Post-partum cerebral venous sinus thrombosis Case

Cerebral venous sinus thrombosis (CVST) is a rare neurological emergency occurring during pregnancy and puerperium. It is reported to be associated with varied symptoms ranging from isolated headache to profound coma. Herein, we report a case of a 39 year old woman on her eighteenth day of postpartum, admitted with dull headache and seizure. She was initially managed for eclampsia. Later, she was diagnosed as CVST and successfully treated by heparinization.


Introduction
CVST is a rare but potentially fatal neurological complication, which is reported in women especially during puerperal period due to hypercoagulable state. According to literature, patients present with severe headache, neurological deficits and seizures. A high index of suspicion is needed to diagnose, treat and prevent this life threatening complication. Magnetic Resonance Venography (MRV) is the gold standard diagnostic test for CVST. Herein, we present a rare case of CVST, in which patient initially treated for imminent eclampsia. The diagnosis was timely revised as CVST and successfully managed with a favourable outcome.

Case history
A 39 year old woman was admitted to Colombo South Teaching Hospital with dull headache for 3 days and an episode of short lasting left side tonic clonic seizures on the eighteenth day of her puerperal period. She (G1P1) had an emergency caesarean section due to delayed second stage of labour. Her medical history was unremarkable. Further, her pregnancy period was uneventful including the immediate postpartum period. Hence, she was discharged on 2 nd post-operative day. There was no history of pre eclamptic symptoms, loss of consciousness, neck pain and fever.
On admission, she was conscious and well oriented. Her temperature was normal with no evidence of petechial rashes and peripheral oedema. Her blood pressure (BP) was 140/80mmHg and pulse rate was 88bpm. There was no focal neurological deficit and normal reflexes. Further, fundoscopy revealed no papilledema. Her gynaecologic examination was compatible with postpartum period. Blood investigations revealed normal complete blood count with haemoglobin 10.3g/dl and normal renal, hepatic, and coagulation profiles.
Further, she developed a short lasting partial seizures followed by secondary generalized tonic clonic seizure, few hours after admission. Hence, she was clinically suspected as a case of imminent eclampsia and immediately treated. However, due to normal BP, urine albumin and blood investigations throughout hospital stay, other causes also had been considered.
Due to ongoing convulsions, antiepileptic was initiated. Non contrast computerised tomography (NCCT) brain was found to be normal. Magnetic resonance imaging (MRI) with MRV confirmed superior sagittal sinus thrombosis (SSST) and left transverse sinus thrombosis (LTST) up to sigmoid sinus with right parietal venous haemorrhagic infarction. Hence, it was diagnosed as cerebral venous sinus thrombosis. Upon conclusive diagnosis of CVST, she was managed by team of gynaecologist, neurologist and haematologist. She was admitted to intensive care unit (ICU) and LMW Heparin therapeutic dose was commenced. Her symptoms improved within a few days. LMW Heparin was continued and planned to do repeat MRI after 2 weeks to decide about oral anticoagulant.

Discussion
CVST is a rare form of venous thromboembolism (VTE). It is characterized by a highly variable clinical spectra, difficult diagnosis, variable aetiologies and prognosis. Its incidence varies between 1 in 11000 to 1 in 45000 pregnancies 1 . Superior and transverse sinuses are commonly involved.
CVST refers to complete or partial obstruction of cerebral veins results in venous congestion, cerebral oedema caused by increasing the capillary hydrostatic pressure, venous infarction, petechial haemorrhages and occlusion of venous sinuses results in intracranial hypertension 2 . Risk factors of CVST are associated with the classical Virchow triad of thrombogenesis: vessel wall damage, blood stasis and hypercoagulability. Hypercoagulability is the most important factor in development of cerebral venous thrombosis. Reported risk factors of CVST are obesity, smoking, congenital or acquired thrombophilia, malignancy, oral contraceptive pills and pregnancy. Pregnancy related risk factors include sepsis, preeclampsia, thrombophilia and delivery by caesarean section 1 . Risk factors in above case were caesarean section and post-partum period.
Headache (80-90%) is the common presenting symptom, which initially make it difficult to differentiate this rare complication from several common diagnoses such as eclampsia 3 . Focal or generalized seizures are reported in 40% of the cases: some have neurological deficit 4 . The specific presentation depends on location, extent of the thrombosis and the presence of associated cortical lesions. Patient presented in above case with seizures and dull headache on the eighteenth day of the postpartum period and managed as eclampsia. As the symptoms continued, other possible causes were considered.
Imaging studies remain the cornerstone of diagnosis. MRI shows right parietal venous haemorrhagic infarction.
The most sensitive diagnostic test is MRI with venography. If MRI is not available then high resolution CT is a useful investigation. However, it should be kept in mind that CT may result normal in 20-25% of cases but often abnormal in patients who do exhibit neurological signs 5 . In above case, NCCT brain was normal, but MRI and MRV revealed superior sagittal sinus thrombosis, left transverse sinus thrombosis and right parietal area haemorrhagic infarction. Above case highlights the importance of keeping a high index of suspicion to differentiate CVST from its several important differential diagnoses like eclampsia, cerebrovascular accidents, meningitis, post-dural puncture headache and posterior reversible encephalopathy syndrome (PRES).
Treatment strategies are aimed to control or resolve the underlying pathology, controlling ICH and treatment of seizures or focal deficits caused by cerebral oedema or infarction. Initial anticoagulation with adjusted-dose UFH or LMWH in therapeutic dose is recommended, followed by vitamin K antagonists, regardless of the presence of ICH 6 . In patients, with impending herniation, surgical decompression should be considered. Even though, recurrence rate in subsequent pregnancy is low, indication for thromboprophylaxis in next pregnancy is unknown 6 .
In conclusion, post-partum seizures should be evaluated in broader perspective to arrive at a diagnosis without undue delay. CVST is a potentially life threatening condition if it is undiagnosed. However, timely recognition and early treatment result in favourable outcome.