Jan Chrastina

The Role of Palliative Radiotherapy in Bleeding from Locally Advanced Gastrointestinal Tumors

Backround: Because of the dismal prognosis of untreated brain lymphoma early histological verification using stereobiopsy is decisive for patient with this disease. The study analysed the diagnostic yield of stereobiopsy in brain lymphoma patients with respect to prebiopsy corticosteroid administration.nnnPATIENTS AND METHODSnPatients with brain lymphomas were identified in a group of 162 stereotactic biopsies (108 frame-based and 54 frameless) of patients harboring suspected brain tumor. Non conclusive biopsies were reevaluated to exclude the possibility of missed lymphoma.nnnRESULTSnTotal 9 patients (8.3%) and 4 patients (7.4%) had lymphomas in the frame-based and frameless stereobiopsy groups, resp. In 10 patients, corticosteroid treatment of perifocal brain oedema was conducted continually up until biopsy (including one patient with corticotherapy for pulmonary disease). Lesion regression was observed in 6 of these patients. Transient lesion remission was observed during corticotherapy in one patient with lesion recurrence after steroid discontinuation. In 2 patients, corticosteroids were not administered before biopsy. The results of stereobiopsy were inconclusive in 8 patients (4.9%). Before biopsy, the possibility of brain lymphoma was considered in 3 patients, but the final diagnoses were autoimmune vasculitis, histological changes after embolic events from the thrombosed pulmonary veins in pulmonary malformation and local inflammation.nnnCONCLUSIONnAlthough the extent of brain lymphoma decreased after corticosteroid administration, corticotherapy does not exclude valid diagnostic biopsy.Key words: brain lymphoma - stereotaxic techniques - frameless stereotaxy - stereotactic biopsy - corticosreroids Part of the message was presented on XLI. Brno Oncological Days within the Glio Meeting and published in the form of a short abstract. The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers.Submitted: 27. 5. 2017Accepted: 2. 7. 2017.

16. fMRI and eeg studies of the role of basal ganglia in epilepsy

(1) In the fMRI study the impact of epilepsy on the functional brain connectivity (FC) of the BG in two large-scale networks, the default mode network (DMN) and somatomotor network (SMN), was studied in 10 healthy control subjects (HC) and 24 patients with epilepsy. In HC, the BG were functionally negatively correlated with typical DMN regions. This negative correlation as well as the FC between the BG and SMN was significantly lower in patients ( Rektor et al., 2013 ). (2) SEEG studies: The human striatum and pallidum did not generate specific epileptic EEG activity, not even when the seizures were generalized. The visually observed slowing and amplitude increase in the BG was found with the spread of the epileptic activity from the hippocampus to other areas ( Rektor et al., 2002 ). Significant frequency components of 2–10xa0Hz, with the maximum in the 5–10xa0Hz range, were constantly observed in the BG ( Rektor et al., 2011 ). The frequency of this component slowed by around 2xa0Hz during seizures. There was a significant ictal increase of power spectral density in all frequency ranges. The changes in the BG were consistent while the seizure activity spread over the cortex, and they partially persisted after the clinical seizure ended. They were inconsistently present in the first period after the seizure onset. Conclusion Unlike in HC, in TLE the BG are not correlated with a DMN component, and the FC of the BG is decreased with SMN. The epileptic process reduces the FC between the BG and large-scale brain networks. This may reflect an altered function of the BG in epilepsy. Based on our SEEG studies, the time course of the oscillatory activities together with the absence of the epileptiform EEG activities in the BG lead us to suggest an inhibitory role of the BG in temporal lobe seizures. This “filtering effect” of the BG may act as an obstacle to the spread of ictal activity. The BG should be seriously considered as a potential target for neuromodulatory and pharmacological treatment of TLE.