Subarachinoid Hemorrhage

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					Subarachinoid
 Hemorrhage
      Etiologies of subarachnoid
          hemorrhage (SAH)
   trauma: the most common cause of SAH
   ruptured intracranial aneurysms: 75-80%
    of spontaneous SAHs
   cerebral AVMs: 4-5% of cases
   certain vasculitides that involve the CNS
   rarely due to tumor
   cerebral artery dissection (may also be
    post-traumatic)
   no cause can be determined in 14-22%
        Risk factors for SAH

   hypertension
   cigarette smoking
   oral contraceptives
   alcohol consumption (debatable)
   diurnal variations in blood pressure
   pregnancy and parturition
   slight increased risk during lumbar
    puncture and/or cerebral angiography in
    patient with cerebral aneurysm
   slight increased risk with advancing age
   following cocaine abuse
    Conditions associated with
            aneurysms
.    autosomal dominant polycystic kidney disease
   fibromuscular dysplasia (FMD): incidence of
    aneurysms in renal FMD is 7%, in aortocranial
    FMD 21%
   arteriovenous malformations (AVM)
   connective tissue disorders: Ehlers-Danlos
    type IV (deficient collagen type III), Marfan's
    syndrome, pseudoxanthoma elasticum
   multiple other family members with
    intracranial aneurysms
   coarctation of the aorta
           Clinical features
   Symptoms
   Sudden onset of severe H/A
   vomiting
    syncope (apoplexy)
   neck pain (meningismus)
   photophobia.
   Focal cranial nerve deficits may occur
    (especially third nerve, causing diplopia
    and/or ptosis).
    Low back pain may develop due to
    irritation of lumbar nerve roots by
    dependent blood.
    Hunt and Hess (H&H) classification of SAH


   1   asymptomatic, or mild H/A and slight nuchal rigidity
   2   Cr. N. palsy (e.g. III, VI), moderate to severe H/A, nuchal rigidity
   3   mild focal deficit, lethargy, or confusion
   4   stupor, moderate to severe hemiparesis, early decerebrate rigidity
   5   deep coma, decerebrate rigidity, moribund appearance

   Add one grade for serious systemic disease (e.g. HTN, DM, severe
    atherosclerosis, COPD) or severe vasospasm on arteriography.
   Modified classification adds the following
   0   unruptured
   1a acute meningeal/brain reaction, but with fixed neuro deficit
             Evaluation
1. tests to diagnose SAH
   1. non-contrast high-resolution CT scan
   2. if CT is negative: LP in questionable cases
2. cerebral angiography in confirmed cases or if high
   degree of suspicion
            Lumbar puncture
  The most sensitive test for SAH.
 LP findings:

1. opening pressure: elevated

2. appearance:

-non-clotting bloody fluid that does not clear with
   sequential tubes
-xanthochromia: yellow discoloration. Usually
   takes 1-2 days to develop
3. cell count: RBC count usually > 100,000
   RBCs/mm3. Compare RBC count in first to last
   tube (should not drop significantly). For
   questionable case
            Initial management
                  concerns
1.   rebleeding
2.   hydrocephalus
3.   delayed ischemic neurologic deficit
     (DIND), usually attributed to
     vasospasm.
4.   hyponatremia with hypovolemia
5.   DVT and pulmonary embolism
6.   seizures
7.   determining source of bleeding: 4-vessel
     cerebral angiography is required.
           Rebleeding
 Maximal frequency of rebleeding is
  in the 1st day
- 4% on day 1
- then 1.5% daily for 13 d

- 15-20% rebleed within 14 d,

- 50% will rebleed within 6 months,

- thereafter the risk is 3%/yr with a
  mortality rate of 2%/yr
            Rebleeding
-   In a study of 33 patients who
    rebled, the highest risk of
    rebleeding occurred in the first 6
    hours following SAH.
-   The rebleeding risk is higher in
    patients with a high Hunt and Hess
    grade.
-   Risk did not appear to be altered by
    BP on admission or site of
    aneurysm.
    Treatment of aneurysm
The best treatment for an
 aneurysm depends on the:
-condition of the patient
-the anatomy of the
 aneurysm
-the ability of the surgeon
    Timing of aneurysm surgery

   Controversy exists between so-
    called "early surgery"
    (generally, but not precisely
    defined as < 48 hrs post SAH)
    and "late surgery" > 48 hrs
    (usually 10-14 days post SAH).
Guglielmi detachable
     coil (GDC)
Basilar tip aneurysm
Vasospasm
     Unruptured Intracranial
          Aneurysm
Unruptured intracranial aneurysms
 (UIA) includes:
A- incidental aneurysms
B-aneurysms that produce symptoms
 other than those due to hemorrhage
Estimated prevalence of UIA is 5-10% of
 population.

				
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posted:12/11/2011
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