Mutations of the thyroid hormone transporter MCT8 cause prenatal brain damage and persistent hypomyelination.

CONTEXT: Mutations in the MCT8 (SLC16A2) gene, encoding a specific thyroid hormone transporter, cause an X-linked disease with profound psychomotor retardation, neurological impairment, and abnormal serum thyroid hormone levels. The nature of the central nervous system damage is unknown. OBJECTIVE: The objective of the study was to define the neuropathology of the syndrome by analyzing brain tissue sections from MCT8-deficient subjects. DESIGN: We analyzed brain sections from a 30th gestational week male fetus and an 11-year-old boy and as controls, brain tissue from a 30th and 28th gestational week male and female fetuses, respectively, and a 10-year-old girl and a 12-year-old boy. METHODS: Staining with hematoxylin-eosin and immunostaining for myelin basic protein, 70-kDa neurofilament, parvalbumin, calbindin-D28k, and synaptophysin were performed. Thyroid hormone determinations and quantitative PCR for deiodinases were also performed. RESULTS: The MCT8-deficient fetus showed a delay in cortical and cerebellar development and myelination, loss of parvalbumin expression, abnormal calbindin-D28k content, impaired axonal maturation, and diminished biochemical differentiation of Purkinje cells. The 11-year-old boy showed altered cerebellar structure, deficient myelination, deficient synaptophysin and parvalbumin expression, and abnormal calbindin-D28k expression. The MCT8-deficient fetal cerebral cortex showed 50% reduction of thyroid hormones and increased type 2 deiodinase and decreased type 3 deiodinase mRNAs. CONCLUSIONS: The following conclusions were reached: 1) brain damage in MCT8 deficiency is diffuse, without evidence of focal lesions, and present from fetal stages despite apparent normality at birth; 2) deficient hypomyelination persists up to 11 years of age; and 3) the findings are compatible with the deficient action of thyroid hormones in the developing brain caused by impaired transport to the target neural cells.

Atypical clinical presentation and long-term survival in a patient with optic nerve medulloepithelioma: a case report.

INTRODUCTION: Medulloepithelioma is a rare congenital tumor of the primitive medullary neuroepithelium. A significant proportion of patients with medulloepithelioma arising from the optic nerve die from intracranial spread or cerebral metastasis. Because it has no known distinct clinical features and because of its low frequency, this tumor presents within the first two to six years of life and is usually misdiagnosed clinically as a different type of optic nerve tumor. Here, we describe a new and atypical case of medulloepithelioma of the optic nerve in a 12-year-old boy. To the best of our knowledge, he is the oldest reported patient to present with this disease and, now as an adult, has the longest documented period of disease-free survival. CASE PRESENTATION: A 12-year-old Caucasian boy with headache and unilateral amaurosis was referred for a presumed optic nerve glioma to our hospital. A computed tomography scan showed optic nerve enlargement, and fundoscopy showed a whitish mass at the optic disc. Our patient had been followed at his local hospital for four years for an 'optic disc cyst' with no change or progression. He experienced mild progressive visual impairment during that period. He was admitted for resection, and a histopathological analysis revealed a medulloepithelioma of the optic nerve. Supplemental orbital radiotherapy was performed. He remained disease-free for 25 years. CONCLUSIONS: Medulloepithelioma of the optic nerve can clinically mimic more common pediatric tumors, such as optic glioma, meningioma, or retinoblastoma. Thus, medulloepithelioma should be included in the differential diagnoses of pediatric optic nerve lesions. Fundoscopy in these patients may provide relevant information for diagnosis. Anterior optic nerve medulloepitheliomas may behave differently from and have a better prognosis than medulloepitheliomas that have a more posterior location. Our case report illustrates that long-term survival can be achieved in patients with this malignant tumor.

Rheumatoid meningitis mimicking progressive supranuclear palsy.

INTRODUCTION: Rheumatoid meningitis is an uncommon manifestation of longstanding rheumatoid arthritis and few cases have been described. The clinical presentation is extremely variable as reported in medical literature. CASE REPORT: We report a 71-year-old woman with 15 years of seropositive rheumatoid arthritis who developed neurological complications: cognitive deterioration; hypomimia; limitation on vertical gaze; and axial stiffness, resembling progressive supranuclear palsy and seizures. Brain magnetic resonance imaging showed a diffuse dural plaque on both frontal and temporal lobes exhibiting homogeneous gadolinium enhancement. There was diffuse leptomeningeal enhancement and hyperintense white matter lesions. The final diagnosis made by image-guided biopsy showed rheumatoid pachymeningitis. After the definitive diagnosis, high doses of corticosteroids and immunosuppressive treatment were started. CONCLUSIONS: We emphasize the diagnostic importance of the biopsy in cases of chronic pachymeningitis and stress that diverse entities can cause progressive supranuclear palsy-like phenotypes.

Primary diffuse leptomeningeal gliomatosis mimicking meningeal tuberculosis.

Primary diffuse leptomeningeal gliomatosis (PDLG) is a rare condition, with only 45 cases recorded to date, characterized by infiltration of the meninges by glial cells without evidence of primary tumor in the brain or spinal cord parenchyma. Here, we describe a patient with PDLG who was managed with tuberculostatic drugs owing to multiple findings that were suggestive of tuberculous meningitis. A 19-year-old woman presented with headaches and behavioral changes. A sudden decrease in visual acuity with papilledema, bilateral sixth nerve palsies, and neck stiffness developed. Lumbar puncture showed elevated opening pressure (50 cm H2O). Cerebrospinal fluid (CSF) analysis showed glucose 30 mg/dL, protein 26.5 mg/dL, white blood cell count 150 (60% lymphocytes, 40% neutrophils). The second sample of CSF provided adenosine deaminase activity 21.9 U/L. Polymerase chain reaction for Koch's bacillus was positive in the third CSF sample. Magnetic resonance imaging revealed meningeal thickening of the quadrigeminal cistern, tentorium cerebelli, cerebral convexity, and spinal cord, with gadolinium enhancement in nodular lesions. The patient died 22 weeks after symptom onset owing to brainstem infarction. Postmortem pathologic studies revealed PDLG. This entity should be included in the differential diagnosis of tuberculous meningitis that does not respond to treatment with antituberculous drugs. Surgical biopsy should be considered in contrast-enhanced areas in magnetic resonance imaging.

[Cerebral hemisphere tumours in neurofibromatosis type 1 during childhood]. / Tumores de los hemisferios cerebrales en la neurofibromatosis tipo 1 durante la infancia.

AIM: To present seven tumors of the cerebral hemispheres in 6 children with neurofibromatosis type 1 (NF1). PATIENTS AND METHODS: Six patients (three males and three females) of 600 cases of a series with NF1 showed features of cerebral hemispheres tumor (seizures, headache and hemiparesis). They were studied neurologically, by EEG and by image (MR and/or spectroscopic-MR) because of these features or simply because having NF1. RESULTS: All the patients had the two diagnostic criteria of the NF1. Six patients had seven tumors (it was because one of them had one tumor in every frontal lobe, both with the same image characteristics), but they did not were removed and they were not studied histologically. The histological study was made to the other five patients and showed that the histological nature corresponded to pilocytic astrocytoma in one patient, neuroepitelial dysembryoplastic tumor in one, polymorphe xanthoastrocytoma in one, neuroectodermic hamartoma in one, and inflammatory chronic non-granulomatose lesion in one. CONCLUSION: The prevalence of the tumors in the cerebral hemispheres is very low (1%) in the patients with NF1. The tumors commonly are histologically benign, and they can be found in peripheral or deep region of the cerebral hemispheres. Identity of the tumors by MR study commonly is easy and the treatment is surgical in most cases. However, urgent treatment very seldom is necessary in these tumors, and most frequently is possible to take the attitude of 'wait and see' before to decide the definite treatment.

Lesiones hipoxico-isquémicas del sistema nervioso central en el período perinatal / No disponible

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