November 13, 2019
2 min read

Lateral subdermic plexus may be tied to restless leg syndrome, nighttime cramping

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Swar Shah

LAS VEGAS — Treating lateral subdermic venous plexus reflux alleviated symptoms associated with restless leg syndrome and nighttime cramping, according to a presentation at VIVA 19.

The results suggest these specific but previously poorly understood varicose veins on the lateral thigh and calf may be the etiology of restless leg syndrome and nighttime cramping, Swar Shah, MD, interventional radiology resident at Rochester General Hospital and the Vein Institute, said during a presentation.

Patients with chronic venous insufficiency often also have restless leg syndrome and/or nighttime cramping/charley horses, so the researchers began prospectively tracking symptoms of those with chronic venous insufficiency in 2015, Shah said.

Shah said as a result of the prospective tracking, he and Raj Pyne, MD, FSIR, noticed many patients had the same distribution of varicosities and/or spider vein clusters, predominantly along the lateral lower thigh, knee and calf.

The researchers hypothesized that these patients had an abnormality in the lateral subdermic plexus, which drains the superficial skin and tissue in the lateral lower thigh, knee and calf, and proposed an etiology, Shah said.

“Without the aid of gravity when laying supine, there is impaired flow from the lateral subdermic plexus to the deep veins, especially the thigh component,” he said. “Poor flow and reflux in the lateral subdermic plexus leads to venous stasis. Restless legs and cramping occur as the body attempts to correct the venous reflux and stasis, theoretically hypothesized as an irritation of the iliotibial band causing muscle microspasms.”

To test the hypothesis, the researchers performed ultrasound-guided foam sclerotherapy, which is traditionally used to treat varicose veins throughout the legs, often in association with ablation or phlebectomy.

The researchers performed a comprehensive venous ultrasound on 510 patients presenting with chronic venous insufficiency between 2015 and 2017. Of those, 63.1% had an abnormal lateral subdermic plexus, Shah said.

Patients with restless leg symptoms were more likely to be positive for chronic venous insufficiency than those without such symptoms (83% vs. 50%; P < .001), and those with nighttime cramping were more likely to have chronic venous insufficiency diagnosed than those without it (89% vs. 44%; P < .001), according to the researchers.

Among patients who had both conditions, 91% had chronic venous insufficiency, and among patients who had neither, 98% did not have chronic venous insufficiency (P < .001 for both), Shah said.

Of the 242 patients who underwent ultrasound-guided foam sclerotherapy, 94% reported symptom resolution at the time of the procedure, 93% reported symptom resolution at 90 days and 92% reported symptom resolution at 1 year, he said, noting there were only two minor, self-limiting complications.


“Establishing the lateral subdermic plexus as part of the workup for varicose veins would allow for diagnosis of previously misunderstood symptoms and provide a safe, effective and cost-effective treatment for patients with restless leg syndrome and nighttime cramping/charley horses. This could be a major paradigm shift in understanding the etiology for restless leg syndrome and nighttime cramping,” Shah said.

He said the next step is to conduct a multicenter study to confirm the findings. – by Erik Swain


Shah S, et al. Late-Breaking Clinical Trials. Presented at: VIVA 19; Nov. 4-7, 2019; Las Vegas.

Disclosure: Shah reports no relevant financial disclosures.