Therapy-Disability-Neurology Grade

Determine severity of peri-operative complications in neurosurgery.


The most used adverse events grading systems in neurosurgery are based on the therapy used to counteract them. This is an important limitation, as some frequent adverse events such as new neurologic deficits may have dramatic consequences on quality of life but cannot be treated and are thus regarded as low-grade in solely therapy-based grading systems. For example, a severe hemiparesis following tumor resection is usually reported as a grade 1 complication. As a solution, the Therapy-Disability-Neurology grade (TDN) takes into account the therapy used to treat adveres events , as well as the associated neurologic deficits and resulting disability. The TDN Grade was already validated on two cohorts with a total of 6071 patients and an association between the classification and functional outcome as well as costs was shown. The classification scheme was already used in other studies and the grading system is increasingly used in various countries.


Terrapon APR, Zattra CM, Voglis S, Velz J, Vasella F, Akeret K, Held U, Schiavolin S, Bozinov O, Ferroli P, Broggi M, Sarnthein J, Regli L, Neidert MC.

Neurosurgery. 2021 Jul 15;89(2):236-245. doi: 10.1093/neuros/nyab121. PMID: 33887774.

Gómez Vecchio T, Corell A, Buvarp D, Rydén I, Smits A, Jakola AS.

Front Oncol. 2021 Dec 21;11:792878. doi: 10.3389/fonc.2021.792878. PMID: 34993147; PMCID: PMC8724913.

Millward CP, Doherty JA, Mustafa MA, Humphries TJ, Islim AI, Richardson GE, Clynch AL, Gillespie CS, Keshwara SM, Kolamunnage-Dona R, Brodbelt AR, Jenkinson MD, Duncan C, Sinha A, McMahon CJ.

Br J Neurosurg. 2022 Jun;36(3):385-393. doi: 10.1080/02688697.2022.2077311. Epub 2022 May 24. PMID: 35608052.

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