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Biomedical subjects

D Petersen

Publications and source records attributed to D Petersen.

At least 73 records · Page 4Linked to original sources
PubMed1993

Dysarthria in bilateral thalamic infarction. A case study.

A patient suffering from bilateral thalamic infarction in the region supplied by the paramedian arteries sparing the internal capsules underwent acoustic analysis of sentence utterances. The results were compared with the findings obtained in parkinsonian subjects, in patients with upper motor neuron lesions, and in normal subjects. Acoustic measurements revealed increased pitch, monotonous speech, rough voice quality, and normal speech tempo concomitant with articulatory impreciseness in terms of incomplete closure productions. This constellation resembled parkinsonian dysarthria. Damage to the thalamic projection area of the pallidal efferents, therefore, seems to be the most probable cause of the patient's speech disorders. In parkinsonian subjects stereotactical lesions of this structure ameliorate rigor, but not akinesia. Thus, our patient's speech deficits, and by analogy the corresponding parkinsonian dysarthric disturbances, may be considered akinetic signs.

Adult↗
PubMed1993

Hemodynamics in subclavian-steal syndrome: difficulties in their evaluation.

In a patient with subclavian-steal syndrome transcranial Doppler sonography detected transient retrograde basilar blood flow whereas routine angiography failed to document this condition. Thus, orthograde basilar blood flow at routine angiography does not rule out basilar steal. Presumably the forced injection of contrast media conceals less pronounced steal phenomena. Our exemplary case indicates that a subgroup of patients with vertebro-basilar symptoms concomitant with basilar flow abnormalities may benefit from invasive or semi-invasive treatment.

Angiography↗
PubMed1993

Isolated fracture of the medial cuneiform.

We report a case of a 21-year-old man who sustained an isolated fracture of the medial cuneiform in a motorcycle accident. To our knowledge, this is the first report of such an injury. We describe his treatment, which included anatomical fixation of the fracture.

Accidents, Traffic↗
PubMed1993

The reversibility of alcoholic brain damage is not due to rehydration: a CT study.

Alcoholic brain damage is reversible when the patients are continually abstinent. An increase of brain water content was the putative explanation for this phenomenon. We tested the rehydration hypothesis using CT density measurements in 29 alcohol-dependent male inpatients. During a 5-week period of controlled abstinence, CT density measures did not decrease in any of the investigated regions of the brain as one would expect with an increase in brain water. Although the volumetry of the ventricular system and the subarachnoidal spaces revealed a significant reduction of CSF volume, we found a slight increase in CT density measures. Thus, our results are in contradiction to the rehydration hypothesis. Under discussion is whether neuronal plasticity might be the explanation of the reversibility of alcoholic brain damage in abstinent patients.

Adult↗
PubMed1993

Magnetic resonance imaging in hereditary and idiopathic ataxia.

We used magnetic resonance imaging (MRI) to study brain and spinal cord morphology in hereditary and idiopathic ataxia. Our interest was in whether the classical neuropathologic categories--cerebellar cortical atrophy (CCA), olivopontocerebellar atrophy (OPCA), and spinal atrophy (SA)--could be identified in vivo and which clinical phenotype corresponded to which morphologic category. To this end, we measured the size of the cerebellar vermis, cerebellar hemispheres, fourth ventricle, middle cerebellar peduncles, basis pontis, medulla oblongata, and cervical spinal cord on T1-weighted images of 61 patients and 24 healthy controls. Five patients with Friedreich's ataxia (n = 7) and all with late-onset Friedreich's ataxia (n = 3) had SA without major involvement of the brainstem or cerebellum. Morphologic findings in patients with early-onset cerebellar ataxia with retained tendon reflexes (n = 11) were heterogeneous: six patients had MRI findings compatible with CCA, and two patients had a combination of SA and CCA. The three remaining patients had an atypical pattern of atrophy. Similarly, the morphologic changes in patients with autosomal-dominant cerebellar ataxia with additional noncerebellar symptoms (ADCA-I; n = 13) were nonuniform: atrophic changes typical for CCA, OPCA, or SA were each present in one case, four patients had a combination of OPCA and SA, and the remaining patients could not be assigned to one of the morphologic categories. In autosomal-dominant cerebellar ataxia with a pure cerebellar syndrome (ADCA-III; n = 6), all patients except one had CCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Monitoring cyclosporin A (ciclosporin, INN) concentrations in whole blood: evaluation of the EMIT assay in comparison with HPLC and RIA.

We report here on an evaluation of the enzyme-multiplied immunoassay technique (EMIT) from Syva for cyclosporin A (ciclosporin, INN) concentration measurements in whole blood. The assay incorporates a monoclonal antibody for specific determination of ciclosporin. Measurements by EMIT were performed on the Cobas Mira-S from Roche. A total of 197 blood specimens from heart-(n = 74), kidney-(n = 62) and liver-(n = 61) transplant recipients were analyzed. EMIT values correlated well with those obtained by HPLC, as well as with those obtained by a selective radioimmunoassay (INCStar). Ciclosporin concentrations determined by EMIT (y) agreed very well with those by RIA, and averaged 8% higher than those by HPLC (x) [n = 197, mean = 143 micrograms/l, y = 155 micrograms/l, y = 1.09x - 0.6, r = 0.969]. Within-series and between-days CVs ranged from 4.6% to 7.3% for ciclosporin concentrations > 100 micrograms/l, and from 5.5% to 10.5% for ciclosporin concentrations between 69.5 micrograms/l and 100 micrograms/l. The within-series CV for a concentration of 45.5 micrograms/l was 14.8%. Calibration employing a 2-point mode instead of a continuous mode of UV-signal evaluation improved the precision of the EMIT assay at low ciclosporin concentrations. Sample pretreatment required thorough and skillful performance to avoid false positive ciclosporin measurements. We conclude that the EMIT assay is specific, and rapid to perform. It can be effectively used in the monitoring of ciclosporin concentrations in whole blood.

Antibodies, Monoclonal↗
PubMed1993

Disseminated BK type polyomavirus infection in an AIDS patient associated with central nervous system disease.

A 27-year-old man with hemophilia type A and acquired immunodeficiency syndrome developed a subacute meningoencephalitis, associated with a normotensive internal hydrocephalus, 14 weeks before his death. From cerebrospinal fluid and brain autopsy material, a virus could be isolated and was classified by Southern blot analysis and restriction endonuclease reactions as the human polyomavirus BK. The postmortem findings of polyomavirus antigen and BK virus DNA in various cell types of the kidneys, lungs, and central nervous system strongly suggest that BK virus was the causative agent of a tubulointerstitial nephropathy, an interstitial desquamative pneumonitis, and a subacute meningoencephalitis with accentuation of the ventricular and meningeal surfaces of the brain. Besides distinctive cytopathic effects, the presence of intranuclear inclusions was a prominent histopathological feature. Therefore, the human polyomavirus BK should be regarded as a new candidate on the still growing list of opportunistic pathogens in acquired immunodeficiency syndrome.

AIDS-Related Opportunistic Infections↗
PubMed1992

MR imaging of experimental meningeal melanomatosis in nude rats.

MR imaging of the rat brain has become an increasingly frequently used method in experimental neuroradiology. On a generally available 1.5 T whole body tomograph, supplemented with an individually made small coil and a special SE sequence we obtained fairly fine images of the structures of the rat brain. With gadolinium-DTPA, we were able to visualize posterior fossa and cervical leptomeningeal growth of intrathecally injected B16 melanoma in nude rats. Using MRI to follow experimental leptomeningeal metastasis, may provide a new means for diagnostic evaluation and preclinical testing of treatment modalities.

Animals↗
PubMed1992

Speech deficits in ischaemic cerebellar lesions.

Twelve patients with cerebellar infarction, 8 in the region supplied by the posterior inferior cerebellar artery (PICA) and 4 in the territory of the superior cerebellar artery, underwent formal perceptual examination for speech deficits. With respect to topography the results firstly underline the significance of the paravermal region of the superior cerebellar portion for speech functions. In all patients with dysarthric impairment the lesion extended to this area, whereas patients with PICA infarction sparing the superior portion of the cerebellum showed no speech deficits. Secondly the findings do not corroborate the notion of an exclusively left-sided cerebellar speech motor control, since 3 of the 4 dysarthric subjects had unilateral right-sided ischaemia. This study thirdly demonstrates that lesions of the cerebellar cortex without involvement of the dentate nucleus can cause dysarthric impairment. Phonetic analysis revealed irregularly distributed articulatory deficits and slowed speech tempo as the most common dysarthric features.

Adult↗
PubMed1992

[The detailed imaging of vessels in MR angiography via projections from irregularly restricted data sets].

A new method for postprocessing of three dimensional magnetic resonance angiography data sets is described. Two operations are performed with the data set prior to maximum intensity projection. First, an irregular part of interest is marked interactively within the data set. By restricting the projection algorithm to this region, a disturbing overlay by vessels of other regions is avoided. Secondly, a three dimensional interpolation of the original data set is performed. While the spatial resolution of vessel representation is unchanged, the quality of the maximum intensity projection is improved significantly. The diagnostic value of this method is demonstrated by visualisation of a carotid aneurysm and of the deep and superficial cerebral veins.

Algorithms↗
PubMed1992

[Narrowing of the palpebral fissure as the first symptom of extensive osteoma with orbital involvement].

Unilateral narrowing of palpebral fissure and moderately impaired visual acuity induced a 14 years old woman to consult an ophthalmologist. Neuroradiological examination revealed a large osteoma starting from the ethmoid cells and invading both the orbit and the cranial cavity. This case illustrates that proptosis may be absent even in cases of extensive and compact orbital tumors. Therefore, exophthalmos is a common but not an indispensable sign of an orbital tumor. In Gardner's syndrome osteomas are associated with soft tissue tumors, intestinal polyposis and colonic adenomatosis that ultimately progresses to colorectal cancer. This association is frequent enough that a colon examination should be suggested to all patients with osteoma.

Adolescent↗
PubMed1992

Bilateral spastic cerebral palsy--pathogenetic aspects from MRI.

Thirty eight children with bilateral spastic cerebral palsy underwent MRI at the age of 5 years and more. Twenty nine showed correlates of periventricular leucomalacia, which were found especially in preterms (20 out of 21) but also in 9 of 15 fullterms without birth asphyxia. These findings suggest compromising events in the peri- and neonatal period especially in preterms and prenatal 3rd trimenon compromise in most of the fullterms without birth asphyxia.

Adolescent↗
PubMed1992

Very-late-onset adrenoleukodystrophy: possible precipitation of demyelination by cerebral contusion.

We report the clinical history, neuroradiology, and autopsy findings in a patient with very late onset, at age 57, of adrenoleukodystrophy (ALD) presenting with dementia, hemianopia, and gait apraxia. Open brain biopsy, elevated plasma very-long-chain fatty acids, and autopsy confirmed the diagnosis of ALD. Demyelinative lesions were most extensive at the site of a recent cerebral contusion. CNS trauma may have precipitated or accelerated demyelination in this patient carrying the ALD gene.

Adrenoleukodystrophy↗
PubMed1992

[Compensation in leg length inequality with orthopedic shoe measures].

There are three different methods of compensating for differences in leg length. The first is the construction of special shoes, which is adequate for differences of up to about 3 cm. The heels can be either higher or lower, or a cork sole 5-10 mm thick can be incorporated, the shaft made higher, and supplementary features, such as aids to push-off, can also be implemented. The second method is the wearing of the classic orthopedic boot or shoe, in which the necessary compensation for the shorter leg is incorporated as a part of the orthopedic footwear. The third method is the construction of a shoe within a shoe, for which different designs have crystallized out for the five groups presented. All designs incorporate leather, the tried and tested material, next to the skin. Stabilizing components are made of fiberglass-reinforced synthetic resin or Thermoplast. New materials allow aesthetically acceptable orthopedic footwear. On average, such shoes are 25% lighter than conventional orthopedic boots. The stability and wear-resistance allow large perforations and open-toe designs, which has made it possible to solve the problem of ventilation.

Artificial Limbs↗