1/35. Necrotizing encephalopathy and macrocephaly with mitochondrial complex I deficiency.A neonate presented in the first weeks after birth with vomiting. He was unresponsive, with hypotonia, macrocephaly, and lactic acidosis. The cranial computed tomographic scan revealed a hypodense brain, with increased brain volume and extensive cerebral edema. He died at 6 weeks of age; postmortem examination revealed necrotizing encephalopathy with marked brain edema, spongiosis, thalamic necrosis, and basal ganglia calcifications. Enzyme studies of the mitochondrial respiratory chain revealed complex I deficiency in both muscle and liver.- - - - - - - - - - ranking = 1keywords = brain (Clic here for more details about this article) |
2/35. Pontocerebellar hypoplasia associated with respiratory-chain defects.Pontocerebellar hypoplasias are congenital disorders of brain morphogenesis which include such diverse etiologies as carbohydrate-deficient glycoprotein syndrome type 1, cerebromuscular dystrophies (walker-warburg syndrome, Fukuyama syndrome, muscle-eye-brain disease) and at least two types of autosomal recessive neurodegenerations known as pontocerebellar hypoplasia type I and II. Pontocerebellar hypoplasia type 1 is a lethal phenotype and clinical features include congenital contractures, respiratory insufficiency, central and peripheral motor dysfunction and spinal anterior horn degeneration. Type 2 is characterized by progressive microcephaly, extrapyramidal dyskinesia and normal spinal cord findings. In this paper, we describe a girl, born at 33 weeks of gestation, presenting with respiratory insufficiency and multiple contractures. MRI scan of the brain demonstrated pontocerebellar hypoplasia and cortical and diffuse periventricular white matter abnormalities. Postmortem examination showed pontocerebellar hypoplasia with extensive gliosis of the periventricular white matter and of the basal ganglia with normal spinal cord findings. histology of skeletal muscle was normal. Biochemical analysis demonstrated multiple deficiencies of respiratory chain enzymes in skin fibroblasts. This case demonstrates a lethal phenotype of pontocerebellar hypoplasia without spinal cord abnormalities associated with a respiratory-chain disorder. The diagnostic workup in a patient whose brain image shows pontocerebellar hypoplasia should include a search for respiratory-chain impairment.- - - - - - - - - - ranking = 1.3333333333333keywords = brain (Clic here for more details about this article) |
3/35. Cerebral white matter disease in children may be caused by mitochondrial respiratory chain deficiency.Several mitochondrial diseases are known to occasionally involve the cerebral white matter, namely Leigh syndrome, kearns-sayre syndrome, and melas syndrome, but in these cases the major finding is alteration in the basal ganglia and brainstem. Here we report on severe diffuse white matter involvement and respiratory chain enzyme deficiency or mitochondrial dna rearrangement in 5 unrelated families. It is interesting that white matter lesions were the only abnormal neuroradiologic feature in 3 of the 5 families, and multiple small cyst-like white matter lesions were found in 2 of 5 probands. Respiratory chain deficiency should be considered in the diagnosis of severe white matter involvement in childhood.- - - - - - - - - - ranking = 0.33333333333333keywords = brain (Clic here for more details about this article) |
4/35. Neuropathological and histochemical changes in a multiple mitochondrial dna deletion disorder.The identification of cytochrome c oxidase (COX)-deficient/succinate dehydrogenase (SDH)- positive cells using sequential histochemistry has proved important in the identification of cells with high mitochondrial dna (mtDNA) mutant load. We demonstrate large numbers of COX-deficient/SDH-positive neurons in a mosaic pattern throughout the CNS of a patient with a multiple mtDNA deletion disorder. This patient had prominent central and peripheral nervous system involvement with marked cerebellar ataxia, a parkinsonian extra-pyramidal movement disorder, external ophthalmoplegia, dysphagia, and a severe peripheral neuropathy. There was degeneration of myelin tracts in the cerebellum and dorsal spinal columns, diffuse astrocytosis, and selective neuronal degeneration particularly in the midbrain and cerebral microvacuolation. The proportional distribution of the COX-deficient neurons did not always correlate directly with the degree of neuropathological damage with regions of high neuronal loss having relatively low proportions of these cells. Other clinically affected CNS regions have high levels of COX-deficient neurons without significant cell loss. The role of these COX-deficient neurons in causing neuronal degeneration and clinical symptoms is discussed.- - - - - - - - - - ranking = 0.39177365115192keywords = brain, nervous system (Clic here for more details about this article) |
5/35. Possible mechanisms in infants for selective basal ganglia damage from asphyxia, kernicterus, or mitochondrial encephalopathies.magnetic resonance imaging and neuropathologic studies have demonstrated remarkably selective patterns of injury to subregions of the basal ganglia in children. Examples are kernicterus and certain mitochondrial encephalopathies, which cause selective injury to the globus pallidus, and near-total perinatal asphyxia, which causes lesions in the putamen and thalamus. To explain the differential vulnerability of nuclei within millimeters of each other, we hypothesize that their locations within the neurotransmitter-specific circuitry of the basal ganglia motor loop are important. In severe hypoxic-ischemic encephalopathy, excitatory glutamatergic pathways into the putamen and thalamus are overactive, but the globus pallidus might be protected because its activity is silenced by inhibitory neuronal activity. In contrast, the relatively high resting neuronal activity in the globus pallidus might make it more vulnerable to less intense, subacute oxidative stresses from mitochondrial toxins such as bilirubin or from genetic mitochondrial disorders. This hypothesis has implications for designing neuroprotective therapies and for treating associated chronic movement disorders.- - - - - - - - - - ranking = 1856.3596816748keywords = encephalopathies (Clic here for more details about this article) |
6/35. congenital disorders of glycosylation (CDG) may be underdiagnosed when mimicking mitochondrial disease.congenital disorders of glycosylation (CDG) and mitochondrial diseases are multisystem disorders with clinical characteristics that may overlap. We present four patients with CDG whose phenotypes suggested the diagnosis of a mitochondrial disease. patients 1 and 2 are siblings with hemiplegic headache, stroke-like episodes, lactic acidaemia and history of maternal migraine; their initial clinical diagnosis was melas syndrome (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes). Patient 3 suffers from ataxia, neuropathy, ophtalmoplegia and retinitis pigmentosa suggestive of NARP (neuropathy, ataxia, and retinitis pigmentosa) syndrome. Patient 4 presented with neurological regression mimicking leigh disease, with ptosis, myoclonus, ataxia and brainstem and cerebellar atrophy. Screening for mitochondrial disease including enzyme and mtDNA investigations on muscle biopsy were performed on patients 1, 2 and 4 with normal results. However, evidence for a glycosylation disorder was substantiated by an increased carbohydrate deficient transferrin (CDT). The isoelectric focussing pattern of serum sialotransferrin was typical of CDG type I in patients 1, 2 and 3 and was shifted towards the less sialylated bands in case 4. A deficiency of phosphomanomutase (PMM) confirmed the diagnosis of CDG-Ia in patients 1, 2 and 3, who are compound heterozygous for mutations R141H/T237M (patients 1 and 2) and R141H/P113L (Patient 3). In Patient 4, PMM activity was normal, and further enzymatic and molecular studies are underway. As the search for the primary defect in mitochondrial diseases is often unsuccessful, the pool of mitochondrial patients that remain without definite diagnosis might include CDG cases. Routine screening for CDG may avoid precocious invasive investigations.- - - - - - - - - - ranking = 0.33333333333333keywords = brain (Clic here for more details about this article) |
7/35. Multiple mtDNA deletions with features of MNGIE.Two sisters developed gastrointestinal malabsorption with pain and unsteady gait due to polyneuropathy at age 15. Both had ophthalmoplegia, neurogenic EMG, and COX-negative muscle fibers. One patient had low muscle complex I-IV activity, multiple mtDNA deletions, and depletion, but no thymidine phosphorylase (TP) or dNT-2 gene mutations. TP activity and brain MRI were normal. The condition resembles mitochondrial neurogastrointestinal encephalomyopathy, except for the absence of leukoencephalopathy, and is likely caused by a nuclear dna mutation that disrupts intergenomic signaling.- - - - - - - - - - ranking = 0.33333333333333keywords = brain (Clic here for more details about this article) |
8/35. MELAS: clinical phenotype and morphological brain abnormalities.We describe the clinical and neuropathological findings of three unrelated autopsy cases of MELAS harboring the A3243G transition in the mitochondrial dna (mtDNA). Using immunohistochemical techniques, we studied the expression of several subunits of the respiratory chain in various brain regions from the same cases. In all three cases there was a reduced immunocytochemical staining for mtDNA-encoded subunits of the respiratory chain, confirming the presence of a defective mitochondrial protein synthesis in this disease. Mitochondrial abnormalities were mostly confined to multiple areas of different size and shape, in agreement with the focal character of the brain pathology in MELAS, and were most prominent in the cerebral cortex, providing a morphological contribution to the explanation of the cognitive regression of the patients. Immunoreactivity for mtDNA-encoded subunits was reduced in the walls of many pial and intracerebral arterioles of different brain regions but there was no clear correlation between territories of affected vessels and distribution of the histological and immunohistochemical lesions. Cerebral focal lesions in MELAS might have a metabolic nature and several pathogenetic mechanisms might be involved in the genesis of stroke-like episodes when there is a local increased ATP demand.- - - - - - - - - - ranking = 2.3333333333333keywords = brain (Clic here for more details about this article) |
9/35. Brainstem auditory evoked potentials in patients with mitochondrial encephalomyopathy.Brainstem auditory evoked potentials (BAEPs) were evaluated in three patients with mitochondrial encephalomyopathy belonging to the same family. This study showed marked alterations of BAEPs in all patients: reduction of wave amplitude, poor repeatability of responses in test-retest and abnormalities in wave form and latency. The neuroradiological examinations (CT-scan, MRI) did not show significant structural brain abnormalities. Abnormal BAEPs in our patients may be related to central metabolic disorder rather than hearing loss.- - - - - - - - - - ranking = 0.33333333333333keywords = brain (Clic here for more details about this article) |
10/35. Is there a final common pathway in mitochondrial encephalomyopathies? Considerations based on an autopsy case of kearns-sayre syndrome.A case of kearns-sayre syndrome (KSS) diagnosed 18 years prior to death due to stroke and heart failure with postnatal onset was followed over 15 years and confirmed by postmortem examination. Within the brain, an old cystic infarction of the left hemisphere was found. Other features included white matter gliosis and cerebellar atrophy. Equal or similar features were observed in other conditions thought to be due to failure of mitochondrial metabolism, therefore, a common evolution of neuropathological changes must be discussed.- - - - - - - - - - ranking = 0.33333333333333keywords = brain (Clic here for more details about this article) |
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