Italian researchers have discovered that for spinal muscular atrophy (SMA) patients with challenging spinal anatomies, the administration of intrathecal nusinersen with the guidance of ultrasound is an effective option, according to a study published in Muscle & Nerve.
They also discovered that in addition to helping administer intrathecal nusinersen more accurately in patients with atypical spines, additional advantages included the lack of radiation exposure and that neither intravenous sedation nor general anesthesia were needed.
Nusinersen is an antisense oligonucleotide administered intrathecally in patients with SMA via lumbar puncture. It was the first disease modifying therapy to be approved for SMA. Intrathecal administration of nusinersen is generally well tolerated but can prove to be challenging in patients with spinal abnormalities.
Physicians have used computed tomography (CT) scans or fluoroscopy as imaging techniques to guide intrathecal administration. However, using ultrasound as an imaging technique has advantages over both because it does not expose the patient (or physician) to radiation or require the patient to be in the prone position for the procedure.
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Because studies using ultrasound as an imaging technique are limited, researchers wanted to document their own experience performing ultrasound-guided intrathecal administration of nusinersen on patients with SMA to add to the existing body of literature. Researchers recruited 18 SMA patients with atypical spines who consented to have ultrasound-guided intrathecal administration performed. The data recorded included successful administrations, the number of tries, the length of the procedure, and patient satisfaction.
The results were promising. Two or fewer attempts were needed in 50% of patients, and 4 or fewer attempts were needed in 83.3%. The mean length of the procedure was merely 11.8 minutes. The mean patient satisfaction score was 4.97 out of 5, both at 5 minutes and 72 hours postprocedure. No patient required sedation or general anesthesia during the procedure.
The authors concluded, “Ultrasound assistance appears to be a valid choice for intrathecal nusinersen administration in difficult spine patients and may be considered as a first approach” while “avoiding radiation, sedation, and general anesthesia.”
Zanfini BA, Catarci S, Patanella AK, et al. Ultrasound assisted lumbar intrathecal administration of nusinersen in adult patients with spinal muscular atrophy: a case series. Muscle Nerve. Published online August 15, 2021. doi:10.1002/mus.27400