describe the use of a side-cutting aspiration device for treatment of aqueductal stenosis in patients undergoing ETV. METHODS: A retrospective review of 30 consecutive adults with aqueductal stenosis treated with ETV using an adjunct side-cutting aspiration device between 2011 and 2013 was performed. Patients included in the study ranged from 35 to 64 years of age. ETV success was determined by the absence of stoma closure (aqueductal and cisternal flow assessed by high-resolution, gradient-echo magnetic resonance imaging), post-ETV symptom recurrence, and need for subsequent surgical intervention. RESULTS: Patients treated by using a side-cutting aspirator had no observed stoma closure (0%) and a 10% (n = 3) rate of post-ETV symptom recurrence. Three patients (10%) demonstrated a need for surgical revision following initial ETV with the side-cutting aspirator. CONCLUSION: Adult patients with obstructive hydrocephalus secondary to aqueductal stenosis exhibited a low rate of stoma closure with the use of a side-cutting aspiration device, and a rate of complications comparable to the known literature. Likewise, patients treated with a side-cutting aspirator may have lower symptom recurrence post-ETV and require fewer revisions in comparison with the known literature. As such, a side-cutting aspirator may be considered as a useful adjunct to traditional ETV for the treatment of obstructive hydrocephalus secondary to aqueductal stenosis.

Using Commercial Activity Monitors to Measure Gait in Patients with Suspected iNPH: Implications for Ambulatory Monitoring.

OBJECTIVES: This study seeks to validate the use of activity monitors to detect and record gait abnormalities, potentially identifying patients with idiopathic normal pressure hydrocephalus (iNPH) prior to the onset of cognitive or urinary symptoms. METHODS: This study compared the step counts of four common activity monitors (Omron Step Counter HJ-113, New Lifestyles 2000, Nike Fuelband, and Fitbit Ultra) to an observed step count in 17 patients with confirmed iNPH. RESULTS: Of the four devices, the Fitbit Ultra (Fitbit, Inc., San Francisco, CA) provided the most accurate step count. The correlation with the observed step count was significantly higher (p<0.009) for the Fitbit Ultra than for any of the other three devices. CONCLUSIONS: These preliminary findings suggest that existing activity monitors have variable efficacy in the iNPH patient population and that the MEMS tri-axial accelerometer and algorithm of the Fitbit Ultra provides the most accurate gait measurements of the four devices tested.

Risk factors for failed transverse sinus stenting in pseudotumor cerebri patients.

BACKGROUND: Idiopathic intracranial hypertension (IIH) when no underlying etiology is found, is a clinical syndrome characterized by elevated intracranial pressure (ICP) (>25 cm H2O), which may lead to headaches and visual symptoms. In patients with IIH who are found to have transverse sinus stenosis, placement of a venous stent across the stenosis has been shown to lower ICP and to resolve the symptoms in several case series, with generally favorable results. In this study, we examine common risk factors associated with failure of transvenous stenting for IIH. If venous sinus stenting fails, CSF diversion should be considered as the next line of treatment. METHODS: We retrospectively reviewed the records of eighteen patients diagnosed with IIH who underwent venous sinus stenting for transverse sinus stenosis with a mean pressure gradient (MPG) of at least 4 mmHg. Fifteen of these patients did not need further treatment. We compared their pre- and post-treatment, neurological and neuro-ophthalmological evaluations to the three patients who went on to have a shunt placement as a second line treatment. RESULTS: Shunting after stent placement patients (n=3) had a mean age of 30 years and a mean body mass index of 36.6 kg/m(2), whereas the group that underwent stent placement alone (n=15) had a mean age of 40.7 years and a mean body mass index of 33.3 kg/m(2). In the shunting after stent placement group, the mean opening pressure on the most recent lumbar puncture obtained prior to any intervention was 50 cm of H2O, whereas the group that underwent stent placement alone had an opening CSF pressure of 37 cm of H2O which was statistically significant (p<0.05). There were no other significant differences in pre- or post-intervention factors between the two groups. CONCLUSION: In patients with IIH and documented evidence of venous sinus stenosis with a pressure gradient, venous sinus stenting should be the primary treatment of choice; however, some patients may be refractory to stenting and still require permanent CSF diversion, which can be complicated in these chronically anticoagulated patients. Patients with persistent papilledema post-stenting and highly elevated opening pressure pre-stenting should be followed closely as they are at greatest risk of requiring a shunt and failing stenting.