Yonsei Med J.  2011 Nov;52(6):933-938. 10.3349/ymj.2011.52.6.933.

The Assessment of Routine Electroencephalography in Patients with Altered Mental Status

• Seo KD
• Choi YC
• Kim WJ

• KMID: 1058812
• DOI: http://doi.org/10.3349/ymj.2011.52.6.933

Abstract

PURPOSE
Changes in electroencephalography (EEG) patterns may offer a clue to the cause of altered mental status and suggest the prognoses of patients with such mental status. We aimed to identify the EEG patterns in patients with altered mental status and to correlate EEG findings with clinical prognoses.
MATERIALS AND METHODS
We included 105 patients with altered mental status who underwent EEG. EEG and clinical chart reviews with ongoing patient follow-ups were performed to determine the clinical prognosis of the patients. Clinical data were sorted using the Glasgow Coma Scale (GCS) and Glasgow Outcome Scale (GOS). EEG findings were classified according to a method suggested by Scollo-Lavizzari. The EEGs were analyzed to find out whether any correlation existed with the prognoses of patients.
RESULTS
Nonconvulsive status epilepticus (NCSE) was detected in only three patients (2.9%). Specific EEG patterns were observed in 28 patients. Twenty-nine (27.6%) patients expired, and 45 (42.9%) patients were in a vegetative state. EEG grade and GCS significantly correlated with GOS. EEG grade alone had a correlation with GCS. Patients with a severe EEG finding had a poor prognosis.
CONCLUSION
EEG findings reflect the mental status of patients, and EEG grades are correlated with the clinical prognosis of patients. Although EEG is not frequently performed on patients with altered mental state, it can play a supplemental role in establishing a prognosis. Thus, the use of EEG should be emphasized in clinical setting.

Keyword

Electroencephalography; prognosis; NCSE

MeSH Terms

Adolescent
Adult
Aged
Aged, 80 and over
Child
Electroencephalography/*methods
Epilepsy, Generalized/*diagnosis
Female
Glasgow Coma Scale
Humans
Male
Middle Aged
Retrospective Studies
Young Adult

Figure

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  Fig. 1 Correlation analysis between the EEG grade and GOS (A), GCS and GOS (B). (A) Spearman correlation coefficient=-0.353, p<0.01, (B) Spearman correlation coefficient=0.464, p<0.01. GCS, Glasgow Coma Scale; GOS, Glasgow Outcome Scale; EEG, electroencephalography.

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