Cognitive Outcome of Long-Term Survivors of Multisystem Langerhans Cell Histiocytosis: A Single-Institution, Cross-Sectional Study

Abstract

Purpose: Damage to the CNS, including the cerebellum, and to the hypothalamopituitary axis, is documented in Langerhans cell histiocytosis (LCH). Neuropsychologic deficits have been recognized, but this is the first study in which cognitive function has been systematically assessed in a cohort of patients. Patients and Methods: Twenty-eight long-term survivors of multisystem LCH (mean age, 15.1 years) were investigated for intelligence, memory and learning, language, and academic attainments. Results: The mean intelligence quotient (IQ) of the entire group was not significantly different from the mean of the population (ie, mean ± SD, 100 ± 1), but there were wide ranges (Full-Scale IQ [FSIQ]: mean, 93.6; range, 61.7 to 134; Performance IQ [PIQ]: mean, 92.2; range, 46 to 136; and Verbal IQ [VIQ]: mean, 93.7; range, 64.2 to 126). CNS involvement was a significant risk factor for lower scores, but sex, diabetes insipidus, and cranial radiotherapy were not. The CNS group had lower VIQ, PIQ, and FSIQ than patients with no CNS involvement (no CNS group: mean ± SD FSIQ, 102.3 ± 15.6; CNS group: mean ± SD FSIQ, 73.6 ± 7.7; P < .001). A similar pattern of results was obtained for all other cognitive measures. Even when effects of reduction in FSIQ were taken into account, specific deficits were found in patients in the CNS group. Conclusion: Long-term survivors of multisystem LCH, particularly patients with CNS involvement, may develop significant cognitive deficits. All patients should have formal, repeated neuropsychologic assessment as part of long-term follow-up, which will enable abnormalities to be detected early so that appropriate supportive measures can be offered.