Congenital neuromuscular disease with uniform type-1 fibers, presenting early stage dystrophic muscle pathology

Kyphoscoliosis associated with congenital neuromuscular disease with uniform type 1 fibers

OBJECTIVE

To report the first case of surgical treatment for severe kyphoscoliosis associated with respiratory disorder in a patient with congenital neuromuscular disease with uniform type 1 fibers (CNMDU1), including management of the possible onset of malignant hyperthermia (MH) in general anesthesia. CNMDU1 is rare among congenital neuromuscular diseases, and surgery for spinal deformity in CNMDU1 has not been described. Onset of MH in general anesthesia is a concern in this disease.

METHODS

A 13-year-old female with motor retardation, suspected myopathy, and severe spinal deformity was followed at another pediatric hospital before referral to Meijo Hospital. Symptoms at the initial consultation were mild general muscular weakness and muscular atrophy. The rib hump was 60° and trunk balance was poor. The tendon reflex showed hyporeflexia, and blood tests were normal. Vital capacity was 0.69 L and forced expiratory volume percentage in 1 s was 75.5%, showing a restrictive and obstructive ventilatory defect. A plain radiograph showed severe kyphoscoliosis with thoracic scoliosis of 130° (T5-L1) and thoracic kyphosis of 110° (T2-T12) with almost no flexibility in bending or traction film.

RESULTS

After preoperative halo traction for 2 months, one-stage anterior and posterior correction and fusion from T2 to L3 was conducted. MH did not occur, but recovery of respiratory function required 8 days by intubation after surgery. Postoperatively, thoracic kyphosis improved to 25° and thoracic scoliosis was 66° (correction rate: 49%). Pathological results of an intraoperative muscle biopsy from the paraspinal muscles confirmed the diagnosis of CNMDU1. At 6 years after surgery, the patient has no problems in daily life and no respiratory difficulty.

CONCLUSION

Spinal deformity in CNMDU1 has a risk of severe progression, which makes early diagnosis by biopsy important. The surgery may be recommended before severe progression of spinal deformity and respiratory disorder. Perioperative MH is a concern, but can be managed by appropriate procedures.

Anesthetic case in a child with congenital neuromuscular disease with uniform type 1 fibers (CNMDU1)

Congenital neuromuscular disease with uniform type 1 fibers (CNMDU1) is an extremely rare, non-progressive, congenital neuromuscular disorder. Although the etiology is unknown, ryanodine receptor gene mutation is reportedly involved. No descriptions of anesthetic practice in patients with this disease have been reported around the world. We report a case of safe perioperative management with general anesthesia, using total intravenous anesthesia, propofol, fentanyl and a non-depolarizing muscle relaxant but avoiding the use of any inhaled anesthetics or depolarizing muscle relaxants to prevent malignant hyperthermia and postoperative respiratory failure, during anesthetic management for cranioplasty for premature synostosis of the cranial sutures in a pediatric patient of CNMDU1.