DOI: https://doi.org/10.21203/rs.3.rs-542088/v1
Idiopathic intracranial hypertension (IIH) is characterized by increased intracranial pressure without evidence of a tumor or any other underlying cause. Headache and visual disturbances are frequent complaints of IIH patients, but little is known about other symptoms. In this study, we evaluated the patients’ perspective on the burden of IIH.
For this cross-sectional study, we developed an online survey for patients with IIH containing standardized evaluations of headache (HIT-6), sleep (PROMIS Sleep Disturbance Scale) and depression (MDI) in relation to BMI, lumbar puncture opening pressure (LP OP) and treatment.
Between December 2019 and February 2020, 306 patients completed the survey. 285 (93%) were female, mean age was 36.6 years (± 10.8), mean BMI 34.2 (± 7.3) and mean LP OP at diagnosis was 37.8 cmH2O (± 9.5). 219 (72%) of the participants were obese (BMI ≥ 30); 251 (82%) reported severe impacting headaches, 140 (46%) were suffering from sleep disturbances and 169 (56%) from depression. Higher MDI scores correlated with higher BMI and increased sleep disturbances. Patients with a normalized LP opening pressure reported less headaches, less sleep disturbances and less depression than those with a constantly elevated opening pressure.
In addition to headaches and visual disturbances, sleep disturbances and depression are frequent symptoms in IIH and contribute to the patients’ burden. Structured questionnaires can help to identify IIH patients’ needs and can lead to personalized and better treatment.
Idiopathic intracranial hypertension (IIH) or pseudotumor cerebri is a neurological disorder characterized by increased intracranial pressure without evidence of a tumor or any other underlying disease [1, 2]. In the 90s, IIH was considered a rare condition with an initial incidence of one per 100.000 in the general population [3]. In line with the world-wide increase in obesity, the incidence of IIH raised considerably from 2.2 in 2002 to 4.7 per 100.000 in 2016 [4]. Although it can affect all subgroups of the population, studies show a significantly higher risk for young, overweight women of childbearing age [5]. Main symptoms are a throbbing headache, variable vision disturbances, pulsatile tinnitus and generalized weakness [6]. The headache is typically characterized as pressing or pulling, is usually bilateral and fronto-retroorbital and occurs almost daily. Impaired vision is a serious complication and can lead to complete loss of vision [7]. As the acronym implies, the cause of IIH remains unknown and treatment options are focused on reducing intracranial pressure to prevent visual loss [8–11]. A recent publication showed a severely reduced quality of life in IIH patients [12]. To broaden the understanding of patients' symptom burden, we aimed to investigate the role of sleep disturbances, depression and psychosocial aspects in IIH patients.
Survey design
For this cross sectional study, we developed an online survey for patients with IIH, which was carried out using LimeSurvey version 2.56.1. The first part of the questionnaire consisted of 20 open questions and was designed to explore the basic characteristics, including age, sex, size, weight, time since diagnosis as well as the lumbar puncture (LP) opening pressure at diagnosis (OPD) and most recently measured (OPR). We collected additional data on visual disturbances, number of LP, presence of post-lumbar puncture headache, current medication, and psychosocial aspects of the disease, such as the perception of LP, patient satisfaction and physician-patient communication (Appendix 1 in ESM). The second part evaluates the main topics of interest (headaches, sleep and mood disturbances), using validated and standardized questionnaires. For assessment of the impact of headache in daily life, the 6 items Headache Impact Test (HIT-6) is used, for sleep quality the Patient-Reported Outcomes Measurement Information System Sleep Disturbance Short form 8a (PROMIS-SD) and for depression the Major Depression Inventory (MDI) [13–15]. Exclusion criteria for further statistical analysis were incomplete data collection for the main parameters (BMI, LP OPD, HIT 6, MDI, PROMIS) or incoherent data (age <18 or >100 years, LP OPD <20 cmH2O or >60 cmH2O, number of lumbar punctures >100).
Patient recruitment
The German Society for Intracranial Hypertension invited patients diagnosed with IIH (self-report) on their social media platform (https://www.dgih.org/f) to participate in our survey via an encrypted link. In addition, IIH patients treated in our clinic were invited to participate in the study. All data were collected anonymously, and consent was obtained before participation in the survey. The Research Ethics Committee of the University Hospital in Bonn has confirmed that no ethical approval was required for this observational study.
Data Analysis
Standard descriptive measures are provided, including mean (± standard deviation) and frequency distribution where appropriate. Correlations were studied using Spearman’s rank order and correlation and multivariable logistic regression analyses were used to identify independent predictors for depression. Mann-Whitney rank sum test and Kruskal-Wallis test were employed for comparison of two or more than two groups, respectively. Post-hoc analyses were calculated with Dunn-Bonferroni-Test. Cohen’s classification was used to assess the effect size (r). An alpha level of 0.05 was considered statistically significant and all tests are two-sided. Data analysis was performed with SPSS version 25 (Armonk, NY: IBM Corp.).
Between December 2019 and February 2020, 527 of estimated 1000 invited active members of the German Society of Intracranial Hypertension participated in the survey. 159 (30%) patients were excluded due to incomplete information and 62 (12%) because of incoherent data as defined above. The mean time to complete the questionnaire was 13.5 minutes (± 7.6 minutes). Among the 306 participants available for analysis, 285 (93%) were female and the mean age was 36.6 years (± 10.8, Table 1). The mean time since diagnosis was 4.2 years (± 4.0) and a mean time interval between symptom onset and diagnosis of 3.0 years (± 4.9 months) was stated. Upon diagnosis a mean LP OPD of 37.8 cmH2O (± 9.5) was reported. 219 (72%) of the participants were obese; 114 (37%) of them reported weight-gain shortly before diagnosis.
In terms of treatment, 200 (65%) reported taking carbonic anhydrase inhibitors: 114 (37%) received acetazolamide, 31 (10%) topiramate and 55 (18%) reported taking both. In addition, the survey revealed that 101 (33%) of the respondents were taking antidepressants, 79 (26%) oral contraception and 28 (9%) oral antidiabetics. Patients who took acetazolamide showed a trend towards better MDI scores than patients on topiramate or without medication (p=0.246, Table 1 in Appendix 2). Patients reported having received an average of 15 (± 13.1) lumbar punctures. 240 (78%) patients found the LP extremely uncomfortable, 251 (82%) reported post-lumbar puncture headaches.
The majority of the patients reported a high symptom burden in the standardized questionnaires. 251 (82%) reported a severe impact of headaches on their daily life (HIT-6 ≥60), 140 (46%) reported suffering from moderate or severe sleep disturbances (PROMIS SD T-score ≥60) and 169 (59%) suffering from moderate or severe depression (MDI >25, Figure 1). 236 (77%) reported frequent visual problems and 116 (49%) of these felt that their daily life was very often severely impacted as a result. Furthermore, 184 of the patients (60%) complained about a lack of psychological support and 245 (80%) claimed that physicians were insufficiently informed about the disease.
In Spearman’s correlation analysis, BMI (r=0.2, p<0.001), HIT-6 (r=0.5, p<0.001) and PROMIS SD score (r=0.1, p<0.001) were all correlated with MDI scores, while OPR was not (p=0.124). In line with these findings, patients with depression (MDI >20) were more frequently obese and reported both a stronger impact of headaches on their daily life and more severe sleep disturbances. With regard to sleep disturbances, post-hoc analyses showed a strong effect size between MDI ≤20 and MDI>30 (r=0.5, p< 0.001), a medium effect size between MDI ≤20 and MDI 21-30 (r=0.3, p=0.003) and a small effect size between MDI 21-30 and >30 (r=0.2, p=0.006; Table 2 and 3 in Appendix 2). In multivariable logistic regression analysis adjusted for age and gender, the presence of obesity, sleep disturbances and severe impact of headaches on daily life were independent predictors for depression (MDI>20; Table 2). Finally, patients with an OPR ≤25 cmH2O had a lower BMI (r=0.3, p<0.001) and reported lower scores in all questionnaires compared to patients with an OPR >25 cmH2O: HIT-6 (r=0.1, p=0.049), PROMIS SD (r=0.2, p=0.009) and MDI (r=0.1, p=0.036; Figure 2 and Table 4 in Appendix 2).
Headaches and visual disturbances are the most obvious symptoms in IIH and the main reason why IIH patients present to the neurologist or the ophthalmologist. In our study, more than 75% of the participants reported visual disturbances and headaches severely impacting their daily lives. In addition to these cardinal symptoms of IIH, almost 50% of the participants reported relevant sleep disturbances and depression. Since sleep disorders and depression are not described as being related to the disease, they might be insufficiently addressed in current clinical practice.
Marcus et al. considered sleep disturbances as a key risk factor for IIH and suggested that nocturnal hypercapnia is responsible for increased intracranial pressure and secondary papilledema [16]. Although obstructive sleep apnea syndrome (OSAS) is often described in IIH patients, it is not clear whether this is induced by IIH or due to the co-occurrence of obesity in IIH patients, which is a known risk factor for OSAS [17]. Daniels et al. showed a correlation between BMI and the risk of IIH [18], furthermore Kesler at al. demonstrated that increased weight is associated with recurrence of the disease [19]. In line with these findings, our survey revealed a strong interaction between a higher BMI and sleep disturbances. In addition, the study showed that in many cases, the onset of the disease was preceded by weight-gain.
Depression has an estimated lifetime prevalence of 15-20% and severe depression has been identified in 37% of IIH patients [20, 21]. An even higher rate of depression (56%) was (self-) reported in our survey, with one third of the participants under an antidepressant medication. Important of note, topiramate (which 86 of the participants reported among their medication) may worsen depression and induce cognitive decline [22]. While the correlation of obesity and depression has been recognized earlier [23], depression also correlates with headaches and sleep disturbances. In our survey obesity, severe impact of headache in daily life and sleep disturbances were confirmed as independent predictors for depression.
60% of the participants complained about a lack of information on IIH and 80% claimed that physicians had insufficient knowledge about the disease. This suggests that physicians focus too much on LP OP and tend to perform procedures rather than consider psychological aspects. Repeated LP was perceived uncomfortable by many and post-lumbar puncture headaches may be understimated in IIH patients. Indeed, in a recent study by Yiangou et al., the authors pointed out that LP should only be performed in severe headaches or to prevent visual loss [24].
Depression and sleep disturbances can impair the ability to treat IIH and may particularly hamper weight loss. Weight gain and lack of exercise in turn promote the development of headache, sleep disturbances and depression. Patients thus find themselves in a vicious circle, with symptoms driving each other; an effect that may be exacerbated by the lockdown measures during the current pandemic [25]. We therefore strongly recommend the use of standardized questionnaires to assess patients' symptoms, followed by multidisciplinary diagnosis and treatment, including referral to psychologists, psychiatrists and sleep physicians.
There are some limitations to our study that should be noted. First there was no external verification of the IIH diagnosis other than self-report and the same applies to all medical data, including symptoms and LP values. Second, the survey contained open questions, representing a subjective and individual view on the collected parameters. Further, there might be a selection bias, as patients with a higher level of suffering might be more likely to participate in the survey.
In addition to headaches and visual disturbances, sleep disturbances and depression are frequent symptoms in IIH and contribute to the patients’ symptom burden. Clinicians should be aware that IIH patients may suffer from high levels of sleep disturbance and depression and assess their psychosocial needs, including their obvious need for more information and psychological support. Here we encourage the use of structured questionnaires, particularly MDI and PROMIS SD in patients with a BMI ≥30, to identify the affected patients and initiate further diagnostics and therapy where applicable.
IIH Idiopathic intracranial hypertension
HIT-6 6 Items Headache Impact Test
PROMIS Patient-Reported Outcomes Measurement Information System for Sleep disturbances
MDI Major Depression Inventory
BMI Body mass index
LP lumbar puncture
OPD opening pressure at diagnose
OPR opening pressure, most recently measured
OSAS obstructive sleep apnea syndrome
Ethics approval
This is an anonymous observational study. Ethical approval was waived by the The Research Ethics Committee of the University Hospital Bonn.
Consent for publication
Informed consent was obtained before participating in the study
Availability of data and material
The Data can be obtained from the corresponding author upon reasonable request. Because of restrictions based on privacy regulations and informed consent of the participants, data cannot be made freely available in a public repository.
Competing interests
The authors have no relevant financial or non-financial interests to disclose.
Funding
No funding was received for conducting this study.
Authors’ contribution
M.W. and U.W. conceived of the idea and created the survey, which was carried out with the help of A.L.. M.W. analyzed the data and drafted the manuscript. C.K. and J.W. aided in interpreting the results and contributed to the statistical analysis. U.W. supervised the findings of this work and contributed to the final version of the manuscript. All authors discussed the results and contributed to the manuscript.
Acknowledgments
The authors would like to extend their thanks to all the respondents and participants who made this survey possible. We would also like to thank the German society for intracranial hypertension for their support and Jens Reimann for constructive criticism of the manuscript.
Table 1: Demographic and clinical characteristics of the participants.
Characteristics |
Mean ± SD |
Min. - Max. |
Age [years] |
36.6 ± 10.8 |
18-61 |
BMI [kg/m2] |
34.2 ± 7.3 |
15-59 |
Time since diagnose [years] |
4.2 ± 4.0 |
1-21 |
LP OPD [cmH2O] a |
37.8 ± 9.5 |
20-60 |
LP OPR [cmH2O] b |
29.7 ± 9.2 |
10-57 |
HIT-6 c |
62.1 ± 5.4 |
36-66 |
PROMIS SD (T-score*) d |
58.8 ± 8.1 |
28.9-76.5 |
MDIe |
26.7 ± 12.9 |
0-54 |
(a) Lumbar puncture opening pressure at diagnose (LP OPD).
(b) Lumbar puncture opening pressure, most recently measured (LP OPR).
(c) Headache Impact Test <50: no impact, HIT-6 50-55: moderate impact, HIT-6 56-59: substantial impact and HIT-6 ≥60: severe impact.
(d) PROMIS Sleep disturbance short form 8a T-score <55%: no, T-score 55-60: mild, T-score 60-70: moderate and T-score >70: severe sleep disturbances, *raw score converted to T-score.
(e) Major Depression Inventory 0-20: no depression, MDI 21-25: mild, MDI 26-30: moderate depression and MDI 31-50: severe depression.
Table 2: Multivariable logistic regression analysis of independent predictors of depression defined as MDI >20, adjusted for age and sex.
Item |
aOR |
95% CI |
Significance p |
Obesity (BMI ≥30) |
5.35 |
1.45-19.76 |
0.012* |
Severe headache impact (HIT-6 ≥60) |
2.06 |
1.19-3.58 |
0.010* |
Relevant sleep disturbances (PROMIS SD T score ≥60) |
4.36 |
2.50-7.61 |
<0.001** |
BMI Body Mass Index (kg/m2), HIT-6 Headache Impact Test, PROMIS SD Patient-Reported Outcomes Measurement Information System Sleep Disturbance Short form 8a, MDI Major Depression Inventory, aOR adjusted odds ratio, 95% CI confidence interval, * statistically significant (p <0.05).