American Board of Surgery Qualifying Exam (ABS QE) Practice Test

Vincristine primarily causes which type of neurological side effect?

1. Myelosuppression

2. Pulmonary fibrosis

3. Peripheral neuropathy

4. Hemorrhagic cystitis

The correct answer is: Peripheral neuropathy

Vincristine is a chemotherapeutic agent that primarily affects the nervous system, leading to the development of peripheral neuropathy. This condition occurs because vincristine acts on the microtubules in cells, disrupting their ability to divide and function normally, particularly in rapidly dividing cells such as those found in the nervous system. Peripheral neuropathy associated with vincristine is characterized by symptoms such as tingling, numbness, or pain in the extremities. This side effect arises because vincristine has a strong affinity for the long axons of peripheral nerves, leading to a loss of function in these neurons. In contrast, myelosuppression, pulmonary fibrosis, and hemorrhagic cystitis are side effects associated with other chemotherapeutic agents. Myelosuppression generally refers to a decrease in bone marrow function leading to reduced production of blood cells, which is more common with drugs like alkylating agents. Pulmonary fibrosis can occur with long-term use of certain agents that affect lung tissue, while hemorrhagic cystitis is associated with drugs such as cyclophosphamide that irritate the bladder lining. Therefore, the specific mechanism of action and neurological impact of vincristine clearly delineates peripheral neuropathy as the primary neurological side effect