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Encephalopathy electroencephalogram

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] ; Associate Editor(s)-in-Chief: Aditya Govindavarjhulla, M.B.B.S. [2]

Overview

Overview

EEG is a test of cerebral function, it indicates any generalized or focal dysfunction of brain. Generalized slowing of EEG waves is seen in diffuse encephalopathies. It helps in differentiating in epileptiform encephalopathies and epilepsy conditions.

Electroencephalogram

Electroencephalogram

  • Generalized slowing – diffuse encephalopathies
  • Generalized periodic epileptiform discharges[1]
  • Low voltage activity is seen all over the brain
  • Triphasic waves can be seen in few cases


EEG characteristics in METABOLIC and ENDOCRINE disorders
Metabolic Abnormality Posterior Background Rhythm Theta/Delta Activity Fast Activity Reactivity Response to photic stimulation Periodic Delta Periodic Sharp waves FIRDA PLEDS TWs Epileptiform activity NCSE
Hyperthyroidism fast increased excessive prolonged high voltage x x x
Hypothyroidism slow increased-low voltage poor x x
HYpercortisolism slow increased excessive x
Hypocortisolism slow increased-high voltage decreased x
Hyperglycemia slow increased-high voltage excessive x x x x
Hypoglycemia slow increased x x x
Hyponatremia slow increased-high voltage x x x x x x
Hypercalcemia slow increased-high voltage x x x x
Hypocalcemia slow increased-high voltage x x
Hypomagnesemia slow increased-focal x
Thiamine deficiency slow increased-low voltage poor x
Porphyria slow increased-high voltage x
References

References

  1. Husain AM, Mebust KA, Radtke RA (1999). “Generalized periodic epileptiform discharges: etiologies, relationship to status epilepticus, and prognosis”. J Clin Neurophysiol. 16 (1): 51–8. PMID 10082092. Unknown parameter |month= ignored (help)

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  1. Faigle R, Sutter R, Kaplan PW (2013). “Electroencephalography of encephalopathy in patients with endocrine and metabolic disorders”. J Clin Neurophysiol. 30 (5): 505–16. doi:10.1097/WNP.0b013e3182a73db9. PMC 3826953. PMID 24084183.

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