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Biomedical subjects

V Engelbrecht

Publications and source records attributed to V Engelbrecht.

At least 55 records · Page 3Linked to original sources
PubMed1997

Cerebral metabolic changes in biotinidase deficiency.

Clinical and metabolic changes in the central nervous system are described in a patient with biotinidase deficiency before and after biotin treatment. Lactate, pyruvate and 3-hydroxyisovaleric acid as metabolic disease markers were measured in blood, cerebrospinal fluid and brain tissue by biochemical analyses or localized magnetic resonance proton spectroscopy. The patient improved markedly with biotin treatment. Nevertheless, neurological sequelae and abnormal intracerebral lactate concentrations persisted despite normalized metabolic disease markers in extracerebral fluids. Therefore, localized in vivo measurements of intracerebral metabolites may be a valuable tool for elucidating the pathogenesis of biotinidase deficiency.

Amidohydrolases↗
PubMed1997

Reversible brain MRI changes in acyclovir neurotoxicity.

This case report shows reversible brain MRI changes probably associated with acyclovir toxicity. So far, neuroimaging in acyclovir toxicity had been negative or uninformative. A 12-year-old girl developed focal secondary generalizing epileptic fits following 4 weeks of prophylactic administration of acyclovir (3 x 10 mg/kg body weight/day i.v.) on day +22 after allogeneic peripheral blood stem cell transplantation for CML. Infective causes were excluded. Brain MRI demonstrated multiple gadolinium-enhancing areas with impairment of the blood-brain barrier in cortical and subcortical regions. Clinical symptoms and neuroimaging pathology resolved completely within 9 days of acyclovir withdrawal.

Acyclovir↗
PubMed1997

MR and proton MR spectroscopy of the brain in hyperhomocysteinemia caused by methylenetetrahydrofolate reductase deficiency.

MR imaging showed severe atrophy and large areas without myelination in the brain of a girl with methylenetetrahydrofolate reductase deficiency. Proton MR spectroscopy revealed mild signal reduction of N-acetylaspartate. After treatment with betaine, a second MR imaging study revealed a decrease in the size of the hypomyelinated zones that was paralleled by improved clinical status and laboratory findings.

Amino Acid Metabolism, Inborn Errors↗
PubMed1996

Fast spin-echo MR imaging of the pediatric brain.

On a 1.5-T MR unit conventional spin-echo (CSE) and fast spin-echo (FSE) images were obtained in 70 consecutive children ranging from 4 days to 13 years in age. They suffered from developmental retardation, neurodegenerative, ischemic or inflammatory diseases. In our prospective study artifacts, lesion conspicuity and general impression were compared between double-echo (proton density- and T2-weighted) CSE and single-echo (T2-weighted) FSE images. Phase artifacts from flowing blood were seen rarely on the FSE images, while motion artifacts appeared more frequently. Assessment of myelination in 43 children with unfinished myelination revealed no difference between FSE and CSE. The lesion conspicuity in 20 children with focal abnormalities compared favorably between FSE and CSE. There was no diagnostically relevant difference between FSE and CSE, although in FSE spin density images were missing. FSE sequences can be used in MR imaging of the pediatric brain without disadvantage and with a time reduction of 67-75%.

Artifacts↗
PubMed1996

Neurological impairment and recovery in Wilson's disease: evidence from PET and MRI.

We studied the relationship of regional cerebral glucose consumption (rCMRGlc) and striatal dopamine D2 receptor binding as assessed with positron emission tomography (PET) with the structural abnormalities of the brain in magnetic resonance images (MR), and the degree of neurological impairment in 18 patients with Wilson's disease (WD). The rCMRGlc was determined in the basal ganglia, the thalamus, the cerebral cortex, and the cerebellar hemispheres. The severity of neurological signs, defined by semiquantitative motor impairment scores, correlated highly (r = -0.80) with the reduction of striatal rCMRGlc. Clinical scores, striatal rCMRGlc, and the degree of MRI abnormalities showed no correlation with different indices of dopamine D2 receptor binding. Sequential PET measurements in three patients during treatment with chelating agents revealed a moderate increase of striatal rCMRGlc (in two patients) and a moderate to marked increase of striatal D2 receptor binding (in three patients) in association with clinical improvement. Our data suggest that the rCMRGlc represents a sensitive and objective measure for assessing and monitoring striatal and extrastriatal involvement in WD. The lack of correlation between the dopamine D2 receptor binding and striatal rCMRGlc and structural abnormalities may be explained by the wide spectrum of clinical manifestations and different responses to treatment in WD patients.

Adult↗
PubMed1996

[Gadodiamide and gadolinium-DTPA as intravenous media in computed tomography].

PURPOSE: To evaluate the effect of intravenously applied gadolinium-based contrast medium in computed tomographic (CT) studies. MATERIAL AND METHODS: Serial dilutions of iohexol 300, Gd-DTPA and gadodiamide were scanned with CT in a phantom study using water filled tubes. For quantification of x-ray attenuation, the mean Hounsfield units (HU) were calculated from the CT scans. Five patients with contraindications against iodine contrast agents were examined with abdominal or thoracic CT before and after application of 0.2 mmol/kg body weight of a gadolinium-based contrast agent. In these patients attenuation values were obtained in ROI from unenhanced and enhanced CT scans. RESULTS: The phantom study revealed a 38.4% enhancement for Gd-DTPA and a 35.7% enhancement for gadodiamide scaled on the reference measurements with iohexol 300. Thus, 130.2 ml Gd-DTPA or 140.1 ml gadodiamide are needed to achieve the same attenuation as an i.v. injection of 50 ml iohexol 300. Consequently the corresponding dose of 1 mmol/kg body weight would exceed the manufacturer's recommended dose. In four patients with complete thoracic or abdominal CT, i.v. applied gadolinium-based contrast medium (0.2 mmol/kg) yielded no visible advantage. In these patients parenchymal enhancement did not exceed 25%. Dynamic CT of a patient with focal liver lesion revealed an arterial enhancement peak of 75%. CONCLUSION: Sufficient parenchymal enhancement in CT studies cannot be achieved with the available gadolinium-based contrast mediums. They might be helpful if only short time vascular enhancement is required.

Contraindications↗
PubMed1996

CNS complications in a girl with angioimmunoblastic lymphadenopathy with dysproteinemia (AILD).

A 13-year-old girl presented with doughy swelling of both hands, a pruritic maculopapular rash, fever, malaise, lymphadenopathy and splenomegaly. Examination of an enlarged cervical lymph node revealed typical histopathological features of AILD. Partial remission was achieved by treatment with prednisolone. During the next 4 years 3 flare-ups of the disease could be controlled by corticosteroids, one going along with an enlargement of the right tonsil, histologically proven as an AILD manifestation, the other two with generalized lymphadenopathy. At the age of 17 years, an acute reduction of visual acuity occurred in both eyes in the absence of lymphadenopathy or cutaneous manifestations. Plasma viscosity was elevated in connection with high levels of IgM and IgG. Fundoscopy revealed papilledema compatible with hyperviscosity syndrome. Plasmapheresis resulted in a slow recovery of vision when suddenly a bilateral loss of vision occurred. MRI at this time revealed a lesion within the optic chiasm and additional high-signal lesions in parietal white matter of brain. All of these regions showed enhancement after i.v. application of Gd-DTPA. Again, high-dose corticosteroids were introduced and a partial restoration of vision could be achieved. This was paralleled by an improvement of the changes on followup MRI examinations. The last examination ten months after onset of CNS complications revealed a single small hyperintense residual area positioned in left parietal white matter. Enhancement of contrast medium was absent. These cerebral and retinal complications are so far undescribed complications of AILD which occurred in a childhood case.

Adolescent↗
PubMed1996

[Magnetic resonance tomography diagnosis of neuronal migration disorders].

Twenty-one MRI examinations of the brain were performed in 19 children with neuronal migration disorders. Multiplanar oriented spin-echo sequences were on a scanner with 1.5 T. In 8 children we performed an additional turbo-inversion recovery (TIR) sequence. Results of sonography or CT from five children were compared with MRI scans. Using the actual nomenclature, we found the following migration disorders: lissencephaly (n = 6), cobblestone lissencephaly with Walker-Warburg syndrome (WWS) (n = 2), polymicrogyria and schizencephaly (n = 2), focal heterotopia (n = 5), diffuse heterotopia (n = 2) and hemimegalencephaly (n = 2). MRI was superior to CT and sonography in all children. Except for the two boys with WWS, the TIR sequence was the best to demonstrate the changes in migration disorder because of the high contrast between gray and white matter. We demonstrate the characteristic features of the different migration disorders and compare them with the existing literature.

Brain↗
PubMed1995

[Follow-up and diagnosis of recurrence of malignant head and neck tumors after radiochemotherapy. Comparison of computed tomography and magnetic resonance tomography].

339 CT and 95 MRT examinations in 210 patients were evaluated retrospectively to determine the value of CT and MRT for follow-up of head and neck tumors and for diagnosing recurrences. Semi-quantitative evaluation of tumor extent during and after radiotherapy showed advantages for MRT since changes induced by treatment, particularly oedema, produced less contrast loss in the images. CT had a sensitivity of 81% for the recognition of recurrences; this was 92% for MRT. Specificity for CT was 76% and for MRT 86%. Concerning the reliability of individual diagnostic criteria, space occupying lesions were the most valuable in CT diagnosis. For MRT, space occupying lesions and infiltration into neighbouring structures were of equal value. Because of differences in the nature of the signals, MRT proved better than CT in characterising recurrent masses and this improved the differentiation between scarring and local tumour recurrence.

Combined Modality Therapy↗
PubMed1995

[Magnetic resonance tomography and localized proton spectroscopy in 2 siblings with Canavan's disease].

We present the findings of magnetic resonance imaging (MRI) and localised 1H magnetic resonance spectroscopy (MRS) in two brothers with Canavan's disease, a rare autosomal recessive leukodystrophy. Urine specimens of one child were evaluated by MRS. All examinations were performed in the same whole body 1.5 T superconducting magnet. MRI revealed the typical pattern of leukodystrophy including a more severe demyelination in the older child. The younger brother showed additional high signal lesions in the globi pallidi on T2-weighted images. MRS of the brain had an elevated ratio of N-acetyl-aspartate (NAA)/phosphocreatin + creatin (Cr) while the ratio of Cholin/Cr was reduced. in urine spectroscopy the concentration of NAA was markedly increased. The ratio of NAA/creatin + creatinin was 880 +/- 10% mmol/mol (normal: 5-21 mmol/mol). Diagnosis of Canavan's disease was supported by gas chromatographic urine examination with an 80-100 fold elevation of NAA concentration. Hence, the diagnosis of Canavan's disease could be established by increased ratio of NAA/Cr and decreased ratio of Cho/Cr relation in brain spectroscopy and high NAA concentration in urine spectroscopy.

Aspartic Acid↗
PubMed1994

Dopamine D2 receptor binding and cerebral glucose metabolism recover after D-penicillamine-therapy in Wilson's disease.

Regional cerebral glucose metabolism (rCMRGlc) and dopamine D2 receptor binding were measured in a 31-year-old, severely affected, untreated patient with Wilson's disease of 3 years' duration using positron emission tomography and 18F-deoxyglucose and 18F-methylspiperone ([18F]MSP), respectively. There was a severe reduction of striatal and extrastriatal rCMRGlc as well as of striatal [18F]MSP accumulation rate. After 1 year of treatment with D-penicillamine, striatal and extrastriatal rCMRGlc and striatal [18F]MSP accumulation rate reached almost normal levels. It is hypothesized that recovery of motor functions due to copper trapping therapy was associated with an increase in basal ganglia activity and a re-expression or upregulation of dopamine D2 receptors.

Adult↗
PubMed1994

Hyperintense lesions of the globus pallidus on MRI in children with chronic liver disease.

UNLABELLED: In three children with chronic liver disease of different aetiology without obvious hepatic encephalopathy, bilateral and symmetrical hyperintensity of the globus pallidus in T1-weighted images was found on cranial MRI. Reversibility was shown in one child with autoimmune hepatitis after normalisation of liver function tests under immunosuppressive therapy. CONCLUSION: As central nervous system involvement in liver disease is only partially understood, brain imaging by MRI offers a potential additional tool to further elucidate the incidence and time course of previously undetected brain alterations.

Adolescent↗
PubMed1994

[Infratentorial brain tumors in childhood and adolescence--value of MRT in initial and recurrence diagnosis].

MRI is the current method of choice for the diagnosis of infratentorial tumors in children and adolescents. The present article discusses the individual tumor entities on the basis of their magnetic resonance imaging characteristics in the patient pool of 1991/1992. New magnetic resonance imaging procedures are considered for infratentorial vascular anomalies. In addition to its use in the primary diagnosis, the significance of MRI for the detection of recurrences is discussed. Problems arising after prior surgery and irradiation as well as metastasization through CSF pathways are also mentioned.

Adolescent↗
PubMed1994

[Cytomegalovirus infection of the intestinal tract. Computed tomographic findings in AIDS patients].

To check the value of computed tomography (CT) in the diagnosis of cytomegalovirus (CMV) infection of the intestine, CT findings in ten patients with coloscopically proven CMV infection were reviewed. All patients were chronically ill men with AIDS. In nine of the ten cases CT scans of the small intestine and/or colon disclosed abnormalities. The predominant alteration (9/9) was a symmetric wall thickening in the bowel segments involved (10-30 mm). The location and extent showed good agreement with the inflammatory areas seen on coloscopy. The cecum and terminal ileum were the regions most frequently affected. In seven of the nine patients with CT abnormalities CT revealed pericolonic inflammation, particularly around the cecum. Lymph nodes were increased but not enlarged. Comparison of the findings in intestinal CMV infection with those in other AIDS-related diseases suggests that CT may be to limit the differential diagnosis. Abdominal CT serves as suitable primary imaging modality for the initial evaluation of patients with AIDS and abdominal symptoms of unknown etiology.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Idiopathic ileoileal intussusception in an adult with spontaneous reduction during enteroclysis: a case report.

We report a rare case of recurring idiopathic ileoileal intussusception in an adult. Diagnosis was established with abdominal computed tomography (CT) and enteroclysis, which led to a spontaneous reduction of the invagination. After a short period of physical improvement, a follow-up CT showed a recurrence. Surgery proved the diagnosis, but no predisposing factor was found.

Adult↗
PubMedDate not supplied

Boswellic acids in the palliative therapy of children with progressive or relapsed brain tumors.

19 children and adolescents with intracranial tumors received a palliative therapy with H 15 at a maximum dose of 126 mg/kg BW/day. All patients had previously been treated with conventional therapy. No side effects were observed during a median 9 months application. The recently reported antiedematous effect of H 15 was documented by MRI in one patient with a peritumoral edema, thus sparing steroid therapy with its typical side effects. Five/19 children reported an improvement of their general health status; this might be a psychological effect of hope for tumor response during palliative care. Three/17 patients with malignant tumors showed a mainly transient improvement of neurological symptoms such as pareses and ataxia. Three further patients showed an increased muscular strength and one cachectic patient achieved a weight gain. These improvements might be attributed to the antiedematous effect of H 15. Because of the palliative situation of these patients, H 15 application was performed without prior rebiopsy for histological evaluation. Overlapping effects with a previous radiotherapy or chemotherapy may have occurred. An antiproliferative effect cannot be stated. To prevent an uncritical use of H 15, further studies with prospective central documentation have to be initiated to evaluate the clinical indications for H 15 in palliative therapy, optimal dosage and duration of application.

Adolescent↗