Skull Base Trauma Disclosures & CSF Leaks ASHNR 2017 No relevant disclosures

Kristen Lloyd Baugnon, M.D.

Department of Radiology and Imaging Sciences Division of Neuroradiology

Objectives Skull base trauma

! Describe patterns of skull base fractures ! Up to 16% of CHI ! High velocity impact ! Identify complications requiring ! Penetrating trauma <10% ! Assoc w complex facial and orbital fractures multidisciplinary treatment ! Detection important ! Tx depends on IC injury and complications ! Algorithim for CSF Leak Diagnosis and Evaluation ! Multidisciplinary care ! Develop a checklist

Detection of skull base fx Detection of skull base fx

! Can be challenging if ! Thin section bone nondisplaced algorithm MDCT with reformats ! NCCT Clues: ! Coronal, Sagittal, tbone ! Pneumocephalus ! 3D VR reformats ! Blood in sinuses/mastoids ! Curved MIP reformats ! Overlying ST swelling ! Beware of pseudofractures! ! Freq missed: Occipital condyle, ACF, tbone Baugnon KL et al NI Clinics, Aug 2014

Supraorbital foramen Baugnon KL et al NI Clinics, Aug 2014 and sphenofrontal suture Suture diastasis Patterns of SB Fracture

! Patterns seen depend on direction of impact ! Many different classification systems ! Location in skull base (ACF, MCF, tbone, PCF) ! Assoc complications ! Fractures often complex/mixed

Baugnon KL et al NI Clinics, Aug 2014

Baugnon KL et al NI Clinics, Aug 2014

Anterior cranial fossa trauma Anterior skull base fractures

! Direct frontal trauma ! “Frontobasal” fractures ! Frontal (upper 1/3 face) ! Basal (ant skull base) ! Type I-III fractures ! Type I – medial, linear ! Type II – lateral ! Type III – mixed, comminuted Type I Frontobasal fracture

Baugnon KL et al NI Clinics, Aug 2014

Manson et al Plast Recon Surg 2009

Anterior skull base fractures Anterior skull base fractures

! Direct frontal trauma ! Direct frontal trauma ! “Frontobasal” fractures ! “Frontobasal” fractures ! Frontal (upper 1/3 face) ! Frontal (upper 1/3 face) ! Basal (ant skull base) ! Basal (ant skull base) ! Type I-III fractures ! Type I-III fractures ! Type I – medial, linear ! Type I – medial, linear ! Type II – lateral ! Type II – lateral ! Type III – mixed, ! Type III – mixed, comminuted comminuted Type II Frontobasal fracture Type III Frontobasal fracture ! Types II& III more assoc with ! Types II& III more assoc with complications Baugnon KL et al NI Clinics, Aug 2014 complications Baugnon KL et al NI Clinics, Aug 2014

Middle cranial fossa trauma Central skull base fractures

! Oblique pattern: frontal impact extending to central skull base ! Facial fxs, type II/III FB fxs, CSF leak ! Transverse: lat impact ! CN and vascular injury ! Often assoc with tbone fxs ! Anterior vs posterior Oblique central skull base fracture Baugnon KL et al NI Clinics, Aug 2014

Central skull base fractures Central skull base fractures

! Oblique pattern: frontal ! Oblique pattern: frontal impact extending to impact extending to central skull base central skull base ! Facial fxs, type II/III FB ! Facial fxs, type II/III FB fxs, CSF leak fxs, CSF leak ! Transverse: lat impact ! Transverse: lat impact ! CN and vascular injury ! CN and vascular injury ! Often assoc with tbone ! Often assoc with tbone Anterior Transverse fx fxs fxs

! Anterior vs posterior Baugnon KL et al NI Clinics, Aug 2014 ! Anterior vs posterior

Posterior Transverse fx

Baugnon KL et al NI Clinics, Aug 2014

Posterior skull base trauma Posterior skull base fractures

! Lateral and/or posterior blow to occiput

! Occipital bone, +/-ext to petrous t bone and FM ! No simple classification scheme ! T bone fxs described independently

Baugnon KL et al NI Clinics, Aug 2014

Clivus fractures Clivus fractures

! Central and posterior skull ! Central and posterior skull base fractures base fractures ! High mortality ! High mortality ! Brainstem, NV ! Brainstem, NV ! Transverse ! Transverse ! Lateral blow ! Lateral blow ! CN/ICA injury (CN VI) ! CN/ICA injury (CN VI)

Baugnon KL et al NI Clinics, Aug 2014 Transverse Clival fx Baugnon KL et al NI Clinics, Aug 2014 Transverse Clival fx

Clivus fractures Clivus fractures

! Central and posterior skull ! Central and posterior skull base fractures base fractures ! High mortality ! High mortality ! Brainstem, NV ! Brainstem, NV ! Transverse ! Transverse ! Lateral blow ! Lateral blow ! CN/ICA injury (CN VI) ! CN/ICA injury (CN VI) ! Longitudinal ! Longitudinal ! Axial loading ! Axial loading ! VB/CC jxn injury, retroclival ! VB/CC jxn injury, retroclival hematoma hematoma

Baugnon KL et al NI Clinics, Aug 2014 Longitudinal Clival fx Baugnon KL et al NI Clinics, Aug 2014 Longitudinal Clival fx

Complications of SB trauma Intracranial injury

! IC injuries common – high ! Depend on location velocity impact ! Intracranial ! Multicompartmental ! Vascular (MCF & PCF) hemorrhage, parenchymal ! CN contusions, DAI ! ACF: CN II (Anosmia) ! MCF: CN II, III, IV, V, VI ! Tbone: CN VII, VIII

! PCF: CN IX, X, XI, XII ! CSF leak (ACF, MCF)

Intracranial injury: MCF Intracranial injury: MCF

! Anterior MCF epidural ! Anterior MCF epidural hematoma hematoma ! Greater wing sphenoid fx ! Greater wing sphenoid fx ! Benign – venous ! Benign – venous (sphenoparietal sinus) (sphenoparietal sinus) ! Self limited ! Self limited ! Lateral MCF epidural – middle meningeal artery

Baugnon KL et al NI Clinics, Aug 2014 Venous epidural hematoma Baugnon KL et al NI Clinics, Aug 2014 Arterial epidural hematoma

Intracranial injury: PCF Vascular Injury: Venous

! Posterior Fossa Epidural ! Traumatic venous sinus Hematoma (PFEDH) thrombosis

! Most common IC comp ! 55% of fxs through assoc with posterior skull jugular bulb/sigmoid base fx sinus ! Venous etiology ! Transverse and sagittal sinus less common ! Children ! ↑ ICP, venous ! Can expand rapidly hemorrhage, infarct ! May require (7%), dural AVF decompression Delgado AJE et al. Radiology 2010 Baugnon KL et al NI Clinics, Aug 2014

Vascular Injury: Venous Vascular Injury: Venous

! Traumatic venous sinus ! Traumatic venous sinus thrombosis thrombosis ! 55% of fxs through ! 55% of fxs through jugular bulb/sigmoid jugular bulb/sigmoid sinus sinus ! Transverse and sagittal ! Transverse and sagittal sinus less common sinus less common ! ↑ ICP, venous ! ↑ ICP, venous hemorrhage, infarct hemorrhage, infarct (7%), dural AVF Non contrast head CT (7%), dural AVF CTA/CTV

Delgado AJE et al. Radiology 2010 Delgado AJE et al. Radiology 2010 Traumatic dural venous sinus thrombosis Traumatic dural venous sinus thrombosis vs extrinsic compression vs extrinsic compression

Baugnon KL et al NI Clinics, Aug 2014

Traumatic dural venous sinus thrombosis Vascular injury - BCVI vs extrinsic compression ! Common comp (8.5%) ! MCF & PCF ! ICA injuries ! York et al: Fractures through carotid canal 35% PPV for ICA injury: 35% PPV ! Modified Denver criteria ! CTA ! Stroke risk decreases with Baugnon KL et al NI Clinics, Aug 2014 anticoagulation ! Vertebrobasilar injuries ! Clivus, occiput, occipital condyle

Vascular injury: CC Fistula Cranial Nerve Injury: ACF

! Traumatic direct ! Anosmia (CN I) connection btwn ICA and ! Overall incidence of 7%, cav sinus increased in ACF injuries ! High flow fistula ! Esp cribriform plate ! Exophthalmos, bruit, ! Frontal lobe contusions chemosis, vision loss, ! CSF leak and repair ophthalmoplegia ! Only 10% recover sense ! Acute or delayed of smell, often delayed ! DSA diagnostic & therapeutic

Baugnon KL et al NI Clinics, Aug 2014 Baugnon KL et al NI Clinics, Aug 2014 Cranial nerve injury: MCF CN Injury: PCF

! Acute or delayed presentation ! Jugular foramen: IX, X, XI

! Delayed: Stretching/edema, ! Hypoglossal canal

better prognosis (occipital condyle): XII ! Optic nerve canal: II ! SOF:III, IV, V1, VI ! Orbital apex syndrome ! Sella: bitemporal heminaopsia (chiasm)

! Cav sinus/clivus: III, IV, V1, Baugnon KL et al NI Clinics, Aug 2014

V2, VI Baugnon KL et al NI Clinics, Aug 2014

CSF Leak Suspected CSF Leak

! 10-30% of skull base fxs ! Beta 2 transferrin (beta trace protein) assay ! Comminuted fxs ! First screening test “gold standard” ! Type II/III FB fxs, tegmen, ! Protein specific to CSF sphenoid ! Unequivocal evidence to support use ! Pneumocephalus ! High sensitivity and specificity ! CSF otorrhea & rhinorrhea ! Patient collects in testtube ! Often resolves ! stores room temp or fridge spontaneously ! Requires only a few drops (0.5 -1 cc) ! Surgery for persistent leak ! Limitations: ! Intermittent or no leak (unable to collect) ! Delayed presentation ! False postive (rare!) Liver failure

Baugnon KL et al NI Clinics, Aug 2014

Imaging evaluation HRCT

! Goals of imaging: ! Standard of care – first line ! LOCALIZE the leak ! Localize osseous defect (s): 95% Sensitivity ! Characterize size of defect ! Do not need active leak to see defect ! Assess for meningocele ! Confirm diagnosis ! Images used for intraop guidance ! Assess for underlying cause ! MDCT : Thin slices (< 1mm) with reformats ! No definite imaging gold standard ! Image sinuses and mastoids ! Difficult diagnosis ! Manipulate data on workstation, optimize W/L settings ! Lacking randomized controlled trials ! Measure defect in mutiple planes ! Correlates with size of defect within 2 mm in 75% in one ! CT/MRI/cisternography (NM, CT, MR) study HRCT – Imaging findings HRCT – Imaging findings

! Nondependent soft tissue in nasal cavity or ME cavity, adj to bony defect ! Concerning for cephalocele ! Consider MRI

Lloyd K, et al Radiology 2008 Osseous defect with fluid level in sinus or mastoid

HRCT 42 yo F w remote h/o trauma

! If only one defect, and positive B2 transferrin ! Surgery ! Limitations: ! Defect does not necessarily = leak ! Multiple osseous defects with adjacent sinus opac

CT - cisternogram CT Cg - Findings

! Pt needs to be actively leaking (or able to elicit) ! Bony defect ! Technique: ! ↑ density adjacent to ! Pre-Cisternogram CT: bony defect (measure ! Supine MDCT with thin sections (reformats) ROI if no visible ! Blood, inspissated secretions, osteogenesis change) ! LP: 5-7 cc of intrathecal contrast ! Pooling of high density ! Head down and provocative maneuvers in adjacent sinuses ! Post-Cisternogram CT: ! Direct coronal in prone position (elicit leak)

! Supine MDCT with thin section reformats Lloyd K, et al Radiology 2008 CTcg Findings CT cg findings ROI Measurement

Pre ROI = - 12 Post ROI = 69 • “Souffle” effect • Dependent drainage • Contrast washout • Mvmt with position

CT-Cg Limitations MR - Cg

! Invasive ! Noninvasive & nonionizing ! Small but inherent risk of infection/lumbar CSF leak ! Indicated if suspected encephalocele ! Intrathecal contrast risk ! Nondependent soft tissue adjacent to bony defect ! Radiation ! Completely opacified sinus or ME (lobulated) adjacent ! Time intensive interpretation to bony defect ! Limited usefulness in slow flow or intermittent ! Heavily T2w FS FSE sequences leaks ! High resolution 3D T2 w SSFP (GRE) sequences ! i.e. CISS, FIESTA, SPACE ! Thin (3 mm) T1 axial, sag, coronal ! Sensitivity (85-89%), best combined w HRCT

MR – Cg Imaging Findings MR – Cg with IT Gad

! Continuous column of T2 ! Promising studies hyperintense CSF ! Sensitivity: up to 100% for high flow extending from SA space ! Selculuk et al: 60-70% sens for intermittent or to extracranial soft tissues suspected leaks ! Frank herniation of brain ! Delayed imaging up to 24 hours later tissue

Lloyd K, et al Radiology 2008 ! No ionizing radiation ! Ease of interpretation ! Improved contrast resolution ! Assess cephaloceles MR – Cg with IT Gad - MR – Cg with IT Gad Limitations ! Off label use, not FDA approved in US ! Technique: ! Many studies from outside US ! Mult osseous defects, no/intermittent leaks, postop ! No unexpected adverse effects (HA, meningitis) with ! HRCT first doses and agents used (up to 107 pts in one study) ! Off-label use consent ! No long term safety or large trials yet ! Pre-gad MR Cg sequences with T1 and T2w images ! Study in 2016 with Avg 4.2 yr F/u, no long term adverse ! LP – 0.5 ml intrathecal gadopentetate dimegulmine in effects 4 cc sterile, pres free saline, or CSF ! Consider carefully, only in pts with nl renal fxn ! Scan at 1 hour, then again at 4-24 hours, as needed

! Fat sat T1w post in multiple planes ! Still need HRCT!

Vanhee A, et al. Neurology 86;16 Supplement P4.113, April 2016

45 yo F w h/o int leak, mult Summary: Algorithm for potential osseous defects bilat Work-up of CSF leak No further Single imaging; most osseous likely site of defect CSF leak Positive HRCT Suspect Meningo- MR encephalocele Cisternogram No Multiple B2- imaging; osseous CT Cisternogram transferrin Negative unlikely to defects be CSF leak

Cor T2W MR Cg Cor T1W FS MR Cg w IT Gad MR Cisternogram, Unable to consider Intrathecal collect fluid HRCT contrast if high suspicion

Summary: SB Trauma Skull base fractures: Checklist

! Complex " Posterior table frontal sinus ! Even linear nondisplaced fractures can be " Anterior skull base assoc with complications " Skull base foramina (ON, SOF, ! CTA/CTV: FR, FO, IAC, hypoglossal canal) ! Carotid canal ! Cavernous sinus " Carotid canal ! Jugular foramen/sigmoid sinus " Sigmoid sinus/jugular foramen ! Clivus " Clivus ! Occipital condyle " Occipital condyle

References References

! Baugnon KL, Hudgins PA. Skull base fractures and their complications. NI Clin N ! Miller PR, et al. Blunt cerebrovascular injuries: diagnosis and treatment. J Trauma Am 2014; 24(3):439-465. 2001;51:279-85.

! Manson PN, Stanwix MG, Yaremchuk MJ, et al. Frontobasal fractures: anatomical ! Ochalski PG, et al. Fractures of the clivus: a contemporary series in the computed classification and clinical significance. Plast Reconstr Surg 2009;124:2096-2106. tomography era. Neurosurgery 2009;65(6):1063-9.

! Guy WM, Brissett AE. Contemporary management of traumatic fracture of the ! Kwong Y, et al. Fracture mimics on temporal bone CT: a guide for the radiologist. frontal sinus. Otolaryngol Clin North Am 2013;46:733-748. AJR Aug 2012; 199(2):428-34

! Gean AD, Fischbein NJ, Purcell DD, et al. Benign anterior temporal epidural ! Delgado AJE, et al. Prevalence of traumatic dural venous sinus thrombosis in hematoma: indolent lesion with a characteristic CT imaging appearance after blunt high-risk acute blunt head trauma patients evaluated with multidetector CT. trauma. Radiology 2010;257(1):212-8.. Radiology 2010 May;255(2):570-7.

! York G, et al. Assoication of internal carotid artery injury with carotid canal fractures in patients with head trauma. Am J Roentgenol 2005;184(5):1672-8.

References References, cont

• Bleier BS, et al. Preliminary study on the stability of beta-2 Transferrin in ! Lloyd KM, Delgaudio JH, Hudgins PA Imaging of Skull Base Cerebrospinal Fluid extracorporeal CSF. Otolaryngol Head Neck Surg 2011;144:101-3. Leaks in Adults. Radiology 2008;248:725-36. ! Dillon WP. Intrathecal Gadolinium: Its Time has Come? AJNR 2008;29:3-4. • Stone JA, et al. Evaluation of CSF Leaks: High-resolution CT compared with ! Manes, RP, Ryan MVV, Marple BF. A novel finding on CT in the diagnosis and contrast-enhanced CT and radionuclide cisternography. AJNR 1999;20:706-712 localization of CSF leaks without a clear bony defect. Int Forum Allergy Rhinol 2012;2(5):402-404. • Shetty PG et al. Evaluation of high-resolution CT and MR cisternography in the ! Sampaio MH, et al. Predictability of quantification of beta-trace protein for diagnosis diagnosis of cerebrospinal fluid fistula. Am J Neuroradiol 1998;19:633-639. of cerebrospinal fluid leak: cutoff determination in nasal fluids with two control groups.

Am J Rhinol Allergy 2009;23(6):585-90. • El Gammal T, et al. Cerebrospinal fluid fistula: detection with MR cisternography. Am J Neuroradiol 1998;19:627-631. ! Selcuk H, et al. Intrathecal Gadolinium-Enhanced MR Cisternography in the Evaluation of CSF leakage. AJNR 2010;31:71-75.

! Lloyd MN, et al. Post-traumatic CSF rhinorrhoea: modern HRCT is all that is ! Algin O, et al. The contribution of 3D-CISS and contrast enhanced MR cisternography required for the effective demonstration of the site of leakage. Clin Radiol in detecting cerebrospinal fluid leak in patients with rhinorrhea. British Journal of 1994;49:100-103. Radiology 2010;83:225-232. ! LaFata V, et al. CSF leaks: Correlation of High-Resolution CT and Multiplanar ! Stone JA, et al. Evaluation of CSF Leaks: High-resolution CT compared with reformations with Intraoperative Endoscopic findings. AJNR 2008;29:536-41. contrast-enhanced CT and radionuclide cisternography. AJNR 1999;20:706-712 ! Vanopdenbosch LJ, et al. MRI with intrathecal Gadolinium to Detect a CSF leak: a prospective open-label cohort study. J Neurol Neursurg Psychiatry 2011;82:456-458.