Zeydan, Burcu

ObjectiveTo describe the clinical and distinctive imaging features of myelopathy associated with Behçet's disease (BD).MethodsWe evaluated the records of patients meeting the following criteria: (1) fulfillment of the International Study Group criteria for BD; (2) clinically suggestive of myelopathy; (3) simultaneous spinal cord and brain magnetic resonance images (MRIs) within 1 month of acute worsening of myelopathy; and (4) follow‐up duration ≥ 1 year after initial MRI evaluation. Patients not fulfilling all inclusion criteria and having MRIs with poor quality or missing sequences were excluded.ResultsIn 11 patients (9 men, 2 women), we studied 14 MRIs during distinct myelopathy episodes and nine follow‐up MRIs. Two distinct MRI patterns of spinal cord involvement were described according to T2‐weighted (T2W) axial images: (1) “Bagel Sign” pattern: a central lesion with hypointense core and hyperintense rim with or without contrast enhancement; and (2) “Motor Neuron” pattern: a symmetric involvement of the anterior horn cells. Bagel Sign was present in 13 of 14 myelopathy episodes whereas Motor Neuron pattern was observed in 1 of 14 MRIs. Of the 13 MRIs with Bagel Sign long myelopathy (n = 9), both long and short myelopathy (n = 2) and short myelopathy (n = 2) was observed. All patterns cleared with some residual lesions after steroid use and immunomodulation with associated clinical recovery in patients.InterpretationThe signal characteristics of the Bagel Sign potentially represent venous engorgement and/or acute blood products within the spinal cord. To our knowledge, Bagel Sign has not been observed in other forms of longitudinal myelopathy outside of BD, including neuromyelitis optica. Ann Neurol 2017;82:288–298

ABSTRACTBACKGROUND AND PURPOSEGlutamate levels may be informative about the declining neuronal health in the central nervous system. We used an advanced proton MR spectroscopy (1H‐MRS) protocol composed of semi‐localization by adiabatic selective refocusing (sLASER) localization and FAST(EST)MAP shimming for detection of alterations in brain glutamate concentrations in patients with amnestic mild cognitive impairment.METHODSParticipants with amnestic mild cognitive impairment (n= 14; median age = 80) and age‐ and sex‐matched clinically normal controls (n= 32; median age = 79) from the population‐based Mayo Clinic Study of Aging were recruited prospectively to the 3T single‐voxel1H‐MRS study that examined metabolite changes in the posterior cingulate gyri. To be included, controls had to have low β‐amyloid load on [11C] Pittsburgh Compound B (PiB)‐PET (standard uptake value ratio; SUVr < 1.42) and patients with amnestic mild cognitive impairment had to have high β‐amyloid load (SUVr ≥ 1.42).RESULTSGlutamate concentration and the glutamate/myo‐inositol ratio were lower in patients with amnestic mild cognitive impairment than clinically normal controls (P< .05). Higher global cortical PiB‐PET SUVr correlated with lower glutamate/myo‐inositol (r= –.3,P= .04).CONCLUSIONSThe advanced sLASER with FAST(EST)MAP shimming is a promising protocol for identifying glutamate alterations. Advanced1H‐MRS protocols may add to the understanding of early Alzheimer's disease pathophysiology through detection of glutamate concentration in posterior cingulate gyri of individuals with amnestic mild cognitive impairment.

Background: There is growing interest in white matter (WM) imaging with positron emission tomography (PET). Objectives: We studied the association of cognitive function in late multiple sclerosis (MS) with cortical and WM Pittsburgh compound-B PET (PiB-PET) binding. Methods: In the population-based Mayo Clinic Study of Aging, 24 of 4869 participants had MS (12 underwent PiB-PET). Controls were age and sex matched (5:1). We used automated or semi-automated processing for quantitative image analyses and conditional logistic regression for group differences. Results: MS patients had lower memory ( p = 0.03) and language ( p = 0.02) performance; smaller thalamic volumes ( p = 0.003); and thinner temporal ( p = 0.001) and frontal ( p = 0.045) cortices on magnetic resonance imaging (MRI) than controls. There was no difference in global cortical PiB standardized uptake value ratios between MS and controls ( p = 0.35). PiB uptake was lower in areas of WM hyperintensities compared to normal-appearing white matter (NAWM) in MS ( p = 0.0002). Reduced PiB uptake in both the areas of WM hyperintensities ( r = 0.65; p = 0.02) and NAWM ( r = 0.69; p = 0.01) was associated with decreased visuospatial performance in MS. Conclusion: PiB uptake in the cortex in late MS is not different from normal age-matched controls. PiB uptake in the WM in late MS may be a marker of the large network structures’ integrity such as those involved in visuospatial performance.