Cranial Nerve Lesion Acoustic Neuroma Presented By Emma

Cranial Nerve Lesion Acoustic Neuroma Presented By: Emma Morales Gigi Sanchez Christine Achenbach Josefina Delgado

Introduction of Cranial Nerve Eight: Vestibulocochlear Nerve b Arises in the inner ear and goes to the pons b Two anatomically and functional parts: f. Cochlear Nerve f Vestibular Nerve b Cranial Nerve XIII functions in hearing and balance

Vestibulocochlear Nerve VIII

Clinical Case of Acoustic Neuroma (Vestibular Shwannoma) b. Robin • European-American woman • 51 years old • Professional Executive • Maintained reasonable diet • Overall in perfectly good health

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

Robin’s 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. 9 cm Acoustic Neuroma

Background: What is Acoustic Neuroma? b Non-cancerous tumor of the eighth cranial Nerve leading from brain to inner ear b Usually grow slowly over a period of years b Not Hereditary: Occur spontaneously without any evidence of inheritable patterns

Common Symptoms b Major symptom: Hearing Loss 95% of those with tumor b Tinnitus b Vertigo b Headaches b Unsteadiness-poor coordination b Facial numbness, tingling, twitching

Signs of Acoustic Neuroma b. Decreased speech discrimination b. Nystagmus b. Abnormal facial electromyogram

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

Clinical Findings: Test b. ENG (Electronystagmography test) Caloric Test b. MRI scan

MRI Classification for AN b Entirely Intracanicular b Intercranial extension without brainstem distortion b Intracranial extension with brainstem distortion

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

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

Clinical Case Plan b Patient Robin decided on RADIATION b FSR treatment • 5 treatments a week • for 5 weeks b Robin’s Follow-up • • • 1 year - improved hearing 2 years – tumor reduced and 92% hearing back no significant side effects

Neurobiology of Acoustic Neuroma: Structures Involved b Eighth Cranial nerve • Vestibular & Cochlear Divisions

Auditory Canal

Internal Auditory Canal

Growth patterns b Stage 1 b Stage 2 b Stage 3