The Basilar Artery

A 60 year old woman started feeling "off" a few weeks ago. Something was just wrong with her balance. She saw her doctor who noted gait instability but her work-up, including a non-contrast head CT, was normal. She was reassured and sent home, but the symptoms didn't abate. Then, she noticed something wrong with her talking; she couldn't speak clearly. Her speech was slurred. Still, she continued with her life as best as she could until she fell several days ago. Her son witnessed the fall and convinced her to go to the hospital even though she didn't lose consciousness or have seizure activity.

In the emergency department, she got the standard work-up for syncope (fainting) which didn't reveal any answers. But then over a half hour period, she went from talking coherently (GCS 15) to completely unresponsive (GCS 3). Even to painful stimuli such as rubbing her sternum or pinching her fingers, she would not wake up. Something had gone terribly wrong.

Neurology came down to assess the patient. Their exam was concerning; her pupils did not react (constrict) with light as they should. She had a few brainstem reflexes such as the corneal reflex (touching her eye causes her to blink) and a gag, but with such a sudden change in her mental status, they were concerned about stroke. She was rushed off to get a CT angiogram which showed a basilar artery thrombosis.

Thrombosis refers to a clot in a blood vessel. Clots in blood vessels to the brain account for the majority of strokes; a clot in the pipe prevents the blood from delivering oxygen and taking away toxins from the brain. Strokes are bad, but basilar artery thromboses are dreaded. The basilar artery supplies the posterior circulation of the brain and brainstem. While strokes in other locations present with a facial droop or one-sided weakness or difficulty with language, strokes involving the basilar artery kill.

Yet she was within the window of trying to dissolve the clot with tissue plasminogen activator, a clot-buster. These potent drugs are incredibly dangerous because they can convert a clot into an unstoppable bleed. They have to be used early, before the brain sustains too much damage. The neurologists wanted to administer this medication by artery (intra-arterial tPA) to break up the clot and restore blood flow to the brain; if they did not, the lack of oxygen would cause the brain cells to die, swell, and kill the patient.

They called interventional radiology, experts in using CTs, MRIs, and other imaging techniques to do precise procedures. They cannulated her vertebral artery, went up into her brain with a catheter, and injected the tPA clot buster. They then threaded a corkscrew-like coil, the Mercy Retriever, through the clot of fat and pulled it out of the brain, restoring blood flow.

The patient came to the ICU at around 3 in the morning. When I saw her, my exam was not reassuring; though she did have a cough, gag, and corneal reflex, she did not withdraw her arms or grimace to pain. I'd seen this disease, basilar artery thrombosis, one other time and that time, we withdrew care on the patient because he didn't get better. Despite heroic measures, I didn't think this woman would make it.

The next morning, I went to round on her. I was shocked. When I asked her to wiggle her toes, give me a thumbs up, and open her eyes, she did them briskly. She was able to nod and shake her head appropriately to questions (she had a breathing tube so she was unable to talk). Her mental status had changed remarkably. She went from comatose to appropriately responsive. The embolectomy (taking out the clot) and intra-arterial tPA had worked. I was floored (so was she, since we sent her out of the intensive care unit to the "floor" - bad pun). Modern medicine truly saved her life.