Recognizing Atypical Presentations of Stroke in Emergency Settings

Why Thinking Outside the Textbook Saves Lives
Stroke is notoriously deceptive. While we’re trained to recognize the classic FAST symptoms—facial droop, arm weakness, speech difficulties, and time sensitivity—the truth in clinical practice is often far murkier. Some strokes walk in looking nothing like a stroke. Others are written off as intoxication, migraine, or psychiatric illness. And some never make it to imaging in time.

For emergency physicians, neurologists, general practitioners, and any front-line doctor, recognizing atypical stroke presentations is not just a clinical bonus—it can be the deciding factor between recovery and irreversible brain damage, or even death.

In this comprehensive discussion, we’ll explore the types of strokes that commonly masquerade as other conditions, why these cases are often missed, and how a sharpened diagnostic lens can help clinicians intervene in time.

1. The Problem With Textbook Thinking in Stroke Diagnosis

While “FAST” campaigns have significantly increased public awareness and timely presentations, they also risk oversimplifying the diverse neurological manifestations of stroke. The reality is:

Not all strokes present with hemiparesis.

Not all aphasia is immediately apparent.

Not all patients with posterior circulation stroke collapse dramatically in triage.

Clinicians must transcend protocol checklists and trust their clinical acumen—especially in cases presenting with vague or non-specific neurological complaints.

2. Common Atypical Stroke Presentations in the Emergency Room

a. Isolated Vertigo or Dizziness

Posterior circulation strokes, especially those involving the cerebellum or brainstem, can present subtly as vertigo. These cases often mimic benign paroxysmal positional vertigo (BPPV) or vestibular neuritis and are easily dismissed.

Red flags that suggest a central origin include:

• Inability to ambulate independently
  
  
• Direction-changing nystagmus
  
  
• Negative Dix-Hallpike maneuver with persistent vertigo
  

These signs call for a deeper neurological workup, not reassurance alone.

b. Sudden-Onset Confusion or Delirium

In elderly patients, confusion without focal deficits is often attributed to metabolic derangements or infections like UTIs. But when the onset is abrupt, clinicians must consider strokes involving the non-dominant hemisphere, frontal lobes, or thalami.

Such cases often receive supportive care only, leading to missed opportunities for early intervention.

c. Isolated Dysarthria or Ataxia

Lacunar strokes can result in isolated dysarthria, facial droop, or ataxia—features easily misread as alcohol intoxication, post-ictal states, or even anxiety-related symptoms.

In reality, these are small-vessel infarcts that demand timely recognition to prevent extension or recurrence.

d. Stroke Mimicking Seizures

Cortical strokes can precipitate seizures or present during the post-ictal state, blurring the clinical picture. For known epileptics, a stroke may be misclassified as a breakthrough seizure, particularly when the focus is placed solely on history rather than physical findings.

Conversely, new-onset seizures in older adults should raise the possibility of a cerebrovascular event as the underlying etiology.

e. Headache as a Primary Symptom

Ischemic strokes are typically painless. However, headaches may predominate in posterior circulation strokes, venous infarctions, or arterial dissections. This is particularly common in young patients, where such symptoms are often attributed to migraine—delaying accurate diagnosis.

f. Visual Loss Without Other Neurological Signs

Occipital strokes may present as isolated homonymous hemianopia or even cortical blindness. Without speech changes or hemiparesis, these patients often receive an ophthalmology consult rather than neurological imaging, leading to diagnostic delays.

3. Why Are Atypical Strokes Often Missed?

Several systemic and cognitive factors contribute to underdiagnosis of atypical strokes:

• Cognitive bias: When the patient is young, female, or lacks classic risk factors, stroke tends to be lower on the differential.
  
  
• Triage challenges: Vague or non-urgent complaints during high ED volumes may not receive timely neurological evaluation.
  
  
• Overreliance on CT scans: Non-contrast CT remains the standard in many EDs, yet its sensitivity for early ischemia—especially in the posterior fossa—is limited.
  
  
• Comorbid masking: In patients with dementia, chronic dizziness, or psychiatric illness, new-onset stroke signs can be overlooked or misattributed.
  

4. Diagnostic Clues That Should Raise Suspicion

The following clinical features should trigger consideration of stroke—even in the absence of typical signs:

• Sudden onset: Any abrupt change in baseline—confusion, vertigo, loss of coordination—should be treated as a possible stroke until ruled out.
  
  
• Subtle lateralizing signs: Even mild asymmetry in strength, reflexes, or coordination (e.g., finger-to-nose drift) can be a vital clue.
  
  
• Abnormal HINTS exam: In dizzy patients, central features on the Head Impulse-Nystagmus-Test of Skew exam can differentiate stroke from benign peripheral causes.
  
  
• Lack of treatment response: When “benign” diagnoses don’t respond to expected therapy (e.g., Epley maneuver, antibiotics for UTI), reconsider stroke.
  

5. The Role of Imaging in Atypical Stroke

a. Non-Contrast CT

This remains the first-line tool in stroke assessment due to speed and accessibility. It is excellent for ruling out hemorrhage but can be misleadingly normal in early ischemic stroke, particularly in the posterior fossa.

b. MRI with DWI

Diffusion-weighted imaging is significantly more sensitive for detecting early infarcts, including small and posterior strokes. However, MRI availability and contraindications (e.g., pacemakers) may limit its routine use in emergency settings.

c. CT Angiography

This modality offers a dynamic assessment of vascular integrity and can detect large vessel occlusions and posterior circulation deficits. It is especially valuable in patients with atypical symptoms where stroke is still suspected.

6. High-Risk Populations Where Atypical Stroke Should Always Be Considered

Certain populations are predisposed to atypical stroke presentations and should trigger heightened vigilance:

• Older adults presenting with functional decline
  
  
• Patients on anticoagulation or dialysis
  
  
• Individuals with atrial fibrillation or known hypercoagulable disorders
  
  
• Oncology patients at increased embolic risk
  
  
• Pregnant or postpartum women due to risk of cerebral venous thrombosis
  

7. Case Vignettes That Illustrate Missed Atypical Strokes

Case 1

A 52-year-old woman presents with vertigo and vomiting. Diagnosed with viral labyrinthitis and sent home. Returns 12 hours later unresponsive. MRI confirms cerebellar infarct with significant mass effect and hydrocephalus.

Case 2

A 78-year-old man is brought in for acute confusion. No hemiparesis, normal CT scan, presumed UTI. Three days later, MRI reveals bilateral thalamic infarcts.

Case 3

A 30-year-old female experiences visual disturbance and headache. Labeled as migraine. Hours later, develops worsening symptoms. Diagnosed with cerebral venous thrombosis associated with undiagnosed lupus.

These are not just dramatic exceptions—they represent real-life pitfalls in emergency stroke care.

8. Improving Clinical Vigilance in Emergency Medicine

Ongoing training is essential: Emergency clinicians and triage staff should receive updated education on stroke variants and their mimics.

Protocols need to evolve: The FAST acronym is not enough. ED algorithms must include red flags for posterior strokes, dizziness, visual complaints, and acute behavioral changes.

Normal imaging does not equal normal brain: A negative CT scan in the setting of sudden neurological symptoms should prompt reconsideration of MRI or CTA, rather than discharge.

Trust your instincts: Clinical intuition matters. If something feels “neurological” despite an atypical presentation, investigate further.

9. The Cost of Missing an Atypical Stroke

Failure to recognize a stroke in time leads to:

• Lost opportunity for thrombolytic therapy or thrombectomy
  
  
• Greater neurological disability
  
  
• Higher long-term care costs
  
  
• Increased risk of mortality
  

Shifting from a rigid diagnostic model to flexible clinical reasoning is no longer optional—it’s a necessity in modern emergency medicine.

10. Final Thoughts: Why This Matters for Every Clinician

Emergency medicine is a high-stakes game of pattern recognition. But not every stroke will play by the rules. Some won’t slur speech or drop a face. They’ll hide in nausea, masquerade as vertigo, or lurk behind a sudden change in personality.

Our job isn’t just to memorize stroke protocols—it’s to think critically, question assumptions, and advocate fiercely for the patients who don’t fit the mold.

Atypical presentations are not rare—they are underrecognized. And every missed opportunity is a missed life.