Thomas M. Freiman

Dr. Thomas M. Freiman

Department of Neurosurgery, University Medical Center Rostock, Schillingallee 35, 18057 Rostock, Germany
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Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 January 2021 in Cancers
Verified
Journal Article
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PBPeter Baumgarten
Peter Baumgarten
MSMana Sarlak
Mana Sarlak
DMDaniel Monden
Daniel Monden
ASAndrea Spyrantis
Andrea Spyrantis
SBSimon Bernatz
Simon Bernatz
TFThomas M. Freiman
Thomas M. Freiman
Seizures are among the most common symptoms of meningioma. This retrospective study sought to identify risk factors for early and late seizures in meningioma patients and to evaluate a modified STAMPE2 score. In 556 patients who underwent meningioma surgery, we correlated different risk factors with the occurrence of postoperative seizures. A modified STAMPE2 score was applied. Risk factors for preoperative seizures were edema (p = 0.039) and temporal location (p = 0.038). For postoperative seizures preoperative tumor size (p < 0.001), sensomotory deficit (p = 0.004) and sphenoid wing location (p = 0.032) were independent risk factors. In terms of postoperative status epilepticus; sphenoid wing location (p = 0.022), tumor volume (p = 0.045) and preoperative seizures (p < 0.001) were independent risk factors. Postoperative seizures lead to a KPS deterioration and thus an impaired quality of life (p < 0.001). Late seizures occurred in 43% of patients with postoperative seizures. The small sub-cohort of patients (2.7%) with a STAMPE2 score of more than six points had a significantly increased risk for seizures (p < 0.001, total risk 70%). We concluded that besides distinct risk factors, high scores of the modified STAMPE2 score could estimate the risk of postoperative seizures. However, it seems not transferable to our cohort

Verified
Journal Article
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FGFlorian Gessler
Florian Gessler
ASAnn Kristin Schmitz
Ann Kristin Schmitz
DDDaniel Dubinski
Daniel Dubinski
JBJoshua Bernstock
Joshua Bernstock
Felix LehmannFelix Lehmann
Felix Lehmann
Patrick SchussPatrick Schuss
Patrick Schuss
Given the ongoing global SARS-CoV-2-vaccination efforts, clinical awareness needs to be raised regarding the possibility of an increased incidence of SARS-CoV-2-vaccine-related immune-mediated thrombocytopenia in patients with intracerebral hemorrhage (ICH) secondary to cerebral sinus and vein thrombosis (CVT) requiring (emergency) neurosurgical treatment in the context of vaccine-induced immune thrombotic thrombocytopenia (VITT). Only recently, an association of vaccinations and cerebral sinus and vein thrombosis has been described. In a number of cases, neurosurgical treatment is warranted for these patients and special considerations are warranted when addressing the perioperative coagulation. We, herein, describe the past management of patients with VITT and established a literature-guided algorithm for the treatment of patients when addressing the impaired coagulation in these patients. Increasing insights addressing the pathophysiology of SARS-CoV-2-vaccine-related immune-mediated thrombocytopenia guide physicians in developing an interdisciplinary algorithm taking into account the special considerations of this disease.

10 November 2021 in Cancers
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Journal Article
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TWTim Wende
Tim Wende
JKJohannes Kasper
Johannes Kasper
GPGordian Prasse
Gordian Prasse
AGAenne Glass
Aenne Glass
TKThomas Kriesen
Thomas Kriesen
CHChristian Henker
Christian Henker
Background: Reduced temporal muscle thickness (TMT) has been discussed as a prognostic marker in IDH-wildtype glioblastoma. This retrospective multicenter study was designed to investigate whether TMT is an independent prognostic marker in newly diagnosed glioblastoma. Methods: TMT was retrospectively measured in 335 patients with newly diagnosed glioblastoma between 1 January 2014 and 31 December 2019 at the University Hospitals of Leipzig and Rostock. The cohort was dichotomized by TMT and tested for association with overall survival (OS) after 12 months by multivariate proportional hazard calculation. Results: TMT of 7.0 mm or more was associated with increased OS (46.3 ± 3.9% versus 36.6 ± 3.9%, p > 0.001). However, the sub-groups showed significant epidemiological differences. In multivariate proportional hazard calculation, patient age (HR 1.01; p = 0.004), MGMT promoter status (HR 0.76; p = 0.002), EOR (HR 0.61), adjuvant irradiation (HR 0.24) and adjuvant chemotherapy (HR 0.40; all p < 0.001) were independent prognostic markers for OS. However, KPS (HR 1.00, p = 0.31), BMI (HR 0.98, p = 0.11) and TMT (HR 1.06; p = 0.07) were not significantly associated with OS. Conclusion: TMT has not appeared as a statistically independent prognostic marker in this cohort of patients with newly diagnosed IDH-wildtype glioblastoma.

28 August 2021 in Epilepsia
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BSBarbara Schmeiser
Barbara Schmeiser
KLKathrin Leicht
Kathrin Leicht
FGFlorian Gessler
Florian Gessler
TFThomas M. Freiman
Thomas M. Freiman
Summary: Objective: The pathoanatomical correlate of temporal lobe epilepsy is hippocampal sclerosis, characterized by selective neuronal death of mossy cells in the hilus and of pyramidal cells in cornu ammonis 1. Although granule cells survive, they lose mossy cells as a target and redirect their axons (mossy fibers) backward into the molecular cell layer. It has been assumed that this process results in excitatory circuits. We therefore examined whether sprouted mossy fibers form synaptic connection not only with excitatory granule cells but also with inhibitory interneurons, such as basket cells.Methods: Resected hippocampal specimens of patients with hippocampal sclerosis were compared to controls of patients with extrahippocampal lesions with only mild sclerosis. Mossy fibers were traced with Neurobiotin or labeled against synaptoporin; inhibitory interneurons were labeled against parvalbumin. Synapses were examined with electron microscopy, labeled with γ‐aminobutyric acid immunogold.Results: Sprouted mossy fibers of epileptic hippocampi innervate not only excitatory granule cells but also inhibitory parvalbuminergic interneurons. Despite neuronal death in hippocampal sclerosis, the axonal plexus of inhibitory parvalbuminergic interneurons surrounding the granule cells is preserved. Connections of sprouted mossy fibers and inhibitory axon terminals were quantified, showing that the number of inhibitory axon terminals significantly exceeds the number of sprouted excitatory mossy fiber terminals (.03 boutons/µm vs. .11 boutons/µm; p < .001).Significance: Although no definite conclusions regarding the function of our findings may be derived from this anatomical study, the observed aberrant connectivity might lead to an increased inhibition and synchronization of granule cells, because the preserved inhibitory interneurons show an additional innervation through sprouted mossy fibers. This might result in the instability of a previously balanced network.

1 October 2014 in Acta Biomaterialia
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RSRyan J. Seelbach
Ryan J. Seelbach
PFPeter Fransen
Peter Fransen
MPMarianna Peroglio
Marianna Peroglio
DMDaniel Pulido Martinez
Daniel Pulido Martinez
PCPatricia Lopez Chicon
Patricia Lopez Chicon
DEDavid Eglin
David Eglin
The controlled presentation of biofunctionality is of key importance for hydrogel applications in cell-based regenerative medicine. Here, a versatile approach was demonstrated to present clustered binding epitopes in an injectable, thermoresponsive hydrogel. Well-defined multivalent dendrimers bearing four integrin binding sequences and an azido moiety were covalently grafted to propargylamine-derived hyaluronic acid (Hyal-pa) using copper-catalyzed alkyne-azide cycloaddition (CuAAC), and then combined with pN-modified hyaluronan (Hyal-pN). The dendrimers were prepared by synthesizing a bifunctional diethylenetriamine pentaacetic acid core with azido and NHBoc oligo(ethylene glycol) aminoethyl branches, then further conjugated with solid-phase synthesized RGDS and DGRS peptides. Azido terminated pN was synthesized by reversible addition-fragmentation chain transfer polymerization and reacted to Hyal-pa via CuAAC. Nuclear magnetic resonance (NMR), high performance liquid chromatography, size exclusion chromatography and mass spectroscopy proved that the dendrimers had well-defined size and were disubstituted. NMR and atomic absorption analysis confirmed the hyaluronan was affixed with dendrimers or pN. Rheological measurements demonstrated that dendrimers do not influence the elastic or viscous moduli of thermoresponsive hyaluronan compositions at a relevant biological concentration. Finally, human mesenchymal stromal cells were encapsulated in the biomaterial and cultured for 21days, demonstrating the faculty of this dendrimer-modified hydrogel as a molecular toolbox for tailoring the biofunctionality of thermoresponsive hyaluronan carriers for biomedical applications.

5 October 2022 in Journal of Clinical Medicine
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Journal Article
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CMCatrin Mann
Catrin Mann
NCNadine Conradi
Nadine Conradi
ENElisabeth Neuhaus
Elisabeth Neuhaus
JKJuergen Konczalla
Juergen Konczalla
TFThomas M. Freiman
Thomas M. Freiman
SSSusanne Schubert-Bast
Susanne Schubert-Bast
Epilepsy surgery in low-grade epilepsy-associated neuroepithelial tumors (LEAT) is usually evaluated in drug-resistant cases, often meaning a time delay from diagnosis to surgery. To identify factors predicting good postoperative seizure control and neuropsychological outcome, the cohort of LEAT patients treated with resective epilepsy surgery at the Epilepsy Center Frankfurt Rhine-Main, Germany between 2015 and 2020 was analyzed. Thirty-five patients (19 males (54.3%) and 16 females, aged 4 to 40 years (M = 18.1), mean follow-up 33 months) were included. Following surgery, 77.1% of patients remained seizure-free (Engel IA/ILAE 1). Hippocampus and amygdala resection was predictive for seizure freedom in temporal lobe epilepsy. In total, 65.7% of all patients showed cognitive deficits during presurgical workup, decreasing to 51.4% after surgery, predominantly due to significantly less impaired memory functions (p = 0.011). Patients with presurgical cognitive deficits showed a tendency toward a longer duration of epilepsy (p = 0.050). Focal to bilateral tonic-clonic seizures (p = 0.019) and young age at onset (p = 0.018) were associated with a higher likelihood of cognitive deficits after surgery. Therefore, we advocate early epilepsy surgery without requiring proof of drug-resistance. This refers especially to lesions associated with the non-eloquent cortex.