Hong Kong Journal of Emergency Medicine
Aseptic cerebral venous sinus thrombosis in early pregnancy
This is a rare case of sagittal sinus thrombosis occurring in the first trimester of pregnancy. A literature
review was performed. (Hong Kong j.emerg.med. 2007;14:237-239)
Keywords: Cerebral veins, first trimester pregnancy, intracranial sinus thrombosis, pregnancy, sagittal sinus
Introduction pregnancy and she had one live birth and one
miscarriage. At presentation, she was nine weeks
Cerebral venous thrombosis (CVT) is an interesting pregnant and complained of increasing headache
but rare condition. It is characterised by its varied over a four-day period; not improving with regular
clinical presentations, wide spectrum of clinical signs analgesia. The headache started suddenly on the left
with highly variable modes of onset, pathogenic temple area whilst she was having a shower. It then
variability and clinical course as well as prognosis.1,2 spread rapidly to the right temple, with persisting
Because of its extremely diverse clinical presentations, p a i n ove r b o t h r e t ro - o r b i t a l a r e a s . T h e p a i n
it remains a diagnostic and therapeutic challenge.3,4 gradually worsened over the next few days.
CVT occurred 10 to 13 times more often during On the day of presentation (4th day of the headache),
puerperium than during pregnancy. 1,2 Amongst all the headache was noted to be aggravated by sneezing
pregnant patients, CVT occurred more frequently in and it felt like her 'head had exploded'. The pain score
the second and third trimesters.1,2,4 It is very rare during was 10/10 at presentation and it was associated with
the first trimester. photophobia, nausea and vomiting. There was no fever
or rash. There was no history of recent head trauma.
She was completely well previously with no significant
Case history medical history except for a minor ear infection one
week prior to this event, which was adequately treated.
Our patient was 27 years old at the time of These symptoms were absent during her previous
presentation in May 2007. This was her third pregnancies. There was no family history of similar
Lim Yong Hwa, MBBS(S’pore), FRCSEd(A&E), DIMC RCSEd The clinical examination was unremarkable. The ears,
Weston General Hospital, Grange Road, Uphill, Weston-Super-
Mare, North Somerset BS23 4TQ, England external auditory canals and tympanic membranes were
Email: email@example.com all normal. All the cranial nerves were intact and she
238 Hong Kong j. emerg. med. Vol. 14(4) Oct 2007
was alert, conscious and rational. Her Glasgow Coma However, the patient presented again to our
Scale score was 15/15. There was no peripheral department with increased headache, nausea and
neurological sign noted. Both her fundi were normal. vomiting 11 days after the initial presentation. An
emergency MRI revealed extensive superior sagittal
In view of the history and presentation, an urgent sinus thrombosis (Figure 2). Her anticoagulation was
computerised tomography (CT) brain scan with optimised till the anticoagulation was at the therapeutic
intravenous contrast (and shielding of the abdomen) level and she was later discharged well neurologically
was done (Figure 1); as magnetic resonance imaging with adequate pain control.
(MRI) scan was not available at that time. The working
diagnosis was exclusion of intracranial bleeding.
The patient was transferred to the Specialist Neurology
Centre in another hospital. The patient was started on There are wide spectrums of well known conditions
low molecular weight heparin and was an inpatient that may cause or predispose to CVT. The most
for five days. She was discharged well with adequate frequently postulated mechanism of CVT in obstetric
pain control. patients is the hypercoagulable state brought about by
Figure 1. Consecutive CT images of the patient, showing the empty delta sign (arrow).
(a) (b) (c)
Figure 2. Magnetic resonance venography of the patient revealing a long segmental sagittal sinus thrombosis.
Lim/Aseptic cerebral venous sinus thrombosis 239
the pregnancy itself. This is also thought to be aggravated pressure, infectious or malignant aetiologies, associated
by dehydration and anaemia. 1,2 There is also a high haemorrhagic infarcts on CT scans and intercurrent
prevalence of anaemia in obstetric patients with CVT. complications such as uncontrolled seizures or pulmonary
Other conditions that have been associated with CVT embolism.5,6 The outcome of CVT remains largely
include inherited disorders such as protein C deficiency, unpredictable and so is the prognosis. It is not unusual
protein S deficiency, antithrombin III deficiency, disorders to note deeply comatose or severely hemiplegic patients
of plasminogen and dysfibrinogenemias. Other medical recover dramatically, without any sequalae.7 Conversely,
illness such as nephrotic syndrome, malignancy and patients presenting only with headache as the main
ulcerative colitis may also predispose one to venous presenting complaint can suddenly deteriorate. 7 It is
thrombosis. Their relative importance may vary in of interest to note that clinical recovery may occur
different parts of the world.1 However, it was noted that much more rapidly than vessel recanalisation and even
CVT in early pregnancy remained extremely rare.2,3 in the absence of recanalisation.7 This may be due to
collateral circulations opening up.
Symptoms and signs associated with CVT include
headache, focal neurological signs or altered level of This rare and interesting condition should be
consciousness. Focal or generalised seizure may occur. considered in pregnant patients who present with
Patients may also present with bilateral pyramidal signs, bizarre neurological symptoms. MRI, if available,
papilloedema or nuchal rigidity. Hence, due to its would probably be the imaging modality of choice
diverse and varied neurological presentations, CVT especially in pregnant patients.4
should be considered in almost any brain syndrome.2,3
Appropriate neuroimaging investigations should be
performed. The present "gold standard" for the References
diagnosis of CVT is probably MRI, which visualises
the thrombosed sinus as an increased signal on both 1. Cantu C, Barinagarrementeria F. Cerebral venous
thrombosis associated with pregnancy and puerperium.
T1- and T2-weighted images. 4 However, in this
Review of 67 cases. Stroke 1993;24(12):1880-4.
patient, due to her acute clinical presentation and 2. Fehr PE. Sagittal sinus thrombosis in early pregnancy.
unavailability of MRI at the time of the first Obstet Gynecol 1982;59(6 Suppl):7S-9S.
presentation, an emergency CT scan with contrast was 3. Bousser MG. Cerebral venous thrombosis: nothing,
heparin, or local thrombolysis? Stroke 1999;30(3):
performed instead. It revealed the empty delta sign − 481-3.
a low attenuating thrombus within the superior sagittal 4. Turkewitz LJ, Jacobs AK, Bidwell JK. Atypical MRI
sinus surrounded by a triangular area of enhancement. findings of venous sinus thrombosis in pregnancy:
clinical significance relating to episodic vascular
headache. Headache 1991;31(4):240-3.
The management of patients with CVT remains 5. Brucker AB, Vollert-Rogenhofer H, Wagner M,
controversial.3,4 Unfractionated heparin, low molecular Stieglbauer K, Felber S, Trenkler J, et al. Heparin
weight heparin and even thrombolytic therapy have treatment in acute cerebral sinus venous thrombosis: a
retrospective clinical and MR analysis of 42 cases.
been advocated.3 One of the most confusing issue about Cerebrovasc Dis 1998;8(6):331-7.
CVT is its diverse and unpredictable outcome. The 6. Bousser MG, Chiras J, Bories J, Castaigne P. Cerebral
overall mortality of patients with CVT is now thought venous thrombosis--a review of 38 cases. Stroke 1985;
to be at about 10%.5 Adverse prognostic factors include
7. Bousser MG, Ross Russell R. Cerebral venous
extremes of age, coma, involvement of cerebellar veins thrombosis. Vol. 1. London, UK: WB Saunders; 1997:
or of the deep venous system, severely raised intracranial p. 175.