In the high-stakes environment of intensive care, observing motor activity in a comatose patient undergoing evaluation for brain death can be deeply unsettling for both clinicians and families. These spinal mediated movements often mimic purposeful or cerebral-mediated actions, potentially complicating the Determination of Death by Neurologic Criteria (DNC). A recent prospective cohort study conducted across 15 Canadian intensive care units provides crucial clarity on the prevalence and neuroimaging correlates of these phenomena.

Understanding Spinal Mediated Movements and MUO

The study included 282 comatose adults with a Glasgow Coma Scale score of 3 who were at risk of DNC. Researchers categorized the motor activities into spinal-mediated movements (SMM) and movements of unclear neuroanatomic origin (MUO). Consequently, the results showed a significant prevalence of these activities. SMM occurred in 27% of the participants, while MUO was observed in 12%. Furthermore, the frequency of these movements remained consistent regardless of whether the patient eventually fulfilled the clinical criteria for DNC.

Neuroimaging and Cerebral Perfusion Findings

A pivotal aspect of this research was the use of brain CT-perfusion and CT-angiography to assess cerebral blood flow. Historically, there has been concern that such movements might indicate residual brain perfusion. However, the study demonstrated that spinal mediated movements and MUOs are not associated with the presence of cerebral blood flow or brain perfusion. Specifically, the adjusted odds ratios (aOR) for SMM and MUO showed no significant correlation with intracranial circulation. Therefore, these movements should be viewed as extracerebral in nature and not as indicators of brain viability.

Clinical Implications for DNC Evaluation

For medical professionals in India, particularly those operating under the Transplantation of Human Organs and Tissues Act (THOTA), these findings reinforce that the presence of spinal reflexes does not preclude a diagnosis of brainstem death. Clinicians must accurately identify these semiologies to avoid unnecessary delays in the DNC process. Moreover, clear communication with the patient’s family regarding the spinal origin of these movements is essential to maintain trust and clarity during organ donation discussions.

Frequently Asked Questions

What are the most common examples of spinal mediated movements in comatose patients?

Common examples include the Lazarus sign (arm flexion and crossing), finger jerks, toe bending, and triple flexion reflexes. These movements originate from the spinal cord and can occur even after the brain has completely ceased to function.

Does the presence of a Lazarus sign mean the patient is still alive?

No, a Lazarus sign is a complex spinal reflex. Research confirms that it is not associated with cerebral blood flow or brainstem activity, meaning it can occur in patients who meet all legal and clinical criteria for brain death.

How quickly should neuroimaging be performed when assessing DNC-risk patients?

While the study used a 2-hour window for CT-perfusion scans to ensure data accuracy, clinical guidelines usually prioritize standardized clinical evaluations first. Ancillary tests like CT-angiography are used primarily when clinical tests are confounded.

Disclaimer: This content is for informational and educational purposes only. It does not constitute medical advice or a professional physician-patient relationship. Refer to the latest local and national guidelines for clinical practice.

References

Neves Briard J et al. Prevalence, semiology and neuroimaging of movements in comatose adults at risk of death by neurologic criteria: a prospective cohort study. Crit Care. 2026 May 14. doi: 10.1186/s13054-026-06037-2. PMID: 42135815.