Innominate Artery Stenosis Causing a Limb Shaking Transient Ischemic Attack: A Rare Phenomenon
Paneeni Lohana1, Emily Pharr2
1Neurology, Wake Forest University School of Med., 2Wake Forest University School of Med.
Background:
Limb shaking transient ischemic attack (LS-TIA) due to innominate artery (IA) stenosis is a rare phenomenon which poses a diagnostic challenge. The incidence of LS-TIA due to innominate artery stenosis is currently unknown. IA stenosis is thought to comprise only 2.5-4% of atherosclerotic lesion of the extracranial cerebral arteries. LS-TIAs present as involuntary jerking movements that occur with position change and are often misdiagnosed as focal seizures. Therefore, a diagnosis of TIA is not usually considered in patients presenting with these symptoms.
Results:
A 68-year-old ambidextrous female with a history of renal cell carcinoma s/p radical nephrectomy in 10/2022, metastatic squamous cell lung cancer with brain metastases to the right parietal-occipital region s/p Gamma Knife Radiation Surgery (GKRS) in 07/2023 was experiencing seizure-like activity characterized as left upper extremity shaking that progressively generalized without loss of consciousness, lasting 15 minutes. The symptoms were triggered by standing up or turning her head. Blood pressures were 130/70 in the left arm and 99/68 in the right arm. Routine EEG did not show any epileptiform activity. Carotid dopplers revealed blunted flow in the right common carotid artery concerning for a proximal occlusion and reversed flow in the right vertebral artery consistent with subclavian steal syndrome. A dynamic CTA showed severe stenosis (85%) of the innominate artery. This stenosis was thought to result in transient ischemia with position change resulting in LS-TIA. Vascular surgery performed stenting of the innominate artery. The patient was discharged with plans to follow up with vascular surgery.
Conclusions:
To help clinicians recognize this entity, we present a case of LS-TIA due to innominate artery stenosis highlighting the challenges of diagnosing this rare phenomenon. In our patient, there was initial concern for seizure. Further investigation revealed severe innominate artery stenosis. Without intervention, this would likely have progressed to cerebrovascular insult.