CT Case 061
A 36-year-old female presents with sudden onset right sided facial drop, right hemiparesis and dysarthria.
She is 6 weeks post-partum with a past medical history including of Immune thrombocytopenic purpura (ITP), hypertension and Ehlers-Danlos syndrome.
Her platelets are 139 on presentation.
A CT brain, angiogram and cerebral perfusion scan are performed.
Describe and interpret the CT scan
CT interpretation
CT brain shows subtle loss of grey-white matter differentiation in the left parietal region.
CT angiogram shows non-opacification of the left internal carotid artery (ICA).
CT cerebral perfusion demonstrates a corresponding perfusion deficit in the middle cerebral artery (MCA) territory.
She is taken immediately to interventional radiology (IR) for endovascular clot retrieval (ECR) of the left ICA; transferred to the intensive care unit and intubated.
A follow up CT the is performed the following day.
CT interpretation at 24 hours
This CT showed extensive cytotoxic oedema, particularly in the MCA and ACA territories with midline shift and ventricle effacement. These findings were consistent with malignant MCA syndrome.
She was taken to theatre for urgent hemicraniectomy
Post operative images
The patient was taken to theatre for urgent hemicraniectomy
These images demonstrate the extensive established infarct. Following the hemicraniectomy there is resolution of ventricle effacement and midline shift.
Clinical Pearls
This is a case of Large Vessel Occlusion (LVO) stroke in a young patient.
10-15% of all strokes occur in patients younger than 50 years old.
There are a wide variety of underlying causes that need to be considered, such as dissection, cardiac emboli, large artery atherosclerosis, vasculitis, and PFO / ASD.
However, in a third of cases the cause is unclear.
A specific workup needs to be performed to try and identify any treatable cause, this includes TOE with a bubble study and thrombophilia and vasculitic screen.
The cause of this patient’s ICA thrombosis remains unclear. She has had a negative thrombophilia screen and normal Echo. Haematology input suggested a number of potential contributing factors;
- ITP can paradoxically increase risk of thrombosis even when platelets are low
- Ehlers Danlos can cause vascular intima abnormalities, increasing the risk of thrombosis
ECR needs to be considered in all patients presenting with an ischaemic stroke and confirmed LVO as listed below;
- internal carotid artery
- middle cerebral artery
- M1 segment
- proximal M2
- basilar artery
Generally, the time window for ECR eligibility is 24 hours from symptom onset. However, this may be extended up to 48 hours, particularly in basilar artery occlusions.
Malignant MCA syndrome is a life-threatening condition caused by complete occlusion of the MCA alone, or may be in combination with ACA occlusion.
It is diagnosed radiologically by the presence of ischaemia in more than two-thirds of the MCA territory, associated with oedema and herniation.
Decompressive craniectomy is a controversial therapy for malignant MCA stroke. The aim is to decrease ICP, improve perfusion to the brain and reduce the risk of transtentorial herniation.
References
TOP 100 CT SERIES
Sydney-based Emergency Physician (MBBS, FACEM) working at Liverpool Hospital. Passionate about education, trainees and travel. Special interests include radiology, orthopaedics and trauma. Creator of the Sydney Emergency XRay interpretation day (SEXI).
Provisional fellow in emergency radiology, Liverpool hospital, Sydney. Other areas of interest include paediatric and cardiac imaging.
Emergency Medicine Education Fellow at Liverpool Hospital NSW. MBBS (Hons) Monash University. Interests in indigenous health and medical education. When not in the emergency department, can most likely be found running up some mountain training for the next ultramarathon.
Dr Leon Lam FRANZCR MBBS BSci(Med). Clinical Radiologist and Senior Staff Specialist at Liverpool Hospital, Sydney