Does Dexmedetomidine Improve or Worsen Restless Leg Syndrome under Sedation: A Case Report and Extensive Review

Abstract

Background. Restless leg syndrome (RLS) is a common neurological condition that manifests as creeping, nonpainful urges to move lower extremities and is relieved with movements of the legs. RLS is associated with comorbidities such as gastric surgery, diabetes mellitus, uremia, and iron deficiency anemia, and it is misdiagnosed in many cases. Drugs like levodopa, ropinirole, pramipexole, cabergoline, and pergolide that target the dopaminergic system have been traditionally used to treat symptoms of RLS. α2-adrenoceptor (α2-AR) agonists, like clonidine and dexmedetomidine, have also been reported to show improvement of RLS symptoms during sedation. Specific Aim. This case report suggests that dexmedetomidine may have worsened RLS during sedation in a 71-year-old male with no prior diagnosis of RLS or reported symptoms. The patient had a procedure for right first metatarsophalangeal joint (MTPJ) fusion, with second digit proximal interphalangeal joint (PIPJ) arthrodesis, and flexor tendon transfer due to pain on walking and failing conservative therapy. He underwent intravenous sedation/monitored anesthesia care (MAC) with propofol, dexmedetomidine, and a peripheral regional block for intraoperative anesthesia and postoperative analgesia. During the surgery, the patient experienced continuous bilateral leg movement, unpredictable, and unrelated to surgical stimulation or level of consciousness within 5 minutes of administration of dexmedetomidine. The patient tolerated the procedure, and the unpredicted leg movement was managed by the surgeons intraoperatively. Conclusion. Although no previous literature exists and mechanisms are unclear, this case report hypothesizes that dexmedetomidine may contribute to worsening RLS symptoms.

The effect of dexmedetomidine on expression of neuronal nitric oxide synthase in spinal dorsal cord in a rat model with chronic neuropathic pain

“…In addition, local analgesia also takes effect by stimulating the α2 acceptor to regulate hypalgesia. 21,22 It was found that TWL increased significantly on the 7 th day after ligation of the sciatic nerve and continuous intraperitoneal injection in the DEX group, thereby signifying that neuropathic pain can be substantially alleviated via continuous intraperitoneal DEX injection. Dexmedetomidine can be characterized by its strong anti-nociceptive effect by directly suppressing the release of excitatory neurotransmitters (like glutamic acid) from the synaptic afferent terminus of the spinal dorsal cord.…”

“…In addition, local analgesia also takes effect by stimulating the α2 acceptor to regulate hypalgesia. 21 22…”