Hej Hej Glasgow it was fun, now back to work.  Day-4 was full of great Canadian thoughts on neurology (Vertigo, SAH, and TIA) all topped off with a sprinkle of Organophosphates

Vertigo – Guide to the big 3

1. Any features that mandate imaging?

• Neurology deficit
• Significant headache
• Neck pain
• Unable to stand or walk
• Spontaneous vertical nystagmus (i.e. not while doing dix-hallpike)

2. History

• Short episodes <2 min brought on by movement, no spontaneous nystagmus (i.e. only on move)
  • BPPV > Dix-Hallpike
• Dizzy for Hours
  • Vestibular neuritis vs central > HINTSplus exam (you can only use HINTS if patient is dizzy and has nystagmus)

Horizontal canal BPPV sounds similar to posterior canal (D-H+eply) but tends sever when moves head when upright – tests and how to treat different

Vestibular migraine

One to think about if patient presents without nystagmus  – patient should state:

• Recurrent (at least 5 episodes)
• Lasts unto 72hrs
• Has a temporal relationship to migraine symptoms (this may be aura symptoms not headache) at least 50% of the time

Apparently 2.5% population get this, most un/miss-diagnosed, metacloprimide can help

SAH

Ottawa rule out strategy Validation

Something to explore with ED/Med/Rad

1. Inclusion/Exclusion criteria

• Inclusion
  • Alert
  • > 15 yr of age
  • New acute severe non-traumatic headache that reaches maximum intensity within 1 h of onset. Not to be used in patients

• Exclusion
  • New neurological deficits
  • Previous aneurysms, SAH or brain tumors
  • History of similar headaches (≥ 3 episodes over ≥ 6 mo)
  • Profound Anaemia

2. Clinical Rule-Out – Patient has NONE of following:

• Symptom of neck pain or stiness
• Age > 40 yr
• Witnessed loss of consciousness
• Onset during exertion
• Thunderclap headache (peak pain instantly)
• Limited neck flexion upon exam

ANY features > CT / NONE > No further investigation required

3. CT Head negative

• SAH excluded if ALL of following :
  • CT performed within 6 hours of headache onset
  • Experienced radiologist (validation used “General radiologists at 2/6 sites, thin slices (initially 10mm at start of study – what can we provide?)
  • NO ‘Ultra-High’ Risk features

Patient doesn’t fit above then need LP.

4. LP results

• LP Positive  – perform CTA
• LP negative (RBC <2000×10 6, no Xanthochromia)
  • No ‘Ultra-High’ Risks – Excluded
  • ‘Ultra-High’ Risks
    • Very few RBC – Excluded
    • Moderate – if still clinical concern  – perform CTA

Validation INFO Presented – Dr Perry

• Studied before and After implementation
• @ 6 centres in canada 2010-2017  (3669 patients)
• Clinical rule out – 100% sensitive
• 6hr rule out CT – 5 misses
  • 1 was miss by radiology
  • 2 un-ruptured aneurysms, (surgeons stated they were incidental but, one open repair no staining of tissues (so no bleed), one coil preventative)
  • 1 Dural vien fistula
  • 1 sickle cell with profound anaemia (Hb 63) – known risk within radiology so profound anaemia included in exclusion
• How testing changed with implimentation
  • CT rate not changed
  • LP’s fell from 38-25%
  • Mean length of stay 6.4hr unchanged (however, ED responsible for LP so withTime in ED would be shorter)
• Prev studies canada & japan

TIA

Vast majority of complications post TIA (i.e. strokes) happen within 7 days (50% within 2days) so time matters

Risk score

• ABCD2 – has the most evidence but only has a sensitivity of 31%
• Canadian risk score – much more complex , but much better characteristics – validation just finishing 

Prevention

• Early specialist and carotid imaging vital (Carotid endarterectomy NNT= 3 if done in first 2weeks)
• Anti-platelet therapy – evidence from CHANCE and POINT trials indicating 21days dual anti-platelet therapy best (then going back to 1)
• TIA with AF – need anticoagulation if possible NOAC’s prob best and would be easiest for us in ED

Organophosphate (nerve agents)

• Used several times recently.
• Decontamination vital – In the Sarin attack (japan), poor decor 20-30% of staff treating the patients @ hospital developed symptoms
• Sign & Symptoms
  • Miosis/Lacrimation
  • Local Fasciculations
  • Sweating/Hypersalivation
  • Bronchoconstriction (wheezy) >  Resp failure/arrest
  • Fits/coma
• Blood and skin tests available – do we have any?
• Therapy
  • Atropine: 2mg im/iv, if not improved double  (i.e. 4mg >8mg>16mg>32mg)
    • looking to have clear chest dry armpits, HR and sBP at about 80
  • Oximes: several available (We get Pralidoxime from LGI see rare antidotes)
    • Can help reverse AChe blockage
    • Earlier the better and may take a long time
• Types of Agent
  • G agents – volatile evaporate quick, onset fast offset fast
  • V agents – stable, onset slower, off set slow
  • OP agents (pestersides) – v slow