Cerebral Cortical Thickness Morphometry and Neurocognitive Correlations in Adolescents With Congenital Hypothyroidism.

CONTEXT: Subtle cognitive impairments have been described in children with congenital hypothyroidism (CH) detected by neonatal screening (NS), even with early and adequate treatment. Patients with CH may present with brain cortical thickness (CT) abnormalities, which may be associated with neurocognitive impairments. OBJECTIVE: This work aimed to evaluate the CT in adolescents with CH detected by the NS Program (Paraná, Brazil), and to correlate possible abnormalities with cognitive level and variables of neurocognitive prognosis. METHODS: A review was conducted of medical records followed by psychometric evaluation of adolescents with CH. Brain magnetic resonance imaging with analysis of 33 brain areas of each hemisphere was performed in 41 patients (29 girls) and in a control group of 20 healthy adolescents. CT values were correlated with Full-scale Intelligence Quotient (FSIQ) scores, age at start of treatment, pretreatment thyroxine levels, and maternal schooling. RESULTS: No significant difference in CT between patients and controls were found. However, there was a trend toward thinning in the right lateral orbitofrontal cortex among patients and in the right postcentral gyrus cortex among controls. CT correlated significantly with FSIQ scores and with age at start of treatment in 1 area, and with hypothyroidism severity in 5 brain areas. Maternal schooling level did not correlate with CT but was significantly correlated with FSIQ. Cognitive level was within average in 44.7% of patients (13.2% had intellectual deficiency). CONCLUSION: There was a trend toward morphometric alterations in the cerebral cortex of adolescents with CH compared with healthy controls. The correlations between CT and variables of neurocognitive prognosis emphasize the influence of hypothyroidism on cortical development. Socioeconomic status exerts a limiting factor on cognitive outcome.

Relationship between hippocampal subfields and Verbal and Visual memory function in Mesial Temporal Lobe Epilepsy patients.

OBJECTIVE: High-resolution protocols used in magnetic resonance imaging (MRI) currently enable the detailed analysis of the hippocampus along with its subfield segmentation. The relationship between episodic memory and the hippocampus is well established, and there is growing evidence that some specific memory processing steps are associated with individual hippocampal segments, but there are inconsistencies in the literature. We focused our analysis on hippocampal subfield volumetry and neuropsychological visual and verbal memory tests in patients with temporal lobe epilepsy (TLE) presenting with unilateral hippocampal atrophy. METHODS: The study involved a cohort of 62 patients with unilateral TLE, including unilateral hippocampal atrophy (29 on the left side) based on MRI and unequivocal ipsilateral ictal onsets based on surface video electroencephalography recordings. The hippocampal subfield volumes were evaluated using FreeSurfer version 7.1. We used the Rey-Auditory Verbal Learning Test to evaluate short-term (A1), learning (ΣA1-A5), immediate (A6), and delayed (A7) recall of episodic verbal memory. We used the Rey-Osterrieth Complex Figure Test to evaluate the immediate and delayed recall of visual memory. We analyzed the correlations between the asymmetry index scores for the hippocampal subfield volumes of thecornu ammonis (CA)1, CA2/3, and CA4 and memory test performance. RESULTS: Moderate associations were established between the CA2/3 asymmetry index scores and visual memory in TLE (both right and left hippocampal atrophy), as well as visual memory and CA4 in the right atrophy cases. The CA1 asymmetry index scores did not correlate with any of the memory test results. We did not find any significant correlation between verbal memory tests and specific hippocampal subfields. CONCLUSIONS: The use of high-resolution MRI protocols andin vivo automated segmentation processing revealed moderate associations between hippocampal subfields and memory parameters. Further investigations are needed to establish the utility of these results for clinical decisions.

Analysis of diffusion tensor parameters in spinocerebellar ataxia type 3 and type 10 patients.

INTRODUCTION: There is a dearth of studies of spinocerebellar ataxias (SCAs) and diffusion tensor magnetic resonance imaging (DTI). OBJECTIVE: To analyze changes observed in DTI parameters and correlate these to clinical findings in SCA3 and SCA10 patients. METHODS: SCA3 (n = 19) and SCA10 (n = 18) patients were compared with a similar number of controls and assessed clinically and with the scale for the assessment and rating of ataxia (SARA) before undergoing the same MRI protocol. TRACULA (TRActs Constrained by UnderLying Anatomy) software was used to analyze the DTI metrics FA, AD, RD and MD. RESULTS: More white matter fiber tracts with changes in diffusivity were found in SCA3 patients than in SCA10 patients. There was a reduction in AD in altered fiber tracts in SCA3 and a greater increase in RD in SCA10. In the SCA3 patients, FA was reduced in the corticospinal tract (CST) and inferior longitudinal fasciculus (ILF), but this was not observed in the SCA10 patients. SARA score was correlated with DTI findings in SCA3 but not in SCA10. CONCLUSION: Changes were observed in DTI for both SCA3 and SCA10 but were more widespread in SCA3. Our finding of myelin-sheath changes in SCA10 and secondary axonal changes in SCA3 may reflect the more rapid, aggressive clinical course of SCA3.

Volumetric MRI Changes in Spinocerebellar Ataxia (SCA3 and SCA10) Patients.

Spinocerebellar ataxias type 3 (SCA3) and type 10 (SCA10) are the most prevalent in southern Brazil. To analyze the relationships between volumetric MRI changes and clinical and genetic findings in SCA3 and SCA10 patients. All patients in the study had a confirmed genetic diagnosis. Demographic data, ataxia severity (SARA score), and the size of the expanded alleles were evaluated. Nineteen SCA3 and 18 SCA10 patients were selected and compared with a similar number of healthy controls. Patient and control groups underwent the same MRI protocol. The standard FreeSurfer pipeline was used for the morphometric data. Our results show more affected brain structures (volume reductions) in SCA3 patients than in SCA10 patients (15 vs. 5 structures). Volume reductions in brain structures were also greater in the former. The main areas with significant volumetric reductions in the former were the cerebellum, basal ganglia, brain stem, and diencephalon, whereas in the latter, significant volume reductions were observed in the cerebellum and pallidum. While SARA scores and disease duration were more correlated with volume reduction in SCA10, in SCA3, the expansion length (CAGn) correlated positively with cerebellar WM, thalamus, brain stem, and total GM volumes. There was no correlation between expansion length (ATTCTn) and neuroimaging findings in SCA10. Neuroimaging results differed significantly between SCA3 and SCA10 patients and were compatible with the differences in clinical presentation, disease progression, and molecular findings.

Mesial temporal lobe epilepsy: Revisiting the relation of hippocampal volumetry with memory deficits.

OBJECTIVE: Neuropsychological tests can infer the lateralization of the epileptogenic focus, associating verbal memory to mesial structures in the left temporal lobe and visual or nonverbal memory to the right side. High-field magnetic resonance imaging (MRI) with high-resolution protocols allows acquisitions suitable for advanced postprocessing with precise volumetry of brain structures, and functional MRI demonstrates evidence that epilepsy should be seen as a network pathology, involving several structures in the brain. Since the literature showing associations between the volumetry of brain structures in left and right mesial temporal lobe epilepsy (MTLE) and verbal and visual memory performance on neuropsychological tests is conflicting, we revisited these relationships, considering the hippocampal volumetry of patients with unilateral MTLE. METHODS: Automatized hippocampal volumes were obtained using FreeSurfer software from MRI exams of 35 patients with unilateral MTLE and hippocampal atrophy and homolateral ictal onset zone defined by video electroencephalography concordant to the side of hippocampal volume reduction (15 on the left side). Verbal memory was assessed using the Rey Auditory-Verbal Learning Test (RAVLT), and visual memory tests employed the Rey-Osterrieth Complex Figure Test (ROCFT). The statistical analysis explored relationships between hippocampal volumetry, lateralization, and performance on memory tests. RESULTS: In general, we observed deficits in both verbal and visual memory for patients with left and right hippocampal volume reduction. Patients with left hippocampal volume reduction had poorer performance on verbal memory tests compared with those with right hippocampal atrophy (t = -3.813, p < 0.001). Visual memory deficits were seen on both left and right MTLE without a statistically significant difference (t = 0.074, p = 0.942). The correlation between the Hippocampal Asymmetry Index (HAI) and visual and verbal Z-scores was significant only for visual Z-score in right MTLE (R = -0.45, p = 0.048). CONCLUSIONS: Verbal memory deficit seems to be more consistent in patients with left hippocampal volume reduction. Although it had only a moderate correlation to HAI, visual memory deficit is suggested as a poorer indicator for right MTLE. Considering that verbal and visual memory deficits are seen on both right and left MTLE, MTLE should not be regarded as a unilateral, focal, or local insult but as a multifactorial and network pathology, possibly involving several brain structures.

Diffusion tensor imaging and tract-based spatial statistics analysis in Friedreich's ataxia patients.

INTRODUCTION: Friedreich's ataxia (FRDA) is the most common hereditary ataxia and thinning of the cervical spinal cord is a consistent observation in Magnetic resonance imaging (MRI), although neuropathological examination in FRDA reveals neuronal loss in gray matter (GM) nuclei and degeneration of white matter (WM) tracts in the spinal cord, brainstem and cerebellum. Using diffusion-tensor (DTI) imaging and tract-based spatial statistics (TBSS) we tested the hypothesis that WM damage in FRDA is more extensive than previously described and probably involves normal-appearing WM. METHODS: This transversal study included 21 genetically confirmed FRDA patients and seventeen healthy controls that underwent structural MRI of the brain on a 1.5 T scanner. We quantify the severity of ataxia using SARA scale. DTI was performed and diffusion data were analyzed using FMRIB's Diffusion Toolbox in FSL 4.1 in order to identify Fractional anisotropy (FA) decreases in specific brain regions and also the mean, radial and axial diffusivities (MD, RD, AD). RESULTS: The greatest decreases in FA were in the left superior cerebellar peduncle, left posterior thalamic radiation, major forceps, left inferior fronto-occipital fasciculus and corpus callosum and had a significance level of p < 0.01. No significant correlation between FA, AD, MD and RD values and the clinical findings, SARA scores and genetic expansion was found. CONCLUSION: DTI and TBSS techniques clearly demonstrate the extensive cerebral and cerebellar involvement in FRDA, partially explaining the clinical phenotype of the disease. Further studies are needed with larger samples to correlate clinical, genetic findings and ataxia scores.

MRI hydrographic 3D sequences in CADASIL.

Two patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) (figure), evolving with cognitive deterioration, had MRI. Hydrographic 3D high-resolution turbo spin-echo (TSE) with variable flip angle sequence (SPACE) was performed to demonstrate the subcortical lacunar lesions (SLL) (figure, A and B), considered specific in CADASIL.(1.)

X-linked adrenoleukodystrophy: correlation between Loes score and diffusion tensor imaging parameters.

OBJECTIVE: The present study was aimed at evaluating the correlation between diffusion tensor imaging parameters and Loes score as well as whether those parameters could indicate early structural alterations. MATERIALS AND METHODS: Diffusion tensor imaging measurements were obtained in 30 studies of 14 patients with X-linked adrenoleukodystrophy and were correlated with Loes scores. A control group including 28 male patients was created to establish agematched diffusion tensor imaging measurements. Inter- and intraobserver statistical analyses were undertaken. RESULTS: Diffusion tensor imaging measurements presented strong Pearson correlation coefficients (r) of -0.86, 0.89, 0.89 and 0.84 for fractional anisotropy and mean, radial and axial diffusivities (p < 0.01). Analysis of changes in diffusion tensor measurements at early stage of the disease indicates that mean and radial diffusivities might be useful to predict the disease progression. CONCLUSION: Measurements of diffusion tensor parameters can be used as an adjunct to the Loes score, aiding in the monitoring of the disease and alerting for possible Loes score progression in the range of interest for therapeutic decisions.

OBJETIVO: Avaliar a correlação dos parâmetros do tensor de difusão com o escore de Loes e se os parâmetros do tensor de difusão poderiam indicar alterações estruturais precoces. MATERIAIS E MÉTODOS: As medidas do tensor de difusão foram obtidas em 30 exames de 14 pacientes com adrenoleucodistrofia ligada ao X e foram correlacionadas com o escore de Loes. Um grupo controle de 28 pacientes masculinos foi avaliado para estabelecer medidas do tensor de difusão pareadas por idade. Análises estatísticas intra e interobservador foram feitas. RESULTADOS: As medidas do tensor de difusão apresentam forte correlação com o escore de Loes segundo o coeficiente de Pearson (r), com valores de ­0,86, 0,89, 0,89 e 0,84 para a fração de anisotropia e difusibilidades média, radial e axial (p < 0,01). A análise da mudança nas medidas do tensor de difusão no estágio inicial da doença indica que os valores de difusibilidades média e radial podem ajudar a predizer a progressão da doença. CONCLUSÃO: As medidas de parâmetros do tensor de difusão poderiam ser usadas como um adjunto ao escore de Loes, auxiliando no monitoramento da doença e alertando uma possível progressão do escore de Loes na faixa de interesse para decisões terapêuticas.

Massive calcification in a pleomorphic adenoma: report of an unusual presentation.

We report a case of histology-proven pleomorphic adenoma of the parapharyngeal space in a 20-year-old man. This case was unusual in that a massive amount of dystrophic calcification was scattered throughout the tumor. The patient underwent successful surgical resection, and he exhibited no signs of recurrence during follow-up. Literature about such an unusual presentation is scarce.

Posterior fossa malformation associated with cerebral anomalies: genetic and imaging features.

Many posterior fossa malformations are associated with other malformations particularly supratentorial ones, which tend to affect the prognosis of these patients. The role of the cerebellum in higher learning is just beginning to be understood, but it is obvious that cerebellar abnormalities may result in higher-cognition defects. Studies have demonstrated cerebellar abnormalities in patients with developmental encephalopathies, such as autism, mental retardation, and Rett syndrome. Disorders that affect cell life cycles and result in abnormal cell proliferation and abnormal cell migration disorders (hemimegalencephaly, dystroglicanopathy, lissencephaly, and gray matter heterotopia) can also be accompanied by posterior fossa malformations. In this article, we discuss hindbrain-midbrain malformations associated with developmental encephalopathies and with supratentorial brain abnormalities that result from abnormal cell proliferation and cell migration.

Subependymal giant cell astrocytoma with high choline/creatine ratio on proton MR spectroscopy.

OBJECTIVE: To report a case of subependymal giant cell astrocytoma (SEGA) in a patient with tuberous sclerosis, emphasizing the proton MR spectroscopy (MRS) findings. CASE: A three year-old boy with tuberous sclerosis presented with a 3-month history of mild headache. The physical examination showed discrete mental retardation and multiple hypomelanic macules in the legs and back. MRI showed many cortical tubers and subependymal nodules. At the left foramen of Monro, there was a 15 mm nodule, with heterogeneous signal on T1 and T2-weighted images, and strong enhancement after contrast administration. MRS study (multi-voxel PRESS, TE=144ms) showed the following ratios: a) left foramen of Monro nodule N-acetylaspartate (NAA)/creatine (Cr)=0.93 and Choline (Cho)/Cr=1.6 and b) at the right Monro foramen NAA/Cr=1.56 and Cho/Cr=1.29. CONCLUSION: The MRS performed at the SEGA may show high Cho/Cr and low NAA/Cr ratios, similar to the other brain neoplasms. As a consequence, MRS may be a valuable tool for the early detection of neoplastic transformation of subependymal nodules near the foramina of Monro in patients with tuberous sclerosis.

Cerebral X-linked adrenoleukodystrophy: follow-up with magnetic resonance imaging.

OBJECTIVE: To report a case of childhood cerebral X-linked adrenoleukodystrophy (X-ADL), emphasizing the magnetic resonance imaging (MRI) findings at initial evaluation and at the follow-up. CASE REPORT: Five year-old boy, who was asymptomatic, presented with diagnosis of X-ADL for MRI evaluation. The initial brain MRI showed a focal area of enhancement at the splenium of the corpus calosum. One year later, the follow-up MRI showed a progression of the corpus calosus lesion, as well as other lesions in the parietal and occipital lobes. CONCLUSION: The brain MRI follow-up of patients with X-ADL is important to show the progression of the lesions.

Intoxication with oral hypoglycemics as a cause of diffuse brain injury: case report.

OBJECTIVE: To present the imaging findings of a patient with diffuse brain injury secondary to intoxication with oral hypoglycemics. CASE REPORT: A nine years-old boy presented with generalized tonic-clonic convulsions and decreased consciousness. Laboratory investigation demonstrated blood glucose level of 21 mg/dL. The magnetic resonance imaging showed cortical and subcortical temporo-parieto-occipital areas of high signal on T2 and low signal on T1, with high signal on the diffusion-weighted images and low signal on apparent diffusion coefficient maps. CONCLUSION: Cortical and subcortical temporal, parietal and occipital ischemic lesions may be seen in patients with intoxication by oral hypoglycemics.

Unusual magnetic resonance findings in two children with sudden sensorineural hearing loss.

OBJECTIVE: To describe the MRI findings of two pediatric patients with sudden sensorineural hearing loss (SSHL). CASE REPORTS: Two male patients (two-year and three-months-old, and one year and four-months-old) presented with sudden dumbness. Physical and neurological examinations were unremarkable besides bilateral hypoacusia. All the laboratory investigation was negative, and brain stem auditory evoked potentials showed deep bilateral deafness in both cases. MRI studies revealed normal inner ears and multifocal white matter areas of slight low signal on T1-weighted images and high signal on FLAIR images. The follow-up MRI studies and neurological examinations did not demonstrate alterations in the previous findings. CONCLUSION: Pediatric patients with SSHL may present cerebral white matter signal abnormalities at the MRI as the only finding. Further studies with larger casuistics need to be conducted to elucidate these findings.

Disseminated tuberculosis in a pregnant woman presenting with numerous brain tuberculomas: case report.

Tuberculosis is an infectious disease caused by Mycobacterium tuberculosis, which has the pulmonary form as the most common presentation. Dissemination of the disease is common in immunocompromised patients, but immunodeficiency related to pregnancy severe enough to cause dissemination of the Mycobacteria is exceedingly rare. When dissemination occurs, any organ may be affected and in central nervous system, the infection presents as meningitis and single brain parenchyma tuberculomas. We report the case of a 17 year-old woman at the 34th week of pregnancy with respiratory and high intracranial pressure symptoms. On the day before admission she had a sudden onset of paraparesis and urinary retention and ten hours after the delivery she presented with paraplegia. The chest X-ray and CT scan were compatible with miliary tuberculosis. The cranial CT scan revealed numerous rounded hypodense lesions located at cerebral and cerebellar hemispheres, which presented ring-like enhancement after contrast injection. The patient underwent a craniotomy with biopsy of the lesions confirming the diagnosis of brain tuberculomas. The three-drug regimen was started and the cranial CT scan performed a year after diagnosis showed no brain lesions. We emphasize the aggressive dissemination of the disease in this case associated with pregnancy and the importance of early diagnosis and institution of therapy resulting in regression of the lesions.

Septo-optic dysplasia plus: case report.

Septo-optic dysplasia (SOD) is a syndrome composed by optic nerve and septum pellucidum dysgenesis. It has been classified into two subsets according to the embryogenesis and the neuropathological findings. Basically, the difference between these two groups is the presence or not of schizencephaly. The term SOD-Plus was recently proposed to describe SOD associated with cortical dysplasia. We report a 6-month-old female patient who presented absent visual fixation since 4 months of age and delayed psychomotor development. Neurological examination demonstrated spastic left hemiparesis and ophtalmological evaluation revealed bilateral optic disc hypoplasia. The head computed tomography (CT) scan showed absence of the septum pellucidum, ventricular asymmetry and schizencephaly. The magnetic resonance imaging (MRI) showed complete absence of the septum pellucidum associated to optic nerves and chiasma atrophy, schizencephaly and cortical dysplasia. The patient underwent an evoked potential examination with flash stimulation, which revealed bilateral absence of cortical evoked potential. She was referred to visual stimulation and physiotherapy. We emphasize the neuroimaging of this syndrome and stress the importance of the clinical investigation for patients with septum pellucidum dysgenesis on MRI or CT scans.