Progressive multifocal leukoencephalopathy in a kidney transplant recipient after conversion to mycophenolic acid therapy.

Progressive multifocal leukoencephalopathy in a kidney transplant recipient after conversion to mycophenolic acid therapy.

Huntington disease-like 2: the first patient with apparent European ancestry.

Huntington disease-like 2 (HDL2) is a rare autosomal dominant disorder of the nervous system, apparently indistinguishable from Huntington disease (HD). HDL2 is caused by the expansion above 40 CTG/CAG repeats, in a variably spliced exon of the junctophilin-3 gene, on chromosome 16q24.3. All patients described so far have been of African ancestry. A clinical evaluation, including the Unified Huntington's Disease Rating Scale, and brain Magnetic resonance imaging were achieved in a 48-year-old Brazilian man of apparent European extraction, and presenting a picture very suggestive of HD. Gene mutation analysis (HD, HDL1, HDL2, dentatorubralpallidoluysian atrophy and spinocerebellar ataxia 17) was performed. After exclusion of the HD mutation and other HDL disorders, we identified an expansion of 47 CTG/CAG at the HDL2 locus. To clarify the origin of the mutation and estimate the patient's ancestry, we performed haplotype studies and used the insertion/deletion polymorphisms method. Despite the fact that this patient had an estimated likelihood of 97.4% of being of European ancestry, the haplotype containing the expanded allele has been found only in Africans. Thus, this is the first HDL2 case reported in a patient with an apparent European ancestry, although bearing an African HDL2 haplotype. This work stresses the importance of performing the diagnosis of HDL2 in HD-like patients of various ethnicities, and particularly in highly mixed populations.

Correlation of MR imaging and MR spectroscopy findings with cognitive impairment in mucopolysaccharidosis II.

BACKGROUND AND PURPOSE: There are no reliable markers to predict neurologic outcome of patients with mucopolysaccharidosis (MPS) II. We hypothesized that brain MR imaging and MR spectroscopy are useful in depicting features related to cognitive impairment (CI) in MPS II. MATERIALS AND METHODS: Nineteen male patients with MPS II were included in this study. They were evaluated through intelligence/developmental tests to be classified in 2 groups: patients with CI (group A) or patients without CI (group B). Brain MR imaging evaluated white matter (WM) lesions, hydrocephalus, and brain atrophy. Voxels from MR spectroscopy (point-resolved spectroscopy TE 30 ms) were positioned in the WM of the deep right frontal lobe and at the gray matter (GM) in the posterior occipital cortex across the midline. Comparison of MR imaging and MR spectroscopy findings between these 2 groups and a control group was performed. RESULTS: The mean age of the patients was 9.6 years (group A, 7.08 years old, 12 patients; group B, 14 years old, 7 patients; P = .076). Brain atrophy and hydrocephalus were more frequently found in group A patients (P=.006 and P=.029, respectively); these patients also presented more severe WM lesions than patients from group B (P=.022). Patients from group A also had a higher myo-inositol (mIns)/creatine (Cr) ratio in the GM (P=.046) and in the WM (P=.032). The choline/Cr and N-acetylaspartate/Cr ratios were similar in both groups. CONCLUSIONS: Our study showed that severe WM lesions, brain atrophy, hydrocephalus, and elevated mIns/Cr were more common in patients with MPS II and with CI.

MR Imaging in Spinocerebellar Ataxias: A Systematic Review.

BACKGROUND AND PURPOSE: Polyglutamine expansion spinocerebellar ataxias are autosomal dominant slowly progressive neurodegenerative diseases with no current treatment. MR imaging is the best-studied surrogate biomarker candidate for polyglutamine expansion spinocerebellar ataxias, though with conflicting results. We aimed to review quantitative central nervous system MR imaging technique findings in patients with polyglutamine expansion spinocerebellar ataxias and correlations with well-established clinical and molecular disease markers. MATERIALS AND METHODS: We searched MEDLINE, LILACS, and Cochrane data bases of clinical trials between January 1995 and January 2016, for quantitative MR imaging volumetric approaches, MR spectroscopy, diffusion tensor imaging, or other quantitative techniques, comparing patients with polyglutamine expansion spinocerebellar ataxias (SCAs) with controls. Pertinent details for each study regarding participants, imaging methods, and results were extracted. RESULTS: After reviewing the 706 results, 18 studies were suitable for inclusion: 2 studies in SCA1, 1 in SCA2, 15 in SCA3, 1 in SCA7, 1 in SCA1 and SCA6 presymptomatic carriers, and none in SCA17 and dentatorubropallidoluysian atrophy. Cerebellar hemispheres and vermis, whole brain stem, midbrain, pons, medulla oblongata, cervical spine, striatum, and thalamus presented significant atrophy in SCA3. The caudate, putamen and whole brain stem presented similar sensitivity to change compared with ataxia scales after 2 years of follow-up in a single prospective study in SCA3. MR spectroscopy and DTI showed abnormalities only in cross-sectional studies in SCA3. Results from single studies in other polyglutamine expansion spinocerebellar ataxias should be replicated in different cohorts. CONCLUSIONS: Additional cross-sectional and prospective volumetric analysis, MR spectroscopy, and DTI studies are necessary in polyglutamine expansion spinocerebellar ataxias. The properties of preclinical disease biomarkers (presymptomatic) of MR imaging should be targeted in future studies.

Inherited cerebellar ataxia in childhood: a pattern-recognition approach using brain MRI.

Ataxia is the principal symptom of many common neurologic diseases in childhood. Ataxias caused by dysfunction of the cerebellum occur in acute, intermittent, and progressive disorders. Most of the chronic progressive processes are secondary to degenerative and metabolic diseases. In addition, congenital malformation of the midbrain and hindbrain can also be present, with posterior fossa symptoms related to ataxia. Brain MR imaging is the most accurate imaging technique to investigate these patients, and imaging abnormalities include size, shape, and/or signal of the brain stem and/or cerebellum. Supratentorial and cord lesions are also common. This review will discuss a pattern-recognition approach to inherited cerebellar ataxia in childhood. The purpose is to provide a comprehensive discussion that ultimately could help neuroradiologists better manage this important topic in pediatric neurology.

Location of periventricular nodular heterotopia is related to the malformation phenotype on MRI.

BACKGROUND AND PURPOSE: Periventricular nodular heterotopia are common malformations of cortical development that are associated with many clinical syndromes and with many different neuroimaging phenotypes. The purpose of this study was to determine whether specific malformation phenotypes may be related to location, side, or number of PNH as assessed by MR imaging. MATERIALS AND METHODS: MR images of 200 patients previously diagnosed with PNH were retrospectively analyzed. PNH were classified according to their location along the ventricles (anterior, posterior, or diffuse), side (unilateral or bilateral), and number of nodules (<5, 6-10, or >10). The cerebrum, brain stem and cerebellum were analyzed to assess associated anomalies. Associations between PNH location and the presence of other anomalies were tested by using Fisher exact test and χ2 test. RESULTS: Posterior PNH were significantly associated with malformations of the cerebral cortex, diminished white matter volume, and mid-/hindbrain anomalies. Diffuse PNH were associated with diminished white matter volume, callosal "anomalies," and the presence of megacisterna magna. Unilateral PNH were strongly associated with cortical malformations. CONCLUSIONS: Certain malformation complexes are associated with PNH in specific locations: posterior PNH with cerebral cortical and mid-/hindbrain malformations and diffuse PNH with callosal anomalies and megacisterna magna. Knowledge of these associations should allow more directed analyses of brain MR imaging in patients with PNH. In addition, knowledge of these associations may help to direct studies to elucidate the causes of these malformation complexes.

Brain MRI in mucopolysaccharidosis: effect of aging and correlation with biochemical findings.

OBJECTIVE: To investigate the influence of aging on conventional MRI and magnetic resonance spectroscopy (MRS) findings of mucopolysaccharidosis (MPS) patients and to test the correlation of enzyme levels, urinary glycosaminoglycans (GAG), and neuroimaging findings. METHODS: Sixty patients with MPS types I (n = 8), II (n = 31), IV-A (n = 4), and VI (n = 17) underwent T2, fluid-attenuated inversion recovery (FLAIR), and MRS of the brain. For analysis of MRI variables, we measured the normalized cerebral volume (NCV), CSF volume (NCSFV), ventricular volume (NVV), and lesion load (NLL) on FLAIR using semiautomated and automated segmentation techniques. For MRS, a point-resolved spectroscopy technique was used. Voxels were positioned at the white and gray matter. Statistical analysis involved Pearson or Spearman tests for correlation between neuroimaging, age, enzyme levels, and urinary GAG. RESULTS: The median age at onset of the disease was 20 months. Patients with longer disease duration had more NLL in the white matter (r = 0.28, p = 0.03), and this difference was more pronounced in MPS II patients (r = 0.44, p = 0.02). Metabolites ratios in MRS, NCV, NCSFV, and NVV did not correlate with disease duration or age of the patients (p > 0.05). MRI and MRS variables in either the white or the gray matter did not correlate with enzymatic activity or GAG levels. Patients with MPS II had a lower mean NCV (p < 0.001). CONCLUSIONS: Our data showed that white matter lesion is more extensive as disease duration increases, especially in mucopolysaccharidosis type II patients. MRI and magnetic resonance spectroscopy findings did not correlate with either enzymatic or glycosaminoglycan levels.

CNS involvement in Fabry disease: clinical and imaging studies before and after 12 months of enzyme replacement therapy.

We report the clinical and radiological central nervous system (CNS) findings of 8 Fabry disease patients, before (8/8) and after (7/8) 12 months of enzyme replacement therapy (ERT) with agalsidase-alpha. Eight biochemically proven Fabry disease patients (from four families) were included. Patients were evaluated at baseline and at regular intervals during 12 months of ERT. Evaluations included a thorough, standardized neurological examination, and magnetic resonance imaging (MRI) and angiography (MRA). Brain proton magnetic resonance spectroscopy (MRS) was also performed in 5/8 patients. The presence and location of grey- and white-matter lesions, the presence of vascular occlusion or ectasia on MRA and the metabolite ratios on MRS were determined, as well as their relation to age, symptoms and neurological examination. Neurological examination showed few abnormalities in these patients: scores varied (on a 0-100 scale) from zero to 5, at baseline and in the 12th month of ERT. The most consistent findings on MRI were asymmetric, widespread patterns of deep white-matter (WM) lesions, hyperintense on T2 and FLAIR-weighted images, found in 4/8 patients at baseline, predominantly in frontal and parietal lobes. These lesions did not correlate with other clinical variables, although there was a trend towards an association of the lesions with age and hearing loss. The youngest patient with MRI lesions was 24 years old. After 12 months of ERT, MRI was normal in 3/7, showed the same WM lesions in 2/7, and showed worsening of WM lesions in 2/7 patients (from the same family). Abnormal MRS metabolite ratios were detected at baseline in 4/5 patients. While neurological examination remained almost normal during the 12 months of ERT, new small-vessel CNS involvement still appeared in 2/7 patients. We do not know why ERT was not able to prevent this in these two related male patients. This could be due either to their older ages (46 and 36 years), or to a more pathogenic mutation. We conclude that MRI was more sensitive than neurological examination in detecting CNS involvement and progression in Fabry disease in the time interval studied.