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D Horoupian

Publications and source records attributed to D Horoupian.

At least 19 recordsLinked to original sources
PubMed2005

Relationship of primary mitochondrial respiratory chain dysfunction to fiber type abnormalities in skeletal muscle.

Variation in the size and relative proportion of type 1 and type 2 muscle fibers can occur in a number of conditions, including structural myopathies, neuropathies, and various syndromes. In most cases, the pathogenesis of such fiber type changes is unknown and the etiology is heterogeneous. Skeletal muscle mitochondrial respiratory chain analysis was performed in 10 children aged 3 weeks to 5 years with abnormalities in muscle fiber type, size, and proportion. Five children were classified as having definite, four as probable, and one as possible mitochondrial disease. Type 1 fiber predominance was the most common histological finding (six of 10). On light microscopy, four cases had subtle concomitants of a mitochondriopathy, including mildly increased glycogen, lipid, and/or succinate dehydrogenase staining, and one case had more prominent evidence of underlying mitochondrial disease with marked subsarcolemmal staining. Most cases (nine of 10) had abnormal mitochondrial morphology on electron microscopy. All were found to have mitochondrial electron transport chain (ETC) abnormalities and met diagnostic criteria for mitochondrial disease. We did not ascertain any patients who had isolated fiber type abnormalities and normal respiratory chain analysis during the period of study. We conclude that mitochondrial ETC disorders may represent an etiology of at least a subset of muscle fiber type abnormalities. To establish an etiologic diagnosis and to determine the frequency of such changes in mitochondrial disease, we suggest analysis of ETC function in individuals with fiber type changes in skeletal muscle, even in the absence of light histological features suggestive of mitochondrial disorders.

Child, Preschool↗
PubMed2002

Office of Rare Diseases neuropathologic criteria for corticobasal degeneration.

A working group supported by the Office of Rare Diseases of the National Institutes of Health formulated neuropathologic criteria for corticobasal degeneration (CBD) that were subsequently validated by an independent group of neuropathologists. The criteria do not require a specific clinical phenotype, since CBD can have diverse clinical presentations, such as progressive asymmetrical rigidity and apraxia, progressive aphasia, or frontal lobe dementia. Cortical atrophy, ballooned neurons, and degeneration of the substantia nigra have been emphasized in previous descriptions and are present in CBD, but the present criteria emphasize tau-immunoreactive lesions in neurons, glia, and cell processes in the neuropathologic diagnosis of CBD. The minimal pathologic features for CBD are cortical and striatal tau-positive neuronal and glial lesions, especially astrocytic plaques and thread-like lesions in both white matter and gray matter, along with neuronal loss in focal cortical regions and in the substantia nigra. The methods required to make this diagnosis include histologic stains to assess neuronal loss, spongiosis and ballooned neurons, and a method to detect tau-positive neuronal and glial lesions. Use of either the Gallyas silver staining method or immunostains with sensitive tau antibodies is acceptable. In cases where ballooned neurons are sparse or difficult to detect, immunostaining for phospho-neurofilament or alpha-B-crystallin may prove helpful. Methods to assess Alzheimer-type pathology and Lewy body pathology are necessary to rule out other causes of dementia and Parkinsonism. Using these criteria provides good differentiation of CBD from other tauopathies, except frontotemporal dementia and Parkinsonism linked to chromosome 17, where additional clinical or molecular genetic information is required to make an accurate diagnosis.

Atrophy↗
PubMed1996

MELAS: Clinical and pathologic correlations with MRI, xenon/CT, and MR spectroscopy.

We describe the clinical, imaging, and pathologic findings in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). The patient experienced her first stroke-like episode at age forty-four. Brain MRI, obtained at symptom onset, at 3 weeks, and at 1 year, revealed migrating T2-weighted hyperintensities in the temporal/parietal and occipital cortices and later revealed atrophy. Abnormal cerebrovascular reserve was evident on xenon/CT four days after the first MRI. MR spectroscopy at 1 year revealed increased lactate in both the occipital and temporal lobes. Histologic sections demonstrated spongy degeneration of the cortex that was most prominent at the crests of the gyri. Electron microscopy of the blood vessels showed increased numbers of abnormal mitochondria within the vascular smooth muscle and in endothelial cells. We hypothesize that the stroke-like episodes in MELAS may be due to impaired autoregulation secondary to the impaired metabolic activity of mitochondria in the endothelial and smooth muscle cells of blood vessels.

Adult↗
PubMed1988

Pediatric acquired immunodeficiency syndrome. Neurologic syndromes.

Central nervous system (CNS) dysfunction was documented in 61 of 68 infants and children with symptomatic human immunodeficiency virus infection. The most frequent manifestations included acquired microcephaly, cognitive deficits, and bilateral pyramidal tract signs. Lymphoma of the CNS, cerebrovascular accidents, and CNS infection caused by conventional pathogens were documented in only ten children (15%). Neurologic deterioration in 11 children was subacute but steadily progressive; in 31 the course was more indolent and began with a plateau. Of these 31 children, 13 had further neurologic deterioration and the conditions of three improved. Seventeen children had a static course with cognitive deficits (seven children) or cognitive plus neurologic impairment (ten children). Neuroradiologic studies in the children with a subacute progressive or plateau course disclosed cerebral atrophy, white matter abnormalities, and calcification of the basal ganglia. Postmortem findings included variable degrees of inflammatory response, multinucleated cells, calcific vasculopathy, and pyramidal tract degeneration. Computed tomographic studies of the children with a static course were normal or showed mild atrophy, but poor brain growth was documented by serial head circumference measurements.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Progressive multifocal leukoencephalopathy of the posterior fossa in an AIDS patient: clinical, radiographic and evoked potential findings.

A 39-year-old intravenous drug user presented with dysarthria and a syndrome of the left cerebellar hemisphere. While in hospital, he developed progressive brainstem findings. Repeated CT scans revealed a lucency in the white matter of the left cerebellar hemisphere. Brainstem auditory and short-latency somatosensory evoked potentials provided evidence of brainstem dysfunction without corresponding lesions on CT. Biopsy of the cerebellum established the diagnosis of progressive multifocal leukoencephalopathy (PML) and the acquired immunodeficiency syndrome (AIDS). Postmortem examination revealed brainstem lesions appropriate to the evoked potential findings and a radiographically inapparent lesion in the right internal capsule. Based on this case and a review of the literature we conclude that: (1) PML occurs with significant prevalence in AIDS patients and may involve the posterior fossa; (2) the diagnosis of posterior fossa PML is suggested by certain clinical and radiographic criteria and may be confirmed by brain biopsy; (3) evoked potentials may be abnormal in PML and can reveal functional abnormalities of white matter without apparent CT abnormalities.

Acquired Immunodeficiency Syndrome↗
PubMed1986

AIDS: calcification of the basal ganglia in infants and children.

CT or postmortem examination demonstrated calcification of the basal ganglia in eight infants and children with acquired immune deficiency syndrome. Serial CT studies documented progression of both bilateral symmetric calcium densities and cerebral atrophy. Clinical features included progressive encephalopathy with dementia, and pyramidal tract signs. Postmortem examination of four children revealed variable degrees of calcific vasopathy of the basal ganglia, involving predominantly the putamen and globus pallidus.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Neurological complications in infants and children with acquired immune deficiency syndrome.

Neurological complications occurred in 6 children, aged 6 months to 5 years, with acquired immune deficiency syndrome who were followed for 14 months. The most frequent manifestations included encephalopathies, acquired microcephaly, and pyramidal tract signs. Computed tomographic examinations showed variable degrees of cortical atrophy with ventricular dilatation and calcification. Electrophysiological abnormalities were demonstrated. Two children had documented central nervous system infections. Neurological deterioration resulted in dementia in 3 children. Cognitive impairment and developmental delays were evident in the other 3. Postmortem examination of the 3 children who died showed subacute cytomegalovirus encephalitis in 1; nonspecific hemispheric white matter changes, calcific vasopathy of the basal ganglia, and striking bilateral corticospinal tract degeneration in the second; and extensive calcific vasopathy of the basal ganglia and frontal centrum semiovale, and bilateral attenuation of the frontopontine and corticospinal tracts in the third.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Deafness in Cockayne's syndrome: morphological, morphometric, and quantitative study of the auditory pathway.

The auditory pathway of a 17-year-old deaf patient with Cockayne's syndrome was examined histologically. The cochlea showed marked atrophy of the spiral ganglion and attenuation of the cochlear division of the eighth cranial nerve. By means of the Computer Image Analyzer, the total number of neurons in the ventral cochlear nucleus was found to be reduced from 30,440 to 18,821. The mean diameter of the neurons in the ventral cochlear nucleus, medial dorsal olivary nucleus, and inferior colliculus was smaller than in a control patient, whereas in the medial geniculate nucleus and anterior transverse gyrus of Heschl, the neuronal size approximated the norm. The changes in the first three auditory relay nuclei were considered to represent transsynaptic atrophy caused by degeneration of the spiral ganglion and, possibly, the cochlear neuroepithelium. This histological report verifies that deafness in Cockayne's syndrome is largely sensorineural and that degeneration of spiral ganglion in humans can lead to a chain of trans-synaptic degeneration in the ventral cochlear nucleus, medial dorsal olivary nucleus, and inferior colliculus.

Adolescent↗
PubMed1983

Xanthogranuloma of the dura in systemic Weber-Christian disease.

A 51-year-old woman who had systemic Weber-Christian disease (WCD) displayed multiple xanthomatous lesions and a large xanthogranuloma of the tentorium cerebelli with signs of brainstem and cerebellar compression. Three other cases of dural xanthomatous lesions associated with systemic WCD have been reported. These dural and leptomeningeal xanthomatous lesions in WCD, a nonsuppurative inflammatory condition, are similar to those of Hand-Schüller-Christian disease, a quasi-neoplastic process.

Dura Mater↗
PubMed1977

Syndrome of normal pressure hydrocephalus: possible relation to hypertensive and arteriosclerotic vasculopathy.

A patient with clinical features of idiopathic normal pressure hydrocephalus, who responded dramatically to shunting, was found a necropsy to have a severe hypertensive and arteriosclerotic vasculopathy with multiple lacunar infarcts. There was no pathological evidence of thickened leptomeninges, fibrosis of the arachnoid villi, or Alzheimer's disease. An abnormal absorption mechanism was demonstrated with cisternography and by an increase in the concentration of homovanillic acid in the cerebrospinal fluid. It is suggested that vascular changes may play an important role in the pathophysiology in some cases of normal pressure hydrocephalus.

Aged↗