Course and clinical impact of magnetic resonance imaging findings in diabetes insipidus associated with Langerhans cell histiocytosis.

BACKGROUND

Diabetes insipidus (DI) is the most frequent sequela in Langerhans cell histiocytosis (LCH). The clinical relevance and therapeutic impact of brain magnetic resonance imaging (MRI) findings in LCH patients with LCH during the disease course is unclear.

PROCEDURE: In this retrospective study, we reviewed 113 brain MRIs from 59 DI patients, in 17 of these serial follow up MR-examination findings were correlated to the clinical course and therapy.

RESULTS

At DI diagnosis, 71% patients showed a thickened stalk, in 24% the stalk was still thickened on MRIs done more than 5 years after DI onset, and in two patients the stalk was already thickened several months before DI onset. The changes of the pituitary stalk thickness were highly variable and did not clearly correlate with the treatment. Regression of pituitary thickness on MRI did not concur with clinical recovery of DI, which persisted in all but one patient with initially partial DI. The occurrence of anterior pituitary hormone deficiencies appeared to be linked to a thickening of the stalk at DI diagnosis. LCH-lesions in the craniofacial bones were seen in 75% DI patients, and 76% of DI patients with follow up MRIs done 5 years or longer after DI diagnosis had parenchymal neurodegenerative brain changes.

CONCLUSIONS

Our study indicates that repeated MR-examinations in DI patients are of limited value for assessing a response to therapy in the pituitary stalk, but are important for the monitoring of craniofacial bone lesions and for the detection of parenchymal CNS disease.