A case of new-onset myasthenia gravis (MG) presented with symptoms similar to spinal cord injury after Zenker’s diverticulum repair surgery, as reported in a study in OTO Open.
The 60-year-old patient complained of new-onset upper and lower extremity weakness following Zenker’s diverticulum repair surgery. Administration of medications and anesthesia, surgery, and emergence from anesthesia were all uneventful.
The patient was able to ambulate only with 2-person assistance but did not show signs of sensory deficit and did not have trouble urinating. Manual muscle testing revealed greater upper extremity weakness than lower extremity weakness.
The symptoms suggested the possibility of acute cervical spinal cord injury, or central cord syndrome, and the physicians were concerned it may have been due to prolonged neck extension. Magnetic resonance imaging (MRI) and computed tomography (CT) scans, however, revealed no spinal cord injury or other traumatic lesions.
Read more about MG differential diagnosis
Further neurological examination discovered mild bilateral ptosis, eye closure weakness, no diplopia, no dysarthria, and a normal cough. The bedside ice pack test was administered for 2 minutes to the eyelids, which resolved the ptosis, indicating a diagnosis of MG. A diagnosis of new-onset MG was confirmed with further clinical and laboratory testing and the patient received further appropriate treatment.
“This report presents a rare case of new-onset MG diagnosed in the immediate postoperative period after a Zenker’s repair,” the authors wrote.
“It demonstrates that intraoperative events can unmask MG during the subclinical stage of the disease, lead physicians to other diagnostic considerations because of the general unfamiliarity with this complication in the postoperative period, and challenges surgeons and anesthesiologists to be aware of this potentially life-threatening clinical scenario,” the authors continued.
The authors hypothesized that the patient’s previously undiagnosed MG was exacerbated through his exposure to several intraoperative drugs that reduced the efficiency of the neuromuscular junction.
Nondepolarizing neuromuscular blocking agents (such as rocuronium), different classes of antibiotics (including aminoglycosides and ampicillin), glucocorticoids, and possibly some local anesthetics (like lidocaine) can affect the neuromuscular junction and were used during the surgery.
This case highlights the careful planning needed for surgery in patients with MG as well as the need for physicians to be aware of the possibility of undiagnosed rare diseases when performing operations.
Meiler SE, Siwemuke TJ, Postma GN. New-onset myasthenia gravis mimics spinal cord injury after Zenker’s diverticulum repair. OTO Open. 2023;7(2):e56. doi:10.1002/oto2.56