Intrathecal administration of nusinersen for spinal muscular atrophy: report of three cases with severe spinal deformity

BACKGROUND: Spinal muscular atrophy (SMA) is a genetic disease characterized by degeneration of the spinal cord, resulting in progressive muscle atrophy. Recently, nusinersen has been approved for treating SMA, which should be administered intrathecally. CASE PRESENTATION: Patient 1 was a 36-year-old woman with SMA type 2. Patients 2 and 3 were 10- and 17-year-old girls with SMA type 1. In patients 1 and 2, the needle was inserted into the spinal column, but outflow of cerebrospinal fluid was unable to be confirmed. CT revealed that the dural sac terminated at the L5 level in patients 1 and 3 and at the L5/S1 level in patient 2. CONCLUSIONS: Patients with SMA often present with high-grade scoliosis, making intrathecal administration difficult. In addition, the dural sac may terminate at a level higher than normal. To ensure intrathecal administration, the level of dural sac termination must be confirmed by CT before puncture.