Somatostatin receptor scintigraphy in the staging of lymphomas

In this prospective study we evaluated the somatostatin receptor scintigraphy in the initial staging of 19 patients suffering from Hodgkin's (HD) and non-Hodgkin's lymphomas (NHL) and in the restaging of 16 patients. Scintigraphy was compared to the results of the methods applied for adequate staging of lymphoma patients in the large multicentre trials. Planar imaging and SPECT was performed after intravenous injection of 110 or 220 MBq of 111In-pentetreotide. The patient-based analysis yielded an overall sensitivity of 88%, contrasting lesion-based sensitivities of 57%, 35%, and 43% in HD, low-grade NHL and high-grade NHL, respectively. The best results were obtained in the head-and-neck region and the worst in the abdomen (sensitivities of 61% and 24%, respectively). Bone marrow infiltration was visible in 1/12 cases only. There was no significant difference between the outcomes of patients in the initial staging and restaging and no influence of the amount of injected radiopharmaceutical on the results. In terms of the Ann-Arbor classification, 10/35 patients were concordant whereas 22 were understaged and 3 overstaged scintigraphically. In conclusion, somatostatin receptor scintigraphy is not useful in the initial staging or restaging of malignant lymphomas, especially NHL, due to low lesion detection rates most probably because of low receptor densities. In addition, intraindividual heterogeneity of somatostatin receptor expression has to be considered.

Assessment of myocardial viability in persistent defects on thallium-201 SPECT after reinjection using gradient-echo MRI

This prospective study assessed myocardial viability in 30 patients with coronary heart disease and persistent defects despite reinjection on TI-201 single-photon computed tomography (SPECT). In each patient, three observers graded TI-201 uptake in 7 left ventricular wall segments. Gradient-echo magnetic resonance imaging in the region of the persistent defect generated 12 to 16 short axis views representing a cardiac cycle. A total of 120 segments were analyzed. Mean end-diastolic wall thickness and systolic wall thickening (+/-SD) was 11.5 +/- 2.7 mm and 5.8 +/- 3.9 mm in 48 segments with normal TI-201 uptake, 10.1 +/- 3.4 mm and 3.7 +/- 3.1 mm in 31 with reversible lesions, 11.3 +/- 2.8 mm and 3.3 +/- 1.9 mm in 10 with mild persistent defects, 9.2 +/- 2.9 mm and 3.2 +/- 2.2 mm in 15 with moderate persistent defects, 5.8 +/- 1.7 mm and 1.3 +/- 1.4 mm in 16 with severe persistent defects, respectively. Significant differences in mean end-diastolic wall thickness (p < 0.0005) and systolic wall thickening (p < 0.005) were found only between segments with severe persistent defects and all other groups, but not among the other groups. On follow-up in 11 patients after revascularization, 6 segments with mild-to-moderate persistent defects showed improvement in mean systolic wall thickening that was not seen in 6 other segments with severe persistent defects. These data indicate that most myocardial segments with mild and moderate persistent TI-201 defects after reinjection still contain viable tissue. Segments with severe persistent defects, however, represent predominantly nonviable myocardium without contractile function.

Quantification of the negative feedback mechanism between pituitary and thyroid in subjects with normal thyroid function

Using sufficiently sensitive and precise assays, we systematically investigated the correlation between thyrotropin, thyroglobulin, index of free thyroxine and index of free triiodothyronine after different doses of thyroxine (25, 50, 100, 150 micrograms), which were administered daily for 10 days to individuals with normal thyroid function and in a control group. Analysis of the data using relative median values expressing changes to basal values before administration of thyroxine yielded the following results: (i) thyrotropin and thyroglobulin decreased monoexponentially, depending on the doses of thyroxine administered; (ii) the extent of their decrease showed a linear correlation with the dose of thyroxine administered and was greater for thyrotropin than for thyroglobulin; (iii) the relative velocity of their decrease increased monoexponentially with the dose of thyroxine and did not differ between thyrotropin and thyroglobulin. These results provide strong evidence for a clear quantitative reaction of the feedback mechanism and confirm that the secretion of thyroglobulin is a physiological process dependent on thyrotropin. The high intra-individual variations obtained for thyrotropin were probably due to its pulsatile secretion.

[Simultaneous double nucleotide scintigraphy with indium 111 antimyosin Fab and technetium sestamibi for evaluation of myocardial viability after experimental and clinical infarct]

This study combined In-111 antimyosin Fab (AM) with Tc-99m sestamibi (MIBI) to assess myocardial viability in the subacute stage of infarction. In 9 pigs, the LAD was occluded for 45 min. Seventy-four MBq of AM were injected after 48 h of reperfusion and 740 MBq of MIBI 24 h later. In myocardial specimens, activity relative to normal myocardium (n = 35) in the region of necrosis (n = 35) was found to be 3.96 +/- 2.48 for AM and 0.30 +/- 0.20 for MIBI, in the intermediate zone of macrohistochemically reversibly damaged myocardium (n = 35) 2.79 +/- 1.29 and 0.83 +/- 0.28, respectively. Discriminant analysis classified all 105 specimens with a sensitivity of 83% and specificity of 96%. On the scans, the intermediate zone presented as overlap between both tracers. Twelve patients aged 40 to 76 years with invasively documented acute myocardial infarction (4 x anterior, 8 x inferior) were injected also with 74 MBq of AM 27 to 110 h after the onset of chest pain and with 740 MBq of MIBI 21 to 26 h later. In 8 patients, the infarct vessel was open not later than 5 h after the onset of chest pain. MIBI markedly supported reconstruction of the sections and localization of the lesions with AM on simultaneous double-nuclide single-photon emission computed tomography (SPECT). In 7 patients both tracers overlapped. Four patients showed only faint AM uptake. This demonstrates that in experimental infarction AM overestimates the region of necrosis while the combination with MIBI allows the delineation towards the intermediate zone and normal myocardium. In patients, SPECT shows similar patterns of tracer distribution. MIBI facilitates AM SPECT.

Leakage measurement during selective limb perfusion using a gamma probe

The objective of this study was to establish a probe system for intraoperative quantitative leakage measurement during selective limb perfusion for adjuvant high-dose chemotherapy in patients with malignant melanomas. We used a portable gamma probe with digital display and investigated the physical properties in a phantom study simulating blood pool activity at different angles of the probe to the surface and different distances. In 20 patients the limb circulation was surgically separated from the systemic blood circulation, and the limb was then selectively perfused (cytostatics added) for 60 min. Initially, 15 MBq technetium-99m labelled autologous red blood cells was injected into the limb circulation, and an equal amount was kept as a standard. Every 10 min, blood samples were drawn from the body circulation and count rates were simultaneously measured by the probe system at the lower end of the sternal body. At the end of perfusion, the circulation of the limb was reconnected, the standard injected into the systemic circulation, and a blood sample drawn after 10 min. All blood samples were counted for calculation of leakage in terms of percent of the injected dose, and the results compared with the intraoperative count rates of the probe system. In the range of leakage observed in this study (0%-86%), the count rate of the probe system (corrected for blood volume, i.e. for body surface) correlated with the results of conventional measurement (r=0.92) according to the equation: %leakage=counts per sx[1.2xbody surface (m2)-1.19]. In conclusion, the use of the described probe system is a feasible approach for leakage quantification which continuously yields data during selective limb perfusion.

Immunoscintigraphy for the detection of brain abscesses

The aim of this prospective study was to assess the diagnostic usefulness of a 99Tcm-anti-granulocyte antibody in the early differentiation of the aetiology of a ring-enhancing structure on computed tomography (CT) scans following neurosurgical intervention. In 26 patients (15 males, 11 females) aged 20-82 years with suspected intracranial infection, 29 SPET scans of the head were obtained 4-6 h following the intravenous injection of 555 MBq 99Tcm-anti-granulocyte antibody. The patients had antibiotic, antimycotic or corticosteroid therapy. The diagnosis was confirmed by surgery (19 cases) or subsequent CT/MRI (magnetic resonance imaging) scans and clinical follow-up (10 cases). The immunoscan was true-positive (abscess) in 6 (sensitivity = 100%), true-negative in 19 and false-positive in 4 (specificity 83%) cases. There was no obvious detrimental effect on the results due to the antibiotic, antimycotic or corticosteroid therapy. In conclusion, despite false-positive results, the 99Tcm-anti-granulocyte antibody is a useful tool in the early detection and exclusion of intracranial abscess after neurosurgical interventions.

Prophylactic application of thyrostatic drugs during excessive iodine exposure in euthyroid patients with thyroid autonomy: a randomized study

In a prospective, randomized study we examined the influence of prophylactic short-term thyrostatic therapy on thyroid iodine metabolism in patients with euthyroid autonomy undergoing elective coronary angiography. From a total of 1177 patients, 51 fulfilled the criteria of euthyroid autonomy before coronary angiography (negative thyrotropin-releasing hormone test, 10-min uptake of at least 1.2%, 99mTc and no elevation of free thyroxine and free triiodothyronine indices) and were randomized into three groups: group 1 (N = 17) received 20mg/day of thiamazole and group 2 (N = 17) received 900 mg/day of sodium perchlorate; thyrostatic therapy was begun on the day before angiography and continued for 14 days; group 3 (N = 17) served as controls without treatment. Parameters of thyroid function-free thyroxine (FT4) index and free triiodothyronine (FT3) index, thyrotropin (TSH) and delta-TSH urine iodine excretion and 99mTc uptake were determined before and 30 days after coronary angiography. At the end of the study the mean FT4 index and FT3 index were elevated significantly in the control group compared with baseline values, but were still within the normal range. In contrast, the mean FT4 index and FT3 index remained unchanged in the treated groups. Four mild cases of hyperthyroidism were observed at the end of the study: two cases in the control group and one case in each of the treated groups. Thyrotropin suppression, urine iodine excretion and 99mTc uptake differed significantly between the treated groups and the control group. In the treated groups TSH suppression, urine iodine excretion and 99mTC uptake remained unchanged 30 days after coronary angiography compared with baseline values. In the control group the degree of TSH suppression and the level of urine iodine excretion increased (about twofold) significantly after coronary angiography, whereas 99mTc uptake decreased significantly (ca. 50%). In conclusion, short-term prophylactic thyrostatic therapy seems to have a protective effect against iodine excess in patients with euthyroid autonomy. However, mild hyperthyroidism could not be prevented in some cases. Probably a combination therapy of thiamazole and perchlorate would be more effective.

[123I]IBZM SPET analysis of dopamine D2 receptor occupancy in narcoleptic patients in the course of treatment

Elevated levels of central D2 dopamine receptors were found on postmortem examination in cases of human narcolepsy. In vivo investigations using positron emission tomography (PET) and single photon emission tomography (SPET) found no changes of D2 binding in the striatal structures. To investigate whether the elevated D2 receptors in postmortem investigations are due to long-term treatment effects, we applied 123I-labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) ([123I]IBZM, a highly selective CNS D2 dopamine receptor ligand) and SPET in narcoleptic patients in the course of treatment with stimulants and/or antidepressants. Before treatment we found no changes in D2 binding in 10 patients (in comparison to 10 normal controls). After treatment (performed in five patients for 3 months) we found changes in D2 binding in four of them, indicating that the results of the postmortem studies could have been influenced by long-term medications. Human narcolepsy seems not to be related to a striatal D2 dopaminergic disturbance.

Falsely negative 99mTc-antigranulocyte immunoscintigraphy and positive 99mTc-HMPAO-labelled leukocyte scan in active Crohn's disease. Possible effects of immunosuppressive therapy?

A 19-year-old woman with active Crohn's disease under immunosuppressive therapy underwent scintigraphy with 99mTc-anti-NCA-95 antigranulocyte antibodies in order to determine the extent of inflammation. It turned out to be falsely negative whereas a 99mTc-HMPAO-labelled leukocyte scan revealed a marked terminal ileitis and pancolitis. It is assumed that immunosuppressive therapy was the main reason for the falsely negative antibody scan, possibly affecting the red bone marrow where most of the antibodies bind to granulocytes. Peripheral leukocytes labelled in vitro do not seem to be subject to these hypothetical effects on red bone marrow.

[Radioiodine therapy of funcitonal autonomy using the functional autonomous volume]

In order to determine the effective radiation dose to be delivered by 131I in functional autonomy we have used the functional autonomous volume calculated from the global 99mTc thyroid uptake under exogenous or endogenous suppression before and 3 to 7 months after treatment. The radiation dose to the autonomous volume was calculated retrospectively in 131 patients with unifocal, multifocal and disseminated autonomy (75 hyperthyroid, 56 euthyroid) who received 131I treatment of 200-300 Gy to the total volume of the gland. It could be shown that at least 350 Gy to the autonomous volume are required to reach the desired effect of treatment which was dependent only on the radiation dose delivered to the functional autonomous volume.

Improved dose concept for radioiodine therapy of multifocal and disseminated functional thyroid autonomy

The present study analyzes the improvement of the outcome of radioidine therapy in non-immunogenic hyperthyroidism by adapting the target dose to the 99mTc-pertechnetate thyroid uptake under suppression (TcTUs) prior to radioiodine therapy. The TcTUs is a substitute for the non-suppressible iodine turnover. The 89 patients presented with a basal thyrotropin level of < 0.1 mU/l, normal values for free triiodothyronine and thyroxine and with multifocal or disseminated thyroid autonomy. These terms describe the scintigraphic distribution pattern of autonomous iodine turnover. Thirty-two patients had a TcTUs between 1.6 and 3.2% (group A) and 57 had a TcTUs > 3.2% (group B). Fifty-five patients (three of group A and 52 of group B) were treated previously for overt hyperthyroidism with antithyroid drugs. Target doses of 150 and 200 Gy were used in both groups and 300 Gy in group B only. Six months after radioiodine therapy, a basal TSH level of > or = 0.5 mU/l as criterion of therapy success was observed in 94% of group A and in 54% of group B. Further differentiation of group B shows an increasing success rate with the target dose used: 45% after 150 Gy, 50% after 200 Gy and 90% after 300 Gy. In patients with a basal TSH level of < 0.5 mU/l after radioiodine therapy, the TcTUs was evaluated again.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrovascular reactivity to acetazolamide in (senile) dementia of Alzheimer's type: relationship to disease severity

Neuropathological reports about denervation and amyloid angiopathy in dementia of Alzheimer's type (DAT) as well as signs of selective incomplete white matter infarctions point to a vascular involvement within the degenerative process. In order to investigate potential alterations of cerebrovascular function we performed cerebral blood flow measurements before and after intravenous injection of 1 g acetazolamide using technetium-99m hexamethylpropyleneamine oxime and single photon emission tomography in 12 patients (6 female, 6 male; mean age 70.8 +/- 9.6 years) with probable (senile) dementia of Alzheimer's type (SDAT) and 9 controls (7 female, 2 male; mean age 71.2 +/- 8.6 years). SDAT patients revealed significantly reduced cerebrovascular reactivity with lower values with increasing cognitive impairment. We discuss possible underlying mechanisms.

99mTc-HMPAO-SPECT in the diagnosis of senile dementia of Alzheimer's type--a study under clinical routine conditions

This study was designed to evaluate, whether investigations of cerebral blood flow can be a helpful diagnostic tool in the differential diagnosis between (senile) dementia of Alzheimer's type [(S)DAT] and geriatric depression with cognitive impairment. Under clinical routine conditions we performed Single Photon Emission Computed Tomography (SPECT) using 99mTc-Hexamethylpropyleneamine Oxime (HMPAO) in 23 patients with (S)DAT (14f, 9m; mean age 68.9 y), 17 patients with geriatric depression (9 f, 8 m; mean age 66.4 y) and 12 age-matched controls (9 f, 3 m; mean age 69.2 y). Semiquantitative analysis (corticocerebellar ratios) of eight different regions of interest (ROI) revealed a significantly (p < 0.05) reduced perfusion in the (S)DAT patients compared to the control group. The depression group exhibited perfusion values between the (S)DAT and control group. The difference between the depression and (S)DAT group was most prominent in the left parieto-occipital ROI (p = 0.008). We discuss the data with extensive regard to the literature and conclude that 99mTc-HMPAO SPECT is a valuable additional tool in the differential diagnosis of depression and dementia in the elderly.

Single photon emission tomography (SPET) imaging of dopamine D2 receptors in the course of dopamine replacement therapy in patients with nocturnal myoclonus syndrome (NMS)

Single photon emission tomography (SPET) permits the in vivo measurements of regional cerebral radioactivity in the human brain following the administration of compounds labeled with photon-emitting isotopes. According to our SPET findings of a reduced binding of [123I]labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) to D2 dopamine receptors in striatal structures in untreated patients with nocturnal myoclonus syndrome (NMS) it seemed to be of interest to investigate whether there are changes in D2 receptor binding under dopamine replacement therapy or not. We studied the uptake and distribution of [123I]IBZM before and in the course of dopamine replacement therapy in four patients with severe insomnia caused by a nocturnal myoclonus syndrome (NMS). We found an increase of the IBZM binding to D2 receptors in the course of treatment, which was associated with an improvement of sleep quality. Reasons for this are discussed. The [123I]IBZM SPET technique in conclusion offers an intersting tool for in vivo investigations of functional changes in the dopaminergic neurotransmitter system in longitudinal studies.

Falsely Negative 99mTc-Antigranulocyte Immunoscintigraphy and Positive 99mTc-HMPAO-La be I led Leukocyte Scan in Active Crohn’s Disease

A 19-year-old woman with active Crohn’s disease under immunosuppressive therapy underwent scintigraphy with 99mTc-anti-NCA-95 antigranulocyte antibodies in order to determine the extent of inflammation. It turned out to be falsely negative whereas a 99mTc-HMPAO-labelled leukocyte scan revealed a marked terminal ileitis and pancolitis. It is assumed that immunosuppressive therapy was the main reason for the falsely negative antibody scan, possibly affecting the red bone marrow where most of the antibodies bind to granulocytes. Peripheral leukocytes labelled in vitro do not seem to be subject to these hypothetical effects on red bone marrow.

Nocturnal myoclonus syndrome (periodic movements in sleep) related to central dopamine D2-receptor alteration

The nocturnal myoclonus syndrome (NMS) consists of stereotyped, repetitive jerks of the lower limbs that occur during sleep or wakefulness. NMS is often related with restless-legs syndrome (RLS) and can cause severe sleep disturbances and daytime sleepiness. The efficacy of dopamine agonists in the treatment points to a dopaminergic dysfunction in NMS. We investigated the central dopamine D2-receptor occupancy with [123I] labeled (S)-2-hydroxy-3-iodo-6-methoxy-([1-ethyl-2-pyrrolidinyl]methyl) benzamide (IBZM) (a highly selective CNS D2 dopamine receptor ligand) ([123I]IBZM) and single photon emission tomography (SPET) in 20 patients with NMS and in 10 healthy controls. In most of the patients with NMS there was a lower [123I]IBZM binding in the striatal structures compared to controls. The results indicate that NMS is related to a decrease of central D2-receptor occupancy.

[Functional autonomy of goiter]

The article summarizes the status of knowledge on functional autonomy of the thyroid gland from the standpoint of definition, pathogenesis, pathophysiology, epidemiology, diagnostics and treatment.

Scintigraphic detection of inflammatory heart disease

Inflammatory diseases of the heart encompass myocarditis, endocarditis and pericarditis. This paper discusses the diagnostic potential of scintigraphy in these entities. In myocarditis, indium-111 antimyosin Fab imaging can visualize active myocyte damage and thus contribute substantially to the diagnosis. Antimyosin uptake is also seen in a large subset of patients with dilated cardiomyopathy, indicating ongoing myocyte injury in these cases. In endocarditis, immunoscintigraphy using monoclonal technetium-99m-labelled antigranulocyte antibodies provides useful diagnostic information in patients with equivocal echocardiographic findings. Immunoscintigraphy seems to indicate the floridity of the inflammatory process in endocarditis and may be used to monitor antibiotic therapy. In pericarditis, the clinical value of scintigraphy has not been convincingly demonstrated.

111In-pentetreotide (somatostatin analogue) scintigraphy as an imaging procedure for endocrine gastro-entero-pancreatic tumors

It was the aim of the present study to examine whether 111In-pentetreotide, a somatostatin analogue with predominantly renal excretion, is a suitable receptor agonist for scintigraphic imaging of endocrine gastro-entero-pancreatic (GEP) tumors, and to evaluate the contribution of the usual imaging times 4 and 24 h p.i. In 36 patients, planar scintigrams obtained 4 h, and 24 h after i.v. injection of 111 or 222 MBq 111In-pentetreotide were compared to the results of other imaging procedures and of surgery. Single photon emission computed tomography (SPECT) was also performed 24 h p.i. Positive scintigraphies were obtained in 32 out of 36 patients (18/19 patients with carcinoid syndrome, 8/9 with non hormone-producing endocrine GEP tumors, 2/4 with gastrinomas, 1/1 with glucagonoma, 1/1 with a VIPoma, 2/2 with paragangliomas). In 9 patients tumor manifestations previously not detected by conventional imaging procedures were disclosed by 111In-pentetreotide scintigraphy. 24-h images yielded significantly more true positive findings than 4-h images. In 4 patients liver metastases missed on planar scans were detected by SPECT. A discrepancy between patient-based and organ-based analysis of the results was encountered thus indicating a possible intraindividual heterogeneity in somatostatin receptor expression. In conclusion, 111In-pentetreotide is a suitable somatostatin analogue for scintigraphic in vivo demonstration of somatostatin receptors and for imaging of most tumor manifestations in patients with endocrine GEP tumors. Further studies will have to evaluate whether or not a positive receptor scintigraphy predicts response to treatment with long-acting somatostatin analogues.

Funktionelle Autonomie der Schilddrüse

In einer Übersicht werden die bisherigen Befunde und Kenntnisse über die funktionelle Autonomie der Schilddrüse unter den Gesichtspunkten Definition, Pathogenese und Pathophysiologie, Epidemiologie, Diagnostik und Therapie zusammengefaßt.

[Immunogenic and non-immunogenic hyperthyroidism--a comparison]

In a retrospective study 161 hyperthyroid patients without treatment were divided into 74 with immunogenic hyperthyroidism (IMH) and 87 with non-immunogenic hyperthyroidism (NIMH). The frequency of complaints and the mean hormone concentrations were significantly higher in IMH and the median thyroid volume was significantly smaller. Diffusely reduced sonographic echoes were observed in only 50% of patients with IMH compared to 5% of those with NIMH. Homogeneous distribution of 99mTc in the thyroid was observed scintigraphically in 95% of patients with IMH and in only 3% of those with NIMH. Although the median of global thyroid uptake of 99mTc was significantly higher in IMH there was a broad overlap between the two groups. The mean hormone production is higher in IMH than in NIMH. In order to separate IMH and NIMH, several criteria have to be employed which differ concerning their diagnostic significance.

Determination of the autonomously functioning volume of the thyroid

The aim of this work was to determine the autonomously functioning volume in euthyroid and hyperthyroid goitres for prognostic and therapeutic purposes. To this end, various groups of patients were selected: individuals without evidence of thyroid disease, euthyroid patients with diffuse goitre of normal structure and function, euthyroid patients with evidence of autonomy and patients with hyperthyroidism due to autonomy. In all of them the thyroid uptake of technetium-99m was determined under exogenous suppression (TcUs) in the euthyroid state and under endogenous suppression (TcU) in the hyperthyroid state. It was demonstrated that: 1. In patients with unifocal autonomy the TcUs and TcU correlated linearly with the autonomous volume delineated and measured by sonography. 2. A nearly identical result was obtained if the mean autonomous volume in individuals without thyroid disease of 2.2 +/- 1.1 ml calculated by TcUs/TcU x total thyroid volume was used as a basis. 3. The critical autonomous volume, i.e. the volume at which hyperthyroidism will occur, was found to be 16 ml at a cumulated sensitivity and specificity of > 0.9. The method can be used to select patients for definitive treatment before hyperthyroidism occurs and to measure the autonomously functioning volume independent of its distribution within the thyroid for treatment with radioiodine. The method is easy to perform and is also an example of how a relative parameter of a function can be converted into an absolute parameter of a functioning volume.

Inverse correlation between disappearance of intrathecally injected 111In-DTPA from CSF with CSF protein content and CSF-to-serum albumin ratio

By means of cerebrospinal fluid (CSF) scintigraphy with 111In-DTPA injected following lumbar puncture in 18 patients after meningitis (12), with traumatic head injury (4), cholesteatoma (1) or a communicating hydrocephalus (1) the hypothesis of whether slow movement of CSF may contribute to the elevation of CSF protein and albumin content in neurological diseases other than spinal block was tested. The ratios of the count rates over the head (geometric mean of anterior and posterior view) at 23-25 h to 4-6 h after 111In-DTPA application (C24 h/C5 h) and the ratio 47-49 h to 23-25 h after injection (C48 h/24 h) were taken as measures of the velocity of 111In-DTPA disappearance from CSF. Both the CSF protein content and the CSF-to-serum albumin ratio correlated with C24 h/C5 h and C48 h/C24 h. Assuming log-linear elimination between 24 and 48 h the elimination half-life of 111In-DTPA was estimated to be 12.4-131.1 h (median = 31.7 h). It was concluded that slow CSF kinetics probably are involved in the elevation of CSF protein content in several neurological diseases.

Dopamine D2 receptor alteration in patients with periodic movements in sleep (nocturnal myoclonus)

Periodic movements in sleep (PMS) can cause severe sleep disturbances. We investigated the central dopamine D2 receptor density in patients with PMS with 123I-IBZM and single photon emission tomography (SPET). In PMS there was a lower 123I-IBZM binding in the basal ganglia compared to the control group. The results indicate a loss of central D2 receptors in PMS.