Investigation of the Predictive Value of Routine EEG Compared to Continuous EEG in the Acute Phase of TBI
Abstract number :
3.47
Submission category :
3. Neurophysiology / 3B. ICU EEG
Year :
2025
Submission ID :
1461
Source :
www.aesnet.org
Presentation date :
12/8/2025 12:00:00 AM
Published date :
Authors :
Presenting Author: Rafael Valeriano, MD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Thiago Lima, PhD – Universidade Federal do Rio Grande do Norte, RN, Brazil
Maira Licia Foresti, PhD – Instituto D'Or de Pesquisa e Ensino (IDOR) - SP, Brazil
João Paulo Oliveira, MD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Carla Baise, MD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Gustavo Santos, MD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Natália Longo, MD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Joaquina Andrade, MD, PhD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Gesael Ferreira Jr, MD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Carlos Oshiro, MD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Luiz Eugênio Mello, MD, PhD – Instituto D'Or de Pesquisa e Ensino (IDOR) - SP, Brazil
Eliana Garzon, MD, PhD – Faculdade de Medicina, Hospital das Clínicas, Universidade de São Paulo, SP, Brazil
Rationale: Continuous EEG (cEEG) increases the sensitivity for detecting epileptiform discharges and electrographic seizures compared to routine EEG (rEEG), which would enable early treatment and prevent secondary brain injury in critically ill patients, but its cost and limited availability restricts its widespread use. Evidence on the impact of cEEG versus rEEG in the management of TBI remains scarce. This study aimed to determine conditions following TBI that could render EEG shortening safer and, on the other hand, when extended monitoring would be most informative.
Methods: Thirty-five adults with acute TBI, admitted between 2018 and 2020 in a hospital unit, underwent prospective 24h cEEG monitoring within 1–10 days post-injury, yielding 134 EEG segments (30min rEEG, 1h rEEG, and 24h cEEG) in total. Patients were clinically followed for two years for post-traumatic epilepsy (PTE). Analyses included established EEG attributes such as background activity, epileptiform discharges and electrographic seizures. For statistics, the Wald test or a generalized likelihood ratio test (GLRT), both based on generalized linear mixed models (GLMM) were used. The weighted mathematical distance between full-length cEEG and shorter recordings was analyzed according to clinical relevance (e.g., weight 1 for basal slow-wave up to 4 for seizures). The risk of not detecting epileptiform discharges and seizures due to EEG shortening was estimated and potential risk factors for seizures were also assessed.
Results: (Ethical approval - HCFMUSP 08533513.6.2002.0068). Of the examinations, 2/90 (2.2%) were normal, a finding that was consistent across 30min rEEG, 1h rEEG, and 24h cEEG. Depressed consciousness, sedative use, polytrauma, midline shift, and TBI severity were associated with reduced distance between cEEG and shorter EEGs, with complete equivalence reaching up to 80% in some cases. Detecting epileptiform discharges only in the cEEG occurred in 10.3% of patients with spontaneous wake–sleep cycle versus 1.8% of those in a coma. Skull fracture was identified as a protective factor for acute seizures, while prolonged sedation was a consistent risk factor for post-traumatic epilepsy.
Conclusions: Continuous EEG in the acute phase of TBI provides additional diagnostic value compared to shorter recordings, particularly in patients with preserved consciousness and without sedation. However, shorter monitoring may be sufficient under other specific clinical conditions. These findings highlight the conditions under which EEG monitoring may be safely shortened, offering clinically relevant evidence to optimize resource use and guide individualized monitoring strategies in TBI.
Funding: São Paulo Research Foundation - FAPESP: 18/24561–5. National Council for Scientific and Technological Development – CNPq: 311619/2019–3.
Neurophysiology