ARTICLE | doi:10.20944/preprints202208.0301.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: corticospinal tract; optic radiations; tractography; transcranial magnetic stimulation; subdural strip electrodes; intra-operative neuro-monitoring; parietal lobe
Online: 17 August 2022 (05:08:09 CEST)
Background: The role played by the non-dominant parietal lobe in motor cognition, attention and spatial awareness networks has potentiated the use of awake surgery. When this is not feasible, asleep monitoring and mapping techniques should be used to achieve an onco-functional balance. Objective: This study aims to assess the feasibility of a dual-strip method to obtain direct cortical stimulation for continuous real-time cortical monitoring and subcortical mapping of motor and visual pathways simultaneously in parietal lobe tumour surgery. Methods: Single-centre prospective study between May’19-November’20 of patients with intrinsic non-dominant parietal-lobe tumours. Two subdural strips were used to simultaneously map and monitor motor and visual pathways. Results: Fifteen patients were included. With regards to motor function, a large proportion of patients had abnormal interhemispheric resting motor threshold ratio (iRMTr) (71.4%), abnormal Cortical Excitability Score (CES) (85.7%), close distance to the corticospinal tract – Lesion-To-Tract Distance (LTD) – 4.2mm, Cavity-To-Tract Distance (CTD) – 7mm and intraoperative subcortical distance - 6.4mm. Concerning visual function, the LTD and CTD for optic radiations (OR) were 0.5mm and 3.4mm, respectively; the mean intensity for positive subcortical stimulation of OR was 12mA±2.3mA and 5/6 patients with deterioration of VEPs>50% had persistent hemianopia and transgression of ORs. 12 patients remained stable, one patient had a de-novo transitory hemiparesis, and two showed improvements in motor symptoms. A higher iRMTr for lower limbs was related with a worse motor outcome (p=0.013) and a longer CTD to OR was directly related with a better visual outcome (p=0.041). At 2 weeks after hospital discharge, all patients were ambulatory at home and all proceeded to have oncological treatment. Conclusion: We propose motor and visual function boundaries for asleep surgery of intrinsic non-dominant parietal tumours. Pre-operative abnormal cortical excitability of the motor cortex, deterioration of the VEP recordings and CTD<2mm from the OR were related to poorer outcomes.
ARTICLE | doi:10.20944/preprints202208.0394.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: acute subdural hematoma; comorbidity; elderly; outcome; surgery; timing of surgery; traumatic brain injury
Online: 23 August 2022 (05:08:46 CEST)
Background: The incidence of traumatic acute subdural hematomas (ASDH) in elderly is increasing. Despite surgical evacuation, these patients have poor survival and low rate of functional outcome, and surgical timing plays a no clear role as predictor. We investigated if the timing of surgery has a major role in influencing outcome in these patients.Methods: We retrospectively retrieved clinical and radiological data of all patients ≥70 years operated on for post-traumatic ASDH in a 3 years period in 5 Italian Hospitals. Patients were divided in 3 surgical timing groups from hospital arrival: ultra-early (within 6h); early (6-24h); delayed (after 24h). Outcome was measured at discharge using two endpoints: survival (alive/dead) and functional outcome at Glasgow Outcome Scale (GOS). Univariate and multivariate predictor models were constructed.Results: We included 136 patients. About 33% died for consequences of ASDH and among the survivors only 24% were in good functional outcome at discharge. Surgical timing groups appeared different according to presenting GCS, which was on average lower in ultra-early surgery group, and radiological findings, which appeared worse in the same group. Delayed surgery was more frequent in patients with subacute clinical deterioration. Surgical timing appeared associated neither with survival nor with functional outcome also after stratification for preoperative GCS. Preoperative midline shift was the strongest outcome predictor. Conclusions: An earlier surgery was offered to patients with worse clinical-radiological findings. Also after stratification for GCS it was not associated with better outcome. Among the radiological markers, preoperative midline shift was the strongest outcome predictor.