1,721,028 research outputs found
Imaging neuronal and axonal degeneration in multiple sclerosis.
No full textNeuronal and axonal damage has become an important issue in multiple sclerosis. This has been emphasised by recent magnetic resonance imaging (MRI) studies that have shown evidence of axonal damage in both lesional and non-lesional white matter and in grey matter. In this respect, proton MR spectroscopy (by monitoring levels of Nacetylaspartate, a putative marker of axonal integrity) and computed measurements of cerebral volumes have been particularly illuminating. Recent studies using these MRI measures have demonstrated that cerebral neuro-axonal damage begins and contributes to disability from the earliest stages of the disease. This implies that the apparently primary role of neuronal pathology in the pathogenesis of the disease should be given due importance and argues for the early treatment of multiple sclerosis with agents directed not only against inflammation, but also towards neuronal protection
Twelve-year monitoring of a patient with megalencephalic leukoencephalopathy with subcortical cysts
No full textMegalencephalic leukoencephalopathy (MLC) with subcortical cysts is an infantile-onset inherited disease of the brain white matter with a defect in brain ion and water homoeostasis, which leads to an abnormal brain volume regulation. Clinical features of the disease can be variable, but patients typically show early-onset macrocephaly, motor abnormalities, seizures, and almost constant late-onset mild mental deterioration. Brain magnetic resonance imaging (MRI) reveals diffusely abnormal and mildly swollen white matter as well as subcortical cysts in the anterior temporal and frontoparietal regions. We describe here clinical findings and volumetric MRI and 1H-MR spectroscopic imaging (1H-MRSI) data of a 12-year follow-up on a patient with MLC. The patient had only slight clinical worsening during the long follow-up. Volumetric findings showed substantially unchanged cystic volumes and mild brain atrophy rate. In addition, there was no over time increase in the volume of white matter hypointense lesions seen on FLAIR images at baseline, but the degree of hypointensity of these white matter voxels increased over 12 years. Longitudinal 1H-MRSI examination showed long-term undetectable metabolite signals in the white matter, whereas the metabolic pattern of gray matter voxels remained unchanged over time. Results show that, in MLC, the chronic brain white matter changes resulting from the brain ion, and water homeostasis can be monitored by quantitative MRI modalities. This might be important for assessing treatment effects
MR evidence of structural and metabolic changes in brains of patients with Werner’s syndrome.
No full textOBJECTIVE:
To assess CNS abnormalities in patients with Werner's syndrome (WS) using MR metrics specific for tissue damage.
BACKGROUND:
WS is a rare autosomal recessive disorder that causes premature aging. The CNS involvement in this disease is still debated.
METHODS:
Two siblings who showed signs of neurological involvement underwent MR spectroscopic imaging (MRSI) and magnetization transfer (MT) imaging. Also, on conventional T1-weighted MR images, measurements of total brain volume were performed.
RESULTS:
Conventional MR images of both WS patients did not show abnormalities on visual inspection. However, both WS patients showed significantly lower values of normalized total brain volume and MT ratio in the white matter than age-matched normal controls. Also, proton MRSI showed significantly lower values of central brain NAA/Cr in WS patients than in normal controls.
CONCLUSIONS:
Our findings suggest that, despite normal appearance on conventional MRI, diffuse structural and metabolic tissue damage can be demonstrated in WS brains by means of sensitive MR methods even in patients with moderate or subclinical CNS involvement
Magnetic resonance spectroscopy as a measure of brain damage in multiple sclerosis.
No full textRecent MR studies have emphasised the importance of neuronal and axonal damage in multiple sclerosis. In this respect, proton MR spectroscopy (by monitoring levels of N-acetylaspartate, a putative marker of axonal integrity) has been particularly illuminating by showing indirect evidence of neurodegeneration in both lesional and non-lesional brain tissues from the earliest stages of the disease. The importance of these changes to patients' clinical disability argues for the primary role of neuronal pathology in the pathogenesis of the disease
Novel human pathological mutations. Gene symbol: NOTCH3. Disease: CADASIL, exon 2 mutation.
No full text
Cortical lesions in radiologically isolated syndrome.
No full textOBJECTIVE:
To assess the presence of cortical lesions (CLs) as detected by MRI in subjects with radiologically isolated syndrome (RIS).
METHODS:
Fifteen subjects with RIS underwent an MRI examination, including a double inversion recovery sequence for CL assessment. T2-hyperintense white matter (WM) lesion volume (LV) and normalized volumes of brain and cortex were also obtained.
RESULTS:
Thirty-four CLs were identified in 6 of 15 (40%) subjects with RIS and predominantly distributed in frontotemporal lobes. CLs were frequent in subjects with RIS with immunoglobulin G oligoclonal bands on CSF, cervical cord lesions, and dissemination in time on brain MRI. WM LV was higher in subjects with CLs than in those without CLs (11.5 ± 10.1 vs 3.9 ± 2.8 cm(3), p = 0.04). Indeed, CL number and volume correlated with WM LV (r = 0.57, p = 0.03 and r = 0.61, p = 0.01). All subjects with CLs were classified in a previous study as having a very high probability of having relapsing-remitting multiple sclerosis (MS) on a logistic regression analysis of quantitative MRI indices.
CONCLUSIONS:
We found CLs in subjects with RIS, a condition characterized by the unanticipated MRI finding of WM lesions highly suggestive of MS in the absence of a clinical scenario. CLs were mainly localized to the frontotemporal lobes and were associated with important markers of evolution to MS
Automated identification of brain new lesions in multiple sclerosis using subtraction images
No full textTo propose and evaluate a new automated method for the identification of new/enlarging multiple sclerosis (MS) lesions on subtracted images (SI). The subtraction of serially acquired images has shown great potential in assessing new/enlarging brain magnetic resonance imaging (MRI) lesions in MS patients. However, this approach relies on the manual definition of lesions, which is labor-intensive and subject to operator-dependent variability
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