Journal of neuroimaging : official journal of the American Society of Neuroimaging
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Previous studies have found gray matter alterations in the cerebellum and in the visual system in both adults and adolescents with schizophrenia. The present study was conducted to investigate whether white matter tracts associated with these regions are also affected in the early stages of the disorder. ⋯ Our findings of altered fiber integrity in the optic radiations in adolescents with schizophrenia are in line with gray matter alterations in the visual cortices previously reported in the same sample and are in accordance with other studies that found decreased fractional anisotropy in these regions. These findings support the view that the visual system plays an important role in the pathogenesis of schizophrenia and may enhance our understanding of associations between the visual cortex and symptoms of the disorder.
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The "ears of the lynx" sign was previously reported as a neuroimaging finding observed in patients with autosomal recessive hereditary spastic paraplegia in association with a thin corpus callosum (ARHSP-TCC). We report a patient with a chronic form of Marchiafava-Bignami disease (MBD) that presented with this imaging feature. Diffusion tensor imaging (DTI) and fiber-tracking data support that this finding is a consequence of the structural derangement, which enlarges a preexisting border zone of the bundles of fibers from the corpus callosum (CC) genu to the forceps minor and anterior corona radiata. Therefore, we assume that despite their pathological differences, damage to the anterior portion of the CC is responsible for the imaging similarities between MBD and ARHSP-TCC.
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Vertebral artery dissection (VAD) is one of the most important etiologies in young stroke patients. VAD causes ischemic stroke by embolism and transcranial Doppler (TCD) monitoring can detect microemboli originating from the dissection point as high intensity transient signals (HITS). We developed a simple but novel method of TCD monitoring at the vertebrobasilar junction in VAD patients. ⋯ We successfully detected HITS at the vertebrobasilar junction in VAD patients, which may lead not only to an appropriate choice of antithrombotic drugs but also to individual evaluation of early risk of ischemic recurrence.
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Hyperargininemia (HA) is a rare autosomal recessive metabolic disorder and the neuroimaging features of this disease have seldom been reported. Hyperammonemic encephalopathy is uncommon in HA, and the clinical presentation of HA is distinct from other urea cycle disorders. This paper describes the brain MRI findings and a magnetic resonance spectroscopy (MRS) study of a series of Brazilian HA patients. ⋯ We present the MRI and MRS findings of a large series of HA patients. Variable degrees of brain atrophy and mild cerebellar atrophy were observed, and these findings were not specific. No metabolic abnormality was observed using MRS in this series of patients.
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In patients with critical carotid stenosis and ischemic stroke, it is crucial to determine whether distal hypoperfusion or artery-to-artery embolism is the predominant mechanism. The role of transcranial doppler (TCD) in this setting is vital. We report a patient with fibromuscular dysplasia and recurrent orthostatic transient ischemic attacks where fall in cerebral perfusion was clearly demonstrated by TCD.