Transient neurologic dysfunction following moderate-dose methotrexate for undifferentiated lymphoma

Area of Science:

• Neurology
• Oncology
• Pharmacology

Background:

• Undifferentiated lymphoma treatment often involves combination chemotherapy.
• Methotrexate is a key chemotherapeutic agent used in various cancers.
• Intrathecal methotrexate is administered to prevent or treat central nervous system involvement.

Observation:

• Two patients with undifferentiated lymphoma developed acute focal neurologic deficits.
• Symptoms appeared 10 days after moderate-dose intravenous and intrathecal methotrexate administration.
• Neurologic deficits included dysarthria, hemiparesis, and quadriparesis.

Findings:

• Cerebrospinal fluid and cranial CT scans were normal.
• Electroencephalograms (EEGs) revealed focal abnormalities in both patients.
• Full neurologic recovery occurred within 48 hours, with no recurrence in one patient on the same regimen.

Implications:

• Moderate-dose methotrexate may cause transient neurotoxicity, presenting as focal neurologic deficits.
• The mechanism of methotrexate-induced neurotoxicity requires further investigation.
• This adverse event is similar to neurotoxicity reported with high-dose methotrexate for osteosarcoma.