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Volker M Tronnier

Publications and source records attributed to Volker M Tronnier.

3 recordsLinked to original sources

Distinguishing of primary cerebral lymphoma from high-grade glioma with perfusion-weighted magnetic resonance imaging.

To assess the usefulness of perfusion-weighted echo-planar magnetic resonance imaging in the differential diagnosis of primary supratentorial lymphoma (PCNSL) and glioblastoma (GBM), 12 patients with a PCNSL and 12 with a GBM were examined using a 1.5 T magnetic resonance (MR) imager. With dynamic-susceptibility contrast MR imaging the intensity-time curves of each tumor were analyzed, and we determined the relative regional cerebral blood volume ratios (rrCBV [tumor/contralateral white matter (WM)]) to find out whether these parameters could be used to separate PCNSL from GBM. The maximum rrCBV ratio in the PCNSL was significantly lower than that of the GBM (P<0.0001). Comparing the intensity-time curves for the two tumor groups, the PCNSL showed a characteristic type of curve with a significant increase in signal intensity above the baseline due to massive leakage of contrast media into the interstitial space. PCNSL tend to have low maximum CBV ratios and typical intensity-time curves. These two parameters may be useful in distinguishing PCNSL from GBM.

Brain Neoplasms↗

Subthalamic nucleus stimulation affects a frontotemporal network: a PET study.

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) has become an effective strategy in the treatment of motor symptoms in advanced Parkinson's disease. However, clinical studies have shown that DBS can affect verbal fluency. Seven Parkinson's disease patients with bilateral DBS of the STN were studied with positron emission tomography (PET) to investigate the effects of STN stimulation on regional cerebral blood flow during a verbal fluency task. Activation of the right orbitofrontal cortex and verbal fluency-associated activation within a left-sided frontotemporal network were decreased during STN stimulation compared with the OFF state. Our results offer an explanation for the commonest neuropsychological side effect of STN stimulation and show that STN stimulation affects a frontotemporal network during a fluency task.

Aged↗

Nerve blocks in stereotactic neurosurgery.

The advantage of performing preoperative nerve blocks of the supraorbital and occipital nerves facilitates frame fixation and the perioperative management of patients in stereotactic neurosurgery, resulting in better patient handling with reduced intraoperative medication and less monitoring by anesthesia personnel.

Aged↗