The goal of this clinical trial is to test CRIS100 treatment in participants with acute thoracic spinal cord injury. The main questions it aims to answer are:

• safety of CRIS100
• efficacy of CRIS100

Participants will receive 100 mcg CRIS100 in the epicenter of the spinal injury, within 72 hours of the trauma.

Participants with complete spinal cord injury between T2 and T10 (ASIA A, according to ISNCSCI, 2019 revision) and:

• occurred less than 72 hours ago
• with surgical indication
• bulbocavernous reflex present
• who can receive treatment with CRIS100 within 72 hours after the trauma (preferably within 24 hours)

Inclusion Criteria:

• Signature of the Free and Informed Consent Term by the participant or legal guardian
• Age between 18 and 70 years old;
• Thoracic spinal cord injury between T2 and T10, with surgical indication, occurred less than 72 hours before surgery;
• Presence of bulbo cavernosum reflex;
• Patients with a lesion classified as ASIA A according to the ISNCSCI (2019 revision);

Exclusion Criteria:

• Absence of bulbocavernous reflex up to 72 hours after the trauma.
• Presence of severe brain trauma.
• Patients with lesions above T2 or below T10.
• More than one site of spinal cord injury.
• History of alcohol or illicit drug abuse, as defined by DSM 5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition or later).
• Patients who need permanent mechanical respiratory support.
• Polytraumatized patients who, in the investigator's assessment, compromise the neurological evolution.
• Neurological diseases or functional dependence of any etiology prior to the trauma.
• Any other comorbidity that, at the discretion of the investigator, makes it impossible to include the patient in the study.