N36) Hyperdense Basilar Artery
Review the Learning Outcomes, Hx, PE and Labs, and begin the module with your Provisional Diagnosis. Keep hitting "Next" to move through the module.
Learning Outcomes
- Understand your relationship with the consulting diagnostic radiologists in the evaluation of a patient with focal neurologic deficits, and the appropriate studies to order.
- Learn the differential diagnostic considerations in a patient who presents with focal neurologic deficits.
- Understand the spectrum of imaging findings in a patient who presents with focal neurological deficits.
History
A 60-year-old male with PMH of CAD, HLD, and atrial fibrillation presents with sudden onset of ataxia, nausea, vomiting and dizziness 3 hours prior, and now is experiencing progressive dysarthria, visual loss, and confusion in the ED.
Physical Exam
BP: 142/91, HR 95, RR 19, Temp 98.6F, O2 saturation 99%.
Neuro exam:
Neurologic exam significant for:
Upward deviation of the right eye, decreased abduction of the left eye, and upward nystagmus in both eyes.
Slurred speech noted.
Left pronator drift, and bilateral dysmetria.
Strength and sensation otherwise intact.
Labs
HbA1C, Glucose, B12, Folate, TSH, lipid panel, and EtOH/tox screen are within normal limits.
Provisional Diagnosis
Select the Dx you believe is most appropriate
The patient’s symptoms are consistent with a stroke in the vertebrobasilar distribution. Patients often present with prodromal symptoms of nausea and vomiting. Opthalmoplegia and visual disturbances are common, as well as dysarthria and facial droop due to cranial nerve nucleus involvement. Due to cerebellar and corticospinal tract involvement, patients often present with ataxia, dizziness, and various degrees of ipsilateral or bilateral hemiparesis. "Top of the basilar” occlusions are often the most severe, and can result in rapid visual loss due to occlusion of the bilateral PCAs and rapid loss of consciousness.
Well done. You were correct
Potential Acuity
What is your assessment of the likely acuity for this patient?
Well done. You were correct
This patient requires immediate workup and management.
First Imaging Study
What is the first imaging study you will order?
Because of the high suspicion for acute stroke with suspected large-vessel involvement, it is important to immediately identify the point of occlusion so that urgent endovascular intervention (if not contra-indicated) can be performed. A CTA head and neck perfusion protocol includes an initial non-contrast CT head, to assess for intracranial hemorrhage prior to administration of TNK or further endovascular intervention.
A CT head without contrast alone would rule out intracranial hemorrhage, but would not be able to confidently identify a large-vessel occlusion (although there are certain signs that might suggest it, to be discussed). Furthermore, it can take up to 6 hours for infarcted brain tissue to develop visible changes on CT, at which point reperfusion intervention would not be likely to affect outcome.
Well done. You were correct
Pertinent Imaging Observations
Click on the links below to view images from the study, and assess these key findings as best you can.
CT head without contrast
There is intracranial hemorrhage.
There is no evidence of hemorrhagic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, epidural hematoma, or subdural hematoma.
There is evidence of thrombosis of a large vessel.
The basilar artery is abnormally hyperdense (bright) , suggesting acute thrombosis. In addition, there is subtle hypoattenuation indicative of developing cytotoxic edema of the left greater than right cerebellar hemispheres.
Watch our video
What is your Diagnosis now that you have seen the imaging results?
That's the end of the module! Once you've reviewed the video(s), you can click here for another case challenge.
