Dr. Pat Dutton
Dr. Pat Dutton
Edited by Dr David Lewis
A 70yr old male presents with a typical zoster rash in the left L1 dermatome. He has a past medical history of chronic renal insufficiency. He is started on Valacyclovir 1000mg TID. He represents 3 days later with hallucinations including a feeling that he was occupying a dead body. What is the differential diagnosis?
VZV and antiviral toxicity can present with similar symptoms
Two main risk factors increase the risk for VZV
The main risk factor for antiviral toxicity is renal insufficiency
Differentiation
Cotard’s Syndrome
“le délire des négations”
(delirium of negation)
https://en.wikipedia.org/wiki/Cotard_delusion
Further Reading
Varicella Zoster Encephalitis case report and outline
Valacyclovir Toxicity case report and outline
Drug Dosing in Chronic Kidney Disease
A 28yr old female presents pain, redness and swelling over the right thigh. She has a past medical history of type 2 diabetes. She is managed as an outpatient with intravenous ceftriaxone q24hrs. Her symptoms failed to respond on follow up. What is the concern now? Are there any red flags? What condition needs to be considered in patients with soft tissue infections that fail to respond to antibiotics?
NSTI first described by Hippocrates 5th century BC
“[m]any were attacked by the erysipelas all over the body when the exciting cause was a trivial accident…flesh, sinews, and bones fell away in large quantities…there were many deaths.”
Necrotizing fasciitis is characterized by rapid destruction of tissue, systemic toxicity, and, if not treated aggressively, gross morbidity and mortality. Early diagnosis and aggressive surgical treatment reduces risk; however, it is often difficult to diagnose NF, and sometimes patients are treated for simple cellulitis until they rapidly deteriorate.
Infection typically spreads along the muscle fascia due to its relatively poor blood supply; muscle tissue is initially spared because of its generous blood supply.
Infection requires inoculation of the pathogen into the subcutaneous tissue or via hematogenous spread.
Classification
Early signs and symptoms of NSTI are often identical to those seen with cellulitis or abscesses potentially making the correct diagnosis difficult
‘Classic’ Signs / Symptoms
(1) the presence of bullae
(2) skin ecchymosis that precedes skin necrosis
(3) crepitus
(4) cutaneous anesthesia
(5) pain out of proportion to examination
(6) edema that extends beyond the skin erythema
(7) systemic toxicity
(8) progression of infection despite antibiotic therapy or rapid progression
First 4 are “hard” signs
Streaking lymphangitis favours the diagnosis of cellulitis over necrotizing fasciitis
Diagnosis
PoCUS
Diagnosis of Necrotizing Faciitis with Bedside Ultrasound: the STAFF Exam
Findings – “STAFF”
ST – subcutaneous thickening
A – air
FF – fascial fluid
Ultrasound video demonstrating Subcutaneous Thickening, Air, and Fascial Fluid (STAFF).
Soft tissue ultrasound findings are significantly different when compared to normal soft tissue ultrasound
Bottom Line: Limited data, but basically PoCUS is not sufficient to rule-in or rule out, but might be helpful in raising suspicion level for necrotising fasciitis for physicians who routinely scan all soft tissue infections.
LRINF Score
Laboratory Risk Indicator for Necrotizing Fasciitis (LRINEC) Score. 2004, retrospective – score >6 negative predictive value of 96.0% and a positive predictive value of 92%.
A validation study looking only at patients with pathology-confirmed necrotizing fasciitis showed that a LRINEC score cutoff of 6 points for necrotizing fasciitis only had a sensitivity of 59.2% and a specificity of 83.8%, yielding a PPV of 37.9% and NPV of 92.5%. However, the study did show that severe cellulitis had a LRINEC Sscore ≥ 6 points only 16.2% of the time. Therefore, the available evidence suggests that the LRINEC score should not be used to rule-out NSTI.
Bottom Line: Doesn’t rule-out…… or rule-in
Suggested Algorithm – UpToDate
EM Cases Review
Further Reading
Necrotizing fasciitis – Can Fam Physician. 2009 Oct; 55(10): 981–987.
A 40yr old female presents with left leg weakness. She has a complex recent past medical history including recently diagnosed pneumonia, previous renal colic and type 2 diabetes. Could this be a stroke? What are the other causes of leg weakness? How does the examination differentiate UMN from LMN lesions? When considering a diagnosis of epidural abscess what investigation is required? How soon should it be performed?
Only 4% of Strokes present with isolated or predominant leg weakness. (Brain. 1994 Apr;117 ( Pt 2):347-54.
doi: 10.1093/brain/117.2.347)
Common mechanisms of weakness:
Full review on Muscle Weakness from the Merck Manual here
Weakness that becomes severe within minutes or less is usually caused by severe trauma or stroke; in stroke, weakness is usually unilateral and can be mild or severe. Sudden weakness, numbness, and severe pain localized to a limb are more likely caused by local arterial occlusion and limb ischemia, which can be differentiated by vascular assessment (eg, pulse, color, temperature, capillary refill, differences in Doppler-measured limb BPs). Spinal cord compression can also cause paralysis that evolves over minutes (but usually over hours or days) and is readily distinguished by incontinence and clinical findings of a discrete cord sensory and motor level.
Unilateral upper motor neuron signs (spasticity, hyperreflexia, extensor plantar response) and weakness involving an arm and a leg on the same side of the body: A contralateral hemispheric lesion, most often a stroke
Upper or lower motor neuron signs (or both) plus loss of sensation below a segmental spinal cord level and loss of bowel or bladder control (or both): A spinal cord lesion
Spinal epidural abscess (SEA) is a severe pyogenic infection of the epidural space that leads to devastating neurological deficits and may be fatal. SEA is usually located in the thoracic and lumbar parts of the vertebral column and injures the spine by direct compression or local ischemia. Spinal injury may be prevented if surgical and medical interventions are implemented early. The diagnosis is difficult, because clinical symptoms are not specific and can mimic many benign conditions. The classical triad of symptoms includes back pain, fever and neurological deterioration.
Spinal Epidural Abscess: Common Symptoms of an Emergency Condition – A Case Report
Further Reading
Edited by Dr David Lewis
A patient presents with recurrent seizures. They have a past medical history of schizophrenia and mental health delay. Following appropriate ED management with complete resolution of seizures and full recovery of the patient – what is the recommended disposition?
Seizure disorder is a common presentation to the Emergency Department. This EM Cases post provides an excellent summary for the ED approach to resolved seizures:
ED approach to resolved seizures – Summary pdf
In this study – Ethanol withdrawal or low antiepileptic drug levels were implicated as contributing factors in 177 (49%) of patients. New‐onset seizures were thought to be present in 94 (26%) patients. Status epilepticus occurred in only 21 (6%) patients.
73% of patients were discharged.
Most authors recommend admission for patients presenting with FIRST Seizure Episode. Patients with a past medical history of recurrent seizure disorder are more likely to be discharged than admitted.
However – this EBMedicine article cites an incidence of 19% seizure recurrence rate within 24 hours of presentation, which decreased to 9% if patients with alcohol related events or focal lesions on CT were excluded. They suggest, that at present, there is insufficient evidence to guide the decision to admit. They recommend this decision be tailored to the patient, taking into consideration the patient’s access to follow-up care and social risk factors (eg, alcoholism or lack of health insurance). Patients with comorbidities, including age > 60 years, known cardiovascular disease, history of cancer, or history of immunocompromise, should be considered for admission to the hospital.
Considerations For Safety On Discharge
Patients and their families should be counseled and instructed on basic safety measures to prevent complications (such as trauma) during seizures. For example, patients should be advised to avoid swimming or cycling following a seizure, at least until they have been reassessed by their neurologist and their antiepileptic therapy optimized, if needed. A particularly important point for seizure patients is education against driving. Although evidence remains controversial on this issue, there is general agreement that uncontrolled epileptic patients who drive are at risk for a motor vehicle crash, with potential injury or death to themselves and others. For this reason, most states do not allow these patients to drive unless they have been seizure-free on medications for 1 year. According to population survey data, 0.01% to 0.1% of all motor vehicle crashes are attributable to seizures
A young female patient with a history of polysubstance drug abuse presents with a psychotic episode. She refuses treatment. What are the competency and capacity implications? She is also pregnant. Does this change the the competency and capacity implications?
This LitFL post provides and excellent outline for Competency and Capacity in the ED:
This article published by the RCPSC provides a useful outline from a Canadian perspective – with the following objectives.
Recommendations from the American College of Obstetricians and Gynecologists
On the basis of the principles outlined in this Committee Opinion, the American College of Obstetricians and Gynecologists (the College) makes the following recommendations:
Further Reading:
How Do I Determine if My Patient has Decision-Making Capacity?
A 12 year old boy presents with scrotal discomfort in the early hours of the morning. The department is very busy and the waiting time to be seen is 4 hours. What triage category is this presenting complaint? If a diagnosis of torsion is considered, how quickly should definitive management be initiated?
Ramachandra et al. demonstrated through multivariate analysis of the factors associated with testicular salvage, that duration of symptoms of less than 6 h was a significant predictor of testicular salvage. They found that the median duration of pain was significantly longer in patients who underwent orchiectomy versus orchidopexy. Similar findings were seen with respect to time to operating room from initial presentation. They concluded that time to presentation is in fact the most important factor in determining salvageability of the testicle in testicular torsion. If surgical exploration is delayed, testicular atrophy will occur by 6 to 8 h, with necrosis ensuing within 8 to 10 h of initial presentation. Salvage rates of over 90% are seen when surgical exploration is performed within 6 h of the onset of symptoms, decreasing to 50% when symptoms last beyond 12 h. The chance of testicular salvage is less than 10%, when symptoms have been present for over 24 h
Factors influencing rate of testicular salvage in acute testicular torsion at a tertiary pediatric center.
Ramachandra P, Palazzi KL, Holmes NM, Marietti S
[PubMed]
This study (Howe et al). confirmed the relationship between duration of torsion and testicle viability and also found a relationship between the degree of torsion
AAFP Review of Testicular Torsion: Diagnosis, Evaluation, and Management
Alyssa BeLong, B.Sc.(Hon)
Dalhousie Medicine New Brunswick
M.D. Candidate, Class of 2021
Reviewed and Edited by Dr. David Lewis
All case histories are illustrative and not based on any individual
A 45-year-old female presented with sudden-onset left-sided vision loss, right arm paralysis and auditory changes 24 hours ago. She subsequently developed a throbbing pain (6/10) behind her left eye which radiated over her scalp, with a sensation of water dripping down the back of her neck. Her symptoms resolved within 30 minutes except for ongoing headache and photophobia.
A variety of conditions may present with transient unilateral weakness or hemiplegia: (4)
Clarification of visual field disturbance revealed a left homonymous hemianopia rather than loss of vision in the left eye. There was no change in speech or facial droop. There were no precipitating events and there were no alleviating or aggravating factors. The patient noted herself to be particularly stressed lately. She was otherwise healthy with a past medical history of migraines without aura many years prior. Family history was negative for thromboembolic events, she was not taking any medications and had no history of smoking or substance use.
On physical exam, the patient appeared well with all vital signs within normal limits. Cranial nerve exam was unremarkable apart from ongoing photophobia in her left eye. There was normal motor, strength, sensation, tone and reflexes bilaterally. There was no evidence of gait disturbance or dysdiadochokinesia.
Migraines typically present as severe episodic headaches often accompanied by photophobia, phonophobia and/or nausea, however presence of an aura can yield a variety of presentations. Migraines are currently thought to be neurologic in origin, although the exact pathophysiology remains unknown (2). Migraines were previously thought to be due to vascular changes, with vasodilation causing headache and vasoconstriction causing aura, however this theory is no longer viable (2).
Migraines affect 17% of women and 6% of men, with an overall prevalence of 12% (2). Migraines typically flow through four phases (2):
While many types of migraines exist, 75% of migraines do not have an aura (2). Some patients also experience aura without headache. Factors thought to be involved in precipitation of migraine include stress, menstruation, fasting, weather, nitrates, wine and visual triggers (2, 3).
Familial hemiplegic migraine requires one first or second degree relative to meet the above criteria for hemiplegic migraine. Sporadic hemiplegic migraine encompasses those who do not meet familial criteria. (4, 5).
Treatment of acute migraine in the emergency department follows similar principles to abortive management in an outpatient setting (6):
Dexamethasone 10-25mg IV (or IM): Recommended in conjunction with the above treatments to lower risk of early headache recurrence.
In general, hemiplegic migraines can be treated the same as typical migraine with aura (4). Triptans and ergotamine are currently contraindicated due to their effect on vasoconstriction and theoretical risk of ischemic events, although this recommendation may change with evolving theory of migraine pathophysiology (4, 7).
Opioids are not recommended as first-line therapy and should not be routinely used in the acute management of migraine (6, 8).
The following medications were given in the emergency department:
The patient’s headache resolved with IV medications. She was advised to take it easy and consider scaling back on her shifts at work – a significant source of her stress. The patient was very pleased with her treatment and was discharged home.
Edited by Dr David Lewis
The full differential diagnosis should be considered in possible cases of DVT including Baker’s cyst, cellulitis, lymphedema, chronic venous insufficiency, superficial thrombophlebitis, popliteal venous or arterial aneurysm, peripheral vascular disease, enlarged lymph nodes compressing the veins, heterotopic ossification, hematoma, and muscle tears.
Ultrasound for Lower Extremity Deep Venous Thrombosis
Multidisciplinary Recommendations From the Society of Radiologists in Ultrasound Consensus Conference
One of the most common ways for doctors to collaborate is through referral and consultation. Poor communication between referring physicians and consultants can lead to disruptions in care, delayed diagnoses, unnecessary testing, iatrogenic complications, and frustrated physicians and patients. Improving the referral-consultation process is one of the most effective ways of providing safer care and reducing the risk of medical-legal difficulties.
See these SJRHEM Reflections post on the same subject:
and this post on the HINTS exam:
The fluctuating presentation of delirium makes it difficult to recognize but we should be attentive to certain hallmarks, including alterations in attention and awareness and acute changes in cognition. These can be associated with hallucinations or other perceptual disturbances. Collateral information and family input can be critical in detecting changes from baseline function and cognition. The more acute temporal course of delirium is important to distinguish from underlying dementia, which is itself one of the most important risk factors for delirium. The most common presentation, the hypoactive form, is a quiet, subdued, withdrawn state.
The Seriousness of Deliriousness: Delirium in the ED
See this SJRHEM Rounds
Edited by Dr David Lewis
Headache is one of the most common reasons for presentation to the emergency department (ED), seen in up to 2% of patients.1 Most are benign, but it is imperative to understand and discern the life-threatening causes of headache when they present. Headache caused by a subarachnoid hemorrhage (SAH) from a ruptured aneurysm is one of the most deadly, with a median case-fatality of 27–44%.2 Fortunately, it is also rare, comprising only 1% of all headaches presenting to the ED
Approach to the Diagnosis and Management of Subarachnoid Hemorrhage
Missed Diagnosis of Subarachnoid Hemorrhage in the Emergency Department
Over 3 years there were 1603 patients hospitalized with a diagnosis of nontraumatic SAH; 1507 (94.0%) of these were admitted through the ED. Of the 176 EDs in the province, 147 (83.5%) admitted at least 1 patient with SAH, ranging from 1 to 49 per ED. Of these, 38 (25.9%) were in small hospitals, 93 (63.3%) in community hospitals, and 16 (10.9%) in teaching hospitals. With the exception of age, triage level, and hospital type, persons with missed SAH did not differ from those initially diagnosed with SAH.
A total of 150 (10.0%; 95% CI, 8.5 to 11.6) patients had an ED visit in the 14 days preceding their SAH admission. SAH was missed on a prior ED visit in 81 (5.4%; 95% CI, 4.3 to 6.6) cases.
The majority of missed cases were diagnosed with “migraine” or “headache” at the prior related visit
…spontaneous bacterial peritonitish…
similar but more subtle
The signs and symptoms of SBP are subtle compared with those seen in patients with bacterial peritonitis in the absence of ascites – By separating the visceral from the parietal peritoneal surfaces, ascites prevents the development of a rigid abdomen
Fever = >37.8
In addition, patients with ascites admitted to the hospital for other reasons should also undergo paracentesis to look for evidence of SBP. A low clinical suspicion for SBP does not obviate the need for testing
E.coli ~50%
It is estimated that 12-25% of patients with ascites in the ED will have spontaneous bacterial peritonitis (SBP) but the classic triad of fever, abdominal pain, and worsening ascites is often absent (Borzio 2001)(Runyon 1988). With a mortality rate approaching 40%, rapid diagnosis and evidence-based treatment is critical in the management of patients presenting with SBP (Salerno 2013).
The 2012 AASLD Guidelines, based largely on the trial by Sort, et al., recommend that patients with ascitic fluid PMN counts greater than or equal to 250 cells/mm3 and clinical suspicion of SBP, who also have a serum creatinine >1 mg/dL, blood urea nitrogen >30 mg/dL, or total bilirubin >4 mg/dL should receive IV albumin (1.5 g/kg) within 6 hours of detection and 1.0 g/kg on day 3. (Class IIa, Level B)
Should You Give Albumin in Spontaneous Bacterial Peritonitis (SBP)?
Edited by Dr David Lewis
Transient Ischemic Attack (TIA): A brief episode of neurological dysfunction caused by focal brain, spinal cord or retinal ischemia, with clinical symptoms and without imaging evidence of acute infarction. Transient ischemic attack and minor stroke are the mildest form of acute ischemic stroke in a continuum that cannot be differentiated by symptom duration alone, but the former typically resolves within one hour.
https://www.strokebestpractices.ca/
Patients who present within 48 hours of a suspected transient ischemic attack are at the highest risk for recurrent stroke
Uptodate – DAPT for high-risk TIA, defined as an ABCD2 score of ≥4
For CVA – ASA only unless already on ASA, then DAPT. For minor CVA/TIA – DAPT
Of all ischemic strokes during the 30 days after a first TIA, 42 percent occurred within the first 24 hours.
Stroke Assessment Pocket Cards
Saskatchewan TIA Referral Pathway
Saskatchewan TIA Patient Information Leaflet
Resident Clinical Pearl (RCP) May 2019
Allyson Cornelis – PGY2 FMEM Dalhousie University, Saint John NB
Copyedited by Renee Amiro
Reviewed by Dr. David Lewis
When patients present with seizure like activity it can be difficult to distinguish true seizure/epilepsy from psychogenic non- epileptic seizures (PNES; also known as pseudoseizures). This task is made more difficult by the fact that 10-30% of patients with PNES can have true epilepsy as well4. The risks associated with diagnosing a psychogenic non-epileptic seizure as true seizure are mainly associated with administration of anti-epileptic drugs during both acute episodes and chronically, with the potential for associated side effects3-4,6. The most severe of these include sedation and even intubation if large enough doses are administered during an acute seizure episode. Additionally, there is added cost to both the patient and the healthcare system for continued use of medications and hospital admissions/investigations.
The underlying mechanism for PNES is believed to be psychiatric in origin, often attributed to conversion disorders, and patients are often not aware of their seizure like behaviours.
The challenge remains distinguishing between true seizures and PNES. There are various historical features and seizure characteristics that can assist in differentiating the two, though no one feature is confirmatory for seizure.
Sign/symptom | Seizure | PNES |
Eyes | *open | Closed, resist forced opening by examiner
*Fluttering |
Seizure onset | *abrupt | Gradual |
Awareness during seizure | Not aware | * awareness during episode |
Influence of the presence of others | Does not change seizure | *May intensify or alleviate
activity may only occur/be triggered by the presence of others |
Seizure activity | Generalized tonic clonic
Synchronous
Stereotyped (first stiff and in extension, then develops synchronous clonic activity) |
May be asynchronous, asymmetrical, waxing and waning
Thrashing/violent Pelvic thrusting |
Post ictal | *Confusion | May recall events during their apparent unresponsive event |
head | One sided | Side to side head turning during event |
**incontinence | common | occasional |
***Tongue biting | Common, may be severe, usually on SIDE of tongue | Occasional, rare to be severe, may be on tip of tongue or the lip |
Post ictal corneal reflex | impaired | normal |
Post ictal babinksi | upgoing | downgoing |
Hand drop test | negative | Positive (patient moves hand away from face) |
Response to sternal rub/nail bed pressure | Usually nonresponsive | May stop seizing, withdraw from stimuli |
****Vital signs | Desaturation more likely
Ictal apnea Ictal bradycardia |
|
*represents elements found to be most useful in distinguishing PNES and ES8
** incontinence has little utility in distinguishing between PNES and true seizure5
*** lateral tongue biting was 100% specific for true seizure vs 38% sensitivity and 75% specificity for any type of tongue bite5
****prospective trial7
No lab value has proven consistently useful for confirming seizure versus PNES.
The American Academy of Neurology released guidelines in 2005 recommending the use of prolactin following a seizure event2.
Edited by Dr David Lewis
Not all benign conditions have a benign outcome. A CT report will occasionally underestimate the clinical impact of an incidental finding. Its always worth reviewing the images yourself.
For example – a report might read – “No acute bleed or infarct, incidental finding of frontal bone fibrous dysplasia” – may sound innocuous and unrelated to the patient’s headache, until you review the scans yourself:
Fibrous dysplasia is a benign condition which can present with new craniofacial asymmetry. Whilst the condition itself may be benign, the location and speed of growth can result in symptoms, especially headache and even cranial nerve compression.
Clinical Guidelines for managing craniofacial fibrous dysplasia
Management of Intracranial Hemorrhage in the Emergency Department can be complex. The diagnosis is usually straightforward with CT (providing it has been considered as a possibility – subarachnoid hemorrhage can present with syncope alone) and the broad category of bleed determined by the history, patient age, CT appearance, etc.
ED Management will depend on the category of bleed (Primary ICH, Subdural, Epidural, Traumatic SAH, Spontaneous SAH).
From ALIEM.com, click here for the full article
Initial management of intracranial hemorrhage can be simplified / summarized as follows:
Airway – ET Intubation if GCS < 9
Breathing – Ventilate if GCS < 9 (SaO2 >94%, ETCO2 35-45 mmHg)
Circulation
I suspect that most emergency physicians/nurses are wondering whether this level of care falls within their remit. In most hospitals the answer will be NO, these cases are stabilised and managed in an Intensive Care Unit. However, there are occasions when this level of care is required prior to transfer to another unit/hospital, in which case it is likely that the care will be directed by the local neurosurgeon / neurointensivist and the receiving specialists.
ED Reflections – CME Quiz – Oct 2017
Click Print, PDF or Email to save a record of this CME
After meeting with Dr. Blacquiere and the ER department regarding stroke management and SAH management, I’m recommending the following based on new literature and evolving management in “high risk” patients.
1) High risk TIA patients, such as those who had a profound motor / speech deficit that is resolving should have a CTA carotid / COW as well as their standard CT head.
2) SAH patients should have CT done prior to LP due to false positive LP rates. If there is any question about vascular malformation / aneurysm, follow with a CTA. The CTA isn’t necessary for every headache patient, etc, just those with a positive bleed on the unenhanced CT.
Reviewed by: Dr Joanna Middleton and Dr David Lewis
Acute vestibular syndrome (AVS) is the rapid onset of vertigo, nausea/vomiting, and gait unsteadiness combined with head-motion intolerance and nystagmus that lasts days-weeks. Often these dizzy patients have a benign, self-limiting cause for their symptoms, however it is estimated that up to 25% of AVS presentations to emergency departments are due to posterior circulation infarcts.
CT scan has low sensitivity for identifying acute infarct, especially in the posterior fossa. MRI is not always available, and will often have false-negative results in acute posterior circulation strokes. Are bedside predictors able to identify central causes of acute vestibular syndrome?
The HINTS exam is a bedside test that carefully assesses eye movements. HINTS stands for Head Impulse-Nystagmus-Test of Skew.
Head Impulse: test of vestibulo-ocular reflex function. A normal Head Impulse test (HIT) strongly indicates a central localization for the AVS. An abnormal HIT usually indicates a peripheral lesion.
Nystagmus: bilateral nystagmus which changes direction on eccentric gaze or primarily vertical nystagmus is predictive of central pathology.
Skew Deviation: a vertical ocular misalignment that is assessed by alternate cover testing
Watch the video! A short and excellent description of the exam with good examples of normal and abnormal:
https://vimeo.com/133033089 (Courtesy of EMCrit)
A benign HINTS exam is defined as abnormal HIT + direction-fixed horizontal nystagmus + absent skew.
A dangerous HINTS exam is defined as any one of:
(Untestable refers to those patients with obvious oculomotor pathology or lethargy in whom the tests were unable to be completed).
The acronym INFARCT can be used to remember what constitutes a dangerous HINTS exam:
Impulse Normal
Fast-phase Alternating
Refixation on Cover Test.
A dangerous HINTS result was found to be 100% sensitive and 96% specific for the presence of a central lesion when applied to patients with acute vestibular syndrome (continuous vertigo and nystagmus) with at least one stroke risk factor. In fact, the HINTS exam is more accurate than MRI to diagnose stroke in patients with AVS in the first 48 hours!