Spinal muscular atrophy (SMA) is a progressive motor neuron disease characterized by the degeneration of anterior horn cells in the spinal cord. Anesthetic management in patients with SMA presents challenges such as respiratory muscle weakness and heightened sensitivity to muscle relaxants. This study reports a case of general anesthesia management in a patient with type Ⅱ SMA.
A 22-year-old woman underwent wisdom tooth extraction under general anesthesia. Neuromuscular monitoring was performed at two sites : the ulnar nerve-abductor digiti minimi and the facial nerve-corrugator supercilii. Following administration of 10 mg rocuronium bromide, the train-of-four count (TOFc) was 0 at the abductor digiti minimi, while the corrugator supercilii maintained a TOFc of 4. However, sufficient muscle relaxation was achieved to allow successful nasal intubation. Postoperatively, the neuromuscular blockade was reversed with sugammadex sodium, and the patient recovered and was extubated without complications.
In general anesthesia for SMA patients, the ulnar nerve-abductor digiti minimi demonstrates higher sensitivity to muscle relaxants compared to the facial nerve-corrugator supercilii. Monitoring the ulnar nerve-abductor digiti minimi may offer a more reliable assessment of the optimal timing for intubation. The reversal of neuromuscular blockade with sugammadex sodium is effective ; however, extubation should be carefully assessed using both neuromuscular monitoring and clinical indicators, such as adequate ventilation volume, to ensure a comprehensive evaluation.
