Successful treatment of vincristine induced ptosis and polyneuropathy with pyridoxine and pyridostigmine in a child with acute lymphoblastic leukemia
A 2-year-old girl with precursor B cell acute lymphoblastic leukemia (ALL) was started on treatment according to the MCP 841 protocol. She had grade 3 protein energy malnutrition at admission. She developed febrile neutropenia with sepsis during the third week of induction. She was treated with parenteral antibiotics and other supportive care. She had received four doses of vincristine (cumulative dose of 2.8 mg) and, on the 25th day of induction, she developed bilateral ptosis. She was afebrile at that time []. Neurological examination revealed bilateral ptosis and complete external opthalmoplegia with normal pupillary and corneal reflexes. She had hypotonia in both lower limbs with power of 2/5 with normal upper limb power, and there was no head lag. There was no ascending or descending pattern of weakness noticed. Bilateral knee and ankle jerks were not elicitable. There was no feature of autonomic neuropathy. Nerve conduction velocity showed motor axonal polyneuropathy with normal sensory conduction. Cerebrospinal fluid analysis showed normal protein, sugar and no cellular response. Her stool culture did not grow any organism. She was not on any drugs that could potentiate neurotoxicity of vincristine. Serum electrolytes and calcium levels were normal. Her polyneuropathy was static but ptosis progressively increased. A neuroprotective and neuroregenerative treatment attempt with pyridoxine (3 mg/kg Twice daily, per orally (BID, PO)) and pyridostigmine (150 mg/m2 BID, PO) was started. Bilateral ptosis, hypotonia and muscle weakness markedly improved after 14 days of pyridoxine and pyridostigmine treatment and ptosis completely resolved after 4 weeks. ([]-recovery of ptosis after 2 weeks of treatment). Both the agents were given for 8 weeks and were well tolerated without any side-effects. There was no recurrence following cessation of pyridoxine and pyridostigmine. Because vincristine is an important drug in the treatment of ALL, after 2 weeks of complete recovery of ptosis, it was reinitiated in lower dose and later increased to the full dose without recurrence of neuropathy. She has received vincristine cumulative dose of 6.1 mg (10 mg/m2) till now and she is in maintenance phase of chemotherapy.