Neuropsychologic deficits in children with Langerhans cell histiocytosis

Manifestations of Langerhans cell histiocytosis (LCH) in children range from only a rash, to bony lesions accompanied by pain, to major organ disease. When the central nervous system (CNS) is affected, the LCH patient may exhibit signs and symptoms of hypothalamic and pituitary dysfunction (most often resulting in diabetes insipidus or other endocrinopathies) or more global neurologic and neuropsychologic sequelae. Surprisingly, researchers have only recently begun to examine the neuropsychologic manifestations of the disease, but early findings suggest that they may, in fact, be significant in a small percentage of children with LCH.

We evaluated two CNS-positive patients with LCH and long-term intermittent treatments, using extensive neuropsychologic assessments, including intellectual functioning, memory, visual-motor functioning, attention and concentration, sensory and motor performance, and gross academic achievement. Objective measures of behavior were obtained through parental report. Neuroradiologic imaging was obtained concurrently with the neuropsychologic evaluations.

The neuropsychologic assessments indicated significant deficits in a number of the measured areas of functioning. Global cognitive deficiencies in full-scale IQ were identified, as were deficits in memory, attention/concentration, and perceptual-organizational capabilities. Similarities were noted in the patterns of deficits obtained with both patients, despite differences in the pathophysiology of their disease. Behavioral functioning in both children had suffered, presumably in relation to the neuropsychologic deficits. There were radiologic findings of gross cerebellar white matter damage in one patient, in addition to focal (e.g., hypothalamic) lesions in the other.

LCH has an adverse impact on cognitive functions in some children with evidence of CNS involvement, and further study into the etiology, incidence, and means of remedial intervention is needed.