The syndrome of headache accompanied with transient neurologic deficits and cerebrospinal fluid lymphocytosis (HaNDL), is a rare, benign and self limiting syndrome. In the 2nd Edition of the International Classification of Headache Disorders, HaNDL syndrome was defined in secondary headache group as "Headache attributed to non-vascular intracranial disorder". The etiology of HaNDL is still unknown. In recent years, some authors have shown that ion channel autoimmunity might at least partially contribute to HaNDL pathogenesis. In this paper, the definition of HaNDL syndrome, clinical picture and epidemiology of HaNDL syndrome, etiopathogenesis, differential diagnosis and treatment will be reviewed with the recent literature.