Paroxysmal Sympathetic Hyperactivity after Locked-in Syndrome: A Case Report

Case Diagnosis: Paroxysmal Sympathetic Hyperactivity in a 30-year-old with Locked-In syndrome

Case Description or Program Description: We describe a case of a 30-year-old male with a history of pontine hemorrhage resulting in Locked-In syndrome, presented with fever and tachypnea. He was tachycardic to 160 beats/min and hypertensive with systolic blood pressures of 200s. He also had nystagmus lasting 20-30 seconds, associated with dystonia, and worsening leg spasms, raising suspicion of seizures. A few days later, the patient exhibited worsening decerebrate posturing with opisthotonus.

Setting: Critical Care Unit of a University Hospital

Assessment/Results: Neurological examination revealed bilateral upper and lower limb spasticity of 1 according to the Modified Ashworth Scale. CT scan of the head showed acute intraparenchymal hemorrhage in the right basal ganglia. Laboratory analysis showed elevated plasma metanephrine levels, with no history of adrenal impairment. EEG was unremarkable for seizures. Chest X-ray and urinalysis were unremarkable, other infectious etiology was ruled out. He was diagnosed with Paroxysmal Sympathetic Hyperactivity (PSH). The patient was managed with antipyretics, opioids, clonidine, and gabapentin. His spasticity was treated with oral baclofen with the consideration of a baclofen pump in the future.

Discussion (relevance): PSH is a syndrome characterized by episodic increases in sympathetic nervous system activity. While it is more commonly associated with traumatic brain injury, it can also manifest following a stroke, particularly in cases of anoxic or ischemic brain injury, as observed in this patient. The acute intraparenchymal hemorrhage in the right basal ganglia likely precipitated the patient's symptoms.

Conclusions: The management of PSH primarily involves addressing its underlying causes and managing its symptoms. It is crucial to exclude other potential etiologies of similar symptoms, such as infection, pulmonary embolism, or seizures. Early recognition and appropriate management are crucial for improving patient outcomes. Failure to promptly identify and treat PSH can result in adverse outcomes and extended hospital stays.