EVOKED POTENTIALS IN CHILDREN

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EVOKED POTENTIALS IN CHILDREN

• M. Mohammadi MD
• Professor of Pediatric Neurology, (TUMS)
• Former Fellow, Clinical Paediatric
  Neurophysiology
• University College of London
• GOS Hospital, London, England.

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DEFINITION

• A modified type of EEG to detect and monitor tiny
  potentials induced by sensory stimulations.
• Superb amplification methods
• Computer based averaging

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Types of EPs

• Brainstem Auditory Evoked Potentials (BAEPs)
• Visual Evoked Potentials (VEPs)
• Somatosensory Evoked Potentials (SSEPs)
• Event Related Potentials (ERPs)

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BAEPs (Generators)
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BAEPs
lesion of the lower brainstem
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BAEPs
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VEPs

• Flash VEPs (F-VEPs)
• Pattern Reversal VEPs (PR-VEPs)

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VEPs (Generators)

1. Geniculate Bodies
2. Optic Radiations
3. Visual Cortex

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VEPs
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Somatosensory EPs

• SEPs (cortical)
• SSEPs (spinocortical)

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SEPs (Generators)
Thalamocortical Projections
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Somatosensory EPs
Median
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Evoked Potentials Indications

• Audiology
• Ophthalmology
• Neonatology
• Pediatric Neurology
• Monitoring Programs

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Audiologic Indications

• Neonates
• VLBW Infants (lt1500gr)
• Hyperbilirubinemia (?at the level of ET)
• Prenatal Infections (esp. CMV)
• Postnatal Meningitides
• Aminoglycoside Administrations
• Head Neck Anomalies
• Family Hx of Deafness
• 10 to 12 of Newborns are in high-risk group.
• 5 of high-risk infants will develop HL.

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Audiologic Indications

• Elder Children
• Chronic or Recurrent Otitis Media or Ear
  Infections
• Basal Skull Fractures
• Ototxic Drugs
• Psychomotor especially Language Developmental
  Delays
• Parental Suspicion (25 of HL Cases)
• Childhood Bacterial or ?Viral Meningitides

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Ophthalmologic Indications

• Visual Acuity (PR-VEPs)
• Evaluation of Afferent Visual Pathways when
  there is some types of opacification (F-VEPs).
• Amblyopia
• Retrobulbar Optic Neuritis
• Refractrometry
• ?Cortical Blindness

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Neonatology

• Neonatal Erb Palsy (SSEPs)
• Neonatal Asphyxia (VEPs)

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Pediatric Neurology

• Childhood Ataxia
• VEPs in AT
• SEPs in Freidrichs Ataxia Abetalipoproteinemia
• Demyelinating Disorders
• Developmental Delays
• Hydrocephalus (F-VEPs)
• Neurodegenerative Disorders
• Neurofibromatosis
• NF1 VEPs for Optic Gliomas
• NF2 BAEPs for CPA Angles Tumors
• CNS Tumors
• Spinal Cord Lesions (SSEPs)

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Monitoring by EPs

• Treatment Protocols
• Desferoxamine Neurotoxicity (F-VEPs)
• Leukemia (Leukoencephalopathies or Myelopathies)
• Coma (SEPs BAEPs)
• During Surgical Operations
• Scoliosis Sx
• Aortic Coarctation Sx
• Spinal Cord Angiography