Surg351 presentation and management of raised intracranial pressure

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Surg351 presentation and management of raised intracranial pressure

  1. 1. Presentation & Management of Raised Intracranial Pressure By Zain Alabedeen B. Jamjoom, M.D. Professor of Neurosurgery
  2. 2. Normal Intracranial Pressure Normal ICP ~10 mmHg (supine at the level of the foramen of Monro) Pulsatile Fluctuates with the respiration ICP >20 mmHg is definitely pathological20 November 2007 Raised ICP 2
  3. 3. Normal ICP Waveform t (sec) ECG Resp. ICP20 November 2007 Raised ICP 3
  4. 4. Cerebral Blood Flow (CBF) Pressure Flow = Resistance CBF = Cerebral perfusion pressure (CPP) Cerebral vascular resistance (CVR) CPP = Mean syst. art. BP - Mean ICP20 November 2007 Raised ICP 4
  5. 5. Intracranial Cavity Its volume is virtually constant. It is filled to capacity with fluids & solid material that are non-compressible. Therefore: Increase in one constituent or an expanding mass within the intracranial space results in raised ICP (Monro-Kellie Doctrine).20 November 2007 Raised ICP 5
  6. 6. Intracranial Cavity Content Brain: – Neurones 500 - 700 ml – Glia 700 - 900 ml – Extracellular fluid 100 - 150 ml Blood: 100 - 150 ml Cerebrospinal fluid: 100 - 150 ml Constituents are non-compressible but partially displaceable20 November 2007 Raised ICP 6
  7. 7. ICP/Volume Curve20 November 2007 Raised ICP 7
  8. 8. Intracranial Cavity 3 compartments 2 supratentorial spaces, separated by the falx cerebri, and 1 infratentorial space, separated from supratentorial spaces by the tentorium.20 November 2007 Raised ICP 8
  9. 9. Intracranial MassShifts(CerebralHerniations)20 November 2007 Raised ICP 9
  10. 10. Transtentorial (Uncal) Herniation Bilateral Unilateral20 November 2007 Raised ICP 10
  11. 11. The Tentorial Hiatus Oculomotor nervePosterior cerebral artery Cerebral peduncle Reticular formation 20 November 2007 Raised ICP 11
  12. 12. Transtentorial Herniation rd Compression of 3 CN: – Dilatation of ipsilateral pupil. Compression of the mid-brain: – Impairment of consciousness. – Hemiparesis (usually contralateral, but occasionally ipsilateral). – Hypertension + Bradycardia (Cushing response). – Respiratory failure. Compression of post. cerebral artery: – Infarction of occipital lobe20 November 2007 Raised ICP 12
  13. 13. Syndromeof Unilateral Uncal HerniationEarly Phase20 November 2007 Raised ICP 13
  14. 14. Syndrome ofUnilateral UncalHerniationLate Phase20 November 2007 Raised ICP 14
  15. 15. A main cause of uncal herniation is Extradural Hematoma20 November 2007 Raised ICP 15
  16. 16. Clinical Symptoms & Signs of Raised ICP Headache Nausea and vomiting Papilledema Impairment of consciousness th 6 cranial nerve palsy: False localizing sign Impaired level of consciousness20 November 2007 Raised ICP 16
  17. 17. Signs of Raised ICP Papilledema Normal Papilledema20 November 2007 Raised ICP 17
  18. 18. Signs of Raised ICP Abducent Nerve Palsy20 November 2007 Raised ICP 18
  19. 19. Clinical Symptoms & Signs of Raised ICP in Infants Large head (Macrocephaly) Tense & enlarged anterior fontanel Separated skull sutures Prominent scalp veins “Sun set” of eyes20 November 2007 Raised ICP 19
  20. 20. Macrocephaly20 November 2007 Raised ICP 20
  21. 21. Investigations Method of choice: URGENT brain CT scan. Skull X-rays: – Separated sutures – Silver beaten appearance Lumbar puncture is CONTRAINDICATED.20 November 2007 Raised ICP 21
  22. 22. Separated Skull Sutures20 November 2007 Raised ICP 22
  23. 23. Silver Beaten Appearance20 November 2007 Raised ICP 23
  24. 24. Causes of Increased ICP Increased volume of normal intracranial constituents: – Brain: Cerebral edema. – Cerebrospinal fluid: Hydrocephalus. o – Blood volume: Vasodilatation 2 to CO2 A space-occupying lesion: - Tumor - Hematoma - Abscess - Cyst Idiopathic: – Pseudotumor cerebri20 November 2007 Raised ICP 24
  25. 25. Cerebral Edema20 November 2007 Raised ICP 25
  26. 26. Hydrocephalus20 November 2007 Raised ICP 26
  27. 27. Intracranial Tumor20 November 2007 Raised ICP 27
  28. 28. Intracranial Tumors Intrinsic: – Arise from brain tissue – Majority are gliomas (Grades I to IV) Extrinsic: – Arise from intracranial tissue other than brain – Include: Meningioma, Pituitary adenoma, Schwannoma Location: – Adults: mainly supratentorial – Children: mainly intratentorial20 November 2007 Raised ICP 28
  29. 29. Brain Abcsess20 November 2007 Raised ICP 29
  30. 30. Brain Abscess Develop as a result of a localized bacterial cerebritis followed by necrosis and encapsulation. Mechanisms: – Hematogenous – Extension from neighbouring structures – Penetrating injuries Symptoms of infection may be absent in 50% of cases20 November 2007 Raised ICP 30
  31. 31. Treatment of Raised ICP General measures for reducing raised ICP Definitive treatment: Removal of the cause20 November 2007 Raised ICP 31
  32. 32. General Measures to Reduce Raised ICP o Head elevation 30o up in neutral position. Diuretics: – Mannitol : 20% 1g/kg iv single dose or 0.25-0.5g/kg Q8h – Furosemide : 1mg/kg iv sinlgle dose or 0.25-.05mg/kg Q8h Normovolemia: IV infusion of cristalloid Controlled hyperventilation: – pCO2 reduction to 30 - 35 mmHg. Sedation & Muscle relaxation. CSF withdrawal. No lumbar puncture20 November 2007 Raised ICP 32
  33. 33. Ventriculo-peritoneal Shunt20 November 2007 Raised ICP 33
  34. 34. Excision of Intracranial Tumor20 November 2007 Raised ICP 34
  35. 35. Drainage of Brain Abscess20 November 2007 Raised ICP 35
  36. 36. Benign Intracranial Hpertension “Pseudotumor cerebri” Young, obese women Pathogenesis not clear Precipitating factors: – Hypoparathyroidism – Vitamin A excess (Tx of acne) – Pernicious anemia – Drugs: oral contraceptives, tetracycline, sulphamethoxazole, indomethacin, a.o.20 November 2007 Raised ICP 36
  37. 37. Benign Intracranial Hypertension Presenting Features Headache Visual disturbance – Blurred vision – Diplopia Papilledema Optic atrophy 6th nerve palsy20 November 2007 Raised ICP 37
  38. 38. Benign Intracranial Hypertension Investigations CT – scan: WNL Lumbar puncture & measurement of CSF pressure: Elevated CSF biochemical & cytological: WNL MRI & MRA: WNL Continuous intracranial pressure measurement (in doubtful cases)20 November 2007 Raised ICP 38
  39. 39. Benign Intracranial Hypertension Treatment Weight reduction Discontinuation of potentially causative drugs ( e.g. contraceptives, vitamin A) Diuretics (e.g. LasixR) Acetazolamide (DiamoxR): Initially 500 mg, later 250 Q6h Intermittent release of CSF20 November 2007 Raised ICP 39
  40. 40. Benign Intracranial Hypertension Indication of Surgery Persistent papilledema despite Tx Failing vision Intractable headache despite Tx20 November 2007 Raised ICP 40
  41. 41. Benign Intracranial Hypertension Surgical Treatment Lumbo-peritoneal shunt Optic nerve sheath decompression20 November 2007 Raised ICP 41
  42. 42. Complications of Untreated Raised ICP Death Neurological disability – Blindness – Mental impairment – Motor disability Disfigurement20 November 2007 Raised ICP 42
  43. 43. Neurological Disability20 November 2007 Raised ICP 43
  44. 44. Measurement of Intracranial Pressure Epidural Subdural Intraparenchymal Intraventricular20 November 2007 Raised ICP 44
  45. 45. Intraventricular Pressure Measurement20 November 2007 Raised ICP 45
  46. 46. A-waves or Plateau waves20 November 2007 Raised ICP 46
  47. 47. Measurement of Intracranial Pressure Indications Severe head trauma Intracerebral hemorrhage Extensive cerebral edema – e.g. after infarct, hypoxia, intoxication, etc. Following major intracranial operations In the assessment of dementia and benign intracranial hypertension20 November 2007 Raised ICP 47
  48. 48. References Essential Neurosurgery by: Andrew Kaye Neurology and Neurosurgery Illustrated by: Lindsay - Bone - Callander20 November 2007 Raised ICP 48
  49. 49. 20 November 2007 Raised ICP 49

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