The syndrome of transient headache and neurologic deficits with cerebrospinal fluid lymphocytosis (HaNDL syndrome) is a self-limited condition. Confusional states are uncommonly reported as a clinical manifestation of this syndrome. Here, I report a 76-year-old female who presented with headache, confusion, and agitation with a mild CSF lymphocytosis. Other workup to determine the cause of her altered mental status was otherwise negative. The literature available in the English language on HaNDL syndrome is reviewed, including its history, pathophysiology, possible associations with migraine and stroke, and previously reported cases of confusional states in this syndrome. While HaNDL syndrome has been a described entity since the 1980s, its pathophysiology has yet to be clearly defined.