I congratulate Blackman et al1 for their valuable effort to bring some order into the chaotic and sketchy literature on autonomic dysregulation after brain injury. They propose the termparoxysmal autonomic instability with dystonia (PAID) to characterize the syndrome. Although I agree with the necessity to introduce a unifying nomenclature, this denomination and the criteria listed by the authors may be too restrictive. In the neurological-neurosurgical intensive care unit, I have often observed patients with brain injuries who have spells of autonomic dysregulation but minimal or no dystonia and in whom no other explanation for these signs can be found. These patients typically respond to the agents cited by the authors (nonselective β-blockers, morphine sulfate, bromocriptine mesylate, or clonidine hydrochloride) and sometimes worsen when they receive haloperidol for sedation. If left untreated, many eventually develop dystonic posturing.
Rabinstein AA. Paroxysmal Autonomic Instability After Brain Injury. Arch Neurol. 2004;61(10):1625. doi:10.1001/archneur.61.10.1625-a