In the early phase after a spinal cord injury, which pattern of motor response below the lesion is most likely?

In the early phase after a spinal cord injury, which pattern of motor response below the lesion is most likely?

• A. Hyperreflexia with spasticity
• B. Flaccid paralysis with absent reflexes
• C. Normal motor function
• D. Autonomic dysreflexia

Answer: (B)

Immediately after a spinal cord injury, the body undergoes spinal shock, which temporarily suppresses the reflex circuits below the level of injury. This causes flaccid paralysis and absent reflexes below the lesion because the motor neurons and their connections are not being activated and the innate spinal reflexes are temporarily muted. As this acute phase resolves over hours to weeks, reflex activity can return and may become hyperactive, leading to spasticity and hyperreflexia. Normal motor function is unlikely in the very early phase because the disrupted pathways prevent voluntary movement and reflexes from functioning. Autonomic dysreflexia is an autonomic syndrome tied to autonomic outflow below the injury and level of injury, not a pattern of motor response, so it doesn’t describe the initial motor presentation.

Immediately after a spinal cord injury, the body undergoes spinal shock, which temporarily suppresses the reflex circuits below the level of injury. This causes flaccid paralysis and absent reflexes below the lesion because the motor neurons and their connections are not being activated and the innate spinal reflexes are temporarily muted. As this acute phase resolves over hours to weeks, reflex activity can return and may become hyperactive, leading to spasticity and hyperreflexia. Normal motor function is unlikely in the very early phase because the disrupted pathways prevent voluntary movement and reflexes from functioning. Autonomic dysreflexia is an autonomic syndrome tied to autonomic outflow below the injury and level of injury, not a pattern of motor response, so it doesn’t describe the initial motor presentation.