Dizzy, Dysarthria, Dysmetria, Dystaxia, and Down and Out

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Dizzy, Dysarthria, Dysmetria, Dystaxia, and Down and Out
Recognition and Treatment of Posterior Circulation Ischemic Stroke

Section IconPosterior Circulation Ischemic Stroke (Introduction)
Posterior circulation strokes (PCS) account for 10-20% of all ischemic strokes.
PCS has same risk factors as anterior circulation strokes and extracranial arterial dissections.
Frequently unrecognized due to vague symptoms and negative initial brain imaging.
  • Dizziness is often misdiagnosed as due to a peripheral cause (acute vestibular syndrome).
Early suspicion and appropriate clinical examination, diagnostic imaging, and neurologic consultation are key to mitigating permanent disability.
  • Diagnosis suggested by:
    • 5 D’s: dizziness, diplopia, dysarthria, dysphagia, dystaxia
    • Crossed neurologic findings
  • Ascertaining central versus peripheral etiology of dizziness in the ED is challenging.
    • Of ~2.6 million annual ED visits for dizziness, only 2.4% are attributable to stroke.
    • Further, 50% of stroke patients are dizzy on presentation.
Reperfusion treatment opportunities similar for anterior circulation strokes.
  1. Hoyer C, Szabo K. Pitfalls in the Diagnosis of Posterior Circulation Stroke in the Emergency Setting. Frontiers in Neurology 2021;12:682827.
  2. Nouh A, Remke J, Ruland S. Ischemic posterior circulation stroke: a review of anatomy, clinical presentations, diagnosis, and current management. Frontiers in Neurology 2014;5:30.
Section IconDetect
Detection of posterior circulation ischemia begins with suspicion:
Assign an emergent priority (e.g., ESI level 2) due to
  • Suspicion requires that the clinician recognize the broad spectrum of clinical symptoms.
  • Diagnosis requires that the clinician act on the suspicion via advanced imaging or consultation.
  • Neck pain / neck trauma associated with neurologic findings may suggest arterial dissection.
  • Keep in mind: If you do not consider it, you cannot diagnose it.
Clinical symptoms vary by the location of the infarct and size of the vessel occluded.
Small vessel disease presents with subtle findings
  • Dizziness / vertigo often with marked vomiting
  • Diplopia, blurred, vision, or vague visual symptoms suggest occipital lobe, midbrain, or pontine involvement.
  • Ataxia, dysarthria, nystagmus
  • Large uncontrollable extremity movements can be seen in thalamic PCS
  • Crossed peripheral deficits are classic for brainstem ischemia.
  • Any of these in combination with other neurological symptoms i.e., unilateral weakness suggest PCS.
Large vessel disease can present with profound neurologic deficits which may not appear focal.
  • Quadriparesis / locked in
    • Sudden onset of quadriparesis should lead to consideration of PCS.
    • A careful eye examination of the unresponsive patient may help suggest PCS, those who are locked-in will retain vertical gaze and voluntary eye blinking.
  • Altered level of consciousness / Comatose
    • Sudden onset of unexplained coma may be caused by basilar artery occlusion.
    • When head CT and labs are all normal in the suddenly comatose patient consider posterior circulation stroke.
  • Posturing
    • Recurring extensor posturing is often confused with seizure activity.
    • Beware of atypical “seizures” that are brief and follow painful stimulation.
  1. Schulz UG and Fischer U. Posterior circulation cerebrovascular syndromes: diagnosis and management. J Neurol Neurosurg Psychiatry. 2017 Jan;88(1):45-53.
  2. Searls DE, Pazdera L, Korbel E, Vysata O, Caplan LR. Symptoms and signs of posterior circulation ischemia in the new England medical center posterior circulation registry. 2012 Mar;69(3):346-51.
Section IconDiagnose (Neuroexam)
A detailed neurologic exam is critical in the evaluation for potential PCS.
Perform the NIHSS on all suspected stroke patients, including those in a coma, but don’t stop with the NIHSS.
Key points for neuro exam in considering PCS – perform detailed cranial nerve exam:
  • Examine visual fields, use confrontation if patient is unable to participate.
  • Examine extraocular movements; if comatose assess for doll’s eyes reflex.
  • Examine closely for nystagmus.
For patients with nystagmus or vertigo and a normal neurological exam, perform the HINTS examination to help determine if vertigo is peripheral or central.
Examine for ataxia:
  • Perform finger to nose / heel to shin for appendicular/extremity ataxia.
  • Gait examination is critical, don’t forget to walk the patient.
  • If unable to stand, examine for postural stability / truncal ataxia while sitting.
  1. Hoyer C and Szabo K. Pitfalls in the Diagnosis of Posterior Circulation Stroke in the Emergency Setting. Front Neurol. 2021;12:1-11.
  2. Newman-Toker DE, et al. HINTS outperforms ABCD2 to screen for stroke in acute continuous vertigo and dizziness. Acad Emerg Med 2013;20(10):986-996.
  3. Newman-Toker, DE et al. TiTrATE: A novel evidence-based approach to diagnosing acute dizziness and vertigo. Neurol Clin. 2015;33:577-599.
  4. Ohle R, et al. Can emergency physicians accurately rule out a central cause of vertigo using the HINTS examination? Acad Emerg Med. 2020; 27:887-896.
Section IconImaging
Neuroimaging is essential in evaluating for PCS and treatment considerations
  • Noncontrast CT (NCCT) is often first used to assess for acute hemorrhage, old strokes, and potential contraindications to reperfusion.
  • CT angiogram (CTA) of head and neck to assess for large vessel occlusions, vessel stenosis, and arterial dissections.
  • CT perfusion (CTP) with posterior fossa windows; cannot reliably exclude diagnosis even with “normal” CTP
  • Negative NCCT/CTA/CTP imaging does not exclude PCS.
  • MRI imaging is far more sensitive to PCS but still not absolute, especially if performed hyperacutely.
  • Diffusion-weighted imaging (DWI) MRI is the sequence of choice to assess for stroke.
  • MRA may be used if contrast allergy in lieu CTA.
  1. Edwards LS, et al. Review of CT perfusion and current applications in posterior circulation stroke. Vessel Plus 2021;5:1-15
  2. Sporns P, et al. Computed Tomography Perfusion Improves Diagnostic Accuracy in Acute Posterior Circulation Stroke. CerebrovDiffasc Dis. 2016;41(56):242-247.
Section IconDifferentiate
Patients use “dizzy” to describe vertigo as well as lightheadedness, confusion, fogginess/lack of clarity. Clinicians should establish what the patient means by “dizzy”. If vertigo, historically establish whether it is:
  • Acute severe vertigo
  • Recurrent positional vertigo
  • Recurrent attacks of vertigo
Benign causes of vertigo include
Acute Severe Vertigo (Vestibular Neuritis).
  • The most common cause of acute severe dizziness.
  • Typically viral in origin, pathophysiology similar to Bell’s palsy.
  • Symptoms severe for 1-2 days, then resolve over weeks to months.
  • Exam Findings:
    • Nystagmus should be on lateral gaze and unidirectional.
    • Bi-directional gaze-evoked nystagmus may be a CNS process and warrants further workup.
    • Pure torsional or vertical nystagmus may also be a CNS process and warrants a workup.
Recurrent Positional Vertigo (Benign Paroxysmal Positional Vertigo - BPPV)
  • Sudden onset of episodic dizziness, typically associated with movement.
  • Exam Findings:
    • Dix-Hallpike test to diagnose BPPV
      • Estimated 79% sensitive and 75% specific
  • Epley Maneuver (canalith repositioning) for treatment.
    • Estimated 79% sensitive and 75% specific
    • Overall success rate is ~75% first attempt, increases to about 95% with multiple maneuvers
  • Sleeping on affected side may increase recurrence rates within a week.
Recurrent Attacks of Vertigo (Meniere’s Disease) or Idiopathic Endolymphatic Hydrops
  • Etiology: Increased hydraulic pressure within the inner ear endolymphatic system.
  • Symptoms include recurrent spontaneous episodes of vertigo, nausea, imbalance.
    • Typically accompanied by unilateral ear features – “roaring” tinnitus, hearing loss, ear fullness.
    • Episodes may last for hours.
  • Exam Findings:
    • Head impulse test is normal (normal 8th nerve).
    • Nystagmus does not follow specific pattern.
    • Patients may present during or after an attack has ended.
  • Treatment is symptomatic relief once central causes ruled out
Clinical red flags
Peripheral vertigo should be a diagnosis of exclusion in patients with risk factors.
  • Two clinical scenarios:
    • Acute severe dizziness that’s atypical for vestibular neuritis
    • Recurrent attacks that are new and only last a few minutes at a time may represent basilar artery TIA
Inability to walk when they could before.
Vague cognitive and memory errors.
“Isolated Dizziness” can still be a stroke.
Dehydration/nausea can exacerbate symptoms; improvement after empiric treatment does not exclude PCS.
Summary of Approach:
Develop a standard approach to history and physical exam when considering PCS.
Perform detailed history and physical exam
  • Viral prodrome, prior history of vertigo, triggering versus exacerbating factors
  • Visual fields
  • Assessment of nystagmus on extremes of gaze
  • Head Impulse Test
  • Skew
  • Dix-Hallpike/Epley
Stroke patients tend to have persistent symptoms (previous caveat of basilar TIA)
If presentation clearly fits peripheral? Treat accordingly
Does not clearly fit? “Rule out stroke” via MRI, neurology consult, admit/observe per local practice
  1. Zwergal A and Dietreich M. Vertigo and dizziness in the emergency room. Curr Opion Neurol. 2020;33:117-125.
Section IconManagement
The goal of early ED-based treatment of PCS posterior circulation stroke is to consider if the patient is eligible for reperfusion strategies
Activate stroke pathway / alert stroke team with suspicion of PCS.
Secure airway as needed.
Manage physiologic variables (blood pressure) to allow for reperfusion eligibility
Reperfusion considerations – Thrombolytic therapy
Posterior circulation strokes, in general, may score low or not at all on the NIHSS so do not rely solely on the NIHSS for thrombolytic consideration. Look at the disability!
  • If disabling, regardless of NIHSS, consider thrombolytics
    • For example, a patient with truncal ataxia with a NIHSS of 0, but cannot ambulate secondary to severe truncal ataxia. Consider the disability to the patient.
  • NIHSS of 0 is not a contraindication to thrombolytics as the NIHSS is not a complete neurologic examination and thrombolytics are FDA approved for disabling acute stroke, not a particular NIHSS.
Thrombolytic dosing is the same as for anterior circulation stroke
Reperfusion considerations – Endovascular therapy
After evaluation for thrombolytic candidacy, head and neck vessel imaging is recommended to evaluate the extracranial and intracranial vasculature.
  • Consider early vessel evaluation to evaluate for large vessel occlusions as well as stroke etiology prior to admission to an inpatient unit.
  • It is important to remember that thrombolytic administration should not be delayed for advanced vascular imaging. Administer thrombolytics as indicated and then complete CTA to assess for LVO.
  • Call for transfer as early as possible and arrange for an emergent transfer for possible thrombectomy.
  • Time windows for endovascular therapy may be longer in some centers compared to anterior circulation stroke. Be aware of your local practice.
Regardless of the presenting stroke syndrome (anterior or posterior), If stroke patients present with a low NIHSS with non-disabling symptoms or a high ABCD2 TIA score, patients should be considered for early dual antiplatelet therapy to reduce early stroke recurrence.
  1. Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2019;50(12):e344-e418.
  2. Powers WJ, Rabinstein AA, Ackerson T, et al. 2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2018;49(3):e46-e110.
Section IconDisposition
Once patient is diagnosed with posterior circulation stroke, management is similar to all other strokes:
Initiate stroke pathway.
  • Maintain NPO status until screened for dysphagia
  • Avoid hypoglycemia and hyperglycemia
Admit posterior circulation strokes to the stroke service or transfer for a higher level of care, err on a higher level of care.
Posterior circulation strokes can develop significant issues with airway and breathing, continuously reassess ABCs.
Patients with posterior circulation ischemia often have waxing and waning presentations. Reassessment can identify deterioration or onset of complications (e.g., hydrocephalus) or need for reperfusion reconsideration.
  1. Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke. 2019;50(12):e344-e418.
Section IconPearls
Consult early
A significant proportion of patients present within reperfusion therapeutic windows and are eligible for intervention if the diagnosis is considered.
Inform radiology of posterior circulation concern.
A “normal” noncontrast CT does not rule out ischemia.
MRI imaging in hyperacute windows of posterior circulation stroke may also not show ongoing ischemia.
Before Discharge
Walk the patient and check truncal balance before discharging a dizzy patient.
Online resources
Educational videos
NOVEL (Neuro-Ophthalmology Virtual Education Library)
Vestibular Testing In Acute Vestibular Syndrome
Vestibulo-ocular reflex and head impulse testing
Neuro-Vestibular Examination (pages 1-3)
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Developed by the ACEP Expert Panel on Posterior Circulation Stroke
Review by the ACEP Clinical Resource Review Committee

Support made possible by Genentech


Edward C. Jauch, MD, MS (Chair) Opeolu Adeoye, MD, MS, FACEP Rhonda Cadena, MD, FNCS, FCCM Christine Holmstedt, DO, FAHA Arthur Pancioli, MD, FACEP


ACEP Staff
Riane V. Gay, MPA, CAE Liz Muth, CAE


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