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Chronic Otorrhea and Otitis Media Isn’t Always What It Appears: Skull Base Defects

Department of Otolaryngology Head and Neck Surgery

Medical University of South Carolina

Ted Meyer, MD, PHD

Mary Ann Howerton, PAC

Learning ObjectivesLearning Objectives

1. Describe the presentation of patients with skull base defects, with emphasis on temporal bone defects.

2. Discuss the etiologies of skull base defects.

3. Describe surgical repair of skull base defects.

4. Discuss nursing implications and post-op care of patients with skull base surgery.

5. Participate in an interactive discussion on the care of the patients with skull base defects.

CSF CSF OtorrheaOtorrhea

• Definitiono Presence of CSF within the confines of the temporal bone

• Causeso Trauma (most common)

o Iatrogenic

o Neoplastic

o Infectious

o Congenital

o Spontaneous

• Spontaneous CSF otorrhea occurs in the absence of any inciting event

AAnatomynatomy

• External ear

o Pinna

o External auditory canal

• Middle ear

o Ossicles

• Inner ear

o cochlea

o Vestibule

o Semicircular canals

From studyblue.com

AAnatomynatomy

From Frank Netter

Anatomy Anatomy –– Axial CTAxial CT

From radiographics.rsna.org

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Anatomy Anatomy –– Coronal CTCoronal CT

From radiographics.rsna.org

PathophysiologyPathophysiology

• Not well understood

• Theories

1. Congenital bony dehiscence in the mastoid tegmen may

predispose to dural herniation and CSF leakage

2. Arachnoid granulations

• Acts as reservoir for CSF

• Site of pressure transmission to underlying bone

• Erosion of bone

PathophysiologyPathophysiology

3. Central venous obstruction impairing normal pressure

• High intracranial CSF pressures cause gradual skull

base attenuation overtime

• Sigmoid or transverse sinus thromboses

• Hypercompliant venous sinuses

4. Anatomical Predispostion involving thinning of

cranial base

• Congenital

• Arachnoid Granulation

• Chronic Idiopathic Intracranial Hypertension

• Obesity

Pathophysiology Pathophysiology -- ObesityObesity

• Obesity defined as BMI ≥ 30kg/m²

• Associated with other co-morbidities

• Hypertension, diabetes, OSA, etc

• Increased intra-abdominal pressure

• Decreased venous return

• Increased intracranial pressure

Pathophysiology Pathophysiology -- ObesityObesity

• Levay, A., Kveton, J. Retrospective review looking at

relationship between obesity, OSA, and spontaneous CSF

otorrhea

• 29 patients with CSF otorrhea

o 14 spontaneous; 14 non-spontaneous

o Avg BMI 35.3 spontaneous; 28.5 non-spontaneous

o Patients with spontaneous otorrhea were more likely to be morbidly obese than non-spontaneous otorrhea patients

o Diagnosis of OSA was more common in spontaneous (4)

than non-spontaneous (0)

Pathophysiology Pathophysiology -- Obesity Obesity

o Scurry, W.C., et al. performed a retrospective review to

determine location, nature, and etiology of encephaloceles

o 8 patients were found to have spontaneous, idiopathic

temporal bone encephaloceles, all of which BMI was > 30

o Avg BMI 48.6 kg/m²

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Pathophysiology Pathophysiology -- ObesityObesity

o Conclusion:

• Morbid obesity leads to Benign intracranial

hypertension

• Coorelation exists between morbid obesity and temporal bone encephaloceles/CSF otorrhea

o Explanation: High intracranial pressures secondary

to morbid obesity lead to chronic trauma to skull base causing bony dehiscence � CSF otorrhea

and encepholocele

From Scurry, W.C., et al.

DemographicsDemographics

• Female

• Middle – aged

• Obese

• Idiopathic Intracranial Hypertension?

Literature ReviewLiterature Review

• Goddard J., Meyer T., Nguyen S., Lambert P.

• Retrospective review

• Patients with spontaneous CSF otorrhea that underwent

primary surgical repair between 2000 and 2009

• Demographic information including age, sex, race,

height, weight and BMI were recorded

• Hypothesis: Spontaneous CSF otorrhea is more common in middle aged, female patients with BMI > 30

Literature ReviewLiterature Review

Results

o 23 patients• 10 men, 13 women

• 14 Caucasian, 9 AA

• Mean age 60• Mean weight 103.7 kg

• Mean BMI 36.3

o Males – mean BMI 36.0o Females – mean BMI 36.5

• Similar demographic profile to CSF rhinorrhea and Idiopathic Intracranial hypertension

• This study and previous studies have demonstrated similar demographic features

Idiopathic Intracranial HypertensionIdiopathic Intracranial Hypertension

Benign IH (BIH)Benign IH (BIH)

• Impaired CSF absorption causing elevated intracranial

pressure

• Obese, middle-aged females (most common)

• Headaches, pulsatile tinnitus, papilledema, visual

disturbances

• Dandy Criteria is used to formally diagnose

• Radiographic imaging demonstrates empty or partially empty sella

Dandy CriteriaDandy Criteria

• Original criteria described by Dandy in 1937

• It was then modified by Smith in 1985

Modified Dandy Criteria

1)Signs and symptoms increased pressure

2) Increased ICP

3) absence of localizing findings on neurologic exam

4) absence of neuroradiographic abnormality (exceptions small

ventricles and empty sella)

5) awake and alert

6) no other cause of ICP

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IIH and Empty IIH and Empty SellaSella

• Common radiographic finding in IIH and CSF leaks

• Empty sella = empty pituitary fossa

• Pituitary fossa which is largely empty of tissue and

replaced by CSF

IIH and Empty IIH and Empty SellaSella

From Pritchard, et al.

Normal Empty Sella

Idiopathic Intracranial HypertensionIdiopathic Intracranial Hypertension

• Research

o Goddard, et al. – 12 of 15 with preoperative MRI demonstrated empty or partially empty sella

o Former studies

• Pritchard et al. – 5 of 7 patients with spontaneous CSF otorrhea demonstrated findings of an empty or partially empty sella

• Schlosser and Bolger noted that nearly all patients with CSF rhinorrhea demonstrated empty sella on MRI and 72% met Dandy criteria for IIH

• Previous studies and reports do seem to suggest the presence of empty/partially empty sella more common in patients with spontaneous CSF leak

Clinical Presentation CSF Clinical Presentation CSF OtorrheaOtorrhea

• Unilateral hearing loss

• Unilateral chronic serous otitis media

• Aural fullness

• Persistent otorrhea with tube placement

• Meningitis

Physical ExamPhysical Exam

• Otoscopy

• Tuning Forks suggesting conductive hearing loss

• Evaluate Nasopharynxfor mass or reason for unilateral symptoms

• Myringotomy – yes or no?

AudiologicalAudiological TestingTesting

• Audiometry

o Unilateral conductive

hearing loss

o Flat tympanogram

From sciencedirect.com

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Laboratory TestingLaboratory Testing

• Beta-2 Transferrin

o Most common laboratory test used to diagnose CSF leak in US

o Only found in CSF, perilymph, and vitreous humor of the

eye

ImagingImaging

• High resolution CT is the initial radiographic test of choice

• MRI is a useful adjunct

o Effective in identifying mengioencephalocele formation

o Effective in recognizing empty sella

• CT/MRI cisternogram - Cisternography with injected contrast

medium usually localizes the CSF leak

High Resolution Axial CTHigh Resolution Axial CT High Resolution Axial CTHigh Resolution Axial CT

Imaging Imaging –– coronal CTcoronal CT

o Tegmen – roof

o Should be solid bone

o Ratty, moth-eaten appearance …..

o Arachnoid granulations, CSF alone, meningocele,

encephalocele, meningoencephalocele

High Resolution Coronal CTHigh Resolution Coronal CT

Normal CSF Otorrhea

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High Resolution Coronal CTHigh Resolution Coronal CT

Normal CSF otorrhea

High Resolution Coronal CTHigh Resolution Coronal CT

High Resolution Coronal CTHigh Resolution Coronal CT MRI MRI

From Kutz et al.

T2 MRI – fluid white

Fluid in right mastoid

Encephalocele hanging down

PreopPreop

• Most patients are obese, many with other co-morbidities –HTN, DM, aspirin, coumadin, ….

• Preop workup

o Chest xray, EKG

o CBC, BMP

o PT/INR, PTT?

• Often require medical clearance from PCP, cardiologist, etc

TreatmentTreatment

• Treatment is surgicalo Trans-mastoid approach

o Middle cranial fossa approach

o Combination

• The age of the patient, medical comorbidities, defect location, history of previous repair, and surgeon experience are all factors to consider

• Materials used to repair defect include temporalis fascia, calvarial bone, bone cement

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TransTrans--mastoid Surgical Approachmastoid Surgical Approach

• Trans-mastoid

o Defects involving posterior fossa and tegmen mastoideum

o PRO

o Least invasive – ear surgery, not brain surgery

o Advantage of visualization of middle fossa, posterior fossa, and middle ear

o fewer risks of bleeding, stroke, …

o CON

o Get as good a seal?

o recurrence rate?

o what if it bleeds – can it be controlled?

TransTrans--mastoid Surgical Approach mastoid Surgical Approach

From aofoundation.org

Middle Fossa Surgical ApproachMiddle Fossa Surgical Approach

• Middle Fossao Defects involving tegmen mastoideum and tegmen tympani

o PRO

o Fixing leak from inside cranial vault – might see defect better

o Maximum exposure

o CON

o More invasive - Brain surgery rather than ear surgery

o Leave inflammation or other tissue behind

o If brain is sitting on heads of ossicles – still have CHL

Middle Fossa Surgical ApproachMiddle Fossa Surgical Approach

From michiganear.com

Middle Fossa Surgical ApproachMiddle Fossa Surgical Approach

From Gubbels et al.

Middle Fossa Surgical ApproachMiddle Fossa Surgical Approach

From Gubbels et al.

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Surgical ApproachSurgical Approach Surgical ApproachSurgical Approach

Surgical ApproachSurgical Approach Surgical ApproachSurgical Approach

Surgical ApproachSurgical Approach Surgical ApproachSurgical Approach

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Lumbar Drain ??Lumbar Drain ??• Yes or no? – No for us

• PRO

o Provides means to measure ICP

o Provides ability to inject intrathecal fluorescein

o Reduces CSF pressure post-operatively

• CON

o Fluorescein is not FDA approved for intra-thecal injection

o Risk of seizure and neurotoxicity with high concentration or

rapid injection

o Must remain bed rest until drain removed – longer hospital

stay

o Risks: bleeding, infection, nerve irritation, paralysis, post-spinal headaches, and pneumocephalus

Acetazolamide?Acetazolamide?

• Carbonic anhydrase inhibitor

• decreases CSF production

• Diuretic often given in management of IIH

• May be important in patients with IIH who have undergone surgical repair for spontaneous CSF otorrhea

PostPost--operative Courseoperative Course

• Inpatient – billing purposes – might not collect anything if done outpatient

• often NPO overnight

• ambulate…tough with obese population

• Foley?

• Steroids?

• Mannitol?

PostPost--operative Courseoperative Course

• Expected phone calls – Questions to ask

• Severe headache?

• Spiking fevers?

• Altered mental status?

• Copious amounts of drainage?

Complications Complications –– Short TermShort Term

• Intracranial bleeding

• Cerebral Edema

• Hydrocephalus

• Meningitis

• Stroke

• Hearing loss

• Changes in taste

• Facial paralysis

• Wind, Water, Wound, Walk

Complications Complications –– Long termLong term

• Recurrence

• Meningitis

• Pulmonary Embolism

• Conductive hearing loss

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Complications of Morbid ObesityComplications of Morbid Obesity

• Diabetes

• Hypertension

• Hypercholesterolemia

• Metabolic Syndrome

• Stroke

• Sleep apnea

Questions?Questions?

ReferencesReferences

• Goddard JC, Meyer T, Nguyen S, Lambert PR. New considerations in the cause of spontaneous

cerebrospinal fluid otorrhea. Otol Neurotol. 2010 Aug;31(6):940-5.

• Schlosser RJ, Woodworth BA, Wilensky EM, Grady MS, Bolger WE. Spontaneous cerebrospinal

fluid leaks: a variant of benign intracranial hypertension. Ann Otol Rhinol Laryngol. 2006

Jul;115(7):495-500.

• Wang E. W., Vandergrift W., Schlosser RJ. Spontaneous CSF leaks. Otolaryngolgic Clinics of

North America. 2011 Aug; 44(4).

• Woodworth, Bradford A, Palmer, James N. Spontaneous cerebrospinal fluid leaks. Current

Opinion in Otolaryngology & Head and Neck Surgery. 2009 Feb; 17(1):59-65.

• Kutz, J. W., Husain, I. A., Isaacson, B. and Roland, P. S. (2008) Management of Spontaneous

Cerebrospinal Fluid Otorrhea. The Laryngoscope, 118: 2195-2199.

• LeVay, A., Kveton, J. Relationship between obesity, obstructive sleep apnea, and spontaneous

cerebrospinal fluid otorrhea. The Laryngoscope, 2008 Feb; 118:275-278.

• Scurry, W. C., Ort, S. A., Peterson, W. M., Sheehan, J.M., Isaacson, Jon, Hershey, PA. Idiopathic

temporal bone encephaloceles in the obese patient. Otolaryngology-Head and Neck Surgery,

2007; 136: 961-965.