Katalin Zámbó

Neuroimaging and cognitive changes during deja vu.

OBJECTIVE The cause or the physiological role of déjà vu (DV) in healthy people is unknown. The pathophysiology of DV-type epileptic aura is also unresolved. Here we describe a 22-year-old woman treated with deep brain stimulation (DBS) of the left internal globus pallidus for hemidystonia. At certain stimulation settings, DBS elicited reproducible episodes of DV. METHODS Neuropsychological tests and single-photon-emission computed tomography (SPECT) were performed during DBS-evoked DV and during normal DBS stimulation without DV. RESULTS SPECT during DBS-evoked DV revealed hyperperfusion of the right (contralateral to the electrode) hippocampus and other limbic structures. Neuropsychological examinations performed during several evoked DV episodes revealed disturbances in nonverbal memory. CONCLUSION Our results confirm the role of mesiotemporal structures in the pathogenesis of DV. We hypothesize that individual neuroanatomy and disturbances in gamma oscillations or in the dopaminergic system played a role in DBS-elicited DV in our patient.

Sentinel lymph nodes in gynaecological malignancies: Frontline between TNM and clinical staging systems?

Numerous investigations have recently proved the importance of sentinel lymph node detection in various malignant tumours. It is widely accepted that this procedure is to be recommended only in patients with early stage tumours. The lymph node status and prognosis are closely related. Appropriate staging is essential in the management of malignant tumours and should be individualised. In many cases, the nodal status does not correlate with the clinical stage of the disease. In this survey, we consider some of the most common gynaecological malignancies and the type of staging most appropriate to them. Differences between these staging systems, and controversies concerning them, are related to the concept of sentinel lymph node investigation. The authors believe that sentinel node sampling is in fact a beneficial method in both early and advanced stage disease for determination of the tumour status and individualisation of surgical interventions.

Application of the parametric scan in the investigation of uteroplacental blood flow

We developed a new radioisotope technique to measure placental blood flow for the early detection of placental insufficiency. Using the parametric scan, placental perfusion was measured in 80 late-pregnant women. The T-maximum pictures obtained made it possible to differentiate between the vascular and intervillous phases of placental blood flow. The time period of intervillous phase calculated as the percentage of the whole placental Tmax was given as the intervillous perfusion index (IPI). It was demonstrated that the IPI was significantly higher in pregnancies complicated with intrauterine growth retardation (64.2%±16.5%), hypertension (60.0±15.2) and oedema (57.9%±10.1%) than in the control group (33.7%±10.5%). These data suggest that the first sign of placental insufficiency is the prolongation of the IPI which is likely to precede the quantitative reduction of placental perfusion.

Platelet-associated regulatory system (PARS) with particular reference to female reproduction.

BackgroundBlood platelets play an essential role in hemostasis, thrombosis and coagulation of blood. Beyond these classic functions their involvement in inflammatory, neoplastic and immune processes was also investigated. It is well known, that platelets have an armament of soluble molecules, factors, mediators, chemokines, cytokines and neurotransmitters in their granules, and have multiple adhesion molecules and receptors on their surface.MethodsSelected relevant literature and own views and experiences as clinical observations have been used.ResultsConsidering that platelets are indispensable in numerous homeostatic endocrine functions, it is reasonable to suppose that a platelet-associated regulatory system (PARS) may exist; internal or external triggers and/or stimuli may complement and connect regulatory pathways aimed towards target tissues and/or cells. The signal (PAF, or other tissue/cell specific factors) comes from the stimulated (by the e.g., hypophyseal hormones, bacteria, external factors, etc.) organs or cells, and activates platelets. Platelet activation means their aggregation, sludge formation, furthermore the release of the for-mentioned biologically very powerful factors, which can locally amplify and deepen the tissue specific cell reactions. If this process is impaired or inhibited for any reason, the specifically stimulated organ shows hypofunction. When PARS is upregulated, organ hyperfunction may occur that culminate in severe diseases.ConclusionBased on clinical and experimental evidences we propose that platelets modulate the function of hypothalamo-hypophyseal-ovarian system. Specifically, hypothalamic GnRH releases FSH from the anterior pituitary, which induces and stimulates follicular and oocyte maturation and steroid hormone secretion in the ovary. At the same time follicular cells enhance PAF production. Through these pathways activated platelets are accumulated in the follicular vessels surrounding the follicle and due to its released soluble molecules (factors, mediators, chemokines, cytokines, neurotransmitters) locally increase oocyte maturation and hormone secretion. Therefore we suggest that platelets are not only a small participant but may be the conductor or active mediator of this complex regulatory system which has several unrevealed mechanisms. In other words platelets are corpuscular messengers, or are more than a member of the family providing hemostasis.

Is the clinical staging system a good choice in the staging of vulvar malignancies

Dear Sir, We have read the article by Sergi Vidal-Sicart and coworkers [1] entitled “Validation and application of the sentinel lymph node concept in malignant vulvar tumours”, published in the March 2007 issue of the European Journal of Nuclear Medicine and Molecular Imaging. We agree with the authors that sentinel lymph node (SLN) identification permits the accurate pathological examination of regional nodes and could reduce the high morbidity of current surgical treatment in vulvar tumour patients. The results are impressive; however, there are some controversies in the explanation for the tumour stage in SLN-positive cases. The clinical stage of vulvar cancers is at least III when lymph node positivity is found. In the publication of Sergi Vidal-Sicart, however, there are ten patients listed with positive SLN, classified as stage Ib or II. During the past 5 years our team has been involved in the development and application of the method of SLN sampling in vulvar neoplasms to determine the level of progression of the disease. Our preliminary results suggest that sentinel node scintigraphy is a reliable method in early vulvar carcinoma and melanoma [2]. An occasional survey was written by us on the comparison of the TNM and clinical (FIGO) staging systems in different gynaecological malignancies. In 1969 FIGO introduced a staging system for vulvar cancer based on the TNM classification, utilising the clinical assessment of tumour size, tumour site, status of the regional lymph nodes and a limited search for distant metastases. The most serious drawback of this staging system was the inaccuracy of clinical assessment in determining groin node status, especially given that microscopic metastases may be present in clinically normal nodes and cancer-free nodes may be enlarged by inflammation [3]. The TNM system is a dual system distinguishing between a clinical (pretreatment) classification (TNM or cTNM) and a pathological (post-surgical histopathological) classification (pTNM). Thus, in TNM, each patient is staged clinically as well as pathologically. We should realise that not only surgical and pathological, but also clinical staging is important. We should continue to rely upon clinical staging when planning treatment and making prognostic assessments [4]. In the case of vulvar carcinoma, the TNM staging system is obviously superior to clinical (FIGO) staging. Of all the gynaecological malignancies, vulvar carcinoma is the one for which the SLN concept is most relevant. We suggest that in publications dealing with SLN investigations, TNM staging should be preferred over clinical staging. Eur J Nucl Med Mol Imaging (2007) 34:1878–1879 DOI 10.1007/s00259-007-0511-5

Is sentinel lymph node investigation useful for early tumour stages only

We have read the article by Pieter J. Tanis and co-workers [1] on sentinel node lymphoscintigraphy in stage I testicular cancer and the editorial by Nicholas Hyde and Elizabeth Prvulovich [2] on its use in mucosal squamous cell carcinoma of the head and neck region (both were published in the May 2002 issue of the European Journal of Nuclear Medicine). During the past 2 years our team has been involved in the development of a new method to determine the level of progression of vulvar neoplasms. The results of our preliminary study are encouraging and suggest that lymphoscintigraphy is an easy and reliable method for detection of the sentinel lymph node in early vulvar carcinoma [3]. Malignant neoplasms are characterised by two fundamental properties: the ability to expand locally by invasion and the ability to spread distantly by metastasis. Lymph node status is the most important prognostic factor in all kinds of cancer. Radical resection of the primary tumour with extensive lymphadenectomy remains the standard therapeutic intervention in most cases; however, the concept of sentinel lymph node sampling may provide a new opportunity to determine the eligibility of patients for less extensive surgical treatment. The procedure is minimally invasive and enables us to perform accurate preoperative staging of the lymph node status. Initial studies conducted on breast carcinoma, using vital blue dye, showed that the concept was biologically valid, although that method failed to locate the sentinel lymph node in up to 30%–40% of cases. If radioactive tracer is injected adjacent to the tumour, then the sentinel lymph node can be identified by lymphoscintigraphy [4]. Although in general we agree with sentinel lymph node methodology, we consider the tumour stage explanation to be controversial. It is generally accepted that investigation of sentinel lymph nodes is recommended in early tumour stages. According to the clinical and TNM staging of various tumours (summarised in Table 1), the clinical stage of most tumours is at least III when the sentinel lymph node is positive. However, with positive lymph nodes the clinical stage of stomach carcinoma is I and that of breast and lung cancer is II, while that of urinary bladder and prostate carcinoma is already IV. This staging is independent of the size of the primary tumour. We believe that clinical stage II and higher should not be regarded as early stage. On this basis, we would like to suggest that TNM staging should be preferred to clinical staging in publications dealing with sentinel lymph node investigations.

The impact of post-radioiodine therapy SPECT/CT on early risk stratification in differentiated thyroid cancer; a bi-institutional study

Objective SPECT/CT has numerous advantages over planar and traditional SPECT images. The aim of this study was to evaluate the role of post-radioiodine therapy SPECT/CT of patients with differentiated thyroid cancer (DTC) in early risk classification and in prediction of late prognosis. Patients and methods 323 consecutive patients were investigated after their first radioiodine treatment (1100–3700 MBq). Both whole body scan and SPECT/CT images of the head, neck, chest and abdomen regions were taken 4–6 days after radioiodine therapy. Patients were re-evaluated 9–12 months later as well as at the end of follow up (median 37 months). Results Post-radioiodine therapy SPECT/CT showed metastases in 22% of patients. Lymph node, lung and bone metastases were detected in 61, 13 and 5 patients, respectively, resulting in early reclassification of 115 cases (36%). No evidence of disease was found in 251 cases at 9–12 months after radioiodine treatment and 269 patients at the end of follow-up. To predict residual disease at the end of follow-up, the sensitivities, specificities and diagnostic accuracies of the current risk classification systems and SPECT/CT were: ATA: 77%, 47% and 53%; ETA: 70%, 62% and 64%; SPECT/CT: 61%, 88% and 83%, respectively. There was no difference between cohorts of the two institutions when data were analyzed separately. Conclusions Based on our bi-institutional experience, the accuracy of post-radioiodine SPECT/CT outweighs that of the currently used ATA and ETA risk classification systems in the prediction of long-term outcome of DTC.

SIGNIFICANCE OF BOLUS TIME IN FIRST-PASS RADIONUCLIDE CARDIOGRAPHY

We were extremely interested to read the very important article by Bell and Peters (1991) in which they demonstrated that the radionuclide technique for measuring blood flow from a first-pass study is independent of the bolus volume up to volumes of about 20 ml. However, if this technique is used to measure bolus volumes greater than 20 ml, the estimates of organ blood flow are not reliable. We analysed the time relationship of a bolus during first-pass radionuclide cardiography using 550 MBq technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) in 36 patients with cor pulmonale. The bolus time was characterized by bolus t25o/0 and calculated from a time-activity curve. The pulmonary circulation index (PCI), mean transit time (MTT) and pulmonary arterial pressure (PAP) were investigated to check the bolus quality. PCI is the time interval between the peaks of the time-activity curves of the right and left ventricles; MTT was calculated from a peripheral pulmonary timeactivity curve using gamma-fit. PAP was measured by the microcatheter technique. We observed that bolus times shorter than 12 s yield significantly positive linear correlations between PCI and PAP (r = 0.61; P < 0.001) and MTT and PAP (r=0.67; P<0.001) . There was no correlation between these parameters (PCI-PAP: r = 0.38; NS and MTT-PAP: r = 0 . 0 8 ; NS) when the bolus times were longer than 12 s. Our results suggest that a bolus time up to about 12 s has no influence on blood flow.

Effect of Metoclopramide Treatment on Thyrotropin and Prolactin Levels in Sick Neonates

The present study was carried out to define whether dopaminergic mechanisms contribute to the regulation of thyrotropin (TSH) and prolactin PRL release in the immediate neonatal period. 14 full-term neonates with a mean birth weight of 3,240 g and a mean gestational age of 39.1 weeks were administered metoclopramide (MTC), a specific dopamine antagonist, in a dose of 0.1 mg/kg/day to treat delayed gastric emptying, regurgitation and abdominal distension. Prior to and after 3-day MTC administration, blood samples were taken to determine serum TSH and PRL levels using a radioimmunoassay method. It has been demonstrated that in response to MTC administration PRL increased significantly from 4,010 +/- 383 to 5,478 +/- 441 mU/l (p less than 0.01), while TSH showed only a tendency to rise independent of the pretreatment hormone levels (from 2.85 +/- 0.44 to 3.06 +/- 0.38 mU/L. In healthy control infants and in those infants with similar functional gastrointestinal disturbances who were treated without MTC, serum PRL levels fell significantly from days 3-4 to days 6-7, serum TSH, triiodothyronine and free thyroxine, however, remained unaltered. It is concluded that dopaminergic inhibitory mechanism may be involved in the control of pituitary PRL and TSH release already in the neonatal period.