[The syndrome of transient headache and neurologic deficits with cerebrospinal fluid lymphocytosis (HaNDL)].

The syndrome of transient headache and neurologic deficits with cerebrospinal fluid lymphocytosis (HaNDL) is a self-limited disorder with an unknown pathogenesis, characterized by one or more transient episodes of severe headache accompanied with neurologic deficits, and lymphocytic pleocytosis in the cerebrospinal fluid (CSF). Despite being uncommon and benign it is important for clinicians to identify and differentiate HaNDL from other potentially fatal neurologic disorders. We present six HaNDL patients from our institution. All had a relatively typical course with repeated migraine-like headaches accompanied by various transient neurologic deficits and a mean CSF lymphocytic pleocytosis of 178 cells/mm3. Most of the patients were disorientated during the attacks, which has been described previously. When neurofilament light in CSF was measured, there was a substantial increase of this marker which normalized after several months, suggesting certain nerve damage.