TIAs and Posterior Circulation Problems with Prof Helen Dewey, Head of Austin Neurology

 

Gold from Prof Helen Dewey’s TIA and Posterior thecirculation talk at ED teaching February 23rd.  Look at her talk here

Thanks to Amanda for the YouTube link for the abnormal head impulse test (the guy in the video has a peripheral vestibular problem).  People with cerebellar problems have a normal test. Scott Weingart of EMCrit fame as an iphone approach.

TIAs

  1. True TIAs last minutes and are resolved before we see them in ED.  They are diagnosed on history.
  2. Anyone who still has symptoms in ED is a stroke - highly likely to show a stoke on MRI even if they are almost back to normal.
  3. Strokes and TIA happen suddenly and patients are usually very well at the time.
  4. Don’t annoy neurologists by not doing a BSL.  Think about other causes like dissection (carotid, aorta) or vasculitis.
  5. Order a CTBrain – tells you if the patient is having multiple bilateral old strokes from paroxysmal AF, tells you the patient is bleeding, has subdural, has tumour, about strokes the patient might not be aware of (non dominatnt).
  6. Don’t call something a TIA if its really confusion, syncope, patient is unwell, the patient has lost consciousness without focal signs etc etc.
  7. The greatest risk of stroke after TIA is in 48 hours.  The risk drops substantially after this.  TIAs are a serious warning for bad things to happen to our patients.
  8. ABCD2 underestimates risk in Monash study but helps people focus on what needs to be done.
  9. What needs to be done: Investigations: Carotid Doppler, ECG and fasting bloods as an inpatient in short stay.

10.  How hard to you need to chase AF as a cause?  If multiple old bilateral infarcts embolism becomes more likely - chase hard or treat with warfarin.  Dilated atrium on echo might be enough to suggest it and commence warfarin (in the setting of multiple infarcts, especially if bilateral).  If no AF immediately apparent, the echo is not important and can be considered in high risk cases by the physician or neurologist when they see them as an outpatient non urgently.

11.   If you diagnose >70% stenosis on carotid Doppler in SSOU then organise transfer same day for endarterectomy that is urgent.

12.   If you diagnose AF, commence them on warfarin immediately.

13.   You should feel bold and supported starting an ACEI and statin after fasting bloods in SSOU (unless the BP is <130systolic).

14.   Always upgrade their antiplatelet therapy – start aspirin or upgrade to assassantin.

 Basilar artery Thrombosis

The main event is often preceded by warning signs such as diplopia, bilateral visual disturbance, LOC WITH quadriparesis that resolves, dysarthria with quadriparesis/sensory loss.

Vertigo rarely/never a cause of posterior circulation ischaemia unless associated with hearing loss or other hard focal neurology. 

Once established: Quadriparesis and upgoing plantars classic. Lack of dolls eye reflex, pupil changes.

Add CT angiogram to CTB in this situation. Not looking for high tech angio 3D reconstructions like for aneurysms – basilar occlusion easy to see.

Basilar occlusion treatment: IV TPA if less than 4.5 hours (little to lose).  Consider time critical transfer for angiographic clot retrieval.

BASICS registry – No benefit of anything after 9 hours in severe cases – palliative.

Cerebeller Stroke

            If delayed presentation and well established significant stroke – beware – further swelling may cause brainstem compression and unconsciousness and require surgical decompression rapidly in the first few days.