Transient Left-Sided Weakness, Facial Palsy in Middle-Age Man

Why did a 51-year-old man with no significant medical history suddenly develop slurred speech and left-sided symptoms — weakness in his arm, a drooping eyebrow and mouth — that seemed to resolve 15 minutes later?

That’s the diagnostic challenge described by Unal Mutlu, MD, PhD, of Erasmus University Medical Center in Rotterdam, the Netherlands, and colleagues.

On neurological examination, clinicians detailed that the left nasolabial fold was completely absent, but found no other focal deficits. The patient’s blood pressure, electrocardiograph, and cardiac monitoring results were normal.

The patient underwent a CT scan that revealed “hypodense areas in the vascular territory of the right medial cerebral artery, indicating cerebral infarctions. These findings were confirmed by subsequent magnetic resonance imaging denoting diffusion restriction to the corresponding areas with a high T2 signal, swelling, and subtle cortical enhancement,” according to the case report in JAMA Neurology.

Clinicians ordered a CT angiography, which revealed a small irregularity on the posterior margin of the right carotid bulb, which raised suspicions that the patient’s symptoms were due to a carotid web.

“In our neurovascular multidisciplinary team, the possibility of either a thrombus or a soft plaque was suggested as an alternative diagnosis to a potential CW [carotid web],” wrote Mutlu and co-authors. They performed a second CT angiography, and were surprised to see that the focal irregularity had moved forward to the anterior wall of the right carotid bulb.

Importantly, the orientation of the two arteries had changed, they observed, such that “the internal carotid artery was oriented medially to the external carotid artery, as opposed to posteriorly in the previous scan and more retropharyngeal.”

Taken together, the medial movement of the carotid artery reflected the possibility that it was wandering and rotating on its own axis, they said, noting that it had twisted approximately 120°. The contralateral carotid arteries were in a fixed position.

The presence of carotid web was confirmed subsequently, when clinicians performed a successful carotid endarterectomy, thus excluding the potential etiologies of soft plaque and thrombus.

Discussion

“To our knowledge, we present the first case of a wandering carotid artery combined with a CW,” wrote Mutlu and co-authors. A carotid web represents a specific form of fibromuscular dysplasia, notable for its presentation of a shelflike projection usually located on the inner lining of the carotid bulb. It presents as a thin layer of proliferative intima, originating exclusively from the posterior wall, they explained.

Among patients affected by symptomatic carotid web, up to 17% of patients will have repeated strokes within 2 years despite receiving medical management, “suggesting that medication alone may not provide sufficient protection,” according to the case authors.

This makes timely recognition of a carotid web crucial to provision of optimal stroke prevention. In this specific case, “the CW appeared to be on the anterior side and could have been missed or misinterpreted as a potential cause of stroke due to the changing position and rotation of the carotid artery,” the authors detailed.

“The underlying mechanism of this rare anomaly in which the carotid artery changes its position remains unknown,” they continued. “Awareness of this phenomenon is important for neck surgical procedures to avoid perioperative and postoperative complications. At which degree this movement and twisting predisposes an individual to stroke remains to be elucidated.”

In patients with no other causes of stroke, the presence of a focal irregularity of the carotid bulb, even on the anterior side, should be investigated for a potential carotid web, in case of a wandering carotid.

“Knowledge of this phenomenon may aid radiologists and other clinicians in properly recognizing this serious condition to optimize secondary prevention of ischemic stroke in these patients,” the case report authors concluded.