Ischaemic Stroke
Dizziness…the good and the ugly…
The differential diagnosis of vertigo can be broken into peripheral and central causes. It is imperative the Emergency Physician consider central causes of vertigo.
Signs/ Symptoms Differentiating Peripheral and Central Vertigo
| Peripheral | Central | |
| Onset | Sudden or Insidious | Sudden |
| Severity of Vertigo | Intense Spinning | Ill-defined, may be severe or less intense |
| Prodromal Dizziness | Occurs in up to 25%, often single episode | Occurs in up to 25%, recurrent episodes suggest TIA’s |
| Intolerant of head movements/Dix-Hallpike Maneuver | Yes | Varies, but often intolerant |
| Associated Nausea/Diaphoresis | Frequent | Variable, but often frequent |
| Auditory Symptoms | Points to peripheral causes | May be present |
| Proportionality of Symptoms | Usually proportional | Often disproportionate |
| Headache/Neck Pain | Unusual | More likely |
| CNS signs/symptoms | Absent | Usually present |
| Head Impulse Test | Abnormal | Often normal |
| Nystagmus | Horizontal | Vertical/direction-changing |
| HINTS Testing | Negative | Abnormal in at least 1 out of 3 tests |
Dual antiplatelet therapy (DAPT) improves outcomes in patients with high-risk TIA or minor ischemic stroke
In patients with minor ischemic stroke or high-risk TIA, those who received a combination of clopidogrel and aspirin had a lower risk of major ischemic events but a higher risk of major haemorrhage at 90 days than those who received aspirin alone. However, the relative reduction in recurrent stroke occurred almost entirely during the first week, whereas bleeding events (most of which were not intracranial) were distributed fairly evenly throughout
Oxygen therapy for acutely ill medical patients: a clinical practice guideline
What you need to know
- It is a longstanding cultural norm to provide supplemental oxygen to sick patients regardless of their blood oxygen saturation
- A recent systematic review and meta-analysis has shown that too much supplemental oxygen increases mortality for medical patients in the hospital
- For patients receiving oxygen therapy, aim for peripheral capillary oxygen saturation (SpO2) of ≤ 96% (strong recommendation)
- For patients with acute myocardial infarction or stroke, do not initiate oxygen therapy in patients with SpO2 ≥ 90% (for ≥ 93% strong recommendation, for 90-92% weak recommendation)
- A target SpO2 range of 90-94% seems reasonable for most patients and 88-92% for patients at risk of hypercapnic respiratory failure; use the minimum amount of oxygen necessary
TIA (Transient Ischaemic Attack)
- TIA is defined as a brief episode of neurologic dysfunction with no permanent infarction.
- Head CT noncontrast is not reliable for acute ischemia, but it can find alternative conditions necessitating management. MRI with DWI displays greater diagnostic ability.
- Risk scores that predict future stroke are not reliable when used alone.
- Patients are typically admitted for inpatient management due to this risk of future stroke.
Acute Visual Loss in the ED
- History including specific eye involvement, sudden vs. chronic loss, pain, redness and discharge, trauma, other symptoms, and medication use are vital.
- Physicians should be comfortable completing an appropriate history and physical examination including general inspection, visual acuity, pupils, EOMs, visual fields, fluorescein, lids, IOP, slit lamp, and US.
- Emergent consultation is required for acute angle closure glaucoma, retinal detachment, CRAO, open globe, endophthalmitis, chemical burn, infectious keratitis, and giant cell arteritis.
- Urgent referral is needed for uveitis, vitreous hemorrhage, acute maculopathy, CRVO, and optic neuritis.
- Keep in mind other etiologies of vision loss including ischemia, stroke, toxin, infection, and functional.
TIA
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Cornerstones of treatment for TIA revolve around reducing the risk of future events with blood pressure control, lipid control, and antiplatelet agents. Blood pressure should be maintained at 140/90 with a thiazide diuretic and/or an ACE inhibitor. Statins should be given to keep LDL of under 100mg/dL or 70mg/dL in high risk patients. Niacin or gemfibrozil are recommended to maintain HDL above 40mg/dL. Antiplatelet agents include aspirin with or without dipyridamole, or clopidogrel alone.