HaNDL Syndrome: Case Report and Literature Review.

Headache and Neurologic Deficits with cerebrospinal fluid Lymphocytosis (HaNDL) syndrome is a rare stroke mimicker characterized by moderate to severe headache temporally associated with transient neurologic deficits, typically hemiparesis, hemisensory disturbance, and/or aphasia. Cerebrospinal fluid studies reveal a lymphocytosis and elevated protein. Episodes recur over a period no longer than 3 months. Here we describe the case of a 16-year-old boy who presented with 3 episodes of self-resolving neurologic deficits, papilledema on fundoscopic examination, and leptomeningeal enhancement on magnetic resonance imaging (MRI). We additionally review the 30 previously reported pediatric cases of HaNDL syndrome, with a focus on possible etiologic and pathophysiologic mechanisms of disease. The reported case and literature review highlight the benign episodic nature of this likely underrecognized syndrome as well as the higher than expected frequency of abnormal neuroimaging findings.