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Trichothiodystrophy (TTD), an autosomal recessive disorder characterized by sulfur-deficient brittle hair, identifies a group of genetic disorders with an altered synthesis of high-sulfur matrix proteins and a defect in excision repair of ultraviolet damage in fibroblasts of most TTD patients. In contrast to patients with xeroderma pigmentosum (XP), TTD patients do not have an increased frequency of skin cancers. TTD patients may be grouped into four categories: 1) those without photosensitivity and without a defect in excision repair of UV damage; 2) those without photosensitivity and with an excision-repair defect in the same gene as in XP-D (complementation group D); 3) those with photosensitivity and with the XP-D repair defect; 4) those with photosensitivity and with a repair defect distinct from that in XP-D. We present a brother and sister in the third category of TTD. Clinically, the patients have brittle hair, short stature, ichthyosis, photosensitivity, nail and dental dysplasias, cataracts, mental retardation, and pyramidal tract abnormalities. Diagnosis was made by hair mount, which shows the characteristic banding pattern with polarizing microscopy, and by hair amino acid analysis, which demonstrated decreased high-sulfur matrix proteins. Fibroblasts cultured from skin biopsies had a marked DNA excision repair defect similar to the repair defect seen in XP-D. We have documented a unique dysmyelinating disorder on magnetic resonance imaging of the brain that might explain their mental retardation, marked hyperactivity, and neurologic deficits. Following the discovery that the human excision repair cross complementing rodent ultraviolet group 2 (ERCC2) gene is able to correct the ultraviolet sensitivity of XP-D cell strains, the ERCC2 cDNA from previous TTD patients was sequenced and shows frameshifts, deletions and point mutations in the ERCC2 gene. Molecular analysis of our patients is in progress. Molecular analysis of the defects in ERCC2 in clinically distinct patients with XP,XP/Cockayne's syndrome, and TTD may provide insight into the molecular mechanisms of these genetically related but clinically distinct disorders.

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PURPOSE: To review the frequency, distribution, and extent of deep gray matter disease in children with acute disseminated encephalomyelitis. METHODS: The MR examinations of 10 patients, who were discharged with the clinical diagnosis of acute disseminated encephalomyelitis between 1986 and 1992, were retrospectively reviewed. Locations of abnormal signal in the cerebral and cerebellar cortices, white matter, and deep gray matter nuclei were recorded. Precontrast and postcontrast images were compared, when available, to assess degree of enhancement (if any). RESULTS: Six patients had foci of prolonged T2 relaxation in the deep gray matter, ranging in size from less than 1 cm to 4 cm. The caudate heads were involved in 4 patients, caudate body in 3, globus pallidus in 3, putamina in 3, and thalami in 4. In 1 patient, the thalami were involved nearly symmetrically, with mild mass effect. Asymmetric subcortical white matter involvement was present as well. Prolonged T2 relaxation was present within the cerebral cortex in 4 patients and was associated with subcortical white matter abnormality in 3 and more central white matter disease in 1. Nine of 10 patients demonstrated foci of T2 prolongation in white matter, most commonly involving the subcortical region, corona radiata, and centrum semiovale. Three patients also had periventricular foci. Of the 3 patients receiving gadolinium, one showed no enhancement. Two of the patients showed enhancement of some but not all lesions. One patient, who had normal brain MR findings and symptoms of myelopathy, underwent spine MR which demonstrated focal linear areas of T2 prolongation in the spinal cord at levels C-1 to C-2 and T-6. CONCLUSION: Involvement of deep gray matter was common in our small series. The finding of T2 prolongation in these structures does not preclude the diagnosis of acute disseminated encephalomyelitis in the proper clinical setting. Because thalamic involvement is reported to be rare in multiple sclerosis, it may prove useful in distinguishing between acute disseminated encephalomyelitis and the initial presentation of multiple sclerosis.

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PURPOSE: Investigation of the clinical, imaging, and in vivo MR spectroscopy (MRS) characteristics of disorders of mitochondrial function. METHODS: Clinical, imaging (five CT and 20 MR examinations), and MRS (six studies in five patients) findings in 19 patients with mitochondrial disorders were retrospectively reviewed. Results were critically analyzed and, when applicable, compared with results in the literature. RESULTS: Patients included four with mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS), two with myoclonus, epilepsy, and ragged red fibers (MERRF), two with Kearns-Sayre syndrome, seven with Leigh syndrome, one with progressive cerebral poliodystrophy (Alpers syndrome), and three with trichopoliodystrophy (Menkes disease). MELAS, MERRF, and Kearns-Sayre tended to occur in older children and adults, whereas Leigh syndrome, Alpers syndrome, and Menkes disease occurred in infants and young children. All diseases involved gray matter early in their course, manifest primarily as T2 prolongation, with the deep cerebral nuclei being involved more often than the cerebral cortex. When T2 prolongation was seen in the white matter (MELAS, MERRF, Kearns-Sayre, Leigh), the peripheral and retrotrigonal white matter showed early involvement. Patients with Menkes disease showed rapidly progressive atrophy accompanied by large subdural hematomas. Proton MRS showed an elevated lactate level in involved regions of the brain; the lactate peak disappeared in old areas of T2 prolongation. CONCLUSIONS: Mitochondrial disorders have a wide range of both clinical and imaging findings. Although no one set of findings is diagnostic of these disorders, the combination of deep gray matter involvement and peripheral white matter involvement in young adults or children should suggest the diagnosis, especially when associated with an elevated lactate level on proton MRS.

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Two children who had classic maple syrup urine disease developed an eruptive dermatitis when plasma isoleucine levels, leucine levels, or both fell below normal during periods of protein restriction. The dermatitis was resistant to topical corticosteroid therapy. Rapid resolution occurred after treatment with isoleucine and leucine dietary supplements.

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Two siblings, a 27-year-old man and his 24-year-old sister were diagnosed with classic transferase deficiency galactosemia at birth and were treated with strict lactose restriction. Despite well-documented dietary management, both siblings are mentally retarded and manifest a progressive neurologic condition characterized by hypotonia, hyperreflexia, dysarthria, ataxia, and a postural and kinetic tremor. Magnetic resonance imaging revealed moderate cortical atrophy, a complete lack of normal myelination, and multifocal areas of increased signal in the periventricular white matter on T2-weighting. These patients suggest that even with early diagnosis and treatment, individuals with galactosemia may have significant neurologic morbidity with abnormalities of white matter development. This finding raises the possibility of biochemical heterogeneity within the classic transferase deficiency group, as well as the possibility of a lack of available galactose metabolites necessary for glycolipid synthesis causing a disruption of normal myelin development.

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PURPOSE: We used MR to retrospectively analyze the brains of patients suffering from cerebral palsy, our aim being to determine MR's role in the assessment of brain damage and the relationship of pre-, peri-, and post-natal events to cerebral palsy. METHODS: Forty patients (aged 1 month to 41 years) underwent MR scanning and findings were correlated with clinical histories in all cases. RESULTS: Review of MR scans of 11 patients who had been born prematurely revealed findings of periventricular white matter damage, indicative of hypoxic-ischemic brain injury (82%), the chronology of which was difficult to determine. Among 29 patients who had been born at term, three major patterns emerged: (1), gyral anomalies, suggestive of polymicrogyria, consistent with mid-second trimester injury; (2), isolated periventricular leukomalacia reflecting late second- or early third-trimester injury; and (3), watershed cortical or deep gray nuclear damage, consistent with late third-trimester, perinatal or postnatal injury. In 16 (55%) of 29 patients born at term, MR findings of intrauterine brain damage were observed; in over half of these cases MR revealed developmental anomalies, which is nearly twice the rate reported in prior studies employing CT. CONCLUSIONS: Our results support a growing consensus that cerebral palsy in term infants is often the result of prenatal factors, and less commonly related to the perinatal period.

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Four children are reported who always looked above objects of visual interest (overlooking). All had bilateral central scotomata (loss of central visual field). Three had optic nerve disease selectively affecting the papillomacular fibers; the fourth had ocular colobomata affecting the maculae. Overlooking is an important sign of bilateral central scotomata in children: it is an adaptation to loss of central vision.

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Clinical data and magnetic resonance imaging scans from 10 patients with lissencephaly were reviewed. Although 6 of the 10 patients were less than 1 year old at the time of their most recent examination, those who were old enough for developmental assessment were, with a single exception, severely developmentally delayed. All patients had anatomical features compatible with impaired neuronal migration but normal myelination and, consequently, adequate glial migration. The severity of the lissencephaly did not seem to correlate with the severity of the clinical manifestations. One patient showed less delayed development than anticipated, perhaps because the most severely involved region of the brain was the prefrontal area.

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We describe two patients with chronic unilateral ptosis and contralateral hemispheric arteriovenous malformations. Both patients were brought to our attention after a subacute or acute neurological deterioration. Analysis of prior photographs showed the ptosis progressed up to the time of presentation and significantly resolved following surgical removal of the arteriovenous malformation. The partially reversible and chronic nature of the ptosis in these two patients represents a particularly unusual forms of cerebral ptosis.

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Leigh disease is a disorder with great clinical variability and for which diverse biochemical causes have been proposed. Clarification requires rigorous correlation of biochemical abnormalities with strict morphologic diagnosis; such an unambiguous association is the subject of this report. A patient with well-documented clinical and biochemical pyruvate dehydrogenase complex deficiency is shown on postmortem examination to have the specific CNS pathology of Leigh disease. These findings, considered together with the aggregate data in the literature, suggest strongly that pyruvate dehydrogenase complex deficiency is the basic defect in a subgroup of patients with Leigh disease.

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Magnetic resonance imaging (MRI) offers a sensitive alternative to computed tomography (CT) for lesion localization. Patients with subacute necrotizing encephalomyelopathy (SNE) may be diagnosed by finding focal lesions on CT that correspond to sites of anatomical involvement. We report serial CT and MRI scanning findings in a patient with clinical, radiographic, and laboratory evidence of SNE. MRI was more sensitive in detecting lesions involving the basal ganglia, brainstem, and cortex. We believe MRI is a valuable and sensitive means to establish an antemortem diagnosis of SNE.

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Four members of a consanguineous middle eastern family had a lipid storage disease characterized by congenital ichthyosiform erythroderma, neurosensory deafness, cataracts, mild myopathy, and leukocyte vacuoles. These patients are similar to several others recently reported and represent a unique disorder of lipid metabolism. The clinical and biochemical manifestations of this lipid storage disease are reviewed. Evidence is presented that the disorder is inherited as an autosomal recessive trait, and that heterozygotes may be detected by the presence of vacuoles within circulating eosinophils.

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Posterior fossa hemorrhage detected by computed tomography (CT) in seven term newborns was managed by nonsurgical means. All infants were developmentally normal two to four years later with the exception of one infant who died with a massive posterior fossa hemorrhage. Two infants with extensive hemorrhages developed hydrocephalus. Spinal fluid drainage and diuretic therapy resulted in the resolution of hydrocephalus in one infant and delayed the placement of a ventriculoperitoneal shunt in the other. This series documents normal outcome in nonsurgically managed neonatal posterior fossa hemorrhages of varying degrees of severity.

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Computed tomographic (CT) brain scans of patients with subacute necrotizing encephalomyelopathy (SNE) may reveal focal lesions that correspond to sites of anatomic involvement of the disease. Three patients with SNE were followed with serial CT brain scans. In two patients radiographic abnormalities appeared well after the onset of clinical symptoms. In all three patients the radiographic lesions changed with time. This variability seen with serial scanning is an important feature of SNE.

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