Aetiology and prognosis of encephalopathic patterns on electroencephalogram in a general hospital

Metronidazole Encephalopathy EEG Features: A Case Report with Systematic Review of the Literature

Metronidazole-induced encephalopathy (MIE) is a rare and often under-recognized iatrogenic condition. The diagnosis should be considered in metronidazole-treated patients presenting with acute encephalopathy, unprovoked seizures and cerebellar signs. While typical magnetic resonance imaging (MRI) findings strongly support the diagnosis, electroencephalography (EEG) features have been rarely reported and poorly described. We present a longitudinal EEG assessment in one patient with encephalopathy due to metronidazole toxicity who presented a peculiar EEG pattern presentation and evolution. During the acute phase of encephalopathy, the EEG showed a monomorphic, sharply contoured theta activity symmetrically represented over frontal regions with an anterior-posterior progression which evolved in parallel with clinical worsening. Together with a systematic review of the literature, we discuss whether this EEG activity may represent a distinct neurophysiological correlate of 'cerebellar encephalopathy'.

Quantitative EEG evaluation in patients with acute encephalopathy

Objective To investigate the use of quantitative EEG (qEEG) in patients with acute encephalopathies (AEs) and EEG background abnormalities. Method Patients were divided into favorable outcome (group A, 43 patients) and an unfavorable outcome (group B, 5 patients). EEGLAB software was used for the qEEG analysis. A graphic of the spectral power from all channels was generated for each participant. Statistical comparisons between the groups were performed. Results In group A, spectral analysis revealed spectral peaks (theta and alpha frequency bands) in 84% (38/45) of the patients. In group B, a spectral peak in the delta frequency range was detected in one patient. The remainder of the patients in both groups did not present spectral peaks. Statistical analysis showed lower frequencies recorded from the posterior electrodes in group B patients. Conclusion qEEG may be useful in the evaluations of patients with AEs by assisting with the prognostic determination.

The EEG as an independent indicator of mortality and healthcare utilization

OBJECTIVE

Determine whether EEG findings could be used as an independent prognostic indicator of outcomes in a general patient population.

METHODS

A large electronic medical record was used to merge the results of EEG studies with the results of medical evaluations including: medications prescribed, medical diagnoses, blood test results, imaging results, and outcomes in 3193 patients. Univariable and multivariable analyses were undertaken to determine whether the EEG had a role in predicting outcomes independent of other factors in a clinic population.

RESULTS

Patients with abnormal EEG's had significantly higher mortalities, greater cost of healthcare and more evaluation visits than patients with normal EEG's in every age range independent of the presence other medical conditions. The costs associated with caring for a patient with an abnormal EEG were roughly three times that of a patient with a normal EEG. The risk of death in the multivariable analysis was 3.7 times higher in patients with an abnormal EEG than in patients with a normal EEG.

CONCLUSIONS

In addition to its traditional diagnostic implications, the EEG may convey information about general level of illness and the cost of caring for patients.

SIGNIFICANCE

Certain EEG findings may identify high risk patients and thus may open the door to possible interventions.