An unusual case of posterior reversible encephalopathy syndrome and cerebral venous sinus thrombosis in eclampsia

A 20-year-old primigravida with 36 weeks of pregnancy presented to the emergency room with seizures in a drowsy state. Her blood pressure was 150/110 mmHg, SpO2 was 98%, and Glasgow Coma Scale was E2V3M4. She had a history of headache, vomiting, and multiple episodes of seizures over the past few days, for which she had consulted locally. There was no history of diabetes, hypertension, or use of oral contraceptive pills. She was diagnosed with eclampsia at presentation. Antihypertensives, anticonvulsants, and other supportive measures were initiated, and emergency lower segment cesarean section (LSCS) was performed. On postpartum day 1, she complained of sudden painless bilateral loss of vision. On examination, she was irritable with visual acuity of hand motions bilaterally, extraocular motility was full and free, and pupils were round, regular, and reacting briskly to light with no relative afferent pupillary defect in either eye. Fundus examination showed clear media with normal finding in both eyes [Fig. 1a and b]. An urgent magnetic resonance imaging (MRI) of brain was requested, which showed the presence of vasogenic edema in bilateral parieto-occipital region [Fig. 1c] on T2 fluid attenuated inversion recovery (FLAIR) image and restricted diffusion on diffusion weighted image (DWI) [Fig. 1e] with no decrease in apparent diffusion coefficient value [Fig. 1f] suggestive of posterior reversible encephalopathy syndrome (PRES). MRI also showed absence of normal flow void in the left transverse sinus and sigmoid sinus [Fig. 1d], consistent with thrombosis of these sinuses. Patient was urgently started on low-molecular-weight heparin (LMWH) in consultation with an internist.Figure 1: (a and b) Fundus images of the right and left eyes showing normal findings. (c) MRI brain (T2 FLAIR) showing bilaterally symmetrical hyperintense signal in the parieto-occipital region. (d) MRI brain (T2 FLAIR) showing absence of normal signal void in the left sigmoid sinus (arrow). (e) DWI showing restricted diffusion. (f) ADC image showing no corresponding decrease in ADC value. ADC = apparent diffusion coefficient, DWI = diffusion weighted image, FLAIR = fluid attenuated inversion recovery, MRI = magnetic resonance imagingOn postpartum day 3, patient’s general condition showed improvement; her visual acuity improved significantly to 6/9 in both eyes and she was discharged subsequently. Visual field examination could not be done subsequent to improvement. Discussion PRES and cerebral venous sinus thrombosis (CVST) are two uncommon entities that may present with similar signs and symptoms. PRES is a clinicoradiological syndrome characterized by visual disturbances, headache, seizures, and altered consciousness and is mostly associated with severe hypertension and eclampsia.[1] CVST may present with headache, focal neurologic deficits, intracranial hemorrhage, convulsions, altered sensorium, and papilledema.[2,3] Headache is the most common symptom in CVST patients, whereas seizure is the most common clinical manifestation of PRES.[3,4] MRI and magnetic resonance venography (MRV) are the neuroimaging modalities of choice to detect these conditions. On MRI, PRES appears bright on T2-weighted and FLAIR images, typically in bilateral parieto-occipital region, which represents vasogenic edema and should be distinguished on DWI from cytotoxic edema. Thrombosis of the affected sinuses is seen on MRI and MRV, and contrast enhancement on the sinus walls and absence of flow within the sinuses in contrast images represent empty delta sign in cases of CVST. PRES requires urgent management of hypertension and underlying precipitating cause. Anticoagulation with unfractionated heparin or LMWH is needed in cases of CVST. Cases with underlying factors as pregnancy and puerperium have good prognosis generally.[3] Our patient responded well to the antihypertensive and anticoagulation agents. Conclusion PRES and CVST should be kept in mind by ophthalmologists as well as obstetricians, especially in preeclamptic or eclamptic patients (pregnancy being a hypercoagulable state) who present with visual loss and other related symptoms. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.