Which condition can cause severe hypertension and headache due to loss of parasympathetic control?

Autonomic dysreflexia is indeed the condition that leads to severe hypertension and headaches resulting from loss of parasympathetic control, particularly in individuals with spinal cord injuries above the T6 level. In this condition, there is an uncontrolled sympathetic response to stimuli below the level of injury, causing vasoconstriction and subsequently resulting in significantly elevated blood pressure.

The body's natural compensatory mechanisms can be overwhelmed because the parasympathetic system is unable to effectively mitigate this heightened sympathetic reaction. This can lead to classic symptoms such as severe hypertension and headache, as the body attempts to respond to the imbalance in autonomic regulation. Therefore, recognizing autonomic dysreflexia is crucial in managing individuals with spinal cord injuries, as timely intervention is necessary to control the dangerous rise in blood pressure and alleviate the associated symptoms.

Neurogenic shock, spinal shock, and Brown-Séquard syndrome do not primarily feature the same mechanism of sympathetic overactivity coupled with a lack of parasympathetic tone that characterizes autonomic dysreflexia. These conditions have different pathological processes and manifestations, emphasizing the unique aspects of autonomic dysreflexia as a critical clinical entity in emergency situations.