Cerebrospinal fluid rhinorrhea (CSF)

CSF rinorrhea and its investigation and its management

1. CerebroSpinal Fluid Rhinorrhoea By: Dr. Jinu v iype 3 rd year PG Department of ENT

2. References: Scott Brown 7 th edition & 8 th edition Guyton textbook of physiology Cummings otolaryngology head and neck surgery 6 th edition Hathiram - atlas of operative otorhinolaryngology vol 2 Zahir hussain 4 th edition

3. CSF BASICS Cerebrospinal fluid (CSF) is a clear, colourless body fluid found in the brain and spine. It is produced in the choroid plexuses of the ventricles of the brain. It acts as a cushion or buffer for the brain's cortex, providing basic mechanical and immunological protection to the brain.

4. Total volume of CSF varies from 90 to 140 ml . this includes 20 mL in the ventricles, 50 mL in the intracranial subarachnoid space, 70 mL in the paraspinal subarachnoid space. It is secreted @ rate of 0.35-0.4 mL per minute, that 50% of the CSF is replaced in 5 to 6 hours .

5. The typical upper limit of normal CSF pressure ranges from 40 mm H 2 O in infants 140 mm H2O in adults . when one is lying in a horizontal position averages 130 millimeters of water CSF pressure fluctuates with respirations and arterial pulse pressures as well as with changes in head position.

6. Pressure is maintained by balance between CSF secretion and its resorption by the arachnoid villi. Because CSF secretion occurs at a steady rate, the rate of CSF resorption plays the major role in determining CSF pressure . Processes that disrupt CSF resorption will tend to lead to increased intracranial pressure.

7. Osmolartity ( mosm /kg water) 280 280 145-155 2-3.5 15-45 45-85 pH 7.3- 7.4

8. DEFINITION Cerebrospinal fluid (CSF) rhinorrhoea is the leakage of CSF from the subarachnoid space into the nasal cavity due to a defect in the dura , bone and mucosa. The origin of the fluid may be from the anterior, middle or posterior cranial fossae .

9. History Dandy(1926 ): first surgical repair of CSF leak via frontal craniotomy approach Wigand (1981): use of endoscope for the first time to assist with repair of skull base defect 90-95 % success rate with decreased associated morbidity – thus preferred

10. AETIOLOGY The importance of accurate classification was first recognized by Ommaya et al proposed dividing CSF rhinorrhea into Ommaya Classification T raumatic N on traumatic leaks

11. HEAD TRAUMA CSF leaks - 2 % of head injuries and 12% to 30% of skull base fractures . Most CSF leaks occur as a result of blunt trauma . CSF otorrhea CSF oto-rhinorrhea CSF rhinorrhea . Most traumatic CSF leaks will heal with conservative treatment including bedrest .

12. It is likely that only the sinus mucosal aspect of the defect closes as the dura does not regenerate. Leads to risk of meningitis ‘mono-layer of protection ’ may be eroded by either the pulsatile effect of the brain or by inflammation within the nose.

13. With the Massive head trauma with complex comminuted and displaced fractures of the skull base can be incredibly difficult to treat. Open approaches may be useful. In massive ‘egg-shell’ fractures of the sphenoid sinuses, fat obliteration can be considered,

14. CONGENITAL CSF LEAKS Encephalocele

15. Meningoencephaloceles

16. Mondini Dysplasia may present with substantial CSF leaks where the CSF has only briefly transversed the perilymphatic space. presenting as hearing loss recurrent meningitis CSF otorrhea or CSF oto-rhinorrhea

17. CSF LEAKS ASSOCIATED WITH TUMOURS Tumours causing substantial erosion of the skull. Tumour shrinkage occurs, for example during induction chemotherapy.

18. SPONTANEOUS LEAKS Sometimes described as ‘idiopathic ’ The association of spontaneous leaks M iddle-aged women with a raised body mass index. Variant of benign intra-cranial hypertension E levated intra-cranial pressure. this diagnosis being made on lumbar puncture after surgical repair. Not possible to measure this pre-operatively as the persistent leak reduces the pressure.

19. Radiological features of increased intra-cranial pressure such as an empty sella , enlarged ventricles or diffuse erosion of the skull base Spontaneous leaks are most likely to recur Success rates for endoscopic closure are worse than for other causes

20. Benign intracranial hypertension A lso known as idiopathic intracranial hypertension and pseudotumor cerebri , is a syndrome of increased ICP in the absence of specific causes such as intracranial masses hydrocephalus dural sinus thrombosis

21. CSF LEAKS COMPLICATING SINUS SURGERY CSF leaks complicating sinus surgery, diagnosed intra-operatively should be repaired under the same anaesthetic . Local intra-nasal tissue can be used for the repair with generally good results .

22. The most likely anatomical sites for CSF leaks complicating sinus surgery very thin bone of the lateral lamella of the cribriform plate Anterior skull base where it is weakened by the anterior ethmoid neurovascular bundle Posteriorly where there may be confusion as to the exact anatomical relationship between the last posterior ethmoidal cell and the sphenoid sinus.

23. Other sites of CSF leak during FESS Olfactory fossa( Keros classification- type 3) Upper attachement of uncinate process attached to Skull base Posterior wall of frontal recess

24. salty or metallic taste

25. Halo sign has been considered an important marker of CSF rhinorrhea after head trauma. The halo sign is considered present when a clear ring surrounds a central bloody spot after bloody nasal discharge is dropped upon a handkerchief or paper towel. Presence of either tears or saliva is likely to give a falsely positive halo sign.

26. INVESTIGATION OF CSF LEAKS An accurate history E xamining the patient including nasal endoscopy. The investigations include: • laboratory investigation of rhinorrhoea fluid; • imaging; • intrathecal dyes and markers.

27. Laboratory investigation obtain fluid for testing- Postural provocation Run up stairs - increase intra-cranial pressure and produce drainage strain on a closed glottis

28. 1) The only test that should be used to determine CSF = immunofixation of beta-2 transferrin. Beta-2 transferrin is a protein involved in ferrous ion transport and it is also found in perilymph and aqueous humour . Sensitivity test Specificity 100 % 95 %

29. False-positive Beta-2 transferrin :- C hronic liver disease Inborn errors of glycogen metabolism genetic variant forms of transferrin Neuropsychiatric disease Rectal carcinoma Abnormal transferrin metabolism thus the beta-2 form can appear in the blood

30. 2) beta-trace protein( βTP ) is an even better test than beta-2-transferin in detecting CSF leaks βTP is produced by the meninges and choroid plexus and is released into CSF. It is also present in other body fluids, including serum, but at much lower concentrations than in CSF. βTP has 100% sensitivity and specificity in cases of confirmed CSF rhinorrhea .

31. βTP false positive result -renal insufficiency bacterial meningitis 3) Another CSF marker protein transthyretin detected by a rapid on-chip immunosubtraction technology. Advan : results within 5 to 10 minutes,

32. Cerebrospinal Fluid Tracers Intrathecal agent tests provide information that can confirm the presence of a CSF leak; location of the skull base defect associated with the CSF leak. All of these tests (except for those based on MRI) require a lumbar puncture for the introduction of a tracer agent into the subarachnoid space. Complications caused by the intrathecal agent can be quite severe.

33. Agents may be categorized visible dyes radionuclide markers radiopaque dyes . Any of these tests are considered positive if the agent is visualized within the nose and paranasal sinuses.

34. Intrathecal fluorescein It is probably the most popular visible agent. Lumbar puncture is performed for the introduction of fluorescein into the intrathecal space, the patient is kept in the head-down position, and nasal endoscopy is performed to identify fluorescein within the nose and sinuses. Fluorescein has a characteristic green color - identify even in minute. Specific blue-light filters may be used to enhance visual detection of fluorescein,

35. Complications : seizures knee and ankle clonus cranial nerve defects, death Low doses -recommended dilution of fluorescein- 0.1 mL of 10% fluorescein in 10 mL of the patient’s own CSF ; N ot an FDA-approved application.

36. Radionuclide tracer Radioactive iodine ( 131 I) serum albumen(RISA) technetium (99mTc)- labeled serum albumen DTPA( diethylene -triamterene- penta -acetic acid) indium-111 labelled DTPA Can be useful only in active CSF leak

37. used for radionuclide cisternography , intrathecal administration of a radionuclide tracer via a lumbar puncture monitoring of the distribution of tracer with a scintillation camera. intranasal pledgets are also placed proximity to the suspected skull base defect assayed for tracer 12 to 24 hours later with a gamma counter.

38. Computed tomography (CT) cisternography CT imaging after the intrathecal administration of radiopaque contrast ( metrizamide ) Approximately 80 % of CSF leaks can be confirmed through CT cisternography .

39. High resolution coronal CT scans (l-2-mm slices) can offer detection in up to 84 % Axial views are helpful in detecting leaks from the posterior wall of the frontal sinus and sphenoid sinus .

40. Magnetic resonance (MR) cisternography N oninvasive method to assess for the presence of intranasal / intrasinus CSF MRl is advisable in the case of encephalocoeles to delineate the contents and vascularity of the sac before surgical exploration

41. MANAGEMENT Conservative surgical managements

42. CONSERVATIVE TREATMENT Duration- 1- to 2-week period The goal of these measures is to reduce the CSF leak flow by decompressing the intracranial pressure ; in this way, healing at the defect site may seal the leak without surgical intervention.

43. Drug that reduce CSF production rate : Frusemide Acetazolamide 250mg once daily Side effect: Metabolic acidosis Hypokalamia Drowsiness

44. Lumbar drains CSF cell counts, protein, glucose, and cultures should be sent daily-evaluation and pathology. An hourly drainage rate of 10 mL is desirable . Higher rates may lead to abnormally low ICP, which can produce severe headache . Low ICP also may cause pneumocephalus because air is drawn through the skull base defect . If low ICP is suspected ,-> the rate of drainage should be decreased/the drain should be clamped until the ICP equilibrates at a higher level. Prophylactic antibiotic should be used

45. After craniotomy, the defect site is identified a tissue graft is placed to close the defect. Fascia lata grafts, muscle plugs, and pedicled galeal flaps may be used. A tissue sealant- fibrin glue, may be used TRANSCRANIAL TECHNIQUES

46. Access to the cribriform plate region and roof of the ethmoid -> frontal craniotomy; access to the sphenoid sinus defects -> extended craniotomy and skull base techniques Complications: brain compression hematoma seizures anosmia. Despite direct access to the skull base defect, failure rates are quite high> 25 %.

47. Advantages of Intracranial Approch Direct visualization of the defect Better chance of patching the defect in case of high ICP

48. Disadvantage of intracranial approach Not good visualization of the sphenoid sinus Chance of following morbility Anosmia Bleeding Seziures Osteomyelitis of frontal bone Frontal lobe dysfunction – Memory loss

49. EXTRACRANIAL TECHNIQUES This remains the method of choice for accessing most leaks of the posterior wall of the frontal sinus

50. approaches described are as follows: via an external ethmoidectomy for access to the cribriform plate and fovea ethmoidalis transmastoid for defects in the tegmen and petrous temporal bone transseptosphenoidal for access to the sphenoid sinus via a coronal or eyebrow incision to the frontal sinus using an osteoplastic flap.

51. In the frontal and sphenoid sinuses the mucosa can be removed, the defect patched with a fascial graft and the sinus can be obliterated by packing with fat. To support the graft pedicled or free mucosal grafts from the nasal septum or turbinates

52. Complication: facial numbness septal perforation orbital complications- diplopia and epiphora . The success rates vary from 76 to 100% An extradural approach - minimizes the incidence of intracranial complications .

53. ENDOSCOPIC REPAIR OF CSF RHINORRHEA This is the method of choice for repairing the majority of CSF leaks . Success rates are excellent at 76-97 % The grafts described include nasal mucosal flap free graft of nasal mucosa turbinate bone conchal septal cartilage temporalis fascia and fascia lata

54. Different type of graft Middle turbinate flap : Is a posterior pedicle flap with sphenopalatine vessels.

55. Upper septal mucoperiosteal flap

56. Leakage from cribriform plate / Ethmoid roof Procedure: Done under GA 1. Graft harvesting Temporalis fascia is harversted Fat harvested from the ear lobule Septal cartilage 2. Site of leak identified -Evidence of pulsation transmitted from cranial cavity -flow of thin and clear fluid from suspected area -Fluorescein seen

57. 3. Edges of the margin freshened 4. Fat is tied with vicryl suture and positioned into the defect “ bath plug” technique 5.Suture material passed through septal cartilage

58. 6. Temporalis fascia tucked under the mucosal edge- UNDERLAY TECHNIQUE 7. Graft is held in place fibrin glue and supported by gelform 8. Nasal pack with merocel is done

59. Advantage of Endoscopic Procedure Better Magnification and visualization Absence of external scar Minimal invasive procedure Avoid dreadful complication with intracranial approch

60. COMPREHENSIVE MANAGEMENT STRATEGY Indications for operative CSF leak repair :- failed conservative management intraoperative recognition of a leak during sinus surgery skull base surgery or craniotomy large defects or leaks pneumocephalus spontaneous leaks open traumatic head wounds with CSF leakage .

61. It is practical to consider management options in four scenarios : 1) nonsurgical traumatic etiology , 2 ) intraoperative injury with immediate recognition /onset , 3 ) operative injury with delayed recognition /onset , 4 ) nontraumatic , so-called spontaneous leaks.

62. Nonsurgical Traumatic Etiology Result of head injury - If the rhinorrhea does not resolve within several days, operative exploration and repair are necessary. Extracranial endoscopic techniques are applicable; however, open transcranial procedures may be warranted.

63. Intraoperative Injury with Immediate Recognition or Onset If a CSF leak is suspected during FESS, surgeon should confirm the presence of leak repair should be performed .

64. Operative Injury with Delayed Recognition or Onset After nasal surgery, the presence of CSF rhinorrhea may not be confirmed until days, weeks, months, or even years A trial of conservative therapy given some of these leaks will close with these simple measures. Surgical exploration

65. Nontraumatic Leaks/ spontaneous leak Nontraumatic CSF leaks -> require surgical repair. Treatment of nontraumatic CSF rhinorrhea as a result of neoplasm hydrocephalus

66. Complications of CSF leak repair Meningitis Pneumocephalus Brain abscess Epidural abscess Subdural abscess Intra cranial bleeding Postop Infection Formation of scar tissue in sinuses – c/o Nasal obstruction

67. 1. Meningitis Most common complication. Casused by ascending infection from the sinus – involving the meninges and csf space Symptoms:- Headache Photophobia Vomiting Tx : 1.Cephalosporins(2 nd n 3 rd generation)*10days 2. Dexamethasone(0.6mg/kg/day * 5days)

68. 2. Pneumocephalus Collection of air in the cranial cavity- Subarachnoid space. Occurs when air trapped when acutely coughing, sneezing, nasal blowout C/F : Sudden alteration in mental status, Confusion Tx :- Needle aspiration- burr hole

69. Cause of failure of surgery Raised ICP Infection Intraop Bleeding

70. CONCLUSION CSF rhinorrhea occurs when a skull base defect permits the drainage of CSF from the intracranial space to the nose and paranasal sinuses. traumatic and nontraumatic . Diagnosis- β-transferrin assay. Several CSF tracer studies are available High-resolution CT / MR/ CT cisternography Many CSF leaks respond to conservative management Transcranial techniques for CSF leak closure have been present for many decades, they are often a second-line treatment in the contemporary management of CSF rhinorrhea . Extracranial techniques were developed in the middle of the twentieth century Endoscopic repair the preferred surgical modality for those instances in which operative repair is warranted.

71. Thank you!