We identified articles for this Review through searches of PubMed using the search terms “stroke”, “misdiagnosis”, and “atypical presentations” from 1980 to March, 2011. Additional articles were identified from the bibliographies of the initial articles and from the authors' own files. With one exception, we reviewed articles only published in English. The final reference list was generated on the basis of originality and relevance to the broad scope of this Review; therefore, we included
ReviewAtypical presentations of acute cerebrovascular syndromes
Introduction
Worldwide, about 15 million people have a stroke every year, of whom 5 million die and 5 million have a permanent deficit.1 In high-income countries, stroke is the most common cause of disability and is the third most common cause of death. When patients present with acute neurological symptoms, physicians must distinguish between stroke and other causes that mimic it. Accurate and prompt diagnosis is crucial because implementation of time-dependent therapies, identification and treatment of the underlying vascular mechanism, and attention to the underlying risk factors can improve outcomes and prevent subsequent events.
Patients who present with acute neurological symptoms can be divided into four groups (table). The first group includes patients with obvious stroke—eg, an elderly individual with untreated atrial fibrillation who abruptly develops aphasia and hemiparesis. The second group includes patients whose cause of neurological dysfunction is clearly not stroke, such as a patient without vascular risk factors who develops unilateral weakness of the facial muscles in association with hyperacusis and altered taste consistent with a lower motor neuron facial nerve palsy. In the third group, patients seem to have a stroke, but in fact have a non-vascular cause such as conversion reactions, Todd's paralysis (a disorder characterised by a brief period of paralysis with or without aphasia after a seizure), or migraine. Hypoglycaemia is a particularly important stroke mimic because its treatment is simple and effective. In the era of thrombolysis for acute ischaemic stroke, these stroke mimics have received much attention.2, 3, 4, 5 The final group of patients includes those with actual strokes, but whose presentations are unusual or atypical, suggesting a non-vascular cause. Huff has referred to these patients as “stroke chameleons”.2 Compared with stroke mimics, this group of patients with missed or delayed diagnosis of stroke has received much less attention and is the focus of this Review.
Patients with stroke can present with atypical symptoms for various reasons. First, in the first minutes to hours after the event, all the diagnostic information might not be available to the initial health-care providers. Additionally, patients' symptoms can evolve with time. Second, there is substantial variability in the classic cerebrovascular territories that can also result in non-classic presentations. Patients with small strokes, early presentations, young age, posterior circulation location, and deficits that do not result in lateralising motor or speech findings might be more difficult to diagnose clinically.6, 7, 8, 9
In this Review, we aim to help clinicians improve the accuracy and timeliness of their diagnosis of patients with acute stroke by reviewing causes of misdiagnosis and non-classic symptoms of acute stroke (panel 1). Although much of the focus is on acute ischaemic stroke, we also discuss some aspects of misdiagnoses of haemorrhagic strokes, including intracerebral haemorrhage (ICH), subarachnoid haemorrhage (SAH), and haemorrhage resulting from cerebral venous sinus thrombosis (CVST). Panel 2 provides a glossary of terms of atypical symptoms of stroke.
Section snippets
Non-localising symptoms
Stroke is usually characterised by the sudden onset of focal neurological deficits, such as hemiparesis, aphasia, or hemianopia, depending on the affected brain structures and vascular territory. However, some strokes can present in a non-localising manner without clear-cut focal deficits.
Abnormal movements or seizures
Stroke is usually characterised by loss of movement. However, in a small percentage of cases, patients can have various abnormal movements (hyperkinetic, hypokinetic, or seizure-like) at stroke onset.
Peripheral nervous system symptoms
Although stroke is a CNS event, some cases present in ways that suggest a peripheral nervous system (PNS) cause.
Atypical symptoms
Rarely, patients with stroke present with atypical and unusual symptoms and signs. Increased awareness of these unusual presentations facilitates early recognition, minimises unnecessary tests, and facilitates prompt treatment.
Isolated headache
Another stroke presentation, in both ischaemic and haemorrhagic disorders, is the presence of a prominent headache that is either isolated or associated with non-specific symptoms that are not obviously attributable to a cerebrovascular cause.
Isolated headache can occur with arterial dissections, CVST, and SAH.91, 92, 93 Although headache suggests ICH, patients with acute ischaemic stroke can also present with prominent headache.94 Headache at onset (with or without concomitant dizziness,
Limitations of brain imaging
Although stroke is a clinical diagnosis, nearly all patients undergo brain imaging. The purpose of brain imaging in patients with acute neurological symptoms includes establishing a stroke diagnosis and excluding stroke mimics. CT scanning can establish the diagnosis of stroke (ICH, SAH, and occasionally acute ischaemic stroke) and exclude stroke mimics (in patients with acute ischaemic stroke who are candidates for thrombolysis). MRI is being increasingly used to definitively confirm a
Conclusions
The topics covered in this Review might suggest that almost any neurological symptom could be indicative of a stroke; what practical conclusions can the clinician derive from this? By design, we assessed many case reports and case series, which tend to overestimate the atypical manifestations of stroke, but understanding this variability of presentation is key.
In various systematic studies, acute speech and lateralising motor findings consistently correlate with stroke diagnosis.6, 106 In these
Search strategy and selection criteria
References (106)
Stroke mimics and chameleons
Emerg Med Clin North Am
(2002)- et al.
Identification of nonischemic stroke mimics among 411 code strokes at the University of California, San Diego, Stroke Center
J Stroke Cerebrovasc Dis
(2008) - et al.
Patients with acute stroke admitted on the second visit
J Stroke Cerebrovasc Dis
(2008) - et al.
Acute psychiatric manifestations of stroke: a clinical case conference
Psychosomatics
(2003) - et al.
Hyperkinetic movement disorders during and after acute stroke: the Lausanne Stroke Registry
J Neurol Sci
(1997) - et al.
Limb shaking as a manifestation of low-flow TIA
Int J Gerontol
(2010) - et al.
Involuntary masturbation and hemiballismus after bilateral anterior cerebral artery infarction
Clin Neurol Neurosurg
(2008) - et al.
The stroke that struck back: an unusual alien hand presentation
J Stroke Cerebrovasc Dis
(2009) - et al.
Risk of vascular events in emergency department patients discharged home with diagnosis of dizziness or vertigo
Ann Emerg Med
(2011) - et al.
Zero on the NIHSS does not equal the absence of stroke
Ann Emerg Med
(2011)