Paroxysmal sympathetic hyperactivity associated with posterior reversible encephalopathy syndrome

Paroxysmal sympathetic hyperactivity (PSH) causes paroxysms of increased sympathetic hyperactivity in the setting of acquired brain injury. Posterior reversible encephalopathy syndrome (PRES) is a clinico-radiological syndrome characterised by cortical/subcortical vasogenic oedema in multiple brain areas. Patients present with seizures, encephalopathy and headaches. In this article, we report a patient who presented in status epilepticus with a hypertensive peak and decreased level of consciousness. Brain imaging showed diffuse hyperintensities with beading intracranial vessels. Then, the patient improved spontaneously without receiving any treatment except supportive management. Repeated brain imaging showed resolution of the abnormalities. A diagnosis of PRES was made. During her stay, she developed episodes of diffuse body rigidity associated with hypertension, tachycardia and diaphoresis, triggered by non-noxious stimuli suggestive of PSH. She received clonidine with significant improvement. This case illustrates the need to keep a high index of suspicion for PSH in cases of acquired diffuse brain injuries, such as PRES.