1. A First Class Emergency: Headache in Flight David Bordo, MD Department of Emergency Medicine Resurrection Medical Center Chicago, Illinois

2. Objectives Previous cases demonstrated importance of LP This case discusses a complication of LP 1. Who is at risk for complications? 2. What are the CT findings that may help predict who is at risk? 3. When should an LP be avoided?

3. Case Presentation 41 y/o flight attendant, boards a plane in London, with c/o her typical migraine, takes an Imitrex 4 hours later, patient is in severe pain RN on board opens medical kit, administers 10mg diazepam IM and phenergan, lies pt down in first class seating 4 hours later, upon landing in Chicago, patient is unresponsive Paramedics find pt responsive only to painful stimuli, transport patient to our ED

4. PMHx Only significant for migraines Unclear what workup patient has had for headaches in the past Unknown SHx, FHx, Meds, Allergies

5. Physical Exam VS: 96.9, 149/77, 63, 16 Pupils reactive L: 3mm R:4mm Lungs, Heart, Abdomen: Normal No Skin Findings Toes downgoing, localized to painful stimuli, no spontaneous eye opening Occasional moaning

6. Differential Diagnosis Neurologic Subarachnoid Hemorrhage vs Meningitis Toxicologic Metabolic Endocrine Other infectious etiologies Encephalitis, Sepsis

7. ED Course Patient immediately had a noncontrast CT of the brain Upon returning from CT, patient intubated without difficulty for airway protection

8. Lab Results WBC = 15.3, 95% Segs Hgb = 12.4 Hct = 36.2 Platelets = 250 Chemistry = wnl

12. What is the next step in this patient ’ s management?

13. CT Prelim “Hydrocephalus with early cerebral edema. Subtle increased density in the circle of Willis may represent a rather low density subarachnoid hemorrhage. CT with contrast or MRI would be helpful.”

14. Case Course Patient given acyclovir, ceftriaxone, and methylprednisolone LP performed successfully with an opening pressure of 20 cmH2O Patient returned for a CT Brain with contrast, read the same as the previous study Patient became completely unresponsive to all stimuli with fixed pupils bilaterally

15. Lumbar Puncture LP first developed by Henry Quincke in 1890 Complications well documented as early as 1896 Complications include infection, bleeding, post dural puncture headache, and herniation

16. Tentorial and Tonsillar Herniation Two common types: Tentorial: medial portion of the temporal lobe herniates into the tentorial notch and compresses the midbrain, peduncle, and third nerve Tonsillar: herniation of the cerebellar tonsils through the foramen magnum Etiology can include cerebral edema, space occupying lesions (abscesses, tumors, blood), hydrocephalus

18. Tentorial Herniation Clinical features of tentorial (uncal) herniation: Dilated, unreactive pupil due to compression of CN III, begins unilateral and can become bilateral Contralateral hemiparesis from the ipsilateral peduncle compressing against the tentorium In up to 25% of patients, contralateral peduncle is forced against the opposite edge of the tentorial hiatus, hemiparesis on the same side of the dilated pupil: A false localizing sign termed Kernohans notch syndrome

19. Tonsillar Herniation Clinical features of tonsillar herniation: Neck stiffness and head tilt from impaction of the foramen magnum Bradycardia and wide pulse pressure Respiratory irregularities and arrest

20. Herniation after LP in patients with brain masses Marotta in 1954 looked at 447 LPs done in pts with neoplasms, 32% had papilledema, only one patient had a complication Lubic LG, Marotta JT: Brain tumor and lumbar puncture. Arch Neurol Psychiatry 1954. 72: 568-572.

21. Herniation after LP in patients with brain masses Korein in 1954 looked at LPs done in 129 patients with papilledema or intracranial HTN, again only noted one complication Korein J, Cravioto H, Leicach M: Reevaluation of lumbar puncture: A study of 129 patients with papilledema or intracranial hypertension. Neurology 1959; 9:290-297.

22. Herniation after LP in patients with brain masses Conclusion: CT has eliminated this concern In acutely raised ICP, papilledema is absent in 50% of children and at least 15% of adults The foregone assumption that papilledema always meant a patient would herniate is not necessarily true, and papilledema is not always (rarely?) present in patients with increased intracranial pressure

23. Opening pressures compared to CT diagnosis 42 LPs: 13 with elevated pressure∙ 29 Normal OP 6: normal CT 4: mass lesions 1: mass with midline shift No complications No complications 48 hours later 6/13 with inc OP, had normal CT: a normal CT cannot r/o increased ICP, and pts with mass effect on CT may have normal OPs Baker N. The efficacy of routine head computed tomography prior to lumbar puncture in the emergency department. The Journal of Emergency Medicine. 12: 597-601, 1994.

24. Meningitis and Herniation Objective was to determine if the incidence of herniation is increased in children with bacterial meningitis, and whether children with herniation have normal CTs 445 children with bacterial meningitis 19/445 herniated (4.3%) CT performed at time of herniation in 14 of the cases: 5 had normal CTs Rennick G. Cerebral herniation during bacterial meningitis in children. British Medical Journal. 306: 953-955, 1993.

25. Meningitis and Herniation 493 episodes of bacterial meningitis in adults 5 developed signs consistent with herniation minutes to hours after LP Durando ML. Acute bacterial meningitis: A review of 493 episodes. N Engl J Med 328:21-28, 1993.

26. Meningitis and Herniation “LP can cause herniation in bacterial meningitis and that normal results on CT do not mean it is safe to do an LP. If meningitis is suspected in a child with decorticate or decerebrate posturing, focal neurological signs or no response to pain, give abx and do not do an LP, even if the CT is normal.”

27. Who is at risk for herniation? Previous studies proven that it is impossible to tell who will have increased ICP on CT Papilledema is not reliable Although CT findings are not always reliable, there are findings that suggest who is at risk for herniation

28. CT findings that suggest risk for herniation Journal of Neurology 2002 LP may cause herniation if brain shift exists with or without papilledema Perform CT before LP if clinical suspicion exists for brain shift and look for: Loss of differentiation of gray and white matter Effacement of CSF spaces, sulci, fissures, ventricles Displacement of brain structures Crevel H. Lumbar puncture and the Risk of Herniation: When Should We First Perform CT? Journal of Neurology. 2002; 249:129-137.

29. Who should we CT prior to LP: Decreased mental status Papilledema Focal neurological deficits Minimal or absent fever Head trauma Recent seizure

30. Lateral shift of midline structures Loss of basilar cisterns Obliteration of the fourth ventricle Obliteration of superior cerebellar/quadrigeminal cisterns with sparing of the ambient cisterns Holdgate et al. Perils and pitfalls of lumbar puncture in the emergency department. Emergency Medicine. 2001;13: 351-358. CT findings that contraindicate LP

31. Herpes encephalitis Loss of differentiation of grey and white matter Loss of sulci and gyri

32. Large right-sided subdural hematoma producing right to left midline shift and right uncal (arrow) herniationarrow

33. Normal Third Ventricle

34. Normal Fourth Ventricle

35. Abnormally large 4 th ventricle

36. Treatment of Cerebral Herniation 20% mannitol IV – 1g/kg over 15 minutes Effects last 4-6 hours. Corticosteroid: dexamethasone IV 12-24 mg IVP (Rosen states no benefit proven.) Intubate and hyperventilate

37. Case course, cont’d Patient admitted to ICU, ventriculostomy was done, CSF pressure noted to be 40. Patient was pronounced dead the next morning. MRI/MRA done noted a colloid cyst in the third ventricle.

38. Teaching Points CT is not 100% reliable in identifying who will herniate from lumbar puncture CT findings that should be excluded include loss of differentiation of gray and white matter, effacement of CSF spaces, sulci, fissures, and ventricles, and displacement of brain structures Consider deferring LP in patients with focal neurological signs, papilledema, and unconsciousness

39. Questions?