Paraneoplastic neurological syndromes presenting with paraneoplastic ptosis in an infant with acute lymphoblastic leukemia: A case report

Background

Paraneoplastic neurological syndromes (PNS) are rare in children. Unlike adults, children present with a variety of atypical neurological symptoms that are difficult to diagnose. Consequently, PNS remains an underrecognized disorder. Nevertheless, appropriate immunomodulatory therapy is crucial for neurological prognosis and should not be overlooked. We report a case in which intravenous immunoglobulin therapy effectively treated PNS while treating leukemia.

Case report

A 1.5-year-old girl with B-cell precursor acute lymphoblastic leukemia was referred to our neurology department with ptosis that developed 6 weeks after leukemia treatment and worsened over 8 days. Neurological evaluation revealed normal pupils, no ocular paralysis, no proximal muscle weakness, normal tendon reflexes, and no autonomic neuropathy. Cerebrospinal fluid and brain magnetic resonance imaging findings were normal. Antibodies against the acetylcholine receptor and P/Q-type voltage-gated calcium channels were negative. Low- and high-frequency repetitive median nerve stimulation tests revealed normal findings. We suspected PNS at the neuromuscular junction due to the persistent ptosis that occurred during leukemia treatment. Intravenous immunoglobulin therapy was effective, and ptosis disappeared after 2 weeks. The patient received standard chemotherapy for leukemia, and the ptosis did not relapse for 1 year.

Conclusion

Persistent ptosis in cancer patients requires appropriate evaluation and extensive differentiation for myasthenic syndrome. Timely treatment with immunomodulatory therapy improves neurological prognosis when PNS is suspected.