Ultrasound assisted lumbar intrathecal administration of nusinersen in adult patients with spinal muscular atrophy: A case series

Abstract

Introduction/Aims Intrathecal nusinersen administration can be challenging in certain adult spinal muscular atrophy (SMA) patients with difficult spinal anatomy who require imaging techniques (fluoroscopy or computed tomography scans) or invasive approaches (catheter placement, laminotomy) to identify the intrathecal space. We used ultrasound (US) assistance to access the lumbar intrathecal space in patients with SMA who experienced previous difficulties or failures with intrathecal dosing. Methods Eighteen adult patients with difficult spines were enrolled. We used US assistance, and we recorded the successful administrations, number of attempts, procedure times, and “patient satisfaction.” Results There were 57 consecutive successful nusinersen spinal administrations in all patients enrolled. In 50% of patients, two or fewer attempts were needed to obtain a successful administration, with four or fewer attempts in 83.3%; only three patients reported more than four attempts because of both severe scoliosis and severe spine rotation (two patients) and obesity (one patient). The mean procedure time was 11.8 min (range, 1.7–28.9). Patient satisfaction was 4.97/5 (range, 4–5; median, 5) on Likert scale at 5 min and at 72 h. No major adverse events were reported, and two post dural puncture headaches were managed with medical therapy and with complete resolution within 72 h. Discussion US assistance seems to be a valid option among treatment choices for intrathecal nusinersen administration in patients with difficult spine. The absence of radiation exposure and the lack of need for intravenous sedation or general anesthesia are additional potential advantages to US assisted administration.

Innovative Computed Tomography–Assisted Intrathecal Nusinersen Injection in a Pediatric Patient

“…This case report describes an innovative approach using staples to complement CT imaging for the identification of a potential intrathecal access point for nusinersen administration in a pediatric patient with severe spinal deformity. Although recent reports have shown that ultrasound imaging can be helpful in guiding intrathecal injections of nusinersen, 1,2 we failed to identify a suitable intrathecal access point for this patient, despite several attempts using ultrasound imaging. As this patient has severe scoliosis, a completely fused spine, osteopenia, and visceral displacement, further attempts with ultrasound-assisted intrathecal injections would have put the patient at risk of complications such as radiculopathy, subarachnoid hemorrhage, spinal fracture, or accidental puncture of visceral anatomical organs.…”

Impact of Spinal Surgery on Intrathecal Nusinersen Injections in Pediatric Spinal Muscular Atrophy

“…Fluoroscopic or ultrasonographic guidance rather than using the conventional technique may be required to prevent failures with intrathecal administration. 11 For this purpose, in some clinics, permanent placement of an intrathecal catheter with one end extending into a subcutaneous reservoir is performed to make the treatment more manageable and safer. 12 Methods for performing injections through transforaminal approaches [13][14][15] or catheters inserted through drill holes placed in the fusion mass have also been described in patients who had previously undergone fusion.…”

“…Intrathecal injections may also pose a problem for patients with severe deformities who have not undergone surgery. Fluoroscopic or ultrasonographic guidance rather than using the conventional technique may be required to prevent failures with intrathecal administration 11 . For this purpose, in some clinics, permanent placement of an intrathecal catheter with one end extending into a subcutaneous reservoir is performed to make the treatment more manageable and safer 12 .…”

Ultrasound‐guided transforaminal approach for nusinersen delivery in adult spinal muscle atrophy patients with challenging access

“…Previous studies suggest that 40%‐60% of adult SMA patients present with a difficult spine that prevents the conventional lumbar puncture 2,6,9 . Modalities with ionizing radiation are predominantly used as image guidance options 7‐10 .…”

“…Although ultrasound (US) is recognized as a useful adjunct for lumbar spinal anesthesia in adults, there are only a few papers on US utilization for intrathecal nusinersen delivery in spinal muscle atrophy (SMA) patients, all of which describe intrathecal nusinersen delivery via the translaminar approach 1‐6 . Veiga‐Canuto et al reported that US‐guided translaminar approach was unsuccessful in patients without visible interlaminar space on pre‐procedural computed tomography (CT) 2 .…”