Clinically significant neurological signs resulting from leukaemia cell infiltration in the CNS are reported in only 1% of patients with CLL. These include cognitive behavioural symptoms, headache, weakness, gait disorder and seizure.
Autopsy studies suggest that CNS involvement is more frequent (7-71% of patients), although very few are clinically significant.
CLL patients with neurological signs and confirmed CNS involvement require treatment. Given the rarity of CLL patients with significant CNS involvement, there are no standard treatment protocols for these patients.
Intrathecal chemotherapy, with or without radiotherapy, is often used. The chemotherapies commonly injected into the CSF are methotrexate or cytarabine .
Intrathecal chemotherapy is often combined with systemic treatments for CLL. The main systemic drugs that penetrate the blood-brain barrier include high-dose methotrexate, cytarabine, corticosteroids and dasatinib.
Other options include whole-brain radiotherapy and FCR (fludarabine + cyclophosphamide + rituximab).