Clinical CT - October 2016

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Written by Adam Blumenberg MD
Special Thanks to Mark Silverberg MD

A 54 year-old woman with a history of cigarette smoking and uncontrolled hypertension presents to the ED disoriented and mumbling incomprehensible words. Her family members say she began acting strangely about 20 minutes after complaining of severe headache. Her blood pressure in the ED is 200/150mmHg, and heart rate is 65 beats per minute. Two slices of a CT of her head are shown above.

1. Please described the images

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The images depict blood in the subarachnoid space. Blood is visible in the:
A. Supracellar cistern
B. Sylvian cisterns
C. Abutting the falx cerebri
D. Between cerebral gyri
E. In the fourth ventricle.

The “Starfish sign” is specific for subarachnoid hemorrhage.

2. What are the most common etiologies of this illness? Is the etiology of this patient’s illness identifiable?

The most common cause of subarachnoid hemorrhage is trauma. The next most common causes are aneurysm rupture, arteriovenous malformation, coagulopathy, vasculitis, and neoplasm.
These images show a berry aneurysm (F) arising from the left middle cerebral artery. The rupture of this aneurysm is likely the caused of this bleeding. The underlying etiology of the aneurysm is most likely uncontrolled hypertension.

3. What are the fundamental goals of managing this illness?

Airway protection
Hemorrhage control
Management of intracranial hypertension
Prevention of vasospasm
Blood pressure control
Pain control

4. What are the next steps in the management of this patient?

Consider the following: endotracheal intubation & sedation, reversal agents for anti-coagulants or anti-platelets, nimodipine, elevation of the head of the bed, darkening of the room, IV mannitol or hypertonic saline, anti-epileptic drugs, and if absolutely necessary, hyperventilation. Please remember to discuss the prognosis with the family.

5. What is Cushing’s triad?

Cushing’s reflex is a response to elevated intracranial pressure. Systemic blood pressure is increased to maintain cerebral perfusion pressure, meanwhile bradycardia develops in response to the elevated systemic blood pressure through baroreceptor stimulation.
The triad consists of bradycardia, hypertension, and dysregulated respirations.

6. What is autoregulation?

Autoregulation is the maintenance of constant tissue blood flow. Autoregulation is achieved by increasing vascular constriction (resistance) in response to high blood pressure and decreasing vascular resistance in low pressure states. Autoregulation is lost during states of brain injury, and therefore blood pressure control is crucial.

7. What is this patient’s disposition?

Neurosurgery or interventional radiology for aneurysm clipping or endovascular aneurysm coiling. Management typically takes place in a neurological ICU.