A susceptibility-weighted imaging qualitative score of the motor cortex may be a useful tool for distinguishing clinical phenotypes in amyotrophic lateral sclerosis.

OBJECTIVES: To distinguish amyotrophic lateral sclerosis (ALS) and its subtypes from ALS mimics and healthy controls based on the assessment of iron-related hypointensity of the primary motor cortex in susceptibility-weighted imaging (SWI). METHODS: We enrolled 64 patients who had undergone magnetic resonance imaging studies with clinical suspicions of ALS. The ALS group included 48 patients; the ALS-mimicking disorder group had 16 patients. The ALS group was divided into three subgroups according to the prevalence of upper motor neuron (UMN) or lower motor neuron (LMN) impairment, with 12 subjects in the UMN-predominant ALS group (UMN-ALS), 16 in the LMN-predominant ALS group (LMN-ALS), and 20 with no prevalent impairment (C-ALS). The Motor Cortex Susceptibility (MCS) score was defined according to the hypointensity of the primary motor cortex in the SWI sequence. Its diagnostic accuracy in differentiating groups was evaluated. RESULTS: The MCS was higher in the ALS group than in the healthy control and ALS-mimicking disorder groups (p < 0.001). Among ALS subgroups, the MCS was significantly higher in the UMN-ALS group than in the healthy control (p < 0.001), ALS-mimicking disorder (p = 0.002), and LMN-ALS groups (p = 0.002) and higher in the C-ALS group than in the healthy control group (p = 0.019). An MCS value ≥ 2 showed specificity and a positive predictive value of 100% in the detection of both UMN-ALS and C-ALS patients. CONCLUSIONS: The assessment of MCS in the SWI sequence could be a useful tool in supporting diagnosis in patients suspicious for ALS with prevalent signs of UMN impairment or with no prevalence signs of UMN or LMN impairment. KEY POINTS: • The hypointensity of the primary motor cortex in susceptibility-weighted imaging could support the diagnosis of ALS. • Our new qualitative score called MCS shows high specificity and positive predictive value in differentiating ALS patients with upper motor neuron impairment from patients with ALS-mimicking disorders and healthy controls.

Auditory functional magnetic resonance in awake (nonsedated) and propofol-sedated children.

BACKGROUND: Functional Magnetic Resonance Imaging (fMRI) is often used in preoperative assessment before epilepsy surgery, tumor or cavernous malformation resection, or cochlear implantation. As it requires complete immobility, sedation is needed for uncooperative patients. OBJECTIVE: The aim of this study was to compare the fMRI cortical activation pattern after auditory stimuli in propofol-sedated 5- to 8-year-old children with that of similarly aged nonsedated children. METHODS: When possible, children underwent MRI without sedation, otherwise it was induced with i.v. propofol 2 mg·kg(-1) and maintained with i.v. propofol 4-5 mg·kg(-1) ·h(-1) . Following diagnostic MRI, fMRi was carried out, randomly alternating two passive listening tasks (a fairy-tale and nonsense syllables). RESULTS: We studied 14 awake and 15 sedated children. During the fairy-tale task, the nonsedated children's blood-oxygen-level-dependent (BOLD) signal was bilaterally present in the posterior superior temporal gyrus (STG), Wernicke's area, and Broca's area. Sedated children showed similar activation, with lesser extension to Wernicke's area, and no activation in Broca's area. During the syllable task, the nonsedated children's BOLD signal was bilaterally observed in the STG and Wernicke's area, in Broca's area with leftward asymmetry, and in the premotor area. In sedated children, cortical activation was present in the STG, but not in the frontal lobes. BOLD signal change areas in sedated children were less extended than in nonsedated children during both the fairy-tale and syllable tasks. Modeling the temporal derivative during both the fairy-tale and syllable tasks, nonsedated children showed no response while sedated children did. CONCLUSIONS: After auditory stimuli, propofol-sedated 5- to 8-year-old children exhibit an fMRI cortical activation pattern which is different from that in similarly aged nonsedated children.

Maturation of preterm newborn brains: a fMRI-DTI study of auditory processing of linguistic stimuli and white matter development.

To evaluate brain development longitudinally in premature infants without abnormalities as compared to healthy full-term newborns, we assessed fMRI brain activity patterns in response to linguistic stimuli and white matter structural development focusing on language-related fibres. A total sample of 29 preterm newborns and 26 at term control newborns underwent both fMRI and DTI. Griffiths test was performed at 6 months of corrected age to assess development. Auditory fMRI data were analysed in 17 preterm newborns at three time points [34, 41 and 44 weeks of post menstrual age (wPMA)] and in 15 controls, at term. Analysis showed a distinctive pattern of cortical activation in preterm newborns up to 29 wPMA moving from early prevalent left temporal and supramarginal area activation in the preterm period, to a bilateral temporal and frontoopercular activation in the at term equivalent period and to a more fine-grained left pattern of activity at 44 wPMA. At term controls showed instead greater bilateral posterior thalamic activation. The different pattern of brain activity associated to preterm newborns mirrors their white matter maturation delay in peripheral regions of the fibres and thalamo-cortical radiations in subcortical areas of both hemispheres, pointing to different transient thalamo-cortical development due to prematurity. Evidence for functional thalamic activation and more mature subcortical tracts, including thalamic radiations, may represent the substantial gap between preterm and at term infants. The transition between bilateral temporal activations at term age and leftward activations at 44 weeks of PMA is correlated to better neuropsychological results in Griffiths test.