All our studied patients were obese females with high body mass index (BMI) (above 25 kg/m2) as reported in previous studies which reported also that the BMI was not significantly correlated with neither CSF opening pressure nor clinical severity of headache as our study. We found that the CSF pressure tended to be higher in patients with higher BMI [12, 13]. This lack of correlation between BMI and severity of headache may be attributed to the subjective assessment of pain and the different pain threshold among the participants.
IIH was also reported to occur in old age (such as 80 years); however, they present mainly with visual manifestation and mild headache. Their prognosis is usually better than young adults [14, 15]. In contrast, Yri et al. [16] reported that young age and high initial ICP were associated with better headache outcome after 1 year of follow-up. The explanation for their finding was the different etiologies of IIH in young and old age [16], for example, IIH occurring in younger age (especially children) is mostly secondary to endocrinal disturbances, sinusitis, and prepubertal hormonal changes. However, the IIH occurring in adults is idiopathic and the exact cause are unknown. In the current study, there was no correlation between age and follow-up clinical response. This may be due to the short period of follow-up (3 months) in comparison to 1 year follow-up reported in the literature.
Multiple comorbidities and drug use commonly oral contraceptive pills were reported to be associated with IIH. Many studies found that patients with IIH commonly have comorbidities which may have a role in the pathogenesis of the disease such as polycystic ovary syndrome (PCO), anemia, endocrinal disorders as hypothyroidism. We found no correlation between use of hormonal contraception and the severity of headache in contrast to the findings of another study which reported a significant correlation between the use of hormonal contraception and severity of headache assessed by headache impact test [13]. This may be attributed to different headache scales used. Misdiagnosis and delayed diagnosis are common among IIH patients as reported in previous studies. Usually, patients neglect their headache when it is relieved by analgesics. They sought medical advice either due to increase severity of headache, development of diplopia, or decrease in visual acuity, thus indicating IIH diagnosis [17, 18].
Headache is the most common presentation in patients with IIH. However, the headache profile is not pathognomonic in IIH [19]. In previous IIH studies, headache character, site, and frequency varied among patients with the throbbing temporal headache constituting the most common type. Only few patients experienced headache of unclassified character [20, 21]. In agreement with previous studies, it was found in the current study that daily constant, bitemporal, throbbing, and severe headache was the most common type of headache encountered.
Transient visual obscurations are the second most common symptom described in patients with IIH in multiple studies [12, 22]. Other studies, as well as this study, found that blurred vision and diplopia were the predominant visual symptoms. Tinnitus is experienced by many IIH patients which may be due to intensified vascular pulsation and flow disturbances in venous system.
Papilledema is considered the most important cardinal sign in this disease. In agreement with previous studies [12, 13, 22], it was found that most of our patients (84%) had symmetrical grades of papilledema, and only a minority (16%) showed asymmetrical grades. This asymmetry may be due to optic nerve sheath defects and loss of lamina cribrosa compliance. In agreement with previous studies [22, 23], papilledema grade was significantly correlated with CSF opening pressure and the severity of headache. This is in contrary with Friedman study that revealed no correlation between HIT-6 headache severity score and papilledema grade [17].
Previous studies proved the lack of correlation between CSF opening pressure and severity of headache using HIT-6 score [17, 22]. The lack of association between the presence and intensity of headache and CSF opening pressure may be a result of natural fluctuation in CSF pressure throughout the day [24]. In the current study, all patients with high CSF pressure had reported headache with a significant correlation between CSF opening pressure and severity of headache.
In the current study, MRI was normal in only one patient. It showed also separate or combined signs of increased ICP. Posterior globe flattening, optic nerve sheath distension, optic nerve tortuosity, and empty sellaturcica were the most common MRI findings. None of our cases had slit-like ventricles in their MRI as it is highly specific but least sensitive sign as previously proved [25]. Larger sample size may be needed for further detection of slit-like ventricles. Combination of radiological signs of IIH raises the specificity for the diagnosis of IIH.
These radiological signs were reported by Lim et al. [26], Agid et al. [27], and others [6, 27] who had described the specificity and sensitivity of these imaging findings in IIH. Those researchers reported that posterior globe flattening, optic nerve protrusion, and slit-like ventricles had maximum specificity (100%). Empty or partially empty sella is a non-specific sign. It is present in normal individuals or in any cause of elevation in ICP [28], [6, 28]. In agreement with our study, another radiological markers that were revealed in our sample were prominent Meckel’s cave and posterior displacement of pituitary stalk [25, 29]. Transverse sinus abnormalities either unilateral or bilateral were found to be common in our study in agreement with previous studies [13, 25]. The majority of patients have normal finding suggesting that IIH may not be caused by venous cause or stenosis. In spite of the findings from another study that bilateral transverse venous sinus stenosis was present in absence of diagnosis of IIH. The elevated ICP may result in more worsening of TSS. In contrary to Chagot et al. who stated that bilateral TSS was significantly higher among older patients, we found that older patients had normal MRV. This difference may be due to the small size of our sample.
We found no significant improvement on medical therapy only. Unlike other previous studies that reported significant improvement among patients who received medical therapy and further significant improvement when weight loss was added [30]. This denotes that weight loss is an important line of treatment. The present study showed similar total improvement in most of patients who received combined medical and repeated lumbar puncture. In previous studies, repeated spinal tapping was mainly used in pregnant women as the best line of treatment and showed improvement in their symptoms [31].
In the present study, there was an improvement in papilledema grade after treatment in most of the patients. No correlation was found between papilledema grade before treatment in IIH and its improvement after treatment and follow-up. Previous studies showed that treatment effect was greater in patients with a higher papilledema grade at baseline compared to mild grade [22]. The response time for the optic disk to normalize after treatment may depend on the severity of baseline disk edema but, Maren Skau found that severity of papilledema at presentation is not predictive for chronic course of IIH [18]. Thin patients experienced high incidence of relapse of symptoms after 3 months follow-up after medical therapy and weight loss [32]. However, in disagreement with our study, morbid obesity (BMI > 40 kg·m−2) was demonstrated as a factor of poor visual outcome [15]. This difference can be attributed to the different methods used for visual assessment as we used fundus examination for evaluation of papilledema while used perimetry for evaluation of visual outcome.
Our study is the first study in Egypt describing the clinical and radiological criteria in IIH patients and their response o treatment after 3 months follow-up.
Our limitations in this study are short follow-up period, absence of male gender for comparison of results and no OCT or parametric studies done for patients.