254 Practical Neurology

IMAGE OF THE MOMENT

Pract Neurol 2008; 8: 254–255

Pontine infarction
due to intracranial
venous thrombosis
H C A Emsley, J Ramtahal, K S V Das, P S Ray
30-year-old woman presented to
her local hospital with an abrupt
onset of left-sided headache and
retro-orbital pain, dizziness, unsteadiness, vomiting, dysarthria, right facial paresis
and right hemiparesis. She was otherwise well,
and taking the oral contraceptive pill. MR brain
imaging showed high signal intensity in the left
pons (fig 1) and MR venography showed
evidence of left sigmoid sinus and proximal
internal jugular vein thrombosis (figs 2 and 3).
She was anticoagulated with unfractionated iv
heparin followed by warfarin. Her symptoms
gradually improved. An abrupt but transient
worsening of her right hemiparesis 10 days
after the initial onset prompted transfer to our
centre, but there was no haemorrhage on brain
CT or new infarction on repeat MRI. In fact, the
repeat MRI and MRV showed recanalisation in
both the sigmoid sinus and proximal internal
jugular vein (figs 2 and 3), but persistence of
the pontine high signal, implying infarction
rather than venous congestion. Her right
hemiparesis had nearly resolved by day 15,
prior to discharge.
Thrombophilia screening revealed reduced
protein C activity at 36% (normal range 70–
140) and reduced free protein S at 25% (59–
144). These results may have been influenced

A
H C A Emsley, J Ramtahal
Clinical Lecturers in Neurology,
Division of Neuroscience,
University of Liverpool, Clinical
Sciences Centre, Liverpool, UK

K S V Das
Consultant Neuroradiologist

P S Ray
Consultant Neurologist
Walton Centre for Neurology &
Neurosurgery, Liverpool, UK
Correspondence to:
Dr H C A Emsley
Division of Neuroscience,
University of Liverpool, Clinical
Sciences Centre, Lower Lane,
Liverpool L9 7LJ, UK;
h.emsley@liv.ac.uk
10.1136/jnnp.2008.152587

by anticoagulation and therefore screening
will need to be repeated after discontinuation
of warfarin. Because oral contraceptive use
and hereditary prothrombotic conditions are
recognised to interact in a multiplicative way
in the risk of development of intracranial
venous thrombosis (ICVT),1 her oral contraceptive was stopped.
Although ICVT is uncommon, accounting
for only 0.5% of strokes, it is very well
recognised.2 However, specific reference to
brainstem infarction attributable to ICVT is
rare in the literature. We identified only a
single case report describing pontomesencephalic infarction associated with transverse
and sigmoid sinus thrombosis.3 Solitary or
multiple cranial nerve lesions have also been
described in transverse and sigmoid sinus
thrombosis.4 The anatomical arrangement of
the pontine venous drainage is consistent
with infarction in our patient being attributable to sigmoid sinus thrombosis.4, 5
This case is a reminder that brainstem
infarction can sometimes be due to ICVT. The
availability of imaging clearly demonstrating
recanalisation following ICVT, temporally
related to clinical improvement is unusual—
if not unique—in the context of a brainstem
presentation.

Emsley, Ramtahal, Das, et al 255

ACKNOWLEDGEMENTS
This article was reviewed by Joanna Wardlaw,
Edinburgh, UK.

Figure 1
Axial T2 MR image showing pontine
high signal, consistent with venous
infarction (arrow).

REFERENCES
1.

2.
3.

4.

5.

de Bruijn SF, Stam J, Koopman MM, et al. Casecontrol study of risk of cerebral sinus thrombosis in
oral contraceptive users and in carriers of hereditary
prothrombotic conditions. The Cerebral Venous Sinus
Thrombosis Study Group. BMJ 1998;316:589–92.
Bousser MG, Ferro JM. Cerebral venous thrombosis:
an update. Lancet Neurol 2007;6:162–70.
Krespi Y, Gurol ME, Coban O, et al. Venous
infarction of brainstem and cerebellum.
J Neuroimaging 2001;11:425–31.
Kuehnen J, Schwartz A, Neff W, et al. Cranial nerve
syndrome in thrombosis of the transverse/sigmoid
sinuses. Brain 1998;121:381–8.
Bradac GB, Holdoreff B, Simon RS. Aspects of the
venous drainage of the pons and the
mesencephalon. Neuroradiology 1971;3:102–8.
Figure 2
Axial T2 MR images at 2 days after
onset of symptoms showing
thrombosed left proximal internal
jugular vein and sigmoid sinus (left
panel), and at 13 days after onset, with
recanalisation (right panel).

Figure 3
MR venography images. At 2 days after
onset of symptoms, the left sigmoid
sinus is not seen (left panel). There is a
dominant right transverse sinus; the
left transverse sinus is just visible (left
panel). Blood flow is seen in the left
sigmoid sinus at 13 days after onset
(right panel).

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