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

Abstract

Verbal and written informed consent for publication of their clinical presentation and course was obtained from the patient and her parents. We describe a 14-year-old girl (body weight 14 kg) presented at our clinic with type 1 spinal muscular atrophy (SMA), diagnosed since the age of 1. As the patient had limited limb movement after birth and could not sit independently, her attending neurologists put her on a plan to receive intrathecal nusinersen, possibly for the rest of her life. The patient had a history of muscle weakness and presented with severe deformity with rotoscoliosis and vertebrae rotation. Although her heart was in the left pleural at birth, it is currently located in the right pleural. Preprocedural investigation with computed tomography (CT) imaging showed complete bony fusion in the thoracic vertebrae and severe visceral displacement. The Cobb angle was >50°. Considering the patient's age, we first attempted an ultrasound-assisted puncture to avoid excessive exposure to radiation. The procedure was performed in a standard operating theater and the patient was placed under local anesthesia with lidocaine 50 mg. However, we failed to find a possible access point to the intrathecal space with ultrasound scanning due to severe spinal deformity.Consequently, we used an innovative approach, using staples, a commonly available office tool, to complement the CT-guided procedure. First, we strung together staples on a piece of adhesive tape; this was then applied onto the patient's back where her lumbar vertebrae were located, while the patient was placed in the right lateral decubitus position (Figure 1). Next, we used CT imaging to identify suitable lumbar access to the intrathecal space by counting the sequence of staples, which could be viewed as metallic markers on the CT image, from the bottom to the top (Figure 2A). During this procedure, a lead suit cover was used to protect the patient's head and pelvic area from radiation exposure. Once the intrathecal access had been identified, the corresponding staple was marked with a marker pen (Figure 2B). Using a 21-G 8 spinal needle, the needle tip was successfully inserted into the intrathecal space and nusinersen (5 mL, 12 mg) administration was confirmed by the backflow of cerebrospinal fluid.