OHCM - Subarachnoid Hemorrhage Flashcards Preview

Neurology > OHCM - Subarachnoid Hemorrhage > Flashcards

Flashcards in OHCM - Subarachnoid Hemorrhage Deck (35):
1

SAH - Typical age:

35-65.

2

SAH - Etiology:

1. Rupture of saccular aneurysms (80%).
2. AV malformations (AVM; 15%).

3

SAH - No cause is found in ...?

4

SAH - Risk factors:

1. Smoking.
2. Alcohol.
3. HTN.
4. Bleeding disorders.
5. Mycotic aneurysms (SBE).
6. Perhaps post-menopausal decreased ESTROGEN (Female:Male=3:2 if >45yr).

5

SAH - Close relatives have ...?

3-5-fold increased risk of SAH.

6

Berry aneurysms - Common locations:

1. Junction of the posterior communicating with the IC.
2. Junction of the anterior communicating with the anterior cerebral artery.
3. Bifurcation of the MCA.

7

Berry aneurysms - ...% are multiple.

15%.

8

Berry aneurysms - Associations:

1. PKD.
2. COTA.
3. EDS.

9

Symptoms:

1. Sudden (usually, but NOT ALWAYS, within seconds), devastating typically occipital headache.
2. Vomiting.
3. Collapse.
4. Seizures.
5. Coma often follow.

10

Coma/drowsiness may last for ...?

Days.

11

Signs:

1. Neck stiffness.
2. Kernig (takes 6h to develop).
3. Retinal, subhyaloid and vitreous bleeds (=Terson's syndrome).
4. Focal neurology at presentation may suggest site of aneurysm (eg pupil changes indicating a CN III palsy with a Pcom artery aneurysm) or intracerebral hematoma.
5. Later deficits may suggest complications.

12

Terson's syndrome:

Retinal + Subhyaloid + Vitreous bleeds = Carries worse prognosis: mortality increases x5).

13

SAH DDx:

1. In primary care, only 25% of those with severe, sudden "thunderclap" headache have SAH.
2. In 50-60%, no cause is found.
3. The remainder have:
a. Meningitis.
b. Migraine.
c. Intracerebral bleeds.
d. Cortical vein thrombosis.

14

SAH - Sentinel headache:

SAH patients may earlier have experienced a sentinel headache, perhaps due to a small warning leak from the offending aneurysm (6%), but recall-bias clouds the picture.
--> As surgery is more successful in the least symptomatic, be suspicious of any SUDDEN headache especially with neck or back pain.

15

Tests - CT:

Detects >90% of SAH within the 1st 48h.

16

Tests - LP:

LP if CT is -ve --> No contraindication >12h after headache onset.

17

Tests - CSF:

Uniformly bloody early on --> Becomes xanthocromic after several hours due to Hb breakdown products (bilirubin).

18

Finding xanthocromia confirms SAH?

Yes - Because it shows that the LP was not a "bloody tap" (don't rely on finding fewer CSF RBCs in each successive bottle).

19

Refer all proven SAH to ...?

Neurosurgery immediately.

20

Management - Re-examine:

1. CNS often.
2. Chart BP.
3. Pupils and GCS.
4. Repeat CT if deteriorating.

21

Management - Maintain ...?

Cerebral perfusion by keeping well-hydrated, and aim for SBP>160mmHg.
Treat increased BP only if very severe.

22

Management - Nimodipine:

60mg/4h PO for 3weeks, or 1mg/h IVI.
--> CCB that reduces vasospasm and consequent morbidity from cerebral ischemia.

23

Endovascular coiling is preferred to ...?

Surgical clipping where possible (7% increase in independent survival over 7yrs follow-up, but incr. risk of rebleeding).

24

Endovascular coiling - Do what before?

Catheter or CT angio to identify single vs multiple aneurysms BEFORE intervening.

25

Intracranial stents and balloon remodelling ...?

Enable treating wide-necked aneurysms.

26

Complications:

1. Rebleeding (MCC of death).
2. Cerebral ischemia.
3. Hydrocephalus.
4. Hyponatremia.

27

Rebleeding:

MCC of death - Occurs in 20% often in the 1st few days.

28

Cerebral ischemia:

Due to vasospasm may cause a permanent CNS deficit --> MCC of MORBIDITY.
--> If this happens, surgery is NOT helpful at the time but may be so later.

29

Hydrocephalus:

Due to blockage of arachnoid granulations, requires a ventricular or lumbar drain.

30

Hyponatremia:

COMMON - Should NOT be managed with fluid restriction.

31

Mortality in SAH - Grade I-V:

I - No signs --> 0%.
II - Neck stiffness and CN palsies --> 11%.
III - Drowsiness --> 37%.
IV - Drowsy with hemiplegia --> 71%.
V - Prolonged coma --> 100%.

32

Almost all the mortality occurs in the ...?

1st month - Of those who survive the 1st month, 90% surviva a year or more.

33

Data from the 2003 International Study of Unruptured Intracranial Aneurysms (ISUIA) show that ...?

RR of rupture for an aneurysm:
7-12mm across is 3.3 compared with aneurysms 12mm the RR is 17.

34

Patients with previous SAH have increased risk ...?

For new aneurysm formation and enlargement of untreated aneurysms.
--> Screening these patients might be beneficial, eg if multiple aneurysms, HTN, or a history of smoking.

35

SAH - Incidence:

9/100.000/year.