Spinal fusion with motor evoked potential monitoring using remimazolam in Alström syndrome: A case report

Alström syndrome is a rare genetic disorder characterized by obesity, diabetes mellitus, cardiomyopathy, and liver dysfunction. Further, scoliosis, a common symptom of Alström syndrome, often requires surgical intervention for functional impairments. Motor evoked potential (MEP) monitoring and other electrophysiological tests are essential when performing surgery for functional scoliosis. However, there are few reports on how to maintain general anesthesia in Alström syndrome. Here, we describe a patient with Alström syndrome who underwent surgery for scoliosis under general anesthesia with remimazolam and MEP monitoring. A 17-year-old woman (height, 140 cm, weight, 64.5 kg) diagnosed with Alström syndrome was scheduled for a posterior spinal fusion for functional scoliosis. Other associated comorbidities of Alström syndrome present were dilated cardiomyopathy, type 2 diabetes mellitus, obesity (body mass index, 32.1 kg/m2), amblyopia (light perception), and hearing impairment (speech awareness threshold 50 dBHL in each ear). Posterior spinal fusion was planned for functional scoliosis. While investigating the dilated cardiomyopathy, transthoracic echocardiography showed global wall hypokinesis, with 45% left ventricular ejection fraction. The left ventricle was dilated, with left ventricular end-diastolic and end-systolic diameters of 55 and 42 mm, respectively. This finding along with the hypertriglyceridemia associated with Alström syndrome led us to conclude that propofol should be avoided. Thus, we induced general anesthesia using remimazolam. MEP monitoring was performed, and the patient experienced no motor impairments during the surgery. Myocardial and hepatic dysfunction determine the prognosis of patients with Alström syndrome. Thus, anesthesia that preserves liver function should be selected in such cases. In patients with hypertriglyceridemia, propofol should be avoided, and using remimazolam, an ultrashort-acting benzodiazepine, may be appropriate. In this case, reviewing the Patient State Index with SedLine allowed us to perform MEP monitoring uneventfully, and the posterior spinal fusion was completed without any motor impairment.