Arnold Chiari Debate Real or Not?

Arnold Chiari Debate Real or Not? Frederick R. Taylor, MD FAHS FAAN Adjunct Professor of Neurology University of Minnesota SOM & Park Nicollet Headache Center Minneapolis, MN TED Talks Noreena Hertz Why & When to Ignore Experts Too often the listener is addicted to the expert and trades in their independent thinking and decision making - NH 1) Be ready and willing to take on the experts 2) Create space to encourage managed dissent 3) Democratize expertise Advertisement in Neurology Today for The Chiari Care Center AT THE MEDICAL CENTER OF AURORA Professor Dr. Noreena Hertz, b. 1967 English economist, author and campaigner American Headache Society The Patient Headache History 44 yo female: long history of headaches HA onset: adolescence (HAa) At first infrequent, now >15 days/mo Last > 4 hours, not constant, moderate+, throbbing frontal, some nauseating HA of most concern: began in past 5 years (aha) Occurs whenever coughs, holds breath Severe, throbbing pain lasts 30-60 seconds Rather persistent occipital/sub-occipital pain

The Patient Ancillary History What if anything else should we know? Family Hx of HA:? Other sudden HA: NO Positional HA?: NO; only head forward neck pain Other events: Hx syncope, some with cough Exam: no orthostatic BPs; unsteady tandem gait MRI: The Patient s MRI? MRI: Underuse, Overuse or Valuable Use? Can/Must we answer this, to especially our patient: If not done, underuse or efficient quality care? If performed, indicated and needed, or overuse creating VOMIT: Victim Of Medical Imaging Technology When/What is Valuable Use of Resources? VOMIT = first heard from the mouth of Dr. Alan Purdy Our Patient s MRI Valuable use: Cough Headache with syncope;??? Posterior headache if alone??? Tandem abnormality if alone SNOOP: paroxysmal: syncope; cough HA? Overuse: If near daily headache alone, if neck pain without cough/syncope No imaging: Poor quality of care and underuse

Criteria & Definitions CMI: Real or Not? ICHD-II Part 2: The 2º Headaches 5. Headache attributed to head and/or neck trauma 6. Headache attributed to cranial or cervical vascular events 7. Headache attributed to non-vascular intracranial disorder 8. Headache attributed to a substance or its withdrawal 9. Headache attributed to infection 10. Headache attributed to disorder of homestasis 11. Headache or facial pain attributed to disorders of head and neck 12. Headache attributed to psychiatric disorder International Headache Society 2003/4 ICHD-II Cephalalgia 2004;24:Suppl 1 ICHD-II: 7.7 CMI Real 7.1 Headache attributed to high CSF pressure 7.2 Headache attributed to low CSF pressure 7.3 Headache attributed to non-infectious inflammatory disease 7.4 Headache attributed to intracranial neoplasm 7.5 Headache attributed to intrathecal injection 7.6 Headache attributed to epileptic seizure 77 7.7 Headache attributed ttib t dto chiari i malformation type I 7.8 Syndrome of transient Headache and Neurological Deficits with CSF Lymphocytosis 7.9 Headache attributed to other non-vascular intracranial disorder Chiari malformation type 1 = CMI International Headache Society 2003/4 ICHD-II Cephalalgia 2004;24:Suppl 1

CMI ICHD-II Diagnostic Criteria A. Headache characterized by at least one of the following and fulfilling criterion D: precipitated by cough and/or Valsalva maneuver protracted (hours to days) occipital and/or sub-occipital headache associated with symptoms and/or signs of brainstem, cerebellar and/or cervical cord dysfunction B. Cerebellar tonsillar herniation as defined by one of the following on craniocervical MRI: 5 mm caudal descent of the cerebellar tonsils 3 mm caudal descent of the cerebellar tonsils plus at least one of the following indicators of crowding of the subarachnoid space in the area of the craniocervical junction: compression of the CSF spaces posterior and lateral to the cerebellum reduced height of the supraocciput increased slope of the tentorium kinking of the medulla oblongata C. Evidence of posterior fossa dysfunction, based on at least two of the following: otoneurological symptoms and/or signs (eg, dizziness, dysequilibrium, sensations of alteration in ear pressure, hypacusia or hyperacusia, vertigo, down-beat nystagmus, oscillopsia) transient visual symptoms (spark photopsias, visual blurring, diplopia or transient visual field deficits) demonstration of clinical signs relevant to cervical cord, brainstem or lower cranial nerves or ataxia or dysmetria D. Headache resolves within 3 months after successful treatment of the CMI CMI = Chiari Malformation type I ICHD-II Cephalalgia 2004; suppl 1 Chiari by Hans Chiari (1891) CMI limited to CT herniation out of the skull: Hence Chiari defined by many as CT descent of 3-5 mm Research shows degree of CT descent not directly related to clinical severity or outcome. 1 12,000 MRI s, 68 Chiari s with CT descent > 5 mm >12 mm invariably symptomatic 5-10mm 30% without symptoms CMI = Chiari Malformation type 1 CT = Cerebellar Tonsil 1 Elster AD, Chen MY. Radiology. 1992;183:347-353. Primary CMI Secondary HA, but not Secondary Chiari Criteria1) Not a hindbrain malformation but descent >3-5 mm cerebellar tonsils (CT) without brainstem 1,2 not due to other causes Criteria 2) Cranial base dysplasia leading to overcrowding of the posterior cranial fossa. 3 C1 + C2 + appropriate CC = SOLVES dismissing CT descent as benign CMI = Chiari malformation type 1 CC = Chief complaint or clinical context 1 http://www.ninds.nih.gov/disorders/chiari/detail_chiari.htm Accessed 3/20/12. 2 Vega A et al. J Neurol Sci 1990;99:137-145. 3 Milhorat TH et al. Neurosurgery 1999;44:1005-1017.

Primary CM0 Real or Maybe?? Secondary HA, but not Secondary Chiari Criteria C1) Not a hindbrain malformation but 0 - < 3mm descent cerebellar tonsils (CT) without brainstem 1,2 not due to other causes Criteria C2) Cranial base dysplasia leading to overcrowding of the posterior cranial fossa. 2 C1 + C2 + appropriate CC = SOLVES underdiagnosis due to no descent as stress or other 1 http://www.ninds.nih.gov/disorders/chiari/detail_chiari.htm Accessed 3/20/12. 2 Sekula RF at al. Cerebrospinal Fluid Res. 2005; 2:11 (Abstract) CMI Definition Perhaps Real or Not CMI is evolving from a pure anatomical description inherited from over 100 years ago to the concept of a multisystem manifestation or a final common pathway of clinical expression Copyright by the Congress of Neurological Surgeons. Published by Lippincott Williams & Wilkins, Inc. CM0 & CMI Secondary Type CM0 & CMI if defined only by CT descent is likely acquired and therefore secondary (and not therefore CMI or CM0 and without proof of benefit of intervention) CMO & CMI - the only acquired Chiari types BEWARE The Chiari Institute Great Neck, Long Island, New York CMI = Chiari Malformation type I CT = cerebellar tonsils 1 http://www.ninds.nih.gov/disorders/chiari/detail_chiari.htm Accessed 3/20/12.

CMI Secondary Differential ICHD-II Part 2: The 2º Headaches 5. Headache attributed to head and/or neck trauma 6. Headache attributed to cranial or cervical vascular events 7. Headache attributed to non-vascular intracranial disorder 8. Headache attributed to a substance or its withdrawal 9. Headache attributed to infection 10. Headache attributed to disorder of homestasis 11. Headache or facial pain attributed to disorders of head and neck 12. Headache attributed to psychiatric disorder International Headache Society 2003/4 ICHD-II Cephalalgia 2004;24: Suppl 1 Secondary Pseudo Chiari NOT CMI Secondary Chiari or Pseudo Chiari: pathologies characterized by downward displacement of CTs without basal abnormality with low CSF pressure of particular interest - ICHD-II II 7.2 Headache attributed to low CSF pressure 1 7.2.1 Iatrogenic CSF drainage 7.2.3 Spontaneous CSF leak 7.2.2 CSF Fistula CTs = cerebellar tonsils CSF = cerebrospinal fluid CMI = Chiari Malformation type I 1 http://ihs-classification.org/en/02_klassifikation/03_teil2/07.02.01_nonvascular.html 2 Mea E et al. Neurol Sci 2011;32: suppl3: S291-94. Secondary Pseudo Chiari NOT CMI Secondary or Pseudo Chiari Differential Dx: 1. CSF Leaks 2. Hydrocephalus 3. Intracranial mass lesion 4. Prolonged lumboperitoneal shunting 5. Hereditary CTD with OAAJI 6. Tethered cord syndrome 7. Craniosynostosis 8. Acromegaly 9. Paget s disease CTD = connective tissue disorder OAAJI = Occipitoatlantoaxial jount instability Milhorat TH. Act Neurochir 2010;152:1117-1127 Mea E et al. Neurol Sci 2011;32: suppl3: S291-94.

MRI & CINE Imaging Defined Chiari Malformation I Imaging Defined CMI 1. Supraocciput (IO): measured line from the center of the internal occipital protuberance (I) to the opisthion (O). 2. Slope of the tentorium (T): angle (a) formed by the tentorium and the supraocciput. 3. Clivus length: line from the top of the dorsum sella (D) to the basion (B) 4. Tonsillar herniation: measured line from basion (B) to the opisthion (O) to the tips of the cerebellar tonsils. Copyright by the Congress of Neurological Surgeons. Published by Lippincott Williams & Wilkins, Inc. Milhorat TH, et al. Neurosurgery 1999; 44:1005-1017. Imaging Defined CMI 1. Short Supraocciput (IO) 2. Increased tentorium (T) slope 3. Short Clivus length 4. CT Descent exceeding 5mm Greater CT descent associated with shorter clivus length and a wider anteroposterior diameter of foramen magnum Dufton JA, et al. Can J Neurol Sci. 2011;38:452-545

MRI Findings in CMI Copyright by the Congress of Neurological Surgeons. Published by Lippincott Williams & Wilkins, Inc. 8 Milhorat TH. Neurosurgery. 1999;44:1005-1017. CMI: Posterior Cranial Fossa Morphology by etiology OBS PCFV FM CMI Small Small Small CMI / synrinx Small Small Small CMI / craniosynostosis Small Small Small CMI? / tethered cord Normal Normal Large CMI? / intracranial mass Normal Normal Normal CMI? / LP shunt Normal Normal Normal CMI = Chiari I Malformation; OBS = Occipital Bone Size; PCFV = Posterior Cranial Fossa Volume FM= Foramen Magnum Adapted from Milhorat TH et al. Acta Neurochir 2010;152:1117-1127 CMI: Defined by PCF Measurement? If CT descent alone does not define CMI, do PCF measurements? Conclusions: 1) Abnormalities exist and agreement exists. 2) No universally agreed upon measurements adopted by any guideline for use in practice. Considerable variation between studies and overlap between normal and CMI. 3) Another method needed? CMI = Chiari I Malformation; CT = cerebellar descent ; PCF = Posterior Cranial Fossa Adapted from Milhorat TH et al. Acta Neurochir 2010;152:1117-1127

CINE MRI Cine MRI (as in cinema) uses a traditional MRI equipped with software to show the flow of cerebrospinal fluid as it is moving. Using either a wristband or EKG leads measuring the heart beat, MRI images are timed to cerebrospinal fluid flow out of the brain down into the spine in response to the flow of blood that enters the brain with each beat. CINE MRI & PFD in CMI CMI with PFD with pre/post Cine-MRI 1997-2003 130 consecutive subjects with CT descent > 5mm; average 11+/- 5 mm CT descent Abnormal CSF flow defined by: biphasic flow either absent or decreased through the aqueduct, fourth ventricle, foramen magnum, or ventral or dorsal to the cervical spinal cord CSF flow - abnormal 81% 43% complete obstruction 38% reduced flow CMI = Chiari I Malformation; PFD = posterior fossa decompression MRI = magnetic resonance imaging ; CSF = cerebral spinal fluid CT = cerebellar tonsil McGirt MJ et al. Neurosurg 2006;59:140-146. Normal CINE CSF Flow in CMI Normal hindbrain CSF flow 19% 4.8 fold (RR 4.85) more likely to have symptom recurrence regardless of CT descent or syrinx. Isolated frontal headache and scoliosis independent risks for recurrence (RR 4.16) Conclusions: Cine-MRI may be valuable in preoperative determination of success and failure of PFD for CMI CMI = Chiari I Malformation; PFD = posterior fossa decompression MRI = magnetic resonance imaging ; CSF = cerebral spinal fluid CT = cerebellar tonsil McGirt MJ et al. Neurosurg 2006;59:140-146

The Clinic CMI: The Clinical Syndromes Not Always Symptomatic Non-syndrome CMI: Critical : many have no symptoms or signs ~ 50% have no headache of any kind Critical: treatment not needed CMI = Chiari Malformation type I Taylor FR, Larkins MV. Curr Pain HA Rep 2002;6:331-7. Pascual J et al. Neurol 1996;46:1520-24. CMI: The Clinical Syndromes Often Multisystem Manifestations Clinical syndrome(s) CMI : 1 - Headache the classic symptom 2 - Pseudotumor-like episodes 74% 3 - Meniere s disease-like syndrome 4 - Lower cranial nerve signs - 50% 5 - Spinal cord dysfunction s synringomyelia - 66% Gait imbalance/ hand fine motor incoordination CMI = Chiari Malformation type I Taylor FR, Larkins MV. Curr Pain HA Rep 2002;6:331-7. Modified from Milhorat TH et al. Neurosurgery 1999;44:1005-1017.

CMI: The Headache The Clinically Defining Headache: Cough or Valsalva The specific CMI headache ~ 30% with CMI experience cough/valsalva HA ~ 56% of all headaches reported The Other Clinical Headache: Occipital-suboccipital pain - nonspecific CMI HA Chiari distinctive with tendency to increase with Valsalva, head dependency, sudden postural change, physical exertion CMI = Chiari Malformation type I Pascual J et al. Neurol 1996;46:1520-24. Taylor FR, Larkins MV. Curr Pain HA Rep 2002;6:331-7. CMI: The Headache DDx Cough Headache - Primary versus Secondary Pre MRI 80% primary MRI era 66% secondary (structural) Secondary Primary 90% CT descent ----- Younger Older 3:1 female 3:1 male indomethacin response indomethacin negative positive CMI = Chiari Malformation type I DDx: Differential Diagnosis CT= cerebellar tonsil Riviera C. Curr Pain HA Rep 2007;53-55. Taylor FR, Larkins MV. Curr Pain HA Rep 2002;6:331-7. Milhorat TH et al. Neurosurgery 1999;44:1005-1017. CMI: The Headache DDx Occipital suboccipital Headache DDx (partial listing): Chronic tension type Cervicogenic Hydrocephalus with CT descent present SIH with CT descent present CMI = Chiari Malformation type I DDx: = Differential Diagnosis SIH Spontaneous Intracranial Hypotension Riviera C. Curr Pain HA Rep 2007;53-55. Taylor FR, Larkins MV. Curr Pain HA Rep 2002;6:331-7.

CMI & CDH: Our Patient CMI: symptomatic series not associated with 1º HA 1,2,3 rarely associated with basilar-migraine like HA i.e. posterior HA with syncope and episodic primary HA only limited anecdotal reports no clear association with CDH CDH - no clear association with CMI CMI = Chiari I Malformation CDH Chronic Daily Headache MRI = Magnetic Resonance Imaging CSF = cerebral spinal fluid 1 Pascual J Oterino A, Berciano J. Neurol 1992;42:1519-21. 2 Riveira C, Pascual J. Curr Pain Headache Rep 2007;11:53-55 3 Mea E et al. Neurol Sci 2011;32: suppl3: S291-94. CDH &?CMI =?MRI MRI only Valuable with a. Valsalva aggravation b. Cervicogenic features +/- a. +/- syncope? (? possibly the next debate?) MRI with tonsillar herniation and daily headache hydrocephalus? (any type but usually II) rule out low intracranial CSF pressure syndrome CMI = Chiari I Malformation CDH Chronic Daily Headache MRI = Magnetic Resonance Imaging CSF = cerebral spinal fluid 1 Pascual J Oterino A, Berciano J. Neurol 1992;42:1519-21. 2 Riveira C, Pascual J. Curr Pain Headache Rep 2007;11:53-55 3 Mea E et al. Neurol Sci 2011;32: suppl3: S291-94. CMI Selected Demographics Webpage of The Wisconsin Chiari Center The actual occurrence of Chiari malformation in the general population is, in fact, unknown. Why? We do not yet know how to define the problem correctly. Second, many neurosurgeons have come to learn that the current criteria. are much too strict. The Wisconsin Chiari Center at Columbia St. Mary s Hospital of Milwaukee, Wisconsin http://www.wichiaricenter.org/oth/page.asp?pageid=oth000005

Patient Characteristics and Clinical Presentation Copyright by the Congress of Neurological Surgeons. Published by Lippincott Williams & Wilkins, Inc. Milhorat TH. Neurosurgery. 1999;44:1005-1017, 2 CMI Selected Demographics CMI: defined by 3-5mm CT herniation 364 symptomatic subjects: Female/Male =3:1 (275 Female/89 Male) Age of onset: 24.9+/-15.8 years ( +/- SD) 100% MRI head & spine imaging 237 (65%) synringomyelia 153 (42%) scoliosis CT= cerebellar tonsil S.D. = standard deviation; MRI = magnetic resonance imaging Milhorat TH et al. Neurosurgery 1999;44:1005-1017. CMI Treatment http://www.wichiaricenter.org/oth/page.asp?pageid=oth000036

When the Knife or No Knife No Randomized, Controlled Trials to Inform Decisions Significant disagreement exists regarding: 1) when surgery should be recommended 2) extent of bone removal 3) whether to open the dura 4) whether to remove brain tissue 5) what type of dural patch to use. Chiari Complications Concerns exist for complications even without preoperative problems other than CT descent CMI undergoing PFD symptomatic ICP & hydrocephalus ~ <10% 3/4 required permanent VP shunt (6.5% total) PFD = Posterior Fossa Decompression ICP = Increased Intracranial Pressure VP = Ventricular Shunt CT = Cerebellar Tonsils Zakaria R et al. BrJNeurosurg 2012 epub ahead of print CMI and Duraplasty Letter to the editor from Clarence S. Greene Jr. M.D. The recognition of complications after decompression with duraplasty for CMI appears to be ever increasing. Despite what many in the public arena and members of the medical profession view as a straightforward and relatively simple procedure, the literature continues to expand with documentation of complications, which, can be life threatening. Greene CS. J Neurosurg 2012;116:1161-1163

CMI Headache & ONS Trial: CMI & persistent occipital/suboccipital HA refractory to medical/surgical therapies Design: ONS temporary placement; if 50% benefit permanent placement 1-2 weeks later Methods: VAS for improvement Number studied Permanent Placement % Continued Pain Relief % Device related AE with surgery 18 13/18 (72%) 11/13 (85%) FU 23 mo 31% 22 15/22 (68%) 13/15 (87%) FU 19 mo 40% ONS = Occipital Neurostimulation VAS = Visual Analogue Scale Vadivelu S. et al. Prog Neurol Surg 2011;24:118-125. Vadivelu S, et al. Neurosurgery. 2012 Mar 13. [Epub ahead of print] CMI Headache & ONS Conclusions: (Vadivelu 2011 & 2012 ) Vadivelu 2011 : Occipital neuromodulation may provide significant long-term pain relief in selected CMI patients with persistent occipital pain. Larger and longer-term studies are needed to further define appropriate patient selection criteria as well as to refine the surgical technique to minimize device-related complications. Vadivelu 2012 : Occipital stimulation may yprovide significant long- term pain relief in selected CMI patients with persistent occipital pain. Larger and longer-term studies are needed to further define appropriate patient selection criteria as well as to refine the surgical technique to minimize device-related complications. Vadivelu S. et al. Prog Neurol Surg 2011;24:118-125. Vadivelu S, et al. Neurosurgery. 2012 Mar 13. [Epub ahead of print] CMI Associations Acromegaly 15% 1 Familial CMI with syringomyelia (12 reports) 2 Glossopharyngeal Neuralgia (4 reports) 3 ipsilateral asymmetric CT descent requiring tonsillectomy Leber s congenital amaurosis (rare) 4 Neurofibromatosis type 1 5 (1) Associated conditions can be categorized as potential causes or consequences of CMI (2) Diversity of the conditions associated with CMI suggests a multidisciplinary clinical approach to care 6 CMI = Chiari I Malformation CT = cerebellar descent 1 Manara R et al. Pituitary. 2012 Apr 8. [Epub ahead of print]. 2 Mavinkurve GG et al. Childs Nerv Syst. 2005;21:955-959; 3 Ruiz- Juretschke F et al. J Clin Neurosci. 2012 ;19:614-16 4 Petraglia AL et al. Surg Neurol Int 2012;3:4; 5 Tubbs, RS et al. Pediatric Neurology 2004;30:278-280 6 Desouza RM, Zador Z, Frim DM. Neurol Res. 2011;33:278-84.

The Patient Diagnoses Diagnoses for 44 y/o woman: 1 st ever HA (HAa) Migraine without aura Current HA of concern (aha) Cough and occipital-suboccipital HA secondary to CMI Associated symptoms Syncope Secondary to Migraine or CMI or both CMI ICHD-III Possible Criteria A. Headache with one or more of the following characteristics and fulfilling criterion D: precipitated by cough and/or Valsalva maneuver protracted (hours to days) occipital and/or sub-occipital headache associated with one or more morphometric abnormalities of the posterior cranial fossa under C1. B. Cerebellar tonsillar herniation as defined by one of the following on craniocervical MRI: 1. 5 mm caudal descent of the cerebellar tonsils 2. 3 mm caudal descent of the cerebellar tonsils plus at least one of the indicators of crowding of the subarachnoid space in the area of the craniocervical junction listed under C: C. Evidence of cerebellar tonsillar herniation as symptomatic and causal based on 1 and at least one of 2 or 3: 1. Posterior Cranial Fossa morphometric abnormality characterized by one of: a. Compression of the CSF spaces posterior and lateral to the cerebellum by CINE MRI b. Reduced height of the supraocciput c. Increased slope of the tentorium d. Clivus shortening and/or kinking of the medulla oblongata 2. Headache has occurred in temporal relationship to the presence of : a. presence of sleep apnea hypopnea syndrome b. otoneurological symptoms and/or signs (dizziness, dysequilibrium, sensations of alteration in ear pressure, hypacusia or hyperacusia, vertigo, down-beat nystagmus, oscillopsia) c. transient visual symptoms (spark photopsias, blurring, diplopia or transient VF deficits) d. demonstration of clinical signs relevant to cervical cord, brainstem or lower cranial nerves or ataxia or dysmetria 3. Headache has worsened in temporal relationship to worsening of the cerebellar tonsillar herniation or C1 a. D. Headache is not better accounted for by another headache diagnosis CMI = Chiari Malformation type I ICHD-III Cephalalgia 2015?; suppl 1 CMI Conclusions Planting the Seed for Future Headache Research Significant gaps exist in understanding CMI: 1) confusing terminology 2) no clinically relevant definition 3) subjective diagnostic criteria 4) no well-accepted standard of care Translates to: negative patient experiences and outcomes. Labuda R, Loth F, Slavin K. National Institutes of Health Chiari Research Conference: state of the research and new directions. Neurol Res. 2011;33:227-231

Managing Real CMI Now Often not clinically symptomatic Clinical presentation quite variable: varying brain displacement, FM size, compressed structures and syrinx in as many as 2/3. Occipital suboccipital HA correlates best with CINE- MRI CSF abnormal flow & PFD symptom improvement Decompression possibly reserved for posterior HA with concurrent cough HA and significant disability FM = Foramen Magnum PFD = Posterior Fossa Decompression HA = headache CMI Pregnancy/Obstetrics 1) Is Pregnancy safe with CMI? 2) Will CMI symptoms recur or become worse during pregnancy Limited literature & clinical anecdotes CMI is not a problem 7 patients prospectively followed through pregnancy/labor/delivery 0/7 no change any symptom 4/7: epidural anesthesia without change 1 3) Is vaginal delivery possible? Yes, even patients with symptoms may delivery safely 2 Conclusion: Data limited on intubation (apparent fear of intubation) Epidural anesthesia appears favored CMI need not impact Pregnancy with expert OB care CMI = Chiari I Malformation OB = Obstetrics 1 Mueller DM, Oro' J. Am J Perinatol. 2005;22:67-70. 2 Parker JD,Brober JC,Napolitano PG. Am J Perinatol 2002;19:445-450.