Cranial Nerve LesionCranial Nerve Lesion Acoustic Neuroma Acoustic Neuroma

Presented By:Emma MoralesGigi Sanchez

Christine AchenbachJosefina Delgado

Introduction of Cranial Introduction of Cranial Nerve Eight: Nerve Eight: Vestibulocochlear NerveVestibulocochlear Nerve

Arises in the inner ear and goes to the Arises in the inner ear and goes to the ponspons

Two anatomically and functional parts:Two anatomically and functional parts:Cochlear NerveCochlear Nerve Vestibular NerveVestibular Nerve

Cranial Nerve XIII functions in hearing Cranial Nerve XIII functions in hearing and balanceand balance

Vestibulocochlear Nerve Vestibulocochlear Nerve VIIIVIII

Clinical Case of Acoustic Clinical Case of Acoustic Neuroma Neuroma (Vestibular (Vestibular Shwannoma)Shwannoma)

RobinRobin•European-American womanEuropean-American woman•51 years old51 years old•Professional ExecutiveProfessional Executive•Maintained reasonable dietMaintained reasonable diet•Overall in perfectly good Overall in perfectly good

healthhealth

Robin’s SymptomsRobin’s Symptoms

•Symptoms started 2 years agoSymptoms started 2 years ago–telephone communication telephone communication distorted -right eardistorted -right ear

–tinnitus-right eartinnitus-right ear–dizzy spells at workdizzy spells at work–bumping into things bumping into things everywhereeverywhere

Robin’s visit to General Robin’s visit to General PhysicianPhysician

•First General PhysicianFirst General Physician•diagnosed her with inner ear diagnosed her with inner ear imbalance from her last plane trip imbalance from her last plane trip

• Antivert medication was prescribedAntivert medication was prescribed•no change in symptomsno change in symptoms

•Second Physician Second Physician •MRI scanMRI scan•found small 0.9cm Acoustic found small 0.9cm Acoustic NeuromaNeuroma

Background: Background: What is Acoustic What is Acoustic Neuroma?Neuroma?

Non-cancerous tumor of the eighth Non-cancerous tumor of the eighth cranial Nerve leading from brain to cranial Nerve leading from brain to inner earinner ear

Usually grow slowly over a period Usually grow slowly over a period of yearsof years

Not Hereditary: Occur Not Hereditary: Occur spontaneously without any spontaneously without any evidence of inheritable patternsevidence of inheritable patterns

Common SymptomsCommon Symptoms

Major symptom: Hearing Loss Major symptom: Hearing Loss 95% of those with tumor95% of those with tumor

TinnitusTinnitus VertigoVertigo HeadachesHeadaches Unsteadiness-poor coordinationUnsteadiness-poor coordination Facial numbness, tingling, Facial numbness, tingling,

twitchingtwitching

Signs of Acoustic Signs of Acoustic NeuromaNeuroma

Decreased speech Decreased speech discrimination discrimination

NystagmusNystagmusAbnormal facial Abnormal facial

electromyogramelectromyogram

Statistical InformationStatistical Information

Found in autopsy in less than one Found in autopsy in less than one in one-hundred of the general in one-hundred of the general populationpopulation

Hearing loss and symptoms occur Hearing loss and symptoms occur in about one person in 100, 000in about one person in 100, 000

Diagnosed in patients between Diagnosed in patients between the ages of 30-60 the ages of 30-60

Cause unknownCause unknown

Clinical Findings: TestClinical Findings: Test

ENGENG(Electronystagmogr(Electronystagmogr

aphy test)aphy test)

Caloric TestCaloric Test

MRI scanMRI scan

MRI Classification for ANMRI Classification for AN

Entirely IntracanicularEntirely Intracanicular Intercranial extension without Intercranial extension without

brainstem distortionbrainstem distortion Intracranial extension with Intracranial extension with

brainstem distortionbrainstem distortion

Diagnosis: Findings on Diagnosis: Findings on Clinical CaseClinical Case

Detected small .9cm Acoustic Neuromaaffected hearing loss and balance

Treatment OptionsTreatment Options

ObservationObservation Surgery- Microsurgical tumor Surgery- Microsurgical tumor

removalremoval• Partial tumor removalPartial tumor removal• Total tumor removalTotal tumor removal

RadiationRadiation• Gamma KnifeGamma Knife• FSRFSR

Clinical Case PlanClinical Case Plan

Patient Robin decided on RADIATIONPatient Robin decided on RADIATION FSR treatment FSR treatment

• 5 treatments a week5 treatments a week• for 5 weeksfor 5 weeks

Robin’s Follow-upRobin’s Follow-up• 1 year - improved hearing1 year - improved hearing• 2 years – tumor reduced and 92% 2 years – tumor reduced and 92%

hearing backhearing back• no significant side effectsno significant side effects

Neurobiology of Acoustic Neurobiology of Acoustic Neuroma: Structures Neuroma: Structures InvolvedInvolved

Eighth Cranial nerve Eighth Cranial nerve • Vestibular & Cochlear DivisionsVestibular & Cochlear Divisions

Auditory Canal Auditory Canal

Internal Auditory Canal Internal Auditory Canal

Growth patternsGrowth patterns

Stage 1Stage 1

Stage 2Stage 2

Stage 3Stage 3