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Biomedical subjects

E van Royen

Publications and source records attributed to E van Royen.

8 recordsLinked to original sources
PubMed2000

The development of hemispheric asymmetry in human motion VEPs.

In six healthy adults we examined the sources underlying P1 and N2 of the motion VEP. For this purpose was acquired, in addition to the VEP, MRI images and patterns of regional cerebral blood flow with SPECT for three of the subjects. With the same motion stimulus we also examined the spatial distribution of N2 in children. In both adults and children left and right half-field responses were compared. It was found that N2 is generated by extrastriate activity and that motion stimuli are not equivalently processed in the two cerebral hemispheres. In adults, N2 dominates in one hemisphere irrespective of the visual half-field used for stimulation whereas children show an ipsilateral maximum for N2 upon half-field presentation.

Adolescent↗
PubMed2000

Accurate differentiation of parkinsonism and essential tremor using visual assessment of [123I]-FP-CIT SPECT imaging: the [123I]-FP-CIT study group.

OBJECTIVE: To evaluate whether visual assessment of [123I]-FP-CIT (DaTSCAN, Nycomed Amersham, plc) single photon emission computerized tomography (SPECT) images can differentiate between parkinsonism and essential tremor (ET). METHODS: [123I]-FP-CIT SPECT imaging was conducted in a six-center study of 158 patients with a clinical diagnosis of parkinsonism compared with 27 ET cases and 35 healthy volunteers. Striatal uptake of the radioligand was graded normal or abnormal, and abnormal images were further graded to three levels of severity. An institutional read whereby each center visually assessed the images blinded to the clinical data and a consensus blinded read by a panel of five was undertaken. RESULTS: The institutional reading scored 154 of 158 cases of parkinsonism abnormal, all 27 cases of ET as normal, and 34 of 35 healthy volunteers as normal compared with the consensus blinded read scoring 150 cases of parkinsonism as abnormal, 25 ET cases as normal, and 33 healthy volunteers as normal. Sensitivity for the clinical diagnosis of parkinsonism was 97% and specificity for ET was 100% for the institutional read, whereas sensitivity was 95% and specificity 93% for the consensus blinded read. Semiquantitative analysis of specific: nonspecific caudate and putamen uptake were consistent with the results of visual inspection. CONCLUSION: Visual assessment of [123I]-FP-CIT SPECT images is an easily applied diagnostic test which is helpful in the differential diagnosis of tremor disorders and in confirming a clinical diagnosis of a hypokinetic-rigid syndrome.

Adult↗
PubMed1998

D2 receptor imaging with iodine-123-iodobenzamide brain SPECT in infants with hypoxic-ischemic brain injury.

UNLABELLED: The purpose of this study was to evaluate the striatal dopamine D2 receptor density in infants with perinatal hypoxic-ischemic brain injury (HIBI) using 123I-iodobenzamide (IBZM) brain SPECT and to correlate the findings with the severity of HIBI and neurologic outcome. METHODS: Twenty infants who were diagnosed to have perinatal HIBI were included in this study. They were classified as having mild (n = 6), moderate (n = 10) or severe (n = 4) HIBI according to their neurologic findings at birth using the criteria of Sarnat and Sarnat. Neurologic outcome of these infants was determined by serial neurologic examinations and the Denver developmental screening test; 10 infants recovered without any deficit and the remaining 10 were affected to a degree varying from motor impairment to cerebral palsy. All 20 infants were examined using 123I-IBZM brain SPECT at age 7.8 +/- 2.3 mo. Transaxial slices were obtained 2 hr after intravenous injection of 300 micro ci (11.1 MBq) 123I-IBZM and the activity ratios of striatal to occipital cortex (ST/OC) were calculated. RESULTS: The mean ST/OC ratios in patients with mild, moderate and severe HIBI (1.219 +/- 0.078, 1.097 +/- 0.069 and 0.813 +/- 0.140, respectively) were significantly different from each other (p = 0.001). The infants who recovered from HIBI without any neurologic sequelae had higher mean ST/OC ratios than the others (1.184 +/- 0.010 versus 0.969 +/- 0.160, p = 0.002). CONCLUSION: The results of this study show that in infants with HIBI, striatal D2 receptor density decreases as the severity of injury increases. The D2 receptor density is higher in infants who recover without neurologic deficits compared to those who are affected neurologically. Dopamine D2 receptor imaging can be used to assess the severity of HIBI in children.

Benzamides↗
PubMed1993

Multiple system atrophy and progressive supranuclear palsy. Diminished striatal D2 dopamine receptor activity demonstrated by 123I-IBZM single photon emission computed tomography.

OBJECTIVE: To measure D2 dopamine receptors in the striatum in patients with multiple system atrophy and progressive supranuclear palsy by I 3-iodo-6-methoxybenzamide labeled with iodine I 123 (123I-IBZM) single photon emission computed tomography and differentiate them from control subjects. DESIGN: Survey with the following as retrospective criterion standards: (1) parkinsonism, (2) negative apomorphine test, and (3) no or only slight reaction to dopaminergic medication. SETTING: Ambulatory or hospitalized care in an academic referral center. PATIENTS AND CONTROL SUBJECTS: Twenty-one patients with parkinsonism not responding to dopaminergic medication (17 with multiple system atrophy and four with progressive supranuclear palsy) and 21 control subjects without parkinsonism. INTERVENTION: In vivo imaging by single photon emission computed tomography using the D2 dopamine receptor specific radioligand 123I-IBZM. MAIN OUTCOME MEASURE: Striatum/occipital cortex ratio of count rate density as semiquantitative measurement for striatal D2 dopamine receptor density. RESULTS: A highly significant loss of striatal uptake of 123I-IBZM was observed in the patients in comparison to the control subjects with little or no overlap between values. CONCLUSIONS: The hypothesized loss of D2 receptors in multiple system atrophy has been confirmed. Use of 123I-IBZM single photon emission computed tomography may be a cost-effective alternative to positron emission tomography in the differential diagnosis of parkinsonism and in the selection of patients for dopaminergic therapy.

Adult↗
PubMed1990

Early Indium-111 antimyosin scintigraphy for assessment of regional wall motion asynergy on discharge after myocardial infarction.

To assess the relation between early Indium-111 monoclonal antimyosin antibody scintigraphy and degree of regional asynergy on discharge, 38 patients with a first acute myocardial infarct were studied (18 anterior, 20 inferoposterior infarctions). In 21 patients thrombolytic therapy was administered. On the first day of myocardial infarction, 80 MBq Indium-111 Antimyosin was injected. Planar images, anterior, lateral and left anterior oblique, were made 24 hours later. Localized myocardial uptake was present in 37/38 patients, and was evaluated for Count Density Index (count density of infarct zone/left lung count density) in the left anterior oblique images, which displayed the infarct zone well. Regional asynergy on discharge was evaluated by cross-sectional echocardiography and defined mild (hypokinesia) or severe (akinesia or dyskinesia). Count density index was significantly lower in 15 patients with mild asynergy, compared with 22 patients with severe asynergy (1.61 +/- 0.25 vs. 2.42 +/- 0.40, p less than 0.001). This difference was present in both patient groups treated with or without thrombolysis. We conclude that early count density index, reflecting the amount of local necrosis, is highly correlated to the ultimate degree of wall motion impairment.

Antibodies, Monoclonal↗
PubMed1989

Predictive value of indium-111 antimyosin uptake for improvement of left ventricular wall motion after thrombolysis in acute myocardial infarction.

In 21 patients treated with thrombolysis for acute myocardial infarction (AMI), the degree of myocardial uptake of indium-111 monoclonal antimyosin antibodies injected within 24 hours after onset of AMI was compared with the degree and extent of regional asynergy on admission and discharge, as assessed by 2-dimensional echocardiography. On the first day of AMI, 80 MBq of indium-111 antimyosin was injected and planar images were made 24 hours later. Indium-111 antimyosin uptake was evaluated for count density index (count density of infarct zone/left lung count density) in the left anterior oblique projection, in which the infarction zone was well displayed in all patients. Using 2-dimensional echocardiography, the left ventricle was divided into 13 segments and evaluated for regional asynergy, which was considered severe (akinesia or dyskinesia) or mild (hypokinesia). The extent of regional asynergy was measured by the number of asynergic segments. All 21 patients had severe regional asynergy on admission. Nine of 21 showed only mild regional asynergy on discharge and 12 of 21 had persistent severe regional asynergy in at least 1 segment. The count density index was significantly lower in patients with mild regional asynergy on discharge compared with patients with severe regional asynergy (1.63 +/- 0.27 vs 2.50 +/- 0.42, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Radionuclides in detecting active granuloma formation. Gallium-67 scintigraphy and histopathology with autoradiographic findings.

Granuloma formation studies were performed on lungs of guinea pigs sensitized with FCA over 2 to 17 months. Prolonged time of sensitization revealed more granulomatous pulmonary tissue. An intravenous booster of FCA in the animals that had been sensitized for 3 months yielded enhanced granuloma formation within 5 days. The histopathology of these lungs was comparable with that seen in lungs of animals after 17 months of sensitization without booster. Enhanced local proliferation of macrophages, measured by [3H]thymidine incorporation and autoradiography, was seen in the lungs of the animals that had received boosters. Moreover, 67Ga scintigraphy was strongly positive in these animals. Scintigraphy of cell suspensions of pulmonary tissue from these animals showed that 67Ga was predominantly taken up (quantitatively as well as qualitatively) by the alveolar macrophages. Cell suspensions of sarcoidosis patients, prepared in the same way, showed only a low level of 67Ga uptake, one comparable to that of the pulmonary cell suspensions of the sensitized animals that had not received boosters. It is suggested that a negative scintigraphy in patients with chronic pulmonary granulomatous disorders could be (partly) explained by the absence of activated macrophages.

Animals↗