Inpatient and emergency service utilization in patients with idiopathic intracranial hypertension

Thecoperitoneal Shunts—Our 20 Years Experience

Introduction The thecoperitoneal shunt is a modality of cerebrospinal fluid (CSF) diversion used to treat various clinical conditions such as idiopathic intracranial hypertension (IIH), normal pressure hydrocephalus (NPH), and CSF leaks. There is a wide variability in the data regarding the utility and complications associated with it. We thus reviewed the outcomes and complications of the shunt done in our setting.

Methodology The study is a retrospective review of all the thecoperitoneal shunts performed at NIMHANS (National Institute of Mental Health and Neurosciences) from January 2000 to December 2020. The demographic details, clinical profile, indications for the shunt, magnetic resonance imaging, follow-up and complications, and shunt revisions were collected and analyzed.

Results Three-hundred twelve patients underwent shunt primarily at our institute. The mean follow-up of the patients was 5.2 years. The indications include pseudomeningocele in 31.4%, CSF leak from surgical site in 25.3%, IIH in 17.6%, and NPH in 7.3% patients.

The shunt was more effective in pseudomeningocele in up to 95% and CSF leaks in 91% compared to 64‰ in IIH, though it is not significant (p > 0.05). The complication rate was 17% that included shunt block, wound CSF leak, infection, and subdural hygromas. The shunt malfunction was seen in 14.69% patients who underwent revision.

Conclusion Thecoperitoneal shunt is a useful treatment option for various pathologies including IIH, NPH, and wound CSF leaks. They have good clinical outcomes and acceptable revision rates especially in conditions with slit ventricle. The complications such as low-pressure headache can be overcome by using adjuncts as programmable valve or antisiphon device.

Predictive Value of International Classification of Diseases Codes for Idiopathic Intracranial Hypertension in a University Health System

BACKGROUND

Misclassification bias is introduced into medical claims-based research because of reliance on diagnostic coding rather than full medical record review. We sought to characterize this bias for idiopathic intracranial hypertension (IIH) and evaluate strategies to reduce it.

METHODS

A retrospective review of medical records was conducted using a clinical data warehouse containing medical records and administrative data from an academic medical center. Patients with 1 or more instances of International Classification of Diseases (ICD)-9 or -10 codes for IIH (348.2 or G93.2) between 1989 and 2017 and original results of neuroimaging (head CT or MRI), lumbar puncture, and optic nerve examination were included in the study. Diagnosis of IIH was classified as definite, probable, possible, or inaccurate based on review of medical records. The positive predictive value (PPV) for IIH ICD codes was calculated for all subjects, subjects with an IIH code after all testing was completed, subjects with high numbers of IIH ICD codes and codes spanning longer periods, subjects with IIH ICD codes associated with expert encounters (ophthalmology, neurology, or neurosurgery), and subjects with acetazolamide treatment.

RESULTS

Of 1,005 patients with ICD codes for IIH, 103 patients had complete testing results and were included in the study. PPV of ICD-9/-10 codes for IIH was 0.63. PPV in restricted samples was 0.82 (code by an ophthalmologist n = 57), 0.70 (acetazolamide treatment n = 87), and 0.72 (code after all testing, n = 78). High numbers of code instances and longer duration between the first and last code instance also increased the PPV.

CONCLUSIONS

An ICD-9 or -10 code for IIH had a PPV of 63% for probable or definite IIH in patients with necessary diagnostic testing performed at a single institution. Coding accuracy was improved in patients with an IIH ICD code assigned by an ophthalmologist. Use of coding algorithms considering treatment providers, number of codes, and treatment is a potential strategy to reduce misclassification bias in medical claims-based research on IIH. However, these are associated with a reduced sample size.

Factors Associated With Adherence to Outpatient Follow-Up in Patients With Idiopathic Intracranial Hypertension (IIH)

Idiopathic intracranial hypertension (IIH) is a chronic condition characterized by raised intracranial pressure of undetectable origin, that causes morbidity due to debilitating headaches and vision loss. Continuity of outpatient care is important to monitor for permanent vision loss, manage symptoms and limit emergency care. The purpose of this retrospective study was to identify factors associated with neuro-ophthalmology follow-up appointment completion among patients with IIH at a US academic medical center in order to establish evidence-based interventions to improve adherence patterns. Included are 111 completed or no-show neuro-ophthalmology return outpatient appointments by 23 subjects with IIH. Generalized estimating equation models were used to assess association between appointment completion status and factors previously shown to be associated with appointment adherence. Appointments were more likely to be completed during the summer (p=0.08) and by subjects with headache symptoms (p=0.06), however none of the patient factors reached statistical significance. Completed and no-show appointments did not differ by subject demographic or insurance factors. Further studies are needed to identify risk factors for lack of appointment adherence by patients with IIH, particularly those amenable to intervention, in order to improve continuity of care for IIH.

The Effective Management of Idiopathic Intracranial Hypertension Delivered by In-person and Virtual Group Consultations: Results and Reflections from a Phase One Service Delivery

The increasing incidence of idiopathic intracranial hypertension (IIH) with the obesity epidemic is leading to increased pressures on service capacity. Evidence shows that group consultations (GCs) deliver effective, person-centred healthcare, but the feasibility for IIH is unknown. We set out to develop and test a safe and effective GC service for IIH. Through an interactive approach, we co-designed a bespoke in-person and virtual GC model, where patients are reviewed in a group setting. Improvements were made following each session following patient input and team reflections. Outcomes measured included patient satisfaction, self-perceived health literacy, and successful implementation of the GCs. During the pilot, eight in-person GCs were delivered: once-monthly (Oct-Dec 2019), then twice-monthly (Jan-Feb 2020). Feedback was received from 49/53 patients. 100% felt more satisfied and heard, 100% felt more involved in decision-making, 98% had a better understanding of their condition, 96% felt more able to cope with their condition and keep themselves healthy, 94% rated this as a positive experience, and 90% reported improved access and more time with their clinician compared with existing 1:1 appointments. Since September 2020, in response to the COVID-19 pandemic, we transitioned to weekly virtual GCs, receiving overwhelmingly positive feedback (median scores: patient satisfaction 9.5/10; being listened to by clinician 10/10; involved by clinician in treatment decisions 10/10; clinician explanation of treatment 10/10; and opportunity to discuss condition or treatment 10/10). GCs are safe and effective for IIH, and preferred in our patient cohort. This allowed ongoing high-quality, person-centred care despite challenges from the COVID-19 pandemic.

Neurosurgical CSF Diversion in Idiopathic Intracranial Hypertension: A Narrative Review

The prevalence of idiopathic intracranial hypertension (IIH), a complex disorder, is increasing globally in association with obesity. The IIH syndrome occurs as the result of elevated intracranial pressure, which can cause permanent visual impairment and loss if not adequately managed. CSF diversion via ventriculoperitoneal and lumboperitoneal shunts is a well-established strategy to protect vision in medically refractory cases. Success of CSF diversion is compromised by high rates of complication; including over-drainage, obstruction, and infection. This review outlines currently used techniques and technologies in the management of IIH. Neurosurgical CSF diversion is a vital component of the multidisciplinary management of IIH.

An institutional review of hospital resource utilization and patient radiation exposure in shunted idiopathic intracranial hypertension

Patients with idiopathic intracranial hypertension (IIH) frequently utilize healthcare services and undergo radiological studies to assess refractory headache symptoms despite cerebrospinal fluid diversion. To delineate the clinical utility of different imaging modalities and to estimate cumulative patient radiation exposure in shunted patients with IIH, we retrospectively reviewed 100 randomly selected patients with IIH and a prior cerebrospinal fluid diversion procedure treated at our institution between July 2010 and August 2018. Patients had an average of 16.3 office (SD ± 13.8), 12.4 emergency department (± 21.0), and 4.6 inpatient (± 5.1) encounters over an average 4.8 years of follow-up. Patients underwent an average of 9.0 head CTs (± 8.1), 10.3 shunt series x-rays (± 11.2), and 4.3 MRIs (± 3.7). Approximated radiation exposure per patient was 21.4 mSv (± 18.7). Radiological studies performed for acute symptoms usually demonstrated no actionable findings (82.5% CTs, 97.5% shunt series x-rays, and 79.6% MRIs). Shunted IIH patients undergo numerous radiological studies and are subject to considerable levels of radiation, yet imaging shows actionable findings in less than 10% percent of radiographic studies. IIH patients may benefit from radiation-reducing protocols and the use of alternative imaging to assess symptoms.

Big Data Research in Neuro-Ophthalmology: Promises and Pitfalls

BACKGROUND

Big data clinical research involves application of large data sets to the study of disease. It is of interest to neuro-ophthalmologists but also may be a challenge because of the relative rarity of many of the diseases treated.

EVIDENCE ACQUISITION

Evidence for this review was gathered from the authors' experiences performing analysis of large data sets and review of the literature.

RESULTS

Big data sets are heterogeneous, and include prospective surveys, medical administrative and claims data and registries compiled from medical records. High-quality studies must pay careful attention to aspects of data set selection, including potential bias, and data management issues, such as missing data, variable definition, and statistical modeling to generate appropriate conclusions. There are many studies of neuro-ophthalmic diseases that use big data approaches.

CONCLUSIONS

Big data clinical research studies complement other research methodologies to advance our understanding of human disease. A rigorous and careful approach to data set selection, data management, data analysis, and data interpretation characterizes high-quality studies.

Validity of International Classification of Diseases Codes for Identifying Neuro-Ophthalmic Disease in Large Data Sets: A Systematic Review

BACKGROUND

Administrative health claims data have been used for research in neuro-ophthalmology, but the validity of International Classification of Diseases (ICD) codes for identifying neuro-ophthalmic conditions is unclear.

EVIDENCE ACQUISITION

We performed a systematic literature review to assess the validity of administrative claims data for identifying patients with neuro-ophthalmic disorders. Two reviewers independently reviewed all eligible full-length articles and used a standardized abstraction form to identify ICD code-based definitions for 9 neuro-ophthalmic conditions and their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). A quality assessment of eligible studies was also performed.

RESULTS

Eleven articles that met criteria for inclusion are as follows: 3 studies of idiopathic intracranial hypertension (PPV 54%-91% and NPV 74%-85%), 2 studies of giant cell arteritis (sensitivity 30%-96% and PPV 94%), 3 studies of optic neuritis (sensitivity 76%-99%, specificity 83%-100%, PPV 25%-100%, and NPV 98%-100%), 1 study of neuromyelitis optica (sensitivity 60%, specificity 100%, PPV 43%-100%, and NPV 98%-100%), 1 study of ocular motor cranial neuropathies (PPV 98%-99%), and 2 studies of myasthenia gravis (sensitivity 53%-97%, specificity 99%-100%, PPV 5%-90%, and NPV 100%). No studies met eligibility criteria for nonarteritic ischemic optic neuropathy, thyroid eye disease, and blepharospasm. Approximately 45.5% provided only one measure of diagnostic accuracy. Complete information about the validation cohorts, inclusion/exclusion criteria, data collection methods, and expertise of those reviewing charts for diagnostic accuracy was missing in 90.9%, 72.7%, 81.8%, and 36.4% of studies, respectively.

CONCLUSIONS

Few studies have reported the validity of ICD codes for neuro-ophthalmic conditions. The range of diagnostic accuracy for some disorders and study quality varied widely. This should be taken into consideration when interpreting studies of neuro-ophthalmic conditions using administrative claims data.

Drug-Induced Intracranial Hypertension: A Systematic Review and Critical Assessment of Drug-Induced Causes

BACKGROUND

Idiopathic intracranial hypertension (IIH) is a condition with increased intracranial pressure of unknown etiology. Its presenting symptoms include persistent headache, pulsatile tinnitus, and visual obscuration. It tends to occur in obese women of childbearing age, and its greatest risk is irreversible loss of vision. Some of the commonly used medications in dermatology, especially those for acne vulgaris, have been associated with IIH. However, the creation of specific risk categories for drugs as a guide for clinicians has never been performed.

OBJECTIVE

The aim of this study was to critically assess all published cases of IIH and identify high-risk drugs associated with drug-induced intracranial hypertension (DIIH), to assist dermatologists and other physicians with patient education and monitoring of symptoms of secondary intracranial hypertension.

METHODS

MEDLINE, EMBASE, and Cochrane Review Databases were searched for all cases of IIH thought to be drug-related between January 1900 and June 2019. A total of 5117 articles were identified, and 235 articles were found to be relevant. All cases were assessed to satisfy the modified Dandy criteria for diagnosis of IIH, and the likelihood of each case being a 'definite' adverse drug reaction (ADR) was determined using the Koh algorithm for ADR. An association category (from weakly associated [Category I] to strongly associated [Category V]) was assigned based on the number of cases meeting these two criteria.

RESULTS

There were 259 verifiable cases of DIIH. Vitamin A derivatives, tetracycline-class antibiotics, recombinant growth hormone, and lithium were found to be most strongly associated with DIIH (Categories IV and V). Corticosteroids were moderately associated with DIIH (Category III). Drugs that were weakly associated with DIIH (Categories I and II) include cyclosporine, progestin-only contraceptives, combined oral contraceptives, second- and third-generation fluoroquinolones, sulfenazone, gonadotropin-releasing hormones and luteinizing hormone-releasing hormone agonist, nalidixic acid, amiodarone, stanozolol, danazol, divalproic acid, sulfasalazine, ketoconazole, and ustekinumab.

CONCLUSION

We suggest using the term 'drug-induced intracranial hypertension' (DIIH) and propose a set of diagnostic criteria for DIIH. Our review attempts to identify DIIH-associated drugs based on a strict diagnostic and drug-causality algorithm, then stratify them into appropriate risks categories. This may ultimately assist physicians in counselling patients about the risk of DIIH when prescribing medications and recognizing this uncommon yet sight-threatening condition.

Update on the Diagnosis and Treatment of Idiopathic Intracranial Hypertension

Advances in ophthalmic diagnostics and results of interventional clinical trials are shifting diagnosis and management of idiopathic intracranial hypertension (IIH) to be more technology- and evidence-based. In this article, the evidence supporting current diagnostic criteria, evaluation, and medical and surgical management of IIH are reviewed.

Emergency department utilization among individuals with idiopathic intracranial hypertension

PURPOSE

Idiopathic intracranial hypertension (IIH) can be a debilitating disorder that is difficult to identify and treat. Failure to adequately manage IIH symptoms may force patients to present at emergency departments (EDs) seeking symptom relief. The purpose of this paper is to empirically characterize ED use by previously diagnosed IIH patients.

DESIGN/METHODOLOGY/APPROACH

Patients diagnosed with IIH, and who registered with the Intracranial Hypertension Registry by 2014, were solicited for study inclusion. A survey was designed to elicit ED use during the period 2010-2012. Information on demographic and socioeconomic characteristics, IIH signs and symptoms, time since diagnosis, perspectives of ED use and quality of life was collected. Quality of life was assessed using an adaptation of the Migraine-Specific Quality of Life Questionnaire. Data were analyzed using descriptive statistics and nonparametric hypothesis tests.

FINDINGS

In total, 39 percent of IIH patients used emergency services over the study period; those that did used the services intensely. These patients were more likely to be non-white, live in households making less than $25,000 annually, have public insurance and have received a diversional shunt procedure. Patients who used the ED were less likely to live in households making $100,000, or more, annually and have private insurance. Participants who used the ED had significantly lower quality-of-life scores, were younger and had been diagnosed with IIH for less time.

ORIGINALITY/VALUE

ED staff and outside physicians can utilize the information contained in this study to more effectively recognize the unique circumstances of IIH patients who present at EDs.

Improving identification of idiopathic intracranial hypertension patients in Swedish patient register

OBJECTIVE

Idiopathic intracranial hypertension (IIH) is often misdiagnosed. This can cause problems if conducting register-based studies. The study purpose was to produce algorithms that better identify patients with correct diagnosis of IIH in the Swedish National Patient Register (NPR).

METHODS

Patients with ICD-10 code G93.2 for IIH registered in the NPR (2006-2013, Stockholm County) were included and diagnosis validated by medical record reviews. Patients were randomized into two groups: one used to produce the algorithm (n = 105) and one for validation (n = 102). We tested variables possible to extract from registries and used forward stepwise logistic regression which provided a predicted probability of correct diagnosis for each patient.

RESULTS

We included 207 patients of which 135 had confirmed IIH. This gave a positive predictive value of 65.2% (CI: 58.4-71.4). The algorithm produced with variables extracted from registries, that is, age, number of times with diagnosis code G93.2 recorded (>2 times), and acetazolamide treatment, predicted the diagnosis correctly 88.2% (CI: 80.3-93.3) of the time. Excluding treatment data from the algorithm did not change the prediction notably, 86.3% (CI: 78.1-91.7).

CONCLUSION

We produced two algorithms that with improved accuracy predict whether an IIH diagnosis in the NPR is correct. This can be a useful tool when performing register-based studies.

Optic nerve head edema among patients presenting to the emergency department

OBJECTIVE

To determine the frequency of and predictive factors for optic nerve head edema (ONHE) among patients with headache, neurologic deficit, visual loss, or elevated blood pressure in the emergency department (ED).

METHODS

Cross-sectional analysis was done of patients with ONHE in the prospective Fundus Photography vs Ophthalmoscopy Trial Outcomes in the Emergency Department (FOTO-ED) study. Demographics, neuroimaging results, management, and patient disposition were collected. Patients in the ONHE and non-ONHE groups were compared with bivariate and logistic regression analyses.

RESULTS

Of 1,408 patients included, 37 (2.6%, 95% confidence interval 1.9-3.6) had ONHE (median age 31 [interquartile range 26-40] years, women 27 [73%], black 28 [76%]). ONHE was bilateral in 27 of 37 (73%). Presenting complaints were headache (18 of 37), visual loss (10 of 37), acute neurologic deficit (4 of 37), elevated blood pressure (2 of 37), and multiple (3 of 37). The most common final diagnoses were idiopathic intracranial hypertension (19 of 37), CSF shunt malfunction/infection (3 of 37), and optic neuritis (3 of 37). Multivariable logistic regression found that body mass index ≥35 kg/m² (odds ratio [OR] 1.9, p = 0.0002), younger age (OR 0.5 per 10-year increase, p < 0.0001), and visual loss (OR 5, p = 0.0002) were associated with ONHE. Patients with ONHE were more likely to be admitted (62% vs 19%), to be referred to other specialists (100% vs 54%), and to receive neuroimaging (89% vs 63%) than patients without ONHE (p < 0.001). Fundus photographs in the ED allowed initial diagnosis of ONHE for 21 of 37 (57%) patients. Detection of ONHE on ED fundus photography changed the final diagnosis for 10 patients.

CONCLUSIONS

One in 38 patients (2.6%) presenting to the ED with a chief complaint of headache, neurologic deficit, visual loss, or elevated blood pressure had ONHE. Identification of ONHE altered patient disposition and contributed to the final diagnosis, confirming the importance of funduscopic examination in the ED.

Population-based incidence and clinical characteristics of idiopathic intracranial hypertension

OBJECTIVE

To validate the diagnosis of idiopathic intracranial hypertension (IIH) from the Swedish National Patient Register (NPR) and investigate the incidence of IIH, as well as co-morbidities and medication use in a large Swedish population-based sample.

METHODS

We searched the NPR to find all patients ≥18 years old with the ICD-10 diagnosis code (G93.2) for IIH in Stockholm County from Jan 1, 2006, to Dec 31, 2013. All medical records were reviewed to validate the diagnosis and to collect additional information.

RESULTS

We included 207 patients with an IIH diagnosis, of which 135 (65%) were correctly diagnosed when validated by charts review. Eighty-three patients had disease onset during the study period. This gave a yearly incidence of 0.65/100 000. Female-to-male ratio was 6.1:1. Females, mean age 31.0 (CI 28.8-33.1), were younger at time of diagnosis compared to males, mean age 42.9 (CI 36.4-49.5), P<.001. The most common co-morbidities were obesity (92%), hormonal conditions (21%) and recent infections preceding the diagnosis (21%). Prior treatment with tetracycline derivatives were seen in 9%.

CONCLUSION

The incidence of IIH in Stockholm is in the lower range of previously reported rates, possibly due to a lower prevalence of obesity. A substantial proportion of patients (35%) did not fulfill diagnostic criteria. Disease onset occurs at younger age in females. Co-morbidities were mainly associated with diseases affecting hormonal balance or causing inflammatory activation. These findings raise new hypothetical theories regarding mechanisms involved in IIH pathogenesis.

Predictors of admission and shunt revision during emergency department visits for shunt-treated adult patients with idiopathic intracranial hypertension

OBJECTIVE

Factors associated with emergency department admission and/or shunt revision for idiopathic intracranial hypertension (IIH) are unclear. In this study, the associations of several factors with emergency department admission and shunt revision for IIH were explored.

METHODS

The authors performed a retrospective review of 31 patients (169 total emergency department visits) who presented to the emergency department for IIH-related symptoms between 2003 and 2015. Demographics, comorbidities, symptoms, IIH diagnosis and treatment history, ophthalmological examination, diagnostic lumbar puncture (LP), imaging findings, and data regarding admission and management decisions were collected. Multivariable general linear models regression analysis was performed to assess the predictive factors associated with admission and shunt revision.

RESULTS

Thirty-one adult patients with a history of shunt placement for IIH visited the emergency department a total of 169 times for IIH-related symptoms, with a median of 3 visits (interquartile range 2–7 visits) per patient. Five patients had more than 10 emergency department visits. Baseline factors associated with admission included male sex (OR 10.47, 95% CI 2.13–51.56; p = 0.004) and performance of an LP (OR 3.10, 95% CI 1.31–7.31; p = 0.01). Contrastingly, older age at presentation (OR 0.94, 95% CI 0.90–0.99; p = 0.01), and a greater number of prior emergency department visits (OR 0.94, 95% CI 0.89–0.99; p = 0.02) were slightly protective against admission. The presence of papilledema (OR 11.62, 95% CI 3.20–42.16; p < 0.001), Caucasian race (OR 40.53, 95% CI 2.49–660.09 p = 0.009), and systemic hypertension (OR 7.73, 95% CI 1.11–53.62; p = 0.03) were independent risk factors for shunt revision. In addition, a greater number of prior emergency department visits (OR 0.86, 95% CI 0.77–0.96; p = 0.009) and older age at presentation (OR 0.93, 95% CI 0.87–0.99; p = 0.02) were slightly protective against shunt revision, while there was suggestive evidence that presence of a programmable shunt (OR 0.23, 95% CI 0.05–1.14; p = 0.07) was a protective factor against shunt revision. Of note, location of the proximal catheter in the ventricle or lumbar subarachnoid space was not significantly associated with admission or shunt revision in the multivariable analyses.

CONCLUSIONS

The decision to admit a shunt-treated patient from the emergency department for symptoms related to IIH is challenging. Knowledge of factors associated with the need for admission and/or shunt revision is required. In this study, factors such as male sex, younger age at presentation, lower number of prior emergency department visits, and performance of a diagnostic LP were independent predictors of admission. In addition, papilledema was strongly predictive of the need for shunt revision, highlighting the importance of an ophthalmological examination for shunt-treated adults with IIH who present to the emergency department.

The Utility of Computed Tomography in Shunted Patients with Idiopathic Intracranial Hypertension Presenting to the Emergency Department

BACKGROUND

Shunted patients with idiopathic intracranial hypertension (IIH) often present to the emergency department (ED) for symptoms related to their disease. Although brain imaging with computed tomography (CT) is often performed, particularly in the current medicolegal environment, its utility during these ED visits is unclear.

METHODS

The ED visits of all shunted adult patients with IIH from 2003-2015 were retrospectively reviewed. ED visits not related to IIH were excluded from our study.

RESULTS

Thirty-one patients visited the ED 171 times for IIH symptoms. Five patients had greater than 10 ED visits. Twenty-five (81%) patients had 131 visits involving a CT scan, while six (19%) patients were not scanned. The majority of scans (n = 126, 96%) showed no change; five (4%) scans detected new noncritical pathologies. On the basis of CT findings alone, treatment changes occurred in three (2.3%) instances. Of the 131 visits with a CT scan, twenty-five (19%) visits resulted in management changes; of the 40 ED visits without a CT scan, four (10%) visits resulted in a management change (P = 0.23).

CONCLUSIONS

In our cohort, CT imaging rarely showed a change in pathology or affected the management of patients with IIH. There was no difference in the rate of management changes between those patients who underwent a CT scan and those who did not. Given the risk of cumulative radiation exposure and cost of CT scans, CT imaging should be used when there is concern for visual dysfunction and the utility of CT imaging in the ED for the workup of other symptoms related to IIH must be explored further.