The primary objective of the study is to evaluate anxiety level during intrathecal administration (IT) under standard of care (SOC) and virtual reality (VR) conditions using a reliable self-rating scale.

Key Inclusion Criteria:

• Participants aged 7 years and greater
• Genetically documented spinal muscular atrophy linked to chromosome 5q (5q-SMA)
• Loading nusinersen dose period is completed, and ongoing treatment with nusinersen
• Ability of the candidate and/or their legally authorized representatives (e.g., parent, spouse, or legal guardian), as appropriate and applicable, to understand the purpose and risks of the study, to provide informed consent, and to authorize the use of confidential health information in accordance with national and local privacy regulations
• Signed written informed consent from adult participants, or from legal authorized representatives for minors

Key Exclusion Criteria:

• History of any clinically significant abnormalities that would render the candidate unsuitable for VR (e.g., visual or hearing impairment, presence of eye, face or sclap injuries) or for inclusion (e.g. cognitive impairment), as determined by the Investigator
• Conditions that could be exacerbated by the VR environment, such as: (i) current symptomatic nausea, vomiting, dizziness, migraine; (ii) history of psychosis, hallucinations, epilepsy
• Ongoing medical conditions or treatments that according to the Investigator would interfere with the conduct and assessments of the study (e.g. general anesthesia)
• Participants wearing a pacemaker and pregnant woman

NOTE: Other protocol defined Inclusion/Exclusion criteria may apply.

In accordance with Biogen's Clinical Trial Transparency and Data Sharing Policy on https://www.biogentrialtransparency.com/