Pharmacologic Management of Paroxysmal Sympathetic Hyperactivity After Brain Injury

Paroxysmal sympathetic hyperactivity (PSH) is a result of acute brain injury that has been well known for many decades. However, the evidence for management of PSH is almost entirely anecdotal in nature. We reviewed case reports or series of pharmacotherapy management of PSH. These studies mentioned treatment options, but few studies exist to guide treatment strategies. For many years, the syndrome was not clearly understood; therefore, the therapy has focused on control of symptoms. In 2014, a Steering Committee came together to develop a conceptual definition and produced a consensus set of diagnostic criteria. Although understanding the diagnostic criteria is very well needed in management of patients with PSH, pharmacologic management is also crucial. Data describing the drug choices, dosing, and duration of therapy are also sparse. Recognition of appropriate medications is important because PSH is associated with morbidity, longer hospitalization, delaying transfer to rehabilitation units, and increasing cost. In this review article, we discussed the common medications used in the treatment of PSH. Treatment should target symptom abortion, prevention of symptoms, and refractory treatment. Symptom-abortive medications are indicated to control discrete breakthrough episodes, using medications such as morphine and short-acting benzodiazepines. Other medications used for prevention of symptoms and refractory treatment include long-acting benzodiazepines, nonselective β-blockers, α2 agonists, opioids, and GABA agonists. The mechanisms by which these agents improve symptoms of PSH remain speculative. However, a combination of medications from different classes seems the most effective approach in managing PSH symptoms. There is wide variability in clinical practice with regard to drug choices, dosing, and duration of therapy. Future research needs to be conducted using the new PSH assessment measure to appropriately apply drug management.