eMedicine Specialties > Neurology > Electroencephalography and Evoked Potentials

Focal EEG Waveform Abnormalities: Multimedia

Author: Joseph F Hulihan, MD, Vice President, Medical Affairs, Ortho-McNeil Janssen Scientific Affairs, LLC
Contributor Information and Disclosures

Updated: Aug 27, 2007

Multimedia

Focal EEG waveform abnormalities. Polymorphic del...
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Media file 1: Focal EEG waveform abnormalities. Polymorphic delta activity. This EEG of a 62-year-old patient with a right parietal glioblastoma demonstrates polymorphic delta activity on the right, maximal in the parietal and occipital leads. This indicates an abnormality of white matter in that hemisphere. Also note the decrease in amplitude of the ongoing background activity on that side, indicating that an abnormality of cortical gray matter is present as well. The latter finding may be due to edema or neoplastic infiltration of the gray matter. Alternatively, it may be due to suppression of gray matter activity from disruption of axonal connections due to the underlying tumor, without a structural abnormality of the gray matter itself.
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Focal EEG waveform abnormalities. Polymorphic del...

Focal EEG waveform abnormalities. Polymorphic delta activity. This EEG of a 62-year-old patient with a right parietal glioblastoma demonstrates polymorphic delta activity on the right, maximal in the parietal and occipital leads. This indicates an abnormality of white matter in that hemisphere. Also note the decrease in amplitude of the ongoing background activity on that side, indicating that an abnormality of cortical gray matter is present as well. The latter finding may be due to edema or neoplastic infiltration of the gray matter. Alternatively, it may be due to suppression of gray matter activity from disruption of axonal connections due to the underlying tumor, without a structural abnormality of the gray matter itself.

Focal EEG waveform abnormalities. This EEG demons...
(Enlarge Image)
Media file 2: Focal EEG waveform abnormalities. This EEG demonstrates periodic lateralized epileptiform discharges (PLEDs) in the left hemisphere in a 54-year-old patient with a history of left temporal ischemic stroke.
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Focal EEG waveform abnormalities. This EEG demons...

Focal EEG waveform abnormalities. This EEG demonstrates periodic lateralized epileptiform discharges (PLEDs) in the left hemisphere in a 54-year-old patient with a history of left temporal ischemic stroke.

Focal EEG waveform abnormalities. Classification ...
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Media file 3: Focal EEG waveform abnormalities. Classification of periodic EEG patterns (Brenner and Schaul).
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Focal EEG waveform abnormalities. Classification ...

Focal EEG waveform abnormalities. Classification of periodic EEG patterns (Brenner and Schaul).

More on Focal EEG Waveform Abnormalities

References
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References

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Further Reading

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Keywords

electroencephalogram, EEG, transient EEG abnormalities, epileptiform patterns, spikes, sharp waves, continuous focal abnormalities, alterations of ongoing EEG background activity, attenuation, enhancement, focal slow-wave abnormalities, periodic EEG patterns, rhythmic and repetitive sharp wave or spike patterns, epileptiform discharges, epileptiform EEG patterns, EEG background rhythms, focal slowing, periodic EEG patterns, periodic lateralized epileptiform discharges, PLEDs, bilateral independent periodic lateralized epileptiform discharges, BIPLEDs

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Contributor Information and Disclosures

Author

Joseph F Hulihan, MD, Vice President, Medical Affairs, Ortho-McNeil Janssen Scientific Affairs, LLC
Joseph F Hulihan, MD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, American Epilepsy Society, American Headache Society, and American Medical Association
Disclosure: Johnson & Johnson Salary Employment; Johnson & Johnson Stock Employment

Medical Editor

Edward B Bromfield, MD, Associate Professor of Neurology, Faculty Member, Division of Sleep Medicine, Harvard Medical School; Chief, Division of EEG, Epilepsy and Sleep Neurology, Consulting Neurologist, Brigham and Women's Hospital
Edward B Bromfield, MD is a member of the following medical societies: American Academy of Neurology, American Clinical Neurophysiology Society, American Epilepsy Society, American Neurological Association, and Massachusetts Medical Society
Disclosure: UCB Pharma Grant/research funds Other

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Norberto Alvarez, MD, Assistant Professor, Department of Neurology, Harvard Medical School; Consulting Staff, Department of Neurology, Boston Children's Hospital
Norberto Alvarez, MD is a member of the following medical societies: American Academy of Neurology, American Epilepsy Society, and Child Neurology Society
Disclosure: Nothing to disclose.

CME Editor

Selim R Benbadis, MD, Professor of Neurology, Director of Comprehensive Epilepsy Program, Departments of Neurology and Neurosurgery, University of South Florida College of Medicine, Tampa General Hospital
Selim R Benbadis, MD is a member of the following medical societies: American Academy of Neurology, American Academy of Sleep Medicine, American Clinical Neurophysiology Society, American Epilepsy Society, and American Medical Association
Disclosure: Nothing to disclose.

Chief Editor

Nicholas Lorenzo, MD, Chief Editor, eMedicine Neurology; Consulting Staff, Neurology Specialists and Consultants
Nicholas Lorenzo, MD is a member of the following medical societies: Alpha Omega Alpha and American Academy of Neurology
Disclosure: Nothing to disclose.

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