Brain SPECT findings of anosognosia in Alzheimer's disease.

Anosognosia is a common symptom of dementia. The aim of this study was to evaluate the contribution of different regions of the brain to anosognosia in Alzheimer's disease (AD) brains using single photon emission computed tomography (SPECT). Forty-two patients with AD were included in this study. After clinical interviews with the patients and their relatives, the patients were divided into two groups: Anosognosia and No-anosognosia. The patients were studied regarding the severity of dementia. They underwent SPECT with HMPAO and regional cerebral blood flow (rCBF) was measured. Regional CBF significantly differed between Anosognosia and No-anosognosia groups in right prefrontal (P < or = 0.02), right inferior parietal (P < or = 0.00), and right (P < or = 0.01) and left (P < or = 0.01) medial temporal cortex. There was a significant correlation between the severity of dementia and rCBF in medial temporal regions. When comparisons were made between mild and moderate stages separately, the 'right inferior parietal region' was the common region which showed hypoperfusion in both anosognosia subgroups. We conclude that anosognosia may be a reflection of functional impairment in right prefrontal, right frontal and especially right inferior parietal regions in AD.

Plasma levels of amyloid beta1-42 are independent of neuronal function in Alzheimer's disease.

The aggregation of amyloid-beta42 (Abeta42) constitutes one of the major pathogenic events in Alzheimer's disease (AD), and the study of regional cerebral blood flow (rCBF), using single photon emission computed tomography (SPECT), aids the diagnosis of AD. In this study, we evaluated whether there was a correlation between rCBF in brain regions and plasma levels of Abeta1-42 in AD. 29 patients (mean age 71 +/- 9) with a diagnosis of AD who fulfilled NINCDS-ADRDA criteria with a mean Mini-Mental Status Examination score of 15 +/- 9 and 16 normal controls (mean age 64 +/- 8) underwent SPECT brain imaging with hexamethylpropylene amine oxime, and semiquantitative analysis of rCBF was performed. Plasma samples were collected the same day of the SPECT and plasma Abeta1-42 measured by ELISA. A significant reduction of rCBF was observed in most regions in AD compared to controls, whereas mean plasma Abeta42 did not differ between the two groups. There was no correlation between rCBF in any region and plasma Abeta42 nor any correlations between gender, age, and severity with plasma levels of Abeta42. Since rCBF is coupled to neuronal activity, we conclude that plasma Abeta1-42 concentration is independent of neuronal function in every single region of the brain.

[Indium-111-DTPA-phenyl-pentetreotide somatostatin receptors' scintigraphy in the evaluation of patients with suspected gastro-entero-pancreatic tumors. Comparison with computerized tomography].

Gastro-entero-pancreatic tumors (GEP) contain, in their majority, somatostatin receptors. In-111-DTPA-phenyl-pentetreotide has been proved to have high affinity for somatostatin receptors subtypes 2, 3 and 5. The aim of the present study was to evaluate the utility of (111)In-DTPA-O somatostatin receptors' scintigraphy (SRS) in the diagnosis of suspected GEP. Thirty-five consecutive patients (17 males and 18 females-mean age 57.9+/-7.6) with GEP as a possible diagnosis were enrolled in the study. The primary diagnosis was diarrheic syndrome susceptive of intestinal carcinoid tumor (24 patients), carcinoid of the rectum (2 patients), adenocarcinoma of the pancreas (2 patients), insulinoma (2 patients), gastrinoma (3 patients) and hepatocellular carcinoma (2 patients). All patients were submitted to computerized tomography (CT) of the thorax and the abdomen and pentetreotide SRS was performed 4 h (total body and SPET acquisition) and 24 h (planar views), post iv injection of 185 MBq of the radiolabeled compound. Results showed: Four of the patients were false positive diagnosed as having inflammatory intestinal disease and gallbladder dilatation. At the time of the evaluation, 14 of the remaining patients were free of disease, concerning secondary involvement. In these cases, CT and SRS studies matched each other, with no pathological lesions and no abnormal accumulation of the radiopharmaceutical respectively. Concerning pathological cases, only one SRS study in a patient with rectum carcinoid was normal, with liver lesions in the CT study. These lesions were considered as subtypes 2, 3 and 5 somatostatin receptors negative. SRS revealed three lesions more than CT. According to these results, sensitivity of SRS study was 93.8% and specificity 86.9%. The authors believe that molecular imaging of somatostatin receptors, is a sensitive method for the evaluation of patients with GEP tumors. However, in cases of intestinal disease, we should be aware of false positive results due to inflammatory processes and the presence of lymphocyte infiltration.

Evaluation of dopaminergic function in frontotemporal dementia using I-FP-CIT single photon emission computed tomography.

Extrapyramidal symptoms are observed in frontotemporal dementia (FTD). (123)I-FP-CIT (DaT scan) single photon emission computed tomography (SPECT) can detect loss of presynaptic dopamine transporters in the striatum. We aimed to evaluate the dopaminergic status of the striatum in patients with FTD using DaT scan. Seven patients (age range 65-76 years), who fulfilled the Neary criteria and in whom the diagnosis of FTD was confirmed by hexamethylpropyleneamine oxime SPECT, were included in the study. The severity of the extrapyramidal symptoms was evaluated by the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS). SPECT using (123)I-FP-CIT was done. A (region - occipital)/occipital ratio was calculated for the striatum, putamen and caudate nucleus. The results were compared with those of the 7 age-matched normal controls. The uptake of the radiotracer in the right and left striatum was reduced to 62% (p = 0.000) and 68% (p = 0.000), respectively, compared to controls. The motor UPDRS score of the patients with FTD showed a negative correlation to the uptake of the radiotracer. The presynaptic dopamine transporter in FTD is impaired, related to the severity of the extrapyramidal symptoms. Since an effective treatment for FTD is still to be established, there is a need for evaluating the efficacy of dopaminergic drugs.

[Proposals for the revision of radiation protection measures for doses up to 222 MBq iodine-131 for whole body scintiscan for the detection of metastatic lesions].

The goal of this study was to estimate the necessary period of time, required for radiation protection instructions to be followed by patients with differentiated thyroid carcinoma (DTC) after total thyroidectomy who are given iodine-131 ((131)I) for a whole body scintiscan (WBS) in relation to the instructions of the European Commission and the ICRP. In order to estimate and evaluate the dose received by the family members and the general public, we have studied 30 patients and were given a dose of 92-222 MBq of (131)I for a diagnostic WBS. The patients studied were four men with mean age+/-standard deviation (M+/-SD)=55+/-6 y and 26 women with: M+/-SD=47+/-14 y. Dose rate measurements were carried out at the Nuclear Medicine Department of the AHEPA University Hospital; 1 h after the patients had received the (131)I dose and 48 h later when they returned to the hospital for the WBS. The calculated doses received by the in-living relatives of the patients and by the general public, assuming that radiation protection measures were applied for 2d, ranged between 76-640 microSv and 22-171 microSv respectively. In conclusion, the results of this study, compared to the dose constraints suggested by the European Commission, indicate that the duration of radiation protection guidelines for patients receiving (131)I for diagnostic purposes could be reduced to only two days without any potential risk to family members or to members of the public. The case of children of the immediate family environment, aged less than 3 y, was not investigated in this study.

[The clinical and laboratory findings in Graves' multinodular type disease].

Graves' disease (GD) is an autoimmune thyroid disease characterized among other findings by diffuse goiter. It is possible in GD to find a multinodular goiter (mGD). Are they two different diseases that coexist, or do we have a multinodular type of GD. Questions arise as for the time that this mGD appears in the process of GD and also, as for the clinical and laboratory characteristics of mGD. To answer these questions, we have studied retrospectively and randomly from the archives of the Department of Nuclear Medicine of AHEPA University Hospital, from 2000-2004, 20 female patients with multinodular type of GD (Group A) as first diagnosed by us and 50 female patients with diffuse type of GD (Group B) of about the same age. Patients with mGD had been examined before by us and their GD was documented. No other cause for exophthalmus except GD was found. Patients with any other additional disease were excluded from the study. All patients had 7-10 signs of hyperthyroidism (thyroid index). Many of the patients, after the present study, were given (131)I therapeutically. These groups were divided in subgroups of pre- and menopausal women (A1, B1 and A2, B2 respectively). The mean age of our patients in Groups A and B were 46 and 50 years with a range of 25-65 and 38-69 years respectively. Serum free triodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibodies (AbTPO), antithyroglobulin antibodies (AbTG) and anti receptors of thyroid stimulating hormone antibodies (AbTSHR) were tested in all subjects studied by radioimmunoassays (RIA) or radioimmunometric assays (IRMA). All patients were under antithyroid treatment interrupted for about 10 days before the thyroid scan. Thyroid scintiscan was performed 24 h after oral intake of 1.8 MBq of (131)I. Clinical findings were evaluated by a clinical index of hyperthyroidism as modified by us. The time that the mGD appeared since the beginning of GD and the time the GD started were also studied. Our findings were as follows: A mean time of 10.35+/-6.7 years had elapsed from the start of GD till mGD was first diagnosed by us. A mean time of 3.1+/-1.6 years had elapsed after the start of the GD till patients of Group B were examined in this study. No difference in the values of FT3, FT4 and TSH between the two Groups or the Subgroups was found as expected because the clinical status of the patients varied. AbTG, AbTPO and AbTSHR were found in a much higher incidence and in higher values in Group A versus Group B (P=0.007 and 0.001 respectively) and in Subgroups A1, A2 versus B1 and B2 respectively. This increase was significant for AbTG and AbTPO in A2 versus B2 Subgroups and for AbTPO in A1 versus B1 Subgroups (P=0.007, 0.001 and 0.014 respectively). We were unable to find a similar work in the literature. In conclusion, we suggest that mGD as compared to GD: a)develops late in GD and thus patients had more relapses, b) has a higher incidence of abnormal values of AbTPO, AbTG and AbTSHR, c) has significantly higher values of AbTPO and less of AbTG than GD and d) thyroid hormones, clinical index of hyperthyroidism and the incidence of exophthalmos do not differ. Based on the above, we suggest that mGD is a late evolutionary type of GD. The study of patients of both sexes having GD of the same duration as mGD, the study of iodine metabolism and of thyroid gland pathology in these patients, is needed.

[Findings from molecular imaging with SPET camera and 123I-ioflupane in the differential diagnosis of Parkinsonism and essential tremor].

The aim of the present study was to evaluate the use of the radiopharmaceutical 123I-ioflupane in the diagnosis and differential diagnosis of Parkinsonism (P) and essential tremor (ET). Forty-three consecutive patients, aged 35-72 years, presenting symptoms and signs compatible with P, plus 11 normal volunteers, aged 40-60 years, were enrolled for the study. The radiopharmaceutical was injected iv in a dose of 185 MBq and tomographic acquisition in a single-headed Pegasys gamma-camera (ADAC, USA), 3-4 hours post injection was performed in order to evaluate the activity of the presynaptic nigro-striatal dopaminergic transporter. After reconstruction and reorientation, semiquantitative analysis was performed evaluating counts/pixel: a) in the striatum and its parts (caudate nucleus and putamen) of both hemispheres and b) in the visual cortex representing non specific binding. According to our results, all 21 individuals with ET were correctly evaluated with this method, whilst 21/22 patients were diagnosed as having P. No statistical difference concerning the binding of the radioligand to the striatum and its parts was found between normal volunteers and patients with ET. Based on the present results in 21 of our patients, the diagnosis and treatment procedure were changed, while in the remaining 22 patients diagnosis and treatment were confirmed. According to our data, as well as to the data from others, molecular imaging (SPET) with 123I-ioflupane can properly differentiate individuals with ET from those having P, in order to avoid an unnecessary use of drugs that may even cause side effects. All our patients were re-examined after eight months. At that time the above results and the treatment that was given to them meanwhile, were positively evaluated.

Serum estradiol, progesterone, testosterone, FSH and LH levels in postmenopausal women with Alzheimer's dementia.

Several studies have suggested that estrogen replacement therapy lowers the risk of Alzheimer's dementia (AD) among postmenopausal women. Other studies have evaluated serum levels of sex hormones and gonadotropins in women with AD. Estrogens (E(1) and E(2)), luteinizing hormone (LH) and follicular stimulating hormone (FSH), dihydroepiandrosterone and sex hormone binding albumin, which normally responds to circulating testosterone, have been investigated by others using the same protocol in postmenopausal women with AD, older than 65 years. Others have studied in elderly women with AD, also using one protocol, fewer sex hormones and/or gonadotropins. We have studied the serum levels of estradiol, progesterone, testosterone, LH and FSH in the same serum sample of postmenopausal women with AD and other dementias and compared them to a group of controls. We are not aware of a similar study in the literature. All patients were diagnosed on clinical grounds and screened by the mini mental score examination (MMSE). Forty eight women had AD (Group A), mean age 72 years and age range 60-84 years, s even had other types of dementia (Group B), mean age 63.5 years and age range 53-74 years and 33 women had no cognitive impairment and were studied as controls (Group C). Group C women had mean age of 65 years and their age ranged between 55-73 years. Estradiol, progesterone and testosterone were measured by radioimmunoassay (RIA), while FSH and LH by radioimmunometric assay (IRMA). Our results showed that estradiol was significantly lower in Group A as compared to Group C (P=0.04). There was no significant difference in the levels of the other four hormones in the three Groups as studied by the Mann-Whitney U and the Pearson's statistical test. Our results were not influenced by differences due to sex, age, ethnic group or education since these factors were either similar or comparable in all Groups studied. All but two of the subjects, with mild alcoholism, smoking, increased BMI and chronic diseases, had all five hormones studied within reference limits. We consider that the absence of difference we found in the four hormone levels, in Groups A, B and C may be related to free hormones, to the different stage of AD of our patients, to intra assay variability, to assay sensitivity or to other non specified factors. Future study may be directed towards whether a primary or secondary hypogonadism exists in AD and whether hormones are contributing to or are the result of brain degeneration in AD.

Oprimizing the protocol for the calculation of the doses of (131)I administered for the treatment of benign thyroid disease.

The administration of (131)I for the treatment of benign thyroid disease is widely used in clinical practice. The appropriate dose of (131)I, so as the gland could receive the specified absorbed dose, is determined by various methods. The mostly used is the one based on the 24 h uptake. In the present study we examined the time to measure (131)I uptake which better represents the total accumulated activity in the thyroid gland and consequently is more reliable for dose calculation. Fourteen patients, who were referred to the Nuclear Medicine Department of AHEPA University Hospital, were included in the study. 1.85 MBq of (131)I were administered and the uptake at 24, 48, 72 and 192 h was measured. From the curve of the activity vs time we calculated the area under it, which represents the total accumulated thyroid activity. We compared the uptakes of every individual with the total area and we found that the 192 h uptake was best correlated with it (r=0.996). The absorbed dose to the thyroid was calculated in the following ways: a) was based on the 24 h uptake and b) was based on the total accumulated activity on the 192 h uptake. We found differences from -19.9% to +33.7%. In conclusion, the 192 h uptake consists the most representative and reliable parameter for the estimated activity of (131)I given to the thyroid for the treatment of hyperthyroidism.