Bilateral Medial Medullary Infarction in a Patient with Basilar Artery Fenestration – Cause or Coincidence? Raja Godasi MBBS1, Rashid Ahmed MD1, Hesham Masoud MD1
SUNY Upstate Medical University Department of Neurology
Introduction
Case presentation
Conclusion
Fenestration refers to localized duplication of avessel. Basilar artery fenestration is a congenitalvariant with an incidence of 5%. Medial medullaryinfarction (MMI) is a rare stroke syndromeaccounting for 0.5-1.5% of all strokes and bilateralinvolvement is uncommon. The most commonpresentation of bilateral MMI is the sudden onset of avariable constellation of findings which can includequadriparesis/quadriplegia, dysarthria, nystagmus,sensory disturbances, hypoglossal palsy and bulbardysfunction.
A 56-year-old female with no significant
cerebrovascular risk factors except for a remote
history of breast cancer in remission, presented within
5 hours of sudden onset, whole body paresthesia
sparing the face, oscillopsia, nausea and vomiting.
Initially neurological examination was remarkable
only for bilateral vertical nystagmus. MRI brain
disclosed a “V” shaped diffusion restriction in the
medial medulla with ADC correlation. CT
angiography of the head revealed proximal basilar
artery fenestration at the level of medulla. The next
day, patient developed asymmetric quadriparesis,
dysarthria, hypophonia and dysphagia. Repeat MRI
demonstrated evolution of medial medullary
infarction with FLAIR hyperintensity. An extensive
stroke work-up was unremarkable, except for a patent
foramen ovale without evidence of venous
thrombosis.
Our case, as well as several others, show association
between basilar artery fenestration and strokes in the
brainstem. Knowledge of this rare entity is important to
consider when pursing workup for medullary lacunar
strokes.
Discussion
Pontine and lateral medullary infarctions have been
reported in patients with basilar artery fenestrations.
However, to our knowledge, this is the first reported case
of bilateral medial medullary infarction. Hemodynamic
alterations and turbulence are thought to make
fenestrated artery a more common site for thrombosis
compared to a normal artery. It is also noted that partial
endothelium-lined intraluminal septa appearing as spurs
are seen in fenestrated arteries. These are hypothesized to
cause turbulent blood flow leading to thrombosis and
possible embolization from the fenestrated artery.
Paradoxical embolic etiology, though a possibility in our
case was thought to be unlikely in the absence of venous
thrombosis or cortical infarction on DWI.
A B C
A- Initial MRI DWI showing “V” shaped heart sign in medulla, B- Initial MRI ADC sequence, C- Repeat MRI with subtle FLAIR hyperintensity
References
D E F
D- CT Angiography of the head showing proximal basilar fenestration, E- 3D reconstruction of the fenestration, F- Magnified view of the fenestration
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