Headache and neurologic deficits with cerebrospinal fluid lymphocytosis syndrome (HaNDL) is a rare nosographic entity, which mainly affects adults but can also occur in the paediatric age. In the literature, 31 cases in this age group are described. Symptomatology typically lasts about three months with episodes that tend to relapse. An autoimmune pathogenesis has been hypothesized. The paper describes the case of an adolescent who presented with three acute and transient episodes of migraine headache in three days associated with impaired consciousness, focal neurological deficits and CSF lymphocytosis. After treatment with steroidal and non-steroidal anti-inflammatory drugs, the patient did not relapse in the following four months. The treatment indicated in the literature is only supportive (analgesics, antiemetics), however in this case the anti-inflammatory therapy reduced the duration of the episode and the recurrence of further episodes.