J Neurocrit Care.  2019 Jun;12(1):1-8. 10.18700/jnc.190079.

Generalized periodic discharges with triphasic morphology

• Hartshorn
• Foreman B

• KMID: 2452821
• DOI: http://doi.org/10.18700/jnc.190079

Abstract

Generalized periodic discharges (GPDs) with triphasic morphology are an electroencephalographic (EEG) pattern traditionally associated with encephalopathy and coma, although they have been observed in a wide array of neurological disorders. The clinical significance of these waveforms and their relationship to seizures and prognosis has been debated, and differentiation between interictal patterns, patterns associated with seizures, and patterns representing nonconvulsive status epilepticus can at times be a challenge. The most established literature suggests that GPDs, including those with triphasic morphology, are associated with the development of electrographic seizures, but that in the absence of clinical information, distinguishing waveforms based on morphology alone may not be clinically useful. Recent work has advocated for a more proactive approach in evaluating GPDs with triphasic morphology. Further studies of nonsedating antiseizure drugs in patients with GPDs with triphasic morphology that incorporate continuous EEG monitoring will be useful in tailoring therapy to optimize long-term clinical outcomes and recovery.

Keyword

Triphasic waves; Brain diseases; Generalized periodic discharges; Status epilepticus

MeSH Terms

Brain Diseases
Coma
Electroencephalography
Humans
Nervous System Diseases
Prognosis
Seizures
Status Epilepticus

Figure

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  Fig. 1. Generalized periodic discharges: a 51-year-old man with a history of immunosuppression, liver disease, and heart failure with hyponatremia and sepsis. This pattern is described as a 1 Hz generalized periodic discharge pattern; note the features labeled in the figure that constitute this pattern.

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  Fig. 2. Generalized periodic discharges with triphasic morphology: a 59-year-old man with liver diease who presented with encephalopathy and an elevated ammonia. Distinctive features include three phases and an anterior-posterior time lag as shown in the figure.

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