Transient pontine ischemia as a complication of diagnostic cerebral angiography in a patient with vertebral artery dissection of ischemic onset

Abstract

A case of reversible pontine ischemia following diagnostic cerebral angiography performed to evaluate vertebral artery dissection (VAD) of ischemic onset is reported. A 40-year-old man presented with sudden neck pain, dizziness, difficulty in swallowing, and numbness in the left arm. Neurologically, his symptoms were compatible with incomplete Wallenberg syndrome. Diffusion-weighted magnetic resonance imaging (DWI) revealed a small infarction in the medulla oblongata, and the right VA was irregularly stenotic on magnetic resonance angiography (MRA). We suspected that the right VAD was the cause of the medullary infarction. Following conservative treatment, his deficits resolved quickly despite progression of the VAD as revealed by follow-up MRA. Subsequently, diagnostic cerebral angiography was performed with the purpose of evaluating the patency of the right VA and possibility of a dissecting aneurysm. Despite a seemingly uneventful procedure, however, the patient developed altered mental status and right-sided hemiparesis shortly after the placement of an angiographic catheter into the intact left VA. DWI obtained two hours after the procedure revealed a high-intensity signal in the paramedian pons. Following administration of IV heparin and edaravone, the neurological deficits as well as the high-intensity signal disappeared within 24 h. The patient was discharged without deficits 4 weeks after onset. Although cerebral angiography has been considered the gold standard for the diagnosis of VAD, its role in VAD of ischemic onset has recently been questioned, in light of its relatively benign natural history, improved quality of less invasive imaging modalities, and risks of cerebral angiography. From the perspective of avoiding complications, the common practice of obtaining diagnostic cerebral angiography from every patient with VAD of ischemic onset may have to be reviewed, and decision to perform cerebral angiography for those who have already been diagnosed with less invasive imaging modalities should be made cautiously and on case-by-case basis.