Cranial Nerve Lesion Acoustic Neuroma

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Cranial Nerve Lesion Acoustic Neuroma

• Presented By
• Emma Morales
• Gigi Sanchez
• Christine Achenbach
• Josefina Delgado

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Introduction of Cranial Nerve Eight
Vestibulocochlear Nerve

• Arises in the inner ear and goes to the pons
• Two anatomically and functional parts
• Cochlear Nerve
• Vestibular Nerve
• Cranial Nerve XIII functions in hearing and
  balance

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Vestibulocochlear Nerve VIII
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Clinical Case of Acoustic Neuroma (Vestibular
Shwannoma)

• Robin
• European-American woman
• 51 years old
• Professional Executive
• Maintained reasonable diet
• Overall in perfectly good health

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Robins Symptoms

• Symptoms started 2 years ago
• telephone communication distorted -right ear
• tinnitus-right ear
• dizzy spells at work
• bumping into things everywhere

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Robins visit to General Physician

• First General Physician
• diagnosed her with inner ear imbalance from her
  last plane trip
• Antivert medication was prescribed
• no change in symptoms
• Second Physician
• MRI scan
• found small 0.9cm Acoustic Neuroma

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Background What is Acoustic Neuroma?

• Non-cancerous tumor of the eighth cranial Nerve
  leading from brain to inner ear
• Usually grow slowly over a period of years
• Not Hereditary Occur spontaneously without any
  evidence of inheritable patterns

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Common Symptoms

• Major symptom Hearing Loss 95 of those with
  tumor
• Tinnitus
• Vertigo
• Headaches
• Unsteadiness-poor coordination
• Facial numbness, tingling, twitching

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Signs of Acoustic Neuroma

• Decreased speech discrimination
• Nystagmus
• Abnormal facial electromyogram

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Statistical Information

• Found in autopsy in less than one in one-hundred
  of the general population
• Hearing loss and symptoms occur in about one
  person in 100, 000
• Diagnosed in patients between the ages of 30-60
• Cause unknown

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Clinical Findings Test

• ENG
• (Electronystagmography test)
• Caloric Test
• MRI scan

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MRI Classification for AN

• Entirely Intracanicular
• Intercranial extension without brainstem
  distortion
• Intracranial extension with brainstem distortion

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Diagnosis Findings on Clinical Case
Detected small .9cm Acoustic Neuroma affected
hearing loss and balance
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Treatment Options

• Observation
• Surgery- Microsurgical tumor removal
• Partial tumor removal
• Total tumor removal
• Radiation
• Gamma Knife
• FSR

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Clinical Case Plan

• Patient Robin decided on RADIATION
• FSR treatment
• 5 treatments a week
• for 5 weeks
• Robins Follow-up
• 1 year - improved hearing
• 2 years tumor reduced and 92 hearing back
• no significant side effects

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Neurobiology of Acoustic Neuroma Structures
Involved

• Eighth Cranial nerve
• Vestibular Cochlear Divisions

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Auditory Canal
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Internal Auditory Canal

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Growth patterns

• Stage 1
• Stage 2
• Stage 3