Abstract
Objectives: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant disorder characterized by ischemic episodes, cognitive impairment, and migraine, often with aura. Cerebral MRI reveals signal hyperintensities in the white matter, especially of the temporal lobes. We investigated CADASIL patients with 1H-magnetic resonance spectroscopy (MRS) for different cerebral metabolites, namely N-acetylaspartate (NAA), creatine, choline, myoinositole (MI), and lactate.
Methods: To date, we studied 4 CADASIL patients and 4 healthy controls. CADASIL diagnosis was confirmed by skin biopsy and/or genetic analysis. MRS was performed on a 3T Philips MR system. 1H-MRS data were acquired using high resolution multi-spin echo spectroscopic imaging (TSI; TE=288ms, slice thickness =1.5cm, resolution 28x28, FOV=320mm) and conventional chemical shift imaging (CSI; TE=35 ms, resolution 16x16 and TE=288ms, resolution 12x12, slice thickness=2cm, FOV=320mm). Bandwidth was 2500 Hz and repetition time 1520 for all measurements. CSI measurements with TE=288 ms were repeated 6 times consecutively. The 1st and the last two measurements were performed in darkness, in the others visual stimulation with a stroboscope (8 Hz) was applied. Data were obtained from a transversal slice adjusted parallel to the calcarine fissure, including the visual cortex. In addition, we performed single voxel (SV) MRS of the temporal pole.
Results: All CADASIL patients showed characteristic MRI findings including the temporal lobe. NAA/creatine ratios were decreased in all patients, most markedly in temporal lobes and periventricular areas. Choline/creatine ratios were unchanged and no myoinositole was detected. Voxels adjacent to the calcarine fissure showed elevated lactate peaks at baseline in 2 patients without change during visual stimulation.
Conclusion: NAA/creatine ratios were diminished in all CADASIL patients in areas with visible lesions. Decreased NAA/creatine ratios might therefore be used as an additional, possibly more sensitive marker of neuronal damage in CADASIL. Specificity and sensitivity of NAA alterations as well as the significance of lactate changes will be further evaluted in our ongoing study.
