Neurologic dysfunction in patients treated for small cell carcinoma of the lung: a clinical and radiological study

The neurologic dysfunction in 7 patients treated for small cell carcinoma (SCC) of the lung by combination chemotherapy and prophylactic brain irradiation was evaluated. The disease appeared to be a diffuse encephalopathy frequently affecting the higher cortical functions. Five out of seven patients had progressive dysfunction leading to death in 1 to 26 months; one patient had stabilization of symptoms followed by death in 21 months, probably from the neurologic disease as well as SCC; one patient's symptoms improved. The clinical course of the neurologic disorder seemed different from the known reactions to brain irradiation and from the other neurologic syndromes associated with lung cancer. The relative contributions of cranial irradiation and treatment with chemotherapeutic agents in producing the neurotoxicity are not known. Computed tomographic (CT) brain scans done after the onset of symptoms did not show any focal signs or necrosis. However, there was a suggestion of progressive increase in intracranial fluid volume on the scans. The incidence of the disorder, 10.2% among a group of 49 patients, suggests the need for prospective studies to evaluate the problem.