1. CTA is becoming the standard for acute stroke imaging, but options remain for collateral/penumbral assessment in selecting patients for endovascular reperfusion therapy
2. Non-randomized data support the target mismatch theory for patient selection for endovascular reperfusion therapy
3. NCCT remains the standard for IV tPA treatment decision making, but increased use of routine advanced imaging may ultimately provide data supporting CTP use for IV tPA decision making
4. Ability for advanced imaging to predict who will bleed after reperfusion therapy remains a challenge
The Role of the ECG in Acute Nontraumatic BLE Weakness
Acute bilateral lower extremity paralysis
Hypokalemic periodic paralysis
I. Familial hypokalemic periodic paralysis
ECG signs of severe hyperkalemia
1. The first key in assessing a patients with dizziness is to define the problem: dizziness is not a medical term, and vertigo is not a diagnosis.
2. If a patient has nystagmus, it is important to interpret and document the nystagmus in a clinically meaningful way which will support your diagnostic decision making.
3. To adequately test the cerebellum, all three of the following must be assessed: limb ataxia, truncal ataxia, and oculomotor control.
4. Correct patient selection is essential when performing the Dix-Hallpike maneuver or the Head Thrust Test. The only patients who are appropriate candidates for the Dix-Hallpike test are those with a history consistent with BPPV. Similarly, the only patients who are appropriate candidates for the head thrust test (and the HINTS exam) are those with acute vestibular syndrome.
5. If the patient has the constellation of signs and symptoms that comprise acute vestibular syndrome, perform the HINTS exam to attempt to distinguish central from peripheral causes
6. Recognize that brain CT rarely identifies early-stage cerebellar infarction. DWMRI is reasonably sensitive for detecting cerebellar infarction early, but it is less sensitive than appropriately performed oculomotor assessment.
Bifascicular Block and Second Degree AV Block
1. In asymptomatic individuals, chronic bifascicular block does not usually require cardiac work-up; the prognosis is generally benign
2. The following high-risk features, however, warrant urgent evaluation:
a. Bifascicular block and syncope
b. Bifascicular block and intermittent second degree AV block
c. 1:1 AV conduction at slower sinus rates but higher grade block (i.e., 2:1 AV conduction) at faster
sinus rates (“acceleration-dependent AV block”)
3. Evaluation and management of patients with bifascicular block:
a. Actively search for nonconducted P waves in the 12-lead ECG
b. Always review telemetry strips and actively search for episodes of second degree AV block
(blocked P waves)
c. In symptomatic patients with bifascicular block who develop acceleration-dependent second
degree AV block and a very slow ventricular rate, carotid massage or IV beta blocker can
paradoxically restore 1:1 AV conduction
d. Patients with bifascicular block and syncope require admission and cardiology consultation for
possible pacemaker implantation
e. Patients with bifascicular block and intermittent second degree AV block require cardiology
consultation for possible pacemaker implantation
The Pacemaker ECG
1. Ventricular pacing: always try to determine what the atria are doing
2. Sinus P wave in front of each paced QRS complex indicates dual chamber (A-V sequential) pacemaker where the ventricular pacer is tracking sinus rhythm
3. Two pacer spikes about 5 mm apart indicate AV sequential pacing
4. If there are no P waves or 2 pacer spikes, search for the presence of retrograde P waves after the paced QRS complexes; retrograde P waves are sharp negative in the inferior leads (in II, III and aVF) and usually upright in V1
5. If there are no P waves in front of the paced QRS complexes and no retrograde P waves present, always consider the possibility of underlying atrial fibrillation
1. Four recently completed trials demonstrate that early mechanical stent-thrombectomy after tPA in patients with large vessel occlusion and salvageable tissue on brain imaging results in improved reperfusion and functional outcomes.
2. The details of the patient selection paradigm remain a key discussion, but favorable penumbral imaging is a consistent feature of all trials.
3. Systems of acute care, including transfer protocols, will need to be re-organized to deliver this therapy effectively in the real world
1. Use of CTP imaging to determine eligibility for revascularization therapy is unproven in randomized studies.
2. Appropriately performed PCT performs reasonably well at identifying core acute infarct associated with large vessel ischemic strokes.
3. PCT unproven in distinguishing penumbra from benign oligemia.
4. Further standardization and validation of PCT needed.
1. For patients diagnosed with a presumptive TIA, it is relatively common to have infarction demonstrated on DWMRI within the first 24 hours (~33% overall and 30-50% for any time epic within the first 24 hrs).
2. Based on a Scientific Statement issued by the American Stroke Association in 2009, a Transient Ischemic attack (TIA) is best defined as a transient episode of neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without acute infarction (Easton JD et al. Stroke 2009;40:2276-2293). Importantly, no symptom duration limitation is specified in this revised definition.
3. Pure sensory syndromes involving the contralateral face, arm, and/or leg have been described in both ischemic and hemorrhagic thalamic stroke, but these are relatively uncommon and the prevalence of TIAs isolated to the thalamus is unclear.
1. Reflex examination is essential for the timely and correct diagnosis of Guillain-Barré Syndrome.
2. Diagnosis is based on clinical observations, however elevated protein in the CSF is present in 90% of patients suffering from Guillain-Barré.
3. The 20/30/40 rule is an excellent tool to guide decision making with regards to when to intubate patients suffering from this condition.
4. Be on guard for autonomic instability (heart rate, blood pressure, respiratory rate).
1. TIME IS ESSENTIAL! Phase 3 & 4 IV tPA trial data and Phase 3 endovascular intervention data show a consistent association of improved stroke outcomes with earlier treatment.
2. The decision to withhold IV tPA treatment in the setting of mild or rapidly improving symptoms should be determined based on if any remaining deficits will be disabling for the given patient.
3. Randomized data suggest that isolated MCA occlusions respond similarly to either IV tPA or endovascular therapy.
4. The best available evidence suggests no absolute age cutoff for exclusion from IV tPA therapy within 3 hours of symptom onset.
5. Advanced age, hyperglycemia, and a high NIHSS (>20) increase the risk of hemorrhagic transformation for acute stroke treated with revascularization therapy.