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Biomedical subjects

L Schut

Publications and source records attributed to L Schut.

At least 19 recordsLinked to original sources
PubMed1999

Spinal cord arteriovenous fistulas involving the conus medullaris: presentation, management, and embryologic considerations.

BACKGROUND: Spinal cord arteriovenous fistulas (SCAVF) are uncommon congenital lesions that usually involve the most caudal aspects of the cord. We present three cases of SCAVF that illustrate the clinical manifestations and possible management options. The characteristic involvement of the conus medullaris and an associated tethered spinal cord in one of our patient suggests that a disorder of secondary neurulation may be involved in the formation of these arteriovenous shunt lesions. METHODS: Review of records and radiologic studies in three consecutive patients with SCAVF's treated at this institution. RESULTS: All three patients had SCAVF involving the lower lumbar spinal cord segments or the conus. One of the conus lesions was associated with tethering of the spinal cord. One small lesion (Type A) was treated surgically, whereas the two larger lesions (Type B) were treated using interventional neuroradiologic techniques. CONCLUSIONS: Both surgical and endovascular method have a role in management of these unusual spinal cord vascular malformations. The association with tethered cord suggests that the propensity for SCAVM to occur in the most caudal portions of the spinal cord may result from failure of secondary neurulation to properly develop the unique and complex vascular anatomy of the region.

Adult↗
PubMed1999

Extrarenal nephroblastic proliferation in spinal dysraphism. A report of 4 cases.

Four cases of extrarenal nephrogenic proliferation in the sacrococcygeal region with spinal dysraphism are presented. In two of the cases, features of Wilm's or incipient Wilm's tumor were present. The previous literature on sacrococcygeal nephrogenic tissue is reviewed, and the impact of these findings on the histogenesis of extrarenal sacrococcygeal Wilm's tumor is discussed.

Choristoma↗
PubMed1998

Brain glyceraldehyde-3-phosphate dehydrogenase activity in human trinucleotide repeat disorders.

BACKGROUND: Although the abnormal gene products responsible for several hereditary neurodegenerative disorders caused by repeat CAG trinucleotides have been identified, the mechanism by which the proteins containing the expanded polyglutamine domains cause cell death is unknown. The observation that several of the mutant proteins interact in vitro with the key glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) suggests that interaction between the different gene products and GAPDH might damage brain neurons. OBJECTIVE: To measure the activity of GAPDH in postmortem brain of patients with CAG repeat disorders. PATIENTS AND METHODS: Activity of GAPDH was measured in morphologically affected and unaffected brain areas of patients with 4 different CAG repeat disorders (Huntington disease, spinocerebellar ataxia 1 [SCA1], SCA2, and SCA3-Machado-Joseph disease), in brains of patients with Friedreich ataxia (a GAA repeat disorder) and Alzheimer disease, and in brains of matched control subjects. RESULTS: Brain GAPDH activity was normal in all groups with the exception of a slight but statistically significant region-specific reduction in the patients with Huntington disease (caudate nucleus, -12%) and Alzheimer disease (temporal cortex, -19%). CONCLUSION: The presence of the polyglutamine-containing proteins in CAG repeat disorders does not result in substantial irreversible inactivation or in increased activity of GAPDH in human brain.

Adolescent↗
PubMed1998

Visual impairment associated with mutism after posterior fossa surgery in children.

OBJECTIVE: To report four children with visual impairment associated with mutism after posterior fossa surgery. Mutism after posterior fossa surgery is a well-described phenomena, but to our knowledge, visual impairment has not been reported in association with it. METHODS: Record review of four children (age range, 3-7 yr) who underwent posterior fossa surgery (via suboccipital craniotomies) for removal of a medulloblastoma (three patients) or ependymoma (one patient). Each presented with headache, ataxia, or nausea and vomiting, but none had preoperative visual complaints other than diplopia. Postoperatively, all patients were mute, and because of apparent visual loss, neuro-ophthalmic consultation was requested. Postoperative scans and examinations were also reviewed. RESULTS: Each child was awake but appeared withdrawn without verbal output. No child blinked to threat or fixed or followed. In each case, pupillary reactivity was normal, and funduscopic examinations revealed only papilledema. One child reached for money. Within weeks or months postoperatively, the mutism spontaneously resolved, and visual behavior in general improved, roughly in parallel. During the follow-up period, papilledema resolved and the disc color was normal in each case. Magnetic resonance images obtained postoperatively revealed nothing remarkable, except surgical defects, without lesions in the retrogeniculate pathway. CONCLUSION: Impaired visual behavior, mimicking cortical visual loss, may be associated with mutism after posterior fossa surgery in children. The prognosis for recovery is excellent and parallels the return of normal speech. The mechanism is unclear.

Brain Neoplasms↗
PubMed1998

Spontaneous thrombosis of a basilar artery traumatic aneurysm in a child.

Traumatic aneurysms are rare and occur most commonly in young adults; however, the relative frequency in the pediatric population is high, owing to the low prevalence of congenital saccular aneurysms in children. Traumatic aneurysms typically involve the anterior circulation, and spontaneous thrombosis is uncommon; hence, surgery is usually necessary. We present a case of a posttraumatic aneurysm in a child that occurred after a fall from a large height and that spontaneously thrombosed.

Accidental Falls↗
PubMed1998

Imaging studies in a unique familial dysmyelinating disorder.

We report the imaging findings in five patients with a unique dysmyelinating disorder. MR studies of these infants showed obstructive hydrocephalus caused by mass effect produced by an enlarged cerebellum. The white matter of an enlarged cerebrum and cerebellum showed delayed myelination. Proton spectroscopy showed normal N-acetylaspartate (NAA) levels. While the dysmyelinating disorder was clearly differentiated from Canavan disease by an absence of elevated NAA and differing histopathologic findings and autosomal-dominant inheritance pattern, there were similarities to this disease in the presentation and, to some extent, in the initial imaging findings.

Adolescent↗
PubMed1998

[Chiari malformations and hydrosyringomyelia].

INTRODUCTION: The association of hindbrain herniation, better known as Chiari malformation, and cystic cavitation of the spinal cord or hydrosyringomyelia has been well described in the literature although there is little consensus regarding its etiology, pathophysiology or optimal treatment. DEVELOPMENT: Despite a well-accepted and utilized classification system of both Chiari malformation and hydrosyringomyelia, there remains considerable disagreement regarding the proper management of these patients. CONCLUSIONS: This article reviews several popular theories on the etiology and pathophysiology of this disorder, briefly discusses the clinical features and radiologic findings associated with Chiari malformation and hydrosyringomyelia, and reviews basic surgical techniques for decompression of the cranial-cervical junction and treatment of the hydrosyringomyelia.

Arnold-Chiari Malformation↗
PubMed1997

International Cooperative Ataxia Rating Scale for pharmacological assessment of the cerebellar syndrome. The Ataxia Neuropharmacology Committee of the World Federation of Neurology.

Despite the involvement of cerebellar ataxia in a large variety of conditions and its frequent association with other neurological symptoms, the quantification of the specific core of the cerebellar syndrome is possible and useful in Neurology. Recent studies have shown that cerebellar ataxia might be sensitive to various types of pharmacological agents, but the scales used for assessment were all different. With the long-term goal of double-blind controlled trials-multicentric and international-an ad hoc Committee of the World Federation of Neurology has worked to propose a one-hundred-point semi-quantitative International Cooperative Ataxia Rating Scale (ICARS). The scale proposed involves a compartimentalized quantification of postural and stance disorders, limb ataxia, dysarthria and oculomotor disorders, in order that a subscore concerning these symptoms may be separately studied. The weight of each symptomatologic compartment has been carefully designed. The members of the Committee agreed upon precise definitions of the tests, to minimize interobserver variations. The validation of this scale is in progress.

Cerebellar Ataxia↗
PubMed1997

Progressive congenital kyphosis: report of five cases and review of the literature.

For over 60 years congenital kyphotic deformities of the spine have been categorized into two distinct groups, depending on the developmental defect. Those arising from a failure of formation of the vertebral bodies were classified as type 1, while those arising from a failure of segmentation were referred to as type 2. Recognition of the progressive and unstable nature of the type 1 defects alerted physicians to the need for early operative stabilization through decompression and stabilization through instrumentation. As the embryogenesis of the spinal column was further investigated, and as diagnostic imaging methods of the spine improved, unstable congenital kyphoses were further subdivided. Progressive congenital kyphotic deformities now may accompany a host of vertebral column developmental defects as well as genetically mediated mesenchymal tissue defect syndromes. This paper presents 5 patients from The Children's Hospital of Philadelphia with progressive and symptomatic congenital kyphotic deformities of the spine. Two of these lesions resulted from defects of formation of the vertebral bodies, while one resulted from segmental spinal dysgenesis, maldevelopment of both the anterior and posterior vertebral elements. One patient's kyphotic deformity was a result of caudal regression syndrome, and the final case presented experienced a high thoracic kyphosis from a syndrome associated diffuse midline mesenchymal tissue abnormalities known as cerebrocostomandibular syndrome. All patients showed evidence of progressive cord compression and required neural element decompression, fusion, and instrumentation. The cases are discussed individually, and the developmental and clinical aspects of each are explored.

Bone Transplantation↗
PubMed1996

Somatic mosaicism in the central nervous system in spinocerebellar ataxia type 1 and Machado-Joseph disease.

Spinocerebellar ataxia type 1 and Machado-Joseph disease are two autosomal dominant cerebellar ataxias caused by expansions of unstable CAG repeats in the coding region of the causative genes. The selectivity of cell death and the resulting characteristic neuropathological features in each of these diseases are not explained by the gene expression patterns. Since the repeat size correlates with age at onset and severity of these diseases, somatic mosaicism, the result of mitotic instability of the CAG repeat, could be the basis for specificity of neurodegeneration; brain structures with larger expanded repeats would be more severely affected. To study the association between neuropathological changes and somatic mosaicism of the CAG repeat size in the central nervous system of patients with these two ataxias, we determined the size of the (CAG)n expansion in 20 different regions of the brain, brainstem, cerebellum, and spinal cord from 3 patients with spinocerebellar ataxia type 1 and 3 with Machado-Joseph disease; these regions were selected for their differential neuropathological involvement in the two disorders. We observed a considerable homogeneity of repeat size ranges in all but 1 of the 20 regions examined: The cerebellar cortex showed slightly smaller (CAG)n tracts in all specimens from both groups of patients. Our results suggest that the pattern of repeat size mosaicism, similar in spinocerebellar ataxia type 1 and Machado-Joseph disease, reflects the developmental pathways and cell composition of different central nervous system regions and is not the cause of selective cell death in these disorders.

Age of Onset↗
PubMed1996

Immunoreactive levels of alpha-ketoglutarate dehydrogenase subunits in Friedreich's ataxia and spinocerebellar ataxia type 1.

Enzyme activities of a alpha-ketoglutarate dehydrogenase complex (alpha KGDHC) and one of its constituent subunits, dihydrolipoamide dehydrogenase (E3), are reported to be reduced in non-CNS tissues of some patients with Friedreich's ataxia (FA); however, the results are highly conflicting. To determine whether an enzyme abnormality occurs in brain, we measured immunoreactive levels of the three alpha KGDHC subunits, namely, alpha-ketoglutarate dehydrogenase (E1), dihydrolipoamide succinyltransferase (E2) and E3 in postmortem frontal, occipital and cerebellar cortices of 18 control subjects, 9 patients with FA and, for comparison, 12 patients with spinocerebellar ataxia type 1 (SCA1). Decreased (-20 to -31%) levels of E3 were observed in all three examined areas of the patients with FA with the changes statistically significant in cerebellar and frontal cortices. The E3 reduction could be explained by a loss of alpha KGDHC or other dehydrogenase complexes (e.g. pyruvate dehydrogenase complex) which utilize this subunit. In SCA1, enzyme changes were limited to E2 in cerebellar (-26%) and frontal (-19%) cortices. Although the E3 and E2 reductions are only slight, and may represent secondary events, the changes in this key Krebs cycle enzyme could exacerbate degenerative processes in both of the spinocerebellar ataxia disorders.

Acyltransferases↗
PubMed1995

Structural and immunocytochemical features of olivopontocerebellar atrophy caused by the spinocerebellar ataxia type 1 (SCA-1) mutation define a unique phenotype.

Neuropathological investigations performed on autopsied brain and spinal cords from 11 patients showed that spinocerebellar ataxia type 1 (SCA-1) can be distinguished from autosomal dominant spinocerebellar ataxia linked to SCA-2 and -3 loci on chromosomes 12 and 14, spinopontine, and the multisystem atrophies. The major diagnostic criteria were: absence of significant pars compacta nigral and locus coeruleus lesions, severe degeneration of olivocerebellar and dentatorubral pathways, extensive loss of Purkinje cells with partial sparing of flocculonodular lobes, severe atrophy of specific cranial nerve nuclei, mostly the third and 12th, extensive loss of motor neurons in anterior horns and Clarke's columns, and lack of oligodendroglial or neuronal cytoplasmic cytoskeletal inclusions. None of the brains displayed any significant immunoreactivity for the amyloid precursor protein or beta-amyloid peptide throughout the cortex. In conclusion, the type and neuroanatomical distribution of structural lesions were similarly reproduced in all probands at the end stage of SCA-1, to the point that they appeared to constitute a unique phenotype.

Adolescent↗
PubMed1994

Subependymal giant cell astrocytomas in children.

Between 1977 and 1991, at the Children's Hospital of Philadelphia, 10 patients, 5-16 years of age, were diagnosed as having subependymal giant cell astrocytomas. These patients accounted for 1.4% of all pediatric brain tumors seen during that time interval. One patient received a course of radiation therapy, which was ineffective in preventing tumor growth. All underwent surgical resections with the goal being maximal tumor debulking, if not complete resection. In 6 patients this was accomplished by the frontal transventricular route and, in the more recent patients, surgery was performed using a transcallosal approach. There were 2 perioperative deaths, and 2 other patients died later of causes unrelated to tumor progression. The remaining 6 patients remain alive and stable at a mean of 6.7 years of follow-up (range 1.8-12.4). None of these patients has received additional radiation therapy. Two patients have no other evidence of tuberous sclerosis. The use of modern radiographic and surgical techniques has made the treatment of this disease safer than in the past.

Adolescent↗
PubMed1994

Neuropsychological test performance in patients with dominantly inherited spinocerebellar ataxia: relationship to ataxia severity.

To determine whether the cognitive status of patients with dominantly inherited spinocerebellar ataxia (DSCA) might be related to neurologic severity, we administered a comprehensive neuropsychological test battery to 43 patients with DSCA, ranging in ataxia severity from mild to end-stage. As compared with the controls, the mildly ataxic patients scored normally or close to normal as a group on all of the neuropsychological tests. In contrast, approximately one-half of the moderately and all of the severely ataxic patients showed poor performance, independent of age, Hamilton Rating Scale for Depression score, or education, on the Wisconsin Card Sorting Test, suggesting impaired executive system function. In addition, a subgroup of these patients had a neuropsychological profile suggestive of mild generalized cognitive impairment. We conclude that DSCA is not a homogeneous group of disorders with respect to cognitive status and that the neurologic severity of the disorder is a major factor. Impaired executive system function could be explained by damage to olivopontocerebellar system control over cerebral cortical function or to damage to other neuronal systems (especially cholinergic) that degenerate in parallel with the olivopontocerebellar system.

Adult↗