Fate of Papilledema in Cerebral Venous Thrombosis Patients and its Correlation to Affected Cerebral Venous Sinuses

Background: Cerebral venous thrombosis is an important cause of stroke in young and middle-aged adults with estimated (3-4) cases per million annual incidences. Papilledema is the most common sign detected in these patients that can end by blindness if not monitored and treated well. This research aims to assess development and prognosis of papilledema and its association with certain cerebral venous sinuses thrombosis. Evaluation of the optic nerve head has been done clinically and by using optical coherence tomography.
Methods: A descriptive analytic hospital-based study was conducted in neurology unit at wad medani teaching hospital from December 2021 to July 2022. 20 patients were included in the study. Data including optical coherence tomography reports was collected at admission and after 2 months. Analysis was done using SPSS version 25 to report frequency of papilledema, 2months visual outcome, correlation of MRI\MRV findings with the development and outcome of papilledema.
Results: This study include 20 cerebral venous thrombosis patients with mean age of 35.75 years. Papilledema present in 70% at initial presentation in whom the superior sagittal sinus was affected in 78.6%, after two months period papilledema regressed in80%, 10% developed optic atrophy and10% died. There is clear correlation between the sinus affected and the development of papilledema (P value=0.009); in contrast no relation between the sinus affected and the two months visual outcome of papilledema (P value=0.417).
Conclusion: Papilledema regressed in most CVT patients while small number of them developed optic atrophy confirming the importance of regular ophthalmological follow up of CVT patients at frequent intervals using OCT in addition to other papilledema assessment tools in order to prevent irreversible blindness. Affection of certain cerebral venous sinus can predict development of papilledema in CVT patients, but not the outcome.

Cerebral venous thrombosis CVT is an uncommon condition with variable clinical presentation, it was recognized for more than 100 years ago in postmortem autopsies (1). CVT is remarkable cause of stroke with estimated [3-4] cases per million annual incidences. It causes of stroke in young and middle-aged adults with increased incidence in female gender [2, 3]. CVT commonly present with headache (95%), seizures (47%), unilateral or bilateral paresis (43%) and papilledema (41%) [4], with variable prognosis range from complete recovery to death [2, 5]. The most common affected sinuses are superior sagittal sinus and lateral sinuses, nevertheless affection of more than one sinus is common [6], Neuroimaging including MRI and MRV are the best modality to diagnosis CVT [7, 8]. While papilledema account to be the most common ocular finding in CVT [9], therefor our study aims to detect association of papilledema to affection of certain dural venous sinuses. Prognosis of papilledema varies and depend on the grade and the initial visual impairment [10], high grade papilledema due to CVT usually associated with permanent visual impairment and if resolution occur; some visual defects might remain [11], therefore Optical Coherence Tomography is beneficial for detection and prognosis of papilledema with correlated clinical findings [12].

The study was descriptive-analytic hospital-based study. It was conducted from December 2021 to July 2022 at the neurology unit in wad medani teaching hospital, Gezira state, Sudan. Ethical approval was obtained from Sudan medical specialization board ethical committee and written consent was obtained from patients who participated in the study. A total of 20 patients were enrolled in the study. The inclusion criteria were, age above 18 years old, patients confirmed to have CVT by clinical and MRV imaging. Patients documented to have optic neuropathy previously and patients refused to participate in the study were excluded. Data was collected from the patients using data collection sheets. It includes some demographic data (age, gender), MRI-MRV imaging reports to identify which part of cerebral venous system was affected. OCT done at presentation and after 2 months. In order to determine the outcome of papilledema, two months OCT assessment was graded into papilledema regressed and optic atrophy. Data was analyzed by computer using descriptive statistics mean and SD for age, frequency tables and charts using (SPSS) software version 25. Chi-square statistical test was used to assess correlation between cerebral venous sinus affected and development, outcome of papilledema. P value of less than 0.05 was considered to be significant.

All patients were in the age group (20-65) years with the mean age of 35.75 +/-13.4 years. Of them 17(85%) patients were females and 3(15%) patients were males with obvious female predominance 5.7:1. MRI /MRV images showed that the sinus affected was the superior sagittal sinus in 14 (70%) patients, the transverse sinus in 5(25%) patients and the deep venous system in 1 (5%) patient. OCT done for patients at first assessment during their admission period revealed papilledema in 14 (70%) of patients. OCT done after two months revealed that regression of papilledema noted in16 (80%) patients while 2(10%) patients developed optic atrophy and 2(10%) patients died before the second assessment. Regarding CVT patients who developed optic atrophy, the first was young female a case of Behget disease who suffered from headache and blurring of vision for two months before diagnosis as SSS thrombosis and referral to neurology department. The second was an elderly male a case of chronic CVT duo to Anti thrombin III deficiency and who complained of reduced vision. Both had chronic papilledema prescribed anticoagulation therapy, but unfortunately established optic atrophy.
Regarding patients who died before the next assessment, one of them was middle age female patient a case of advanced breast cancer with extensive metastases who died after one week from admission to hospital and the other was young female with a history of self-administration of steroids and complete occlusion of the SSS not responded to initial management and unfortunately interventional techniques was un affordable for them. From Table 1 it is evident that there is clear correlation between cerebral venous sinus affected and development of papilledema in CVT patients, P value was 0.009. Table 2 showed that there is no significant correlation between the cerebral sinus affected and the 2 months outcome of papilledema in CVT patients and P value was 0.417.

Table 1: Correlation between cerebral venous sinus affected and 1st OCT assessment

Table 2: Correlation between cerebral venous sinus affected and 2nd OCT assessment

In this study OCT was used as diagnostic tool to assess papilledema in CVT patients admitted to the neurology unit at Wad medani teaching hospital from December 2021 to July 2022. The female predominance in the study group can be interpreted by the high susceptibility of women to CVT as it is related to pregnancy, puerperium and use of OCP. It revealed that the frequency of papilledema among CVT patients is 70%; in contrast of a multicenter retrospective study done in USA, in which papilledema present in 54% of patients at initial presentation [11]. In the former study more CVT patients developed papilledema as the most affected sinus was the SSS, the chief venous sinus draining the brain and the transverse sinus is difficult to diagnose. Another prospective study done in the national center of neurology in Khartoum, Sudan showed that papilledema present in 13 out of 15 patients studied (86.6%) which is slightly near to what is shown in this study [13]. The similarity may be referred to the number of patients included and the timescale of the two studies. This study showed that the SSS affected in 70% of patients, the transverse in 20% of patients and the deep venous system in 5% of patients; this in contrary to a retrospective study conducted at Sultan Qaboos university hospital, Oman which showed that the SSS affected in 44% of patients, transverse sinus in 52%, internal jugular vein and straight sinus in 8% and cortical vein thrombosis seen in 20% of patients [14]. A cross-sectional study done at a tertiary care Centre in Tamil Nadu, south India in adult CVT patients from august 2018 to august 2019. It revealed that Superior sagittal sinus (75%) was the most common site for venous thrombosis followed by transverse sinus (40 %) (15). In most of patients (78.6%) who developed papilledema the SSS was affected. In an Iranian study both the SSS and the transverse sinuses thrombosis was noted in 66.7% of CVT patients who developed papilledema; that means SSS sinus affection in CVT patients who developed papilledema is lower than in this study [16]. When OCT is used to assess the two months outcome of papilledema in CVT patients it revealed that; in 80% of patient’s papilledema regressed ,10

Papilledema regressed in most CVT patients while small number of them developed optic atrophy confirming the importance of regular ophthalmological follow up of CVT patients at frequent intervals using OCT in addition to other papilledema assessment tools in order to prevent irreversible blindness. Affection of certain cerebral venous sinus can predict development of papilledema in CVT patients, but not the outcome.