CSF RHINORRHOEA

CSF RHINORRHOEA : 

CSF RHINORRHOEA Dr. Manzoor Ahmad Malik Dr mudasir ul islam Postgraduate presentation 01/12/2010

CSF Basics : 

CSF Basics Amount 50-80% produced by choroid plexus Nearly 30% produced by ependymal surfaces 90-150 ml of CSF at any one time 20ml/hr is the normal production rate 500ml produced per day

CSF Basics : 

CSF Basics Production Result of capillary ultrafiltration Regulated by Na+/K+ ATPase activity Na+ ions are taken into the epithelial cell from the vessel Another Na+/K+ ATPase on the ventricular side then pushes the Na+ out into the ventricle Water follows the ions into the ventricle Result is CSF

Concentration of various substances in CSF : 

Concentration of various substances in CSF

Circulation of CSF : 

Circulation of CSF

Classification of CSF Rhinnorhea : 

Classification of CSF Rhinnorhea Etiology – most important factor for success of surgery. Location – most important factor for approach. Size of defect.

Etiology(S. Mirza et al., Laryngoscope; Oct. 2005) : 

Etiology(S. Mirza et al., Laryngoscope; Oct. 2005) Traumatic – 10 to 30% of skull base fractures have associated rhinnorhea 17% - Most common cause - Blunt/Penetrating Congenital 11% - Encephalocele Iatrogenic 37% Sinus surgery (10%), transsphenoidal hypophysectomy (12%), Craniotomy (9%), headight polypectomy(2%), other neuro procedures Tumor 03% Invasion through skull base Spontaneous 29% Usually attributed to increased ICP

Traumatic injury : 

Traumatic injury Rhinnorhea usually presents within 48 hours 70% close with conservative intervention Those not surgically closed associated with 30-40% risk of ascending meningitis

Iatrogenic : 

Iatrogenic FESS -Lateral lamella of cribroform plate -Posterior ethmoid near the roof of the anteriomedial wall of sphenoid Skull base surgery Transsphenoidal hypophysectomy -Disruption of sellar diaphragm Craniofacial resections

Congenital : 

Congenital Relatively rare Presents as meningioencephalocele Congenital hydrocephalus Congenital skull base defects Usually have large funnel shaped defects May have either increased ICP or normal ICP Failure of closure of anterior neuropore->herniation of meninges (encephaloceles) Persistent craniopharyngeal canal

Sites of lesion(S. Mirza et al., Laryngoscope; Oct. 2005) : 

Sites of lesion(S. Mirza et al., Laryngoscope; Oct. 2005) Cribriform plate 26 Fovea Ethmoidalis/Lateral lamella 20 Frontal 18 Sphenoid 30 Septal olfactory dural extension 02

Work-up – H & P : 

Work-up – H & P History Clear watery discharge from single nares Supine positining->increased post-nasal drip Salty taste in mouth Headaches relieved when CSF begins to drain Physical Most cases examination unremarkable Examine with nasal endscopy Have patient lean forward and strain may elicit a leak Compression of both jugular veins may elicit a CSF leak CSF rhinorrhea is typically clear but if trauma has occurred it may be mixed with blood High likelihood of other injuries when trauma is involved (facil fractures, brain injury)

Presenting features(S. Mirza et al., Laryngoscope; Oct. 2005) : 

Presenting features(S. Mirza et al., Laryngoscope; Oct. 2005) Unilateral rhinorrhea 87% Meningitis 06% Bilateral rhinorrrhea 03% Unilateral polyp (enchalocele) 01%

Diagnosis : 

Diagnosis Halo or Ring sign Bloody CSF placed on a piece of filter paper Blood will separate out from the CSF (central blood with clear ring) Dula et al found that the ring sign is not specific to bloody CSF Blood mixed with water, saline, and other mucus will also produce a ring sign

Diagnosis – Laboratory studies : 

Diagnosis – Laboratory studies Glucose testing Not very useful –false finding Presence of blood->increased glucose reading (false positive) Presence of meningitis or other intracranial infections->lower conc. of glucose in CSF (false negative) Glucose oxidase paper Changes color with glucose conc. of 5+ mg /dl False positive results with lacrimal secretios or nasal mucus Both contain enough glucose to cause paper to change color If no blood present may suspect CSF leak with a glucose concentration > 30mg/dl Negative glucose virtually eliminates a diagnosis of CSF fluid

Diagnosis –Laboratory Studies : 

Diagnosis –Laboratory Studies Buffeta-trace protein Found in CSF; heart and serum Not routinely ordered as it may be altered in many cases Elevated with renal insufficiency, multiple sclerosis,cerebral infarction and some CNS tumors If serum level is <1.0mg/L Fluid with a concentration>2.0mg/l=Positive for CSF Concentration<1.5mg/L=Not likely to contain CSF Sensitivity and specficity not as high as Beta-2-tansferrin If test is available, can be accomplished in 15 minutes

Diagnosis-Laboratory Studies : 

Diagnosis-Laboratory Studies Beta-2-transferrin Protein produced by enzymes only in CNS Test requires 0.5cc of fluid Specimens should be refrigerated If not, protein will become unstable at room temperature within 4 hrs If refrigerated,can last 3 days Highly sensitive and specific for CSF If available, can get results within 3 hrs

Diagnosis -Imaging : 

Diagnosis -Imaging High Resolution CT Scans Bony defects , pneumocephalus,soft tissue masses,hydrocephalus Should have 1mm cuts with axial ,sagittal and coronal views CT Cisternography Inject intrathecal contrast dye and obtain CT scan More accurate-especially those with active leaks Sensitivity for detecting leaks drops from nearly 100% with active leaks to 60% with intermittent leaks More invasive MRI Soft tissue abnormalities and pooling of CSF(high signal intensity on T2 Must utilise contrast to differentiate sinus inflammation from CSF fluid More expensive Not as good at defining bony defects

Diagnosis –Imaging : 

Diagnosis –Imaging Nuclear medicine tests(radionuclide cisternography) How it works Intrathecal injection of radioactive tracers(technetium-99, I-131, Indium 111 Pledgets placed at areas suspected of leak and scintigrams of the skull are obtained Pledgets are removed and measured for radioactive tracer Drawbacks Almost always requires an active leak With active leaks detection rate is 70% Inactive leak -30-40% detection rate Poor localization in most cases Radioactive isotope is absored into the circulatory system and deposited in normal tissues

Diagnosis-intrathecal dye : 

Diagnosis-intrathecal dye Intrathecal dye injection of flourescein Good at locating active CSF leaks Inject a solution of 0.5% to 10% and wait thirty minutes to examine patients Most cases dye can be seen without filters Smaller defects may require filters or black light Place yellow filter over endoscope ad blue filter over light source Important to keep low concentration of flourescein as high doses can lead to severe side effects(500 mg) Seizures,pulmonary edema,coma and death

Treatment-Basic : 

Treatment-Basic Conservatie vs Surgical Traumatic respond well to conservative Spontaneous require surgical correction Basic consevative management Bed rest 7 to 10 days Head end of bed 15 to 30 degrees No’s Nose blowing Straining Coughing Weight lifting 75 to 80% of traumatic leaks resolve spontaneously with this management

Treatment-Antibiotics : 

Treatment-Antibiotics Controversial Reason-prevent intracranial infection Evidence Brodie et al meta-analysis in 1997 324 patients in 6 studies 237 treated with antibiotics 87 not treated Meningitis 2.5% in treated cases(6/237) 10% in non-treated cases(9/87) Villalobos et al meta-analysis in 1998 1241 patients in 12 studies 719 treated with antibiotics and 524 not treated 1.34 times more likely to develop meningitis without use of antibiotics in CSF leaks from basilar skull fracture Risk of selecting out more virulent bacterial strains with use

Treatment-Diuretics : 

Treatment-Diuretics Utilized in the presence of CSF leak with increased ICP Acetazolamide Inhibits the conversion of water and Co2 to bicarbonate and proton Loss of proton slows the action of Na/K ATPase enzymes that are responsible for production of CSF,thus decreasing ICP

Treatment –Lumbar drain : 

Treatment –Lumbar drain Consider if CSF leak does not resolve after 5-7 days of conservative management Continuous drainage is recommended over intermittent drainage as it prevents spikes in CSF pressure(10 – 15 cc/hr) Risks Headaches Nausea and emesis Pneumocephalus Infection coma

Treatment -Surgical : 

Treatment -Surgical Intracranial approach when to use Comminuted skull fractures with displaced fragments requiring reduction Extensive skul base fractures Fractures associated with intracranial haemorrhages or contusions that require craniotomy for treatment Dural defects may be closed primarily with/without use of grafts Free or pedicled periosteal or dural flaps Muscle plugs Mobilized portions of the falx cerebri Fascia grafts Many commercial grafts Reinforce grafts with fibrin glue

Intracranial approach(Advantages/Disadvantages) : 

Intracranial approach(Advantages/Disadvantages) Advantages Direct visualiztion of defects Inspection of adjacent cerebral cortex Better chance of patching a defects in the face of increased ICP Disadvantages Increased morbidity Increased hospital time Injury to brain from retraction (hematoma,seizures,congnitive dysfunction,risk of permanent anosmia) Not good for visualization of sphenoid sinus

Treatment-surgical : 

Treatment-surgical Extracranial approach Most often endoscopic(90% success rate) Advantages of endoscopic use Better magnified visualization Angled visualization No external incisions Minimizes intranasal mucosal injuries

Treatment -surgical : 

Treatment -surgical Endoscopic repair Good visualization and exposure If an encephalocele is present Cauterize stalk prio to reduction(prevents intracranial hemorrhage 2-5mm bone should be exposed around the defect Grafts -30% larger than the defect to account for shrinkage Types of grafting materials Cartilage Bone (septum,mastoid tip,middle turbinate) Mucoperichondrium Septal mucosa Turbinate mucosa &/bone Fascia(temporalis/fascia lata) Abdominal fat Pedicled septal or turbinate flaps (tend to tent,fold and contract,so not as good as free tissue use)

Treatment-surgical : 

Treatment-surgical Grafting techniques All mucosa must be removed from the defect to ensure that the mucocele does not form Place the graft over the defect(overlay) Place the graft between the dura and the bony defect(underlay) Both underlay and overlay grafts(combined) Fibrin glue provides improved seal Gelfoam packing over seal with/without nasal packing may further improve seal Multilayered grafting if ICP raised

Slide 31: 

Overlay Underlay

Repair based on defect size : 

Repair based on defect size <2mm almost any grafting technique is successful 2 to 5mm-can typically get away by just utilizing an overlay graft Communited bone segments or significant dural injury Composite graft Seperately harvested bone & mucosa(bone placed in an underlay fashion & mucosa placed in an overlay fashion) >5mm –composite or separate bone & mucosa grafts needed

Post –operative management : 

Post –operative management Bed rest with HOB 15 to 30 degrees for 3 to 5 days Stool softners Try to maintain normal BP No straining,coughing,heavy lifting If lumbar drain is utilized – 3 to 5 days in place No-absorbable packing utlized-antibiotics