UMEM Educational Pearls - Neurology

Patients may present to the ED with new onset weakness due to myasthenia gravis (MG). A group that is frequently missed is late-onset MG, which occurs after the age of 50. It is frequently misdiagnosed as a stroke or transient ischemic attach (TIA).

Two cardinal features:

  • fatiguability: must be distinguished from fatigue. 
  • fluctuation

Bonus pearl: Ocular symptoms are present in up to 85% of patients with MG, with unilateral ptosis or asymmetric bilateral ptosis being the most common presentations.

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Category: Neurology

Title: Driving after concussion: Is it safe to drive after symptoms resolve?

Keywords: concussion, driving performance, cognitive impairment (PubMed Search)

Posted: 1/11/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 
Driving after concussion: Is it safe to drive after symptoms resolve?
  • Limited data is available to guide when individuals should return to driving after a concussion.
  • Cognitive impairments in reaction time, executive function, and attention can persist even after symptoms of a concussion resolve.
  • Schmidt et al. compared driving performance between individuals within 48 hours following symptom resolution after a concussion with matched controls using simulated driving.
  • They found that concussed individuals had poorer driving performance despite being asymptomatic.
  • This study is limited by a small sample size (n=28), however, it raises interesting questions regarding whether driving should be restricted following concussions and how should readiness to return to driving be determined.

 

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Category: Neurology

Title: ED Pharmacist on Time to Thrombolysis

Keywords: pharmacist, thrombolysis, door-to-needle time, acute ischemic stroke (PubMed Search)

Posted: 12/14/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Takeaways

Impact of an ED pharmacist on time to thrombolysis in acute ischemic stroke

  • Prior studies showed that incorporation of ED pharmacists within ED clinical teams lead to more rapid treatment of trauma, stroke, and STEMI.
  • A recent retrospective study conducted by Montgomery et al. showed that having an ED pharmacist on the stroke alert team increased the number of patients meeting goal door-to-needle time of 60 minutes.

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Category: Neurology

Title: Subarachnoid Hemorrhage -- Or Is It?

Keywords: subarachnoid hemorrhage, mimic, pseudosubarachnoid hemorrhage, cerebral edema (PubMed Search)

Posted: 11/9/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Question

Patient found pulseless after submersion in water for 20 minutes.  After ROSC, patient’s GCS was 3 and pupils are dilated and nonreactive.

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Category: Neurology

Title: Spinal Cord Imaging 101

Keywords: contrast, epidural, multiple sclerosis (PubMed Search)

Posted: 10/26/2016 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

Magnetic resonance imaging (MRI) is the method of choice for imaging the spine for the suspicion of non-traumatic disorder, such as multiple sclerosis (MS), transverse myelitis, epidural abscess, spinal cord infarcts, and spondylotic myelopathy (changes in the spinal cord due to disk herniation or osteophytes in degenerative joint disease).

If the differential diagnosis includes infection, neoplasm, demyelination or inflammation, then IV contrast should be administered.

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Category: Neurology

Title: Updated Guidelines for Traumatic Brain Injury

Keywords: Brain Trauma Foundation, BTF, guideline, traumatic brain injury, TBI (PubMed Search)

Posted: 10/12/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Updated Guidelines for Traumatic Brain Injury

The Brain Trauma Foundation (BTF) Guidelines for the Management of Severe Traumatic Brian Injury (TBI) was recently updated and published in September 2016.

Updated recommendations include:

  • Prophylactic hypothermia is not recommended (Level IIB).
  • Phenytoin is recommended for seizure prophylaxis (Level IIA).
    • There is insufficient evidence to recommend levetiracetam over phenytoin.
  • Maintain SBP 100 mmHg for patients 50-69 years old or 110 mmHg for patients 15-49 or >70 years old (Level III).
  • Treat intracranial pressure (ICP) > 22 mmHg (Level III)
  • Target cerebral perfusion pressure (CPP) between 60-70 mmHg (Level IIB).

For the executive summary and complete guidelines, go to https://braintrauma.org/guidelines/guidelines-for-the-management-of-severe-tbi-4th-ed#/


Category: Neurology

Title: PCC before LP in Patients on Anticoagulants?

Keywords: lumbar puncture, meningitis, INR, warfarin, spinal, bleeding (PubMed Search)

Posted: 9/28/2016 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

Takeaways

You have a patient in whom you suspect meningitis, but he is on warfarin for a history of pulmonary embolism. You started empirical antibiotics. His INR is 2.6, and you want to do a lumbar puncture (LP) to confirm your diagnosis. Can you use Prothrombin Complex Concentrate to lower his INR and safely perform the LP?

Take Home Point:

Using PCC to lower INR to enable LP is relatively safe and effective in patients on vitamin K antagonists. The dose used was individually determined by the physician according to initial INR.

Limitation:

This is a retrospective study, with no control group. One patient (2.7%) had a myocardial infarction that was “possibly related” to the PCC administration. 

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Category: Neurology

Title: My Patient Won't Open His/Her Eyes!

Keywords: eyelid apraxia, eye opening apraxia (PubMed Search)

Posted: 9/14/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 
My patient won't open his/her eyes!
 
  • Beware of the patient who can't open his/her eyes but is otherwise awake!
  • This coma mimic is the result of eyelid apraxia, which is the inability to voluntarily open eyes despite intact frontalis muscle contraction and absent oculomotor dysfunction.
  • This can be seen in injuries of the nondominant hemisphere (e.g. R MCA stroke), medial frontal lobe, bilateral thalami (e.g. bilateral thalami stroke), and brainstem (e.g. progressive supranuclear palsy).
  • When asking these patients to open their eyes, they may use their forehead muscles to try and raise their eyelids.

Category: Neurology

Title: What is Ataxia?

Keywords: cerebellar disease, tremor, nystagmus (PubMed Search)

Posted: 8/24/2016 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

Ataxia is an important clinical sign of cerebellar pathology, but how is it actually described?

Stance ataxia: inability to stand with feet together for more than 30 seconds

Gait ataxia

Sensory ataxia: the first 2 elements, in addition to a positive Romberg sign

Truncal ataxia: oscillation of body while sitting or standing

Limb ataxia: functional impairment in performing actions such as writing or buttoning and improves with slowing down the movement

Dysdiadokinesia: impairment of rapidly alternating movement

Intention tremor: tested by finger-to-nose and heel-to-shin.

Dysmetria: pastpointing or undershooting on finger-chasing or shin-tap.

Dysarthria: irregular and slow speech with unnecessary hesitation

Nystagmus and other ocular disturbances, such as ocular flutter and opsoclonus.

The first 3 are present in both cerebellar pathology and loss of proprioceptive input, the rest are usually due to cerebellar pathology or ataxic syndrome.

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Category: Neurology

Title: What's the cause of this patient's hemiplegia?

Keywords: Uncal herniation, ipsilateral hemiplegia, Kernohan's notch, Kernohan's sign (PubMed Search)

Posted: 8/10/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Question

Patient presents after a fall confused, not moving his right side, but moving his left side spontaneously.  What's the diagnosis?
 

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Attachments

20160810_Figure_2.jpg (38 Kb)


Over the past few years, there have been numerous studies discussing the "best" way to diagnose subarachnoid hemorrhage (SAH). These 2016 guidelines review the current evidence.
Classic approach: dry CT, and if negative perform the lumbar puncture (LP)
It is the most common approach, with the most robust evidence. Still considered "standard of care"
Dry CT alone: Sensitivity of a dry CT alone for SAH has increased with improved technology, and the sensitivity is highest when done within the first 6 hours of headache onset. Despite studies quoting a sensitivity of 100% within 6 hours, this evidence is still insufficient due to concerns for selection bias in the study, and the fact that the CTs in the study were read by neuroradiologists.

CT/CTA: CTA is very sensitive for aneurysmal SAH (98% for aneurysms >3mm). CTA would miss non-aneurysmal SAH, but would detect aneurysms that may or may not need to be treated before rupture. It is a reasonable strategy to exclude aneurysmal SAH in select patients, and in patients who refuse LPs or in whom the LP results are equivocal.
Bottom Line: CT/LP is still standard of care, with CT/CTA being an acceptable alternative if LP is equivocal or refused by the patient. CT alone is NOT enough to exclude SAH.

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Category: Neurology

Title: Screening Tool for Large Vessel Occlusion Strokes?

Keywords: Large vessel occlusion stroke, endovascular intervention, Field Assessment Stroke Triage for Emergency Destination, FAST-ED, NIHSS, Rapid Arterial Occlusion Evaluation, RACE, Cincinnati Prehospital Stroke Severity scale, CPSS (PubMed Search)

Posted: 7/13/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 
Screening Tool for Large Vessel Occlusion Strokes (LVOS)?
 
  • Endovascular intervention for acute ischemic stroke from ICA or proximal MCA occlusion is a Level IA recommendation1.
  • Identification of patients who may benefit from endovascular intervention begins in the prehospital setting.
  • Several prehospital stroke scales exist, but have not been validated using arterial imaging to determine the presence of LVOS.
  • The Field Assessment Stroke Triage for Emergency Destination (FAST-ED) scale (see Table 1) was designed based on items of the NIH Stroke Scale (NIHSS) with higher predictive value for LVOS.

  • The FAST-ED scale has comparable accuracy to predict LVOS to the NIHSS, and higher accuracy compared to the Rapid Arterial Occlusion Evaluation (RACE) and the Cincinnati Prehospital Stroke Severity (CPSS) scale
  • The FAST-ED scale also provides 3 distinct groups for the likelihood of LVOS:
    • Score 0 or 1: <15%
    • Score 2 or 3: 30%
    • Score >= 4: >60%

Bottom Line: Additional assessment of gaze deviation, aphasia and neglect, as included in the FAST-ED scale, increases the accuracy of predicting LVOS.  

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Multiple sclerosis (MS) relapses are defined as new or worsening neurologic deficits lasting 24 hours or more in the absence of fever or infection. Symptoms may be visual, motor, sensory, balance or cognitive. It is a clinical diagnosis, but the presence of a new gadolinium-enhancing lesion on MRI can be used as a radiologic marker of an MS relapse. However, it is unclear whether asymptomatic lesions should be treated, making it prudent to rely on the clinical evaluation rather than the MRI for diagnosis.

Moderate to severe relapses should be treated within 1 week of onset. The mainstay of treatment for relapses is IV methylprednisolone, usually dosed at 500mg to 1g per day for 3-7 days.

Similar symptoms occurring in the presence of fever, heat exposure, stress or infection (such as urinary or upper respiratory tract infections) are "pseudoexacerbations", and should not be treated as an MS relapse.

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The PATCH trail, recently published in the Lancet, looked at whether giving platelets to patients, that were on anti-platelet therapy (e.g.: aspirin, clopedrigrel, or dipyridamole) for at least 7 days at the time of their spontaneous intracerebral hemorrhage, improved neurologic outcomes and mortality.

This was a large (60 hospitals) multicener, open-label, masked endpoint, randomized trial that enrolled a total of 190 patients (97 platelet transfusion and 93 standard care).

The outcomes were surprising. Patient in the Platelet group had a higher rat of death or dependence at 3 months (Adjusted OR 2.05; 95% CI 1.18 3.56; p = 0.0114).

The authors concluded "Platelet transfusion seems inferior to standard care for people taking anti-platelet therapy before a spontaneous intracerebral hemorrhage"

Though this is the first study to look at this, the studies design and outcomes should really make use reconsider whether we give these patients platelets. The thought is that ICB or hemorrhagic strokes also have a component of ischemic stroke and a watershed area that's blood flow becomes compromised with the platelet transfusion.

TAKE HOME POINT: We should not routinely transfuse platelets in our patients that were on antiplatelet therapy prior to their ICB.

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Category: Neurology

Title: Gadolinium - To Use or Not Use?

Keywords: MRA, MRV, non-contrast, contrast-enhanced, gadolinium, time-of-flight, TOF (PubMed Search)

Posted: 6/8/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Gadolinium - To Use or Not Use?

  • One advantage of MR imaging is the option between non-contrast vs. contrast-enhanced MR angiography (MRA) and venography (MRV)
  • How do they work and when should you use which?

Non-Contrast MRA/MRV Contrast-Enhanced MRA/MRV
How Does It Work?

* Time-of-flight (TOF) is a commonly used sequence

* Relies on flow of blood into imaging plane

* Difference between signal of blood and suppressed background tissue

* Similar to CT angiography/venography

* Higher intravascular signal purely from gadolinium-based contrast, not dependent on flow

Pros

* Does not require contrast

* Generally better image quality

* Shorter acquisition time

Cons

* Slow, turbulent, or retrograde flow may result in signal loss

* Over-estimates stenosis

* Longer acquisition time

* RIsks associated with contrast use

* Timing of image acquisition important

Applications

* Patients with allergy to gadolinium, renal dysfunction, pregnancy

* Evaluation of intracranial vessels and cerebral venous system

* Evaluation of stenoses and occlusions of the neck vessels and their origins at the aortic arch

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Category: Neurology

Title: Does the Headache Classification Matter in the ED?

Keywords: headache, analgesia, cluster, migraine, oxygen (PubMed Search)

Posted: 5/25/2016 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

Short Answer: No

Classically, some therapies for headaches are thought to be effective in only certain classifications of headaches, such as triptans in migraines, or oxygen in cluster headaches. This is not necessarily true.

Triptans have been successfully used in cluster headaches, as found in the 2013 Cochrane review.1

More recently, "high-flow" oxygen (referring to 12 L/min of oxygen, delivered through a facemask) has been studied in migraine headaches, with promising results. When compared with placebo (air), oxygen used for 15 minutes was more effective in pain relief and improving visual symptom, with no significant adverse events. 2

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Category: Neurology

Title: Shades of Gray Matter - Brain MRI 101

Keywords: magnetic resonance imaging, MRI, T1, T2, FLAIR, DWI, ADC (PubMed Search)

Posted: 5/11/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Shades of Gray Matter - Brain MRI 101

Want to learn more about how to read a brain MRI?  Here are the basics:

  • MRIs are described by signal intensity, as compared to CTs where lesions are described by density.
    • A dark lesion on MRI is “hypointense”
    • A bright lesion on MRI is “hyperintense"
  • The most commonly used MRI sequences are T1-weighted, T2-weighted, FLAIR, and Diffusion-weighted.
    • T1-weighted images are good for brain parenchyma.
      • Contrast enhanced T1 with gadolinium helps differentiate pathological tissue (e.g. tumors, inflammation, infection)
    • T2-weighted images are good for CSF spaces and periventricular white matter.
      • Edema from a tumor, subacute stroke or hemorrhage appears bright
      • Periventricular white matter scarring from multiple sclerosis appears bright
    • FLAIR images are T2 images where CSF is dark.  FLAIR is very sensitive to edema and parenchymal lesions.
    • Diffusion-weighted sequences are good for cellular swelling.
      • Acute ischemia appears bright on Diffusion-Weighted Imaging (DWI) and dark on Apparent Diffusion Coefficient (ADC) maps
      • Some neoplasms, abscesses and toxic/metabolic/demyelinating processes can also appear bright on DWI.

Stay tuned for more pearls in this series on brain MRI!

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A 25 year old patient presents to the emergency department (ED) with a first unprovoked seizure. His ED workup is normal and he is back to his baseline, and you plan to discharge the patient with outpatient follow up within 1 week. The patient is requesting to be discharged on an anti-epileptic drug (AED). What do you do?

Educate the patient about the risk of recurrence, and the possible side effects of AEDs!

The American Academy of Neurology (AAN) specifically addressed this in their 2015 guidelines. A few points to remember:

- The risk of recurrence is greatest within the first 2 years, and occurs in 21-45% of patients.

- The risk of recurrence increases with a remote brain lesion or injury, abnormal EEG, significant brain imaging abnormality or nocturnal seizures.

- AED therapy is likely to reduce the risk of a 2nd unprovoked seizure by about 35% over the next 2 years, but the delay in initiating therapy does not increase the long-term remission risk.

Is it different if the patient had multiple seizures within 24 hours?

Patients presenting with multiple seizures in a 24-hour period were as likely to have seizure recurrence as those presenting with a single seizure, irrespective of etiology or treatment.

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Category: Neurology

Title: What Do You Mean By Dizzy?

Keywords: dizzy, dizzinesss, acute vestibular syndrome, triggered episodic vestibular syndrome, spontaneous episodic vestibular syndrome, HINTS, Dix-Hallpike (PubMed Search)

Posted: 4/13/2016 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 

What Do You Mean By Dizzy?

  • Patients with dizziness account for 3% of ED visits.
  • The traditional approach based on symptom quality (i.e. “What do you mean by dizzy”) is not reliable.
  • Drs. Edlow and Newman-Toker propose a new paradigm based on the timing and triggers of dizziness.
  • Acute vestibular syndrome begins abruptly or rapidly and continues for days.  Patients’ dizziness may be exacerbated by movement but is not triggered by movement.
  • Triggered episodic vestibular syndrome are repetitive episodes of dizziness triggered by some event.  Patients will be completed asymptomatic at rest and will develop dizziness that is reliably triggered by a specific event or postural shift.
  • Spontaneous episodic vestibular syndrome are multiple episodes of dizziness that occur without any clear identifiable trigger.  Patients are asymptomatic between episodes.

 

Table 1 shows common benign and serious causes of these vestibular syndromes.

 

Utilizing the HINTS battery or the Dix-Hallpike maneuver, a “safe to go” algorithm for acute vestibular syndrome and triggered episodic vestibular syndrome is outlined in Figure 2.

 

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Attachments

20160413_Table_1.jpg (139 Kb)

20160413_Figure_2.jpg (89 Kb)


Category: Neurology

Title: Epilepsy in the Elderly: Is it Different?

Keywords: geriatrics, seizures, mimics, TIA, syncope (PubMed Search)

Posted: 3/23/2016 by Danya Khoujah, MBBS
Click here to contact Danya Khoujah, MBBS

Epilepsy in older adults is common, with an incidence equal to (if not higher) than infants.
The most common type is focal seizures, with strokes and neurodegenerative diseases being the most common underlying causes.
Management of epilepsy in the elderly is challenging because of many reasons:
- A large number of disorders may mimic seizures, and 25-50% of patients with presumed epilepsy end up diagnosed with non-epileptic events, such as tremor, non-epileptic myoclonus, syncope, confusion, agitation, cataplexy and limb-shaking TIAs.
- Status epileptics in the elderly has double the incidence of the general population and a significantly higher mortality rate.
- The role of newer anti-epileptics (drugs other than benzodiazepines, phenytoin and phenobarbital) is unclear due to lack of adequate studies in this age group.
- Antiepileptic drug clearance (both renal and hepatic) is affected by normal physiological changes in this age group, increasing the side effects and decreasing tolerance, even to doses lower than usual.

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