Transcranial doppler (TCD) is a useful ancillary test to evaluate cerebral circulatory arrest (CCA) for determination of brain death. TCDs are simple, non-invasive and inexpensive. We present a case where serial TCD’s show progressive loss of flow velocities leading to CCA.

A 53-year-old female presented to the emergency room with a headache for 3 days, followed by unresponsiveness. On arrival, her GCS was 3 and she was intubated emergently. CT scan of the head showed large hemorrhage in the cerebellar vermis extending into bilateral cerebellar hemispheres and fourth ventricle with hydrocephalus. CTA head was concerning for left posterior fossa AVM. She underwent EVD placement followed by embolization of left superior cerebellar artery feeder and suboccipital decompressive craniectomy.

Patient had recurrent ICP crises and Cushing response requiring hyperosmolar therapy. She was now comatose with absent brainstem reflexes. Repeat CT scan of the head showed a new large left thalamic hemorrhage with increased intraventricular hemorrhage and worsening hydrocephalus. TCDs on day 2 showed sharp systolic spikes without diastolic flow in bilateral vertebral arteries and basilar artery consistent with posterior circulatory arrest. Anterior circulation flow was normal. TCDs on day 3 showed persistent posterior circulatory arrest with sharpening of systolic peaks in the MCA on the left. Day 4 TCDs showed sharp systolic upstrokes and absent diastolic flow in the MCAs and ACAs bilaterally, consistent with anterior circulation arrest. These findings met TCD criteria for brain death.

CCA results from cessation of cerebral blood flow due to increased ICP. In setting of posterior fossa space occupying lesions, when ICP waveform from EVD is inconsistent, diagnosis of CCA is challenging. This is especially true if apnea test is unable to be performed. In such cases, serial TCDs can be useful in showing progression to CCA and determining brain death.