Supplementary sensorimotor area seizure and ictal single-photon emission tomography.

Focal tonic seizures [supplementary motor seizures in the terminology of Penfield and Jasper (1) are often difficult to diagnose in terms of this chapter was undertaken to investigate whether ictal single-photon emission CT (SPECT) scanning could contribute to the diagnostic accuracy of this epileptic condition. In 15 patients (mean age, 21.3 years; ranges, 3 to 39 years) suffering from focal tonic seizures as the initial and most prominent seizure type, ictal SPECT scans were obtained after injection of 99mTc HMPAO within 30 seconds after clinical seizure onset. In 6 patients (40%; group I), ictal SPECT scans showed a focal hyperperused area concordant with results of other tests of the preoperative work-up (prolonged EEG/video monitoring, MRI, and positron emission tomography PET) using [18F]fluoro-2-deoxy-D-glucose (18FDG)] In 6 patients (group II), results of the ictal SPECT scans also showed findings of other tests of the clinical work-up. In 3 patients (group III), no ictal hyperperfusion could be observed. Results of the other presurgical tests in groups II and III were not sufficient to identify the seizure onset zone with the certainty needed for surgical resection. Ictal SPECT with HMPAO revealed confirmatory results in 40% of the patients with focal tonic seizures. In the remaining patients, results either were not congruent with other findings or did not show any change at all. This may have a twofold explanation: First (and probably most important), the interval between seizure onset and injection was too long considering the usually short duration of this seizure type, and second, the spatial resolution of SPECT imaging might not be sufficient to reveal a small seizure focus.

Thyroid hormone concentrations in dialysate during hemodialysis in children.

Thyroxine (T4) concentration in dialysate in the course of hemodialysis was determined in 15 children. Concentrations were measured by a modified radioimmunoassay. During hemodialysis there was a slight increase in T4 concentration. At the end of hemodialysis T4 concentration was about 50% higher than soon after the onset of hemodialysis. The loss of T4 into dialysate during hemodialysis was 19.2 microgram; the loss of T3 was less than 75 ng. The amount of the daily loss of thyroid hormones into dialysate was found to be in the range of normal urinary excretion. The lowering of serum thyroid hormone concentrations in children on hemodialysis cannot be explained by the loss of hormones into dialysate.

Functional analysis of magnetic resonance studies of the heart.

To calculate left ventricle volumes and ejection fraction, magnetic resonance images (MRI) were acquired in an oblique position in end-diastole and end-systole. The ejection fraction values were compared with results of gated blood pool studies with 99mTc-labelled erythrocytes (correlation coefficient 0.8). Determination of regional wall motion was also possible. A method for acquiring sequences of 16 images per heartbeat was developed. It allows the detection of disturbances of wall motion by using Fourier analysis.

[Effect of higher molecular urine metabolites on lymphocyte transformation and autohemolysis (author's transl)]. / Lymphozytentransformation und Autohämolyse unter Einwirkung höhermolekularer Urinmetabolite als potentielle Urämietoxine

Possible toxic effects of lyophilised not dialysable residue from urine of healthy persons obtained by 4 days dialysing against water were investigated. Therefore, the substance dissolved at a concentration of 2.22 mg/ml in Medium TC 199 respectively in physiological saline solution was added with increasing quantities (0.1 to 1.0 ml) to lymphocyte cultures (3 x 10(6) cells in 4 ml medium) and to erythrocytes (3 ml of blood after separation of granulocytes) from healthy persons. Spontaneous 3H-thymidine uptake of the lymphocytes ascertained 5 days after beginning of incubation was markedly depressed with dependence upon the doses up to 30.4% of the control value, whereas only 65.2% was reached after stimulation with 400 mug PHA. In both cases LDH activity in the supernatant culture medium measured as a parameter of cell destruction showed a dose-dependent increase with inverse trend as compared to 3H-thymidine uptake levels. This negative correlation may be due to impaired cell viability as the main cause for depressed lymphocyte transformation. The autohemolysis of the erythrocytes was diminished with dependence upon the doses until to 59.3% of the control value. Therefore, only cytotoxic effects of uremic serum on the lymphocytes may be due to higher molecular urine metabolites retained in uremia whereas increased autohemolysis will be induced by toxins of lower molecular weight.