{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,31]],"date-time":"2026-10-31T00:21:37Z","timestamp":1793406097824,"version":"4.5.0"},"reference-count":29,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,5,31]],"date-time":"2026-05-31T00:00:00Z","timestamp":1780185600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Brain Sciences"],"abstract":"<jats:p>Background\/Objectives: Adverse events (AE) associated with neurosurgical interventions can cause neurological deficits and impaired functional outcomes. The Therapy\u2013Disability\u2013Neurology (TDN) grade classifies AE severity based on treatment requirements, disability, and neurological deficits, but has not been validated in aneurysmal subarachnoid hemorrhage (aSAH). We aimed to validate the TDN grade in predicting functional outcomes and length of hospital stay (LOS) in aSAH patients, treated surgically and\/or endovascularly. Methods: We conducted a single-center retrospective cohort study of a prospectively collected database of aSAH patients. Patients were recruited between 2009 and 2022. The TDN grade was retrospectively applied. Primary outcome variables were functional outcomes, assessed using the Glasgow Outcome Scale (GOS, selected for comparability with prior aSAH outcome literature), at discharge and last follow-up, and LOS. Results: We included 355 patients: mean age was 57.2 (12.9 SD) and 235 (66.1%) were female. The TDN grade showed a moderate positive correlation with length of hospital stay (rho = 0.4, p &lt; 0.001). Negative correlations were observed with functional outcomes at discharge (GOS: rho = \u22120.56, p &lt; 0.0001) and at last follow-up (GOS: rho = \u22120.58, p &lt; 0.0001). The TDN grade demonstrated good discrimination for unfavorable outcome at last follow-up (AUC = 0.82) and good discrimination for employment status (AUC = 0.71). Patients with AEs stayed 7.63 days longer on average (p &lt; 0.001). Conclusions: The TDN grade predicted hospital stay and functional outcomes in aSAH patients treated surgically and\/or endovascularly, demonstrating good discrimination for unfavorable outcomes and employment status. These findings extend the grade\u2019s applicability to both treatment- and disease-related complications and support its potential utility as a standardized tool for prognostication and resource planning. Results should be interpreted in light of the single-center retrospective design and selection bias.<\/jats:p>","DOI":"10.3390\/brainsci16060599","type":"journal-article","created":{"date-parts":[[2026,6,3]],"date-time":"2026-06-03T06:17:31Z","timestamp":1780467451000},"page":"599","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Assessment of Adverse Events Using the Therapy\u2013Disability\u2013Neurology (TDN) Grading System in a Cohort of Aneurysmal Subarachnoid Hemorrhage Patients: A Single-Center Retrospective Cohort Study"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-0181-0609","authenticated-orcid":false,"given":"Vincens","family":"K\u00e4lin","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3721-7484","authenticated-orcid":false,"given":"Alexis Paul Romain","family":"Terrapon","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"},{"name":"Department of Neurosurgery, Inselspital, Bern University Hospital, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna Maria","family":"Zeitlberger","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5322-7327","authenticated-orcid":false,"given":"Gareth","family":"Ambler","sequence":"additional","affiliation":[{"name":"Department of Statistical Science, University College London, London WC1E 6BT, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Svenja","family":"Maschke","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8710-6323","authenticated-orcid":false,"given":"Ahmed","family":"El-Garci","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"},{"name":"Department of Pediatric Neurosurgery, Charit\u00e9 Universit\u00e4tsmedizin Berlin, 10117 Berlin, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Bonasia","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"},{"name":"Centro Della Colonna Vertebrale, Clinica Ars Medica, Via Grumo 16, 6929 Gravesano, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oliver","family":"Bozinov","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marian Christoph","family":"Neidert","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isabel Charlotte","family":"Hostettler","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, HOCH Health Ostschweiz, Cantonal Hospital St. Gallen, 9000 St. Gallen, Switzerland"},{"name":"Department of Neurosurgery, Klinikum Rechts der Isar, TUM School of Medicine and Health, Technical University of Munich, 80333 Munich, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1097\/SLA.0b013e31828e3ac3","article-title":"Association between occurrence of a postoperative complication and readmission: Implications for quality improvement and cost savings","volume":"258","author":"Lawson","year":"2013","journal-title":"Ann. Surg."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"100853","DOI":"10.1016\/j.bas.2021.100853","article-title":"Assessment of the incidence and nature of adverse events and their association with human error in neurosurgery. A prospective observation","volume":"2","author":"Meyer","year":"2022","journal-title":"Brain Spine"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1097\/SLA.0b013e3181b13ca2","article-title":"The Clavien-Dindo classification of surgical complications: Five-year experience","volume":"250","author":"Clavien","year":"2009","journal-title":"Ann. Surg."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"100860","DOI":"10.1016\/j.bas.2022.100860","article-title":"Neurosurgery outcomes and complications in a monocentric 7-year patient registry","volume":"2","author":"Sarnthein","year":"2022","journal-title":"Brain Spine"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"E10","DOI":"10.3171\/2021.8.FOCUS20892","article-title":"Validation of the Clavien-Dindo grading system of complications for microsurgical treatment of unruptured intracranial aneurysms","volume":"51","author":"Blum","year":"2021","journal-title":"Neurosurg. Focus."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2555","DOI":"10.1007\/s00701-023-05672-w","article-title":"Association of the classification of intraoperative adverse events (ClassIntra) with complications and neurological outcome after neurosurgical procedures","volume":"165","author":"Drexler","year":"2023","journal-title":"Acta Neurochir."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"709","DOI":"10.1016\/j.wneu.2010.11.010","article-title":"A new classification of complications in neurosurgery","volume":"75","author":"Hem","year":"2011","journal-title":"World Neurosurg."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"236","DOI":"10.1093\/neuros\/nyab121","article-title":"Adverse Events in Neurosurgery: The Novel Therapy-Disability-Neurology Grade","volume":"89","author":"Terrapon","year":"2021","journal-title":"Neurosurgery"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"37600","DOI":"10.1038\/s41598-025-21065-8","article-title":"International survey-based assessment of the reliability, validity, and interpretability of the TDN grade for neurosurgical adverse events","volume":"15","author":"Terrapon","year":"2025","journal-title":"Sci. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"635","DOI":"10.1016\/S1474-4422(09)70126-7","article-title":"Changes in case fatality of aneurysmal subarachnoid haemorrhage over time, according to age, sex, and region: A meta-analysis","volume":"8","author":"Nieuwkamp","year":"2009","journal-title":"Lancet Neurol."},{"key":"ref_11","first-page":"e519","article-title":"Cognitive and functional outcome after aneurysmal subarachnoid hemorrhage","volume":"41","author":"Macdonald","year":"2010","journal-title":"Stroke"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1056\/NEJMra052732","article-title":"Aneurysmal subarachnoid hemorrhage","volume":"354","author":"Suarez","year":"2006","journal-title":"N. Engl. J. Med."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1159\/000346087","article-title":"European Stroke Organization guidelines for the management of intracranial aneurysms and subarachnoid haemorrhage","volume":"35","author":"Steiner","year":"2013","journal-title":"Cerebrovasc. Dis."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1056\/NEJM199701023360106","article-title":"Intracranial aneurysms","volume":"336","author":"Schievink","year":"1997","journal-title":"N. Engl. J. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"e326","DOI":"10.1212\/WNL.0000000000006814","article-title":"Early focal brain injury after subarachnoid hemorrhage correlates with spreading depolarizations","volume":"92","author":"Eriksen","year":"2019","journal-title":"Neurology"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1225","DOI":"10.1161\/01.STR.0000015624.29071.1F","article-title":"Global cerebral edema after subarachnoid hemorrhage: Frequency, predictors, and impact on outcome","volume":"33","author":"Claassen","year":"2002","journal-title":"Stroke"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1711","DOI":"10.1161\/STR.0b013e3182587839","article-title":"Guidelines for the management of aneurysmal subarachnoid hemorrhage: A guideline for healthcare professionals from the American Heart Association\/American Stroke Association","volume":"43","author":"Connolly","year":"2012","journal-title":"Stroke"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/j.neuropharm.2017.09.027","article-title":"Spreading depolarization is not an epiphenomenon but the principal mechanism of the cytotoxic edema in various gray matter structures of the brain during stroke","volume":"134","author":"Dreier","year":"2018","journal-title":"Neuropharmacology"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"800","DOI":"10.1097\/EDE.0b013e3181577654","article-title":"The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: Guidelines for reporting observational studies","volume":"18","author":"Altman","year":"2007","journal-title":"Epidemiology"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1097\/01.CCM.0000201903.46435.35","article-title":"Impact of medical complications on outcome after subarachnoid hemorrhage","volume":"34","author":"Wartenberg","year":"2006","journal-title":"Crit. Care Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1097\/00003246-199506000-00004","article-title":"Medical complications of aneurysmal subarachnoid hemorrhage: A report of the multicenter, cooperative aneurysm study","volume":"23","author":"Solenski","year":"1995","journal-title":"Crit. Care Med."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1136\/jnnp.68.3.337","article-title":"Complications and outcome in patients with aneurysmal subarachnoid haemorrhage: A prospective hospital based cohort study in the Netherlands","volume":"68","author":"Roos","year":"2000","journal-title":"J. Neurol. Neurosurg. Psychiatry"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1016\/j.jocn.2017.03.049","article-title":"Reducing length of stay in aneurysmal subarachnoid hemorrhage: A three year institutional experience","volume":"42","author":"Alaraj","year":"2017","journal-title":"J. Clin. Neurosci."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"204","DOI":"10.1055\/s-0040-1720982","article-title":"Health Economic Aspects of Aneurysmal Subarachnoid Hemorrhage: Factors Determining First Year In-Hospital Treatment Expenses","volume":"82","author":"Ridwan","year":"2021","journal-title":"J. Neurol. Surg. A Cent. Eur. Neurosurg."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"6","DOI":"10.1186\/1478-7547-8-6","article-title":"Burden of disease and costs of aneurysmal subarachnoid haemorrhage (aSAH) in the United Kingdom","volume":"8","author":"Gray","year":"2010","journal-title":"Cost. Eff. Resour. Alloc."},{"key":"ref_26","first-page":"21","article-title":"Prediction of symptomatic vasospasm after subarachnoid hemorrhage: The modified fisher scale","volume":"59","author":"Frontera","year":"2006","journal-title":"Neurosurgery"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"13","DOI":"10.3171\/JNS-07\/07\/0013","article-title":"Relation among aneurysm size amount of subarachnoid blood clinical outcome","volume":"107","author":"Salary","year":"2007","journal-title":"J. Neurosurg."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1093\/neuros\/nyaa316","article-title":"Validation and Optimization of Barrow Neurological Institute Score in Prediction of Adverse Events and Functional Outcome After Subarachnoid Hemorrhage\u2014Creation of the HATCH (Hemorrhage, Age, Treatment, Clinical State, Hydrocephalus) Score","volume":"88","author":"Hostettler","year":"2020","journal-title":"Neurosurgery"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1002\/ana.24675","article-title":"Prognostication of long-term outcomes after subarachnoid hemorrhage: The FRESH score","volume":"80","author":"Witsch","year":"2016","journal-title":"Ann. Neurol."}],"container-title":["Brain Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-3425\/16\/6\/599\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,6,5]],"date-time":"2026-06-05T02:14:06Z","timestamp":1780625646000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-3425\/16\/6\/599"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,31]]},"references-count":29,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,6]]}},"alternative-id":["brainsci16060599"],"URL":"https:\/\/doi.org\/10.3390\/brainsci16060599","relation":{},"ISSN":["2076-3425"],"issn-type":[{"value":"2076-3425","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,31]]}}}