Objective   To explore the incidence, diagnosis, treatment, and prognosis of central nervous system (CNS) infiltration in chronic lymphocytic leukemia (CLL).

    Methods   One case with symptomatic CNS involvement reported dizziness, diplopia, and general fatigue as initial manifestations of CLL, as shown in a literature review.

    Results   Autopsy studies revealed that leukemic invasion of CNS was found in 8% to 71% of CLL patients, whereas incidence of leukemic infiltration in symptomatic CNS was approximately 1%. The complication did not correlate with any evident risk factors, and symptoms in patients with leukemic CNS infiltration were heterogeneous and non-specific. Diagnosis of the disease depends on cerebrospinal fluid (CSF) cytology and flow cytometry. In most of similar cases, neurologic improvement is achieved by either intrathecal chemotherapy or radiation therapy. Failure to treat leukemic CNS infiltration leads to rapid deterioration and death.

    Conclusion   Leukemic involvement of the CNS is very rare in CLL cases and indicates poor prognosis. Prompt diagnosis and aggressive treatment are crucial for long-term remission and complete resolution of neurological symptoms.