1H-MR spectroscopy of adult-onset autosomal dominant leukodystrophy with autonomic symptoms

Introduction

Adult-onset ADLD with autonomic symptoms is a rare disease with a clinical course somewhat similar to chronic progressive MS but with different imaging findings consisting of extensive white matter changes in the cerebrum and cerebellar peduncles. Patients usually present in the fourth to sixth decade with autonomic symptoms, manifesting later symptoms from the pyramidal tracts and ataxia. Here, we present magnetic resonance spectroscopy (MRS) findings in this disease.

Methods

Fourteen subjects, from two non-related families, with genetic linkage to the disease were studied with magnetic resonance imaging and single-voxel MRS. Clinically, they ranged from asymptomatic to wheelchair-using. Their results were compared to those of age- and sex-matched healthy controls.

Results

One MRS was excluded due to suboptimal quality. The remaining 13 subjects manifested characteristic evidence of pathology on MRI, 11 of them exhibited extensive changes. The metabolite concentrations of total Cr, total Cho, and total NAA measured in millimolars, using internal water as a reference, were significantly lower in these 11 subjects compared to controls, and we found linear correlations between all these metabolite levels. When total Cr was used as a reference, we found no difference between subjects and controls. No lactate was detected.

Conclusion

The decreased metabolite concentrations measured using internal water as a reference are most likely due to increased water content in the tissues, diluting all metabolites to a similar degree. This is also in agreement with the high signal intensity exhibited in the white matter on T2-weighted MR images and with the reported histopathological findings of vacuolated myelin.