UMEM Educational Pearls - Neurology

Category: Neurology

Title: A New DAWN for Stroke Intervention?

Keywords: DAWN, thrombectomy, mismatch, wake-up, stroke, penumbra (PubMed Search)

Posted: 12/13/2017 by WanTsu Wendy Chang, MD
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Question

  • The DAWN trial was a multicenter, randomized, open-label study comparing endovascular thrombectomy plus standard medical care with standard medical care alone for patients with:
    • Acute stroke symptoms
    • Last known well 6 to 24 hours earlier
    • Evidence of intracranial ICA or proximal MCA occlusion
    • Mismatch between clinical deficit and infarct volume on CTA or MRA
  • The study found that patients receiving thrombectomy plus standard medical care had improved functional independence at 90 days as defined by modified Rankin Scale (mRS) of 0, 1, or 2 (49% vs 13%).
  • The trial was stopped early based on prespecified interim analysis intended with the adaptive trial design.
  • While the two treatment groups were similar, with median NIHSS score of 17, they had small infarct volumes and short time from symptom observation (4.8 vs 5.6 hours) compared to time of patient's last known well (12.2 vs 13.3 hours). 
  • 88% of the patients had unwitnessed stroke onset (including wake-up strokes), thus it is possible that these patients had actual ischemia times closer to 6 hours, thereby reproducing similar results as prior thrombectomy trials.

Bottom Line: The use of neuroimaging to identify an ischemic penumbra that may benefit from thrombectomy may be considered even for patients with time of last known well beyond 6 hours.

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Category: Neurology

Title: Guillain-Barre's less evil twin - CDIP!

Keywords: GBS, weakness, intubation, CSF, LP (PubMed Search)

Posted: 11/22/2017 by Danya Khoujah, MBBS
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CDIP, or chronic inflammatory demyelinating polyradiculoneuropathy, is an immune-mediated polyneuropathy which presents similarly to Guillain-Barré Syndrome (GBS). However, it is not as dangerous as GBS. Patients present with symmetric proximal and distal weakness with reduced or absent deep tendon reflexes, just like GBS. The difference is that in typical CDIP, patients have prominent sensory signs, no autonomic dysfunction, no facial weakness, no preceding infectious illness, and most importantly no respiratory failure. It also continues to progress past 4 weeks.

CSF is not diagnostic, and may show albuminocytologic dissociation. The diagnostic test is nerve conduction studies. 

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Category: Neurology

Title: Isolated Aphasia - Is It a Stroke?

Keywords: aphasia, stroke, middle cerebral artery, MCA, mimic, NIHSS (PubMed Search)

Posted: 11/8/2017 by WanTsu Wendy Chang, MD
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Question

  • A retrospective single center study reviewed 788 patients who presented to the ED with concern of stroke and found 21 (3%) patients had only aphasia symptoms by the NIHSS.
  • None of these patients had evidence of infarct on neuroimaging.
  • 3 of these patients were diagnosed with possible transient ischemic attack (TIA) though also had other possible diagnoses.
  • Toxic/metabolic disturbances (39%), followed by seizure (11%), syncope (11%), and chronic medical problems (11%) were the most commonly diagnosed stroke mimics.

Take Home PointThis small but interesting study looked at the incidence of isolated aphasia presenting for concern of stroke. They found that none of their patients had evidence of an infarct, suggesting that strokes affecting language without motor or sensory deficits are uncommon.

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Category: Neurology

Title: Guillain- Barr Syndrome

Keywords: weakness, infection, paralysis, intubation, influenza, vaccine (PubMed Search)

Posted: 10/25/2017 by Danya Khoujah, MBBS
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It's respiratory infection and flu vaccine season! Time to brush up on Guillain-Barré Syndrome..

- It is the most common cause of acute or subacute flaccid weakness worldwide

- 70% of cases are preceded by an infection in the past 10-14 days, but most are minimized or forgotten by the patient. 40% of these infections are by Campylobacter jejuni.

- 30% develop respiratory failure requiring intubation and ventilation

- Half of the patients will develop their maximum weakness by 2 weeks, most will develop it by 4 weeks.

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Category: Neurology

Title: Traumatic Brain Injury in Older Adults - The Silver Tsunami?

Keywords: traumatic brain injury, TBI, fall, subdural hematoma, SDH, elderly (PubMed Search)

Posted: 10/11/2017 by WanTsu Wendy Chang, MD
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Traumatic brain injury (TBI) is associated with close to half of major trauma admissions in adults over age 65 in the U.K.

Falls accounted for 85% of all TBIs, while 45% of patients had subdural hematomas (SDH).

More than 3/4 of patients were treated conservatively, though outcomes were not significantly better than those who underwent neurosurgical intervention.

Higher age is associated with higher mortality and greater disability.

Bottom Line: Trauma in older adults is increasing and fall prevention is important in reducing significant injuries.

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Category: Neurology

Title: tPA Contraindications

Keywords: stroke, tPA, thrombolytics, ICH, hemorrhage, adverse events (PubMed Search)

Posted: 9/28/2017 by Danya Khoujah, MBBS
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Classically, the list of contraindications for tPA in stroke has been extensive and excludes a significant percentage of patients. This scientific statement from AHA clarifies the evidence behind these contraindications, and in short, expands the population of patients that should be considered for tPA.
The following is NOT considered a contraindication for tPA: 
- Age over 80 
- Severe stroke (NIHSS >25)
- Improving symptoms, if patient remains moderately impaired and potentially disabled
- A small (<10 mm) unruptured and unsecured intracranial aneurysm (NOT other vascular malformations)
- Extra-axial intracranial neoplasms (e.g. meningiomas, pituitary adenomas)
- Blood glucose of >400mg/dL that is subsequently normalized
- Seizure at onset of stroke if residual impairment is secondary to stroke not a postictal phenomenon 

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Category: Neurology

Title: IV vs. Non-IV Benzodiazepines for Cessation of Seizures

Keywords: seizure, status epilepticus, benzodiazepine, RAMPART, pediatric (PubMed Search)

Posted: 9/13/2017 by WanTsu Wendy Chang, MD (Updated: 9/14/2017)
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Question

IV vs. Non-IV Benzodiazepines for Cessation of Seizures

  • A meta-analysis by Alshehri et al. included 11 studies with a total of 1633 patients, comparing IV vs. non-IV benzodiazepines from any route (buccal, intranasal, intramuscular) for seizure cessation in status epilepticus.
  • They found that non-IV benzodiazepine is more effective than IV benzodiazepine in patients presenting without IV access.
  • The largest and highest quality study included in the meta-analysis was the RAMPART study, which was also the only study to include adults.
  • When considering pediatric studies only, there is no difference between IV vs. non-IV benzodiazepine in seizure cessation for status epilepticus.

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Rapid detection of bacterial meningitis using point-of-care glucometer

  • CSF:blood glucose ratio is a useful characteristic in differentiating bacterial meningitis from viral meningitis. 
  • Normal CSF glucose is at least 2/3 of serum glucose level.
  • In bacterial meningitis, CSF:blood glucose ratio is usually <0.4
  • Rousseau et al. conducted a study comparing CSF:blood glucose ratio obtained using a bedside glucometer with the laboratory.
  • They found the optimal cutoff of CSF:blood glucose ratio using a bedside glucometer is 0.46 compared to 0.44 using the laboratory.
  • This proof-of-concept study suggests that a point-of-care glucometer can be used for rapid diagnosis of abnormal CSF:blood glucose ratio in the evaluation of meningitis.

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Category: Neurology

Title: Pituitary Apoplexy

Keywords: pituitary apoplexy, subarachnoid hemorrhage, meningitis, headache, CT, MRI (PubMed Search)

Posted: 8/9/2017 by Danya Khoujah, MBBS (Updated: 11/1/2024)
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Pituitary apoplexy is a sudden hemorrhage or infarction of the pituitary.
  • It most commonly occurs in patients with preexisting pituitary adenomas, but 3 out of 4 patients with pituitary adenomas are unaware of their diagnosis.
  • Patients may acutely present with thunderclap headache, with or without visual field deficits or cranial nerve dysfunction. They may also have meningeal symptoms due to extravasation of blood into the subarachnoid space.
  • Endocrine dysfunction is common but not readily diagnosed in the ED.
  • Symptoms may be triggered by some hormonal treatments (e.g. GnRH agonists for prostate CA), head trauma, angiographic procedures, or anticoagulation therapy.
  • CT is diagnostic in only one-third of cases, but can reveal the intrasellar mass in 80% of cases, and therefore should be the initial test. Blood may be missed in subacute cases.
  • MRI is the test of choice, with a sensitivity of over 90%.  

Bottomline: Keep pituitary apoplexy in your differential when considering SAH or meningitis, especially in the presence of risk factors, and have a low threshold to order an MRI. 

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Category: Neurology

Title: What is the cause of this patient's decreased vision?

Keywords: Terson syndrome, vitreous hemorrhage, intraocular hemorrhage, subarachnoid hemorrhage (PubMed Search)

Posted: 7/12/2017 by WanTsu Wendy Chang, MD
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Question

50 YOF with acute onset of worst headache of life associated with nausea and vomiting.  Patient is somnolent, will rouse to noxious stimuli and complains of a headache as well as decreased vision.

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Category: Neurology

Title: Autoimmune Neurological Disease

Keywords: autoimmune, cancer, encephalopathy (PubMed Search)

Posted: 6/28/2017 by Danya Khoujah, MBBS
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One of the differentials of a subacute neurological deficit (usually with a fluctuating course) is autoimmune neurologic disorders. This can encompass anything from neuropathic symptoms, to cerebellar pathology, to encephalitis-like picture. A personal or family history of autoimmune disease or malignancy should heighten suspicion, and the CSF is likely an inflammatory CSF profile as well (pleocytosis). Neural autoantibodies confirm the diagnosis, and are usually performed in both the serum and the CSF. Most laboratories perform a global screen for a number of potential antibodies that fit the concerning clinical picture, rather than one or two tests.
In addition, autoimmune CNS pathology is concerning for a paraneoplastic syndrome e.g. teratoma, lymphoma or small cell lung cancer.

Take Home Message: If suspecting an autoimmune pathology due to the risk factors and subacute nature of the disease, obtain some extra CSF to run the necessary tests after consulting with neurology. 

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Category: Neurology

Title: What is the role of EEG for first-time seizures in the ED?

Keywords: seizure, electroencephalogram, EEG, epilepsy, antiepileptic (PubMed Search)

Posted: 6/14/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

Question

 

What is the role of EEG for first-time seizures in the ED?

  • Wyman and colleagues performed a prospective trial on the use of 30-minute routine electroencephalogram (EEG) in the ED after a first-time seizure or recurrent seizure without performance of a previous EEG to guide decision making in the initiation of antiepileptic medication.
  • A diagnosis of epilepsy based on EEG findings was made for 21% of patients (n=15/71).
  • Antiepileptic medication was initiated in 24% of patients (n=17/71), including 2 patients with abnormal but not epileptic EEG findings.

Take Home Point:  A 30-minute routine EEG in the ED in adults with an uncomplicated first-time seizure revealed a substantial number of epilepsy diagnosis and can change ED management with immediate initiation of antiepileptic medication.

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Category: Neurology

Title: Neurally Mediated Syncope - Part 2

Keywords: syncope, vasovagal, orthostatic, blood pressure (PubMed Search)

Posted: 5/24/2017 by Danya Khoujah, MBBS
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Vasovagal syncope is a subtype of neurally mediated syncope, and it is distinctly different from orthostatic hypotension. 

Patients with orthostatic syncope have severe orthostatic hypotension that results in transient loss of consciousness immediately or within moments of standing up. This is different from neurally mediated syncope, which develops gradually under conditions of prolonged orthostatic stress such as standing for several minutes. Tilt table testing is useful for true orthostatic syncope, but not for neurally mediated syncope. In addition, checking for “orthostatic hypotension” may not capture patient with orthostatic syncope, because the hypotension occurs so quickly after standing up. Of note, patients may still have orthostatic tachycardia or intolerance with neurally mediated syncope. 

 
 

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Category: Neurology

Title: Neurally Mediated Syncope - Part 1

Keywords: syncope, vasovagal, seizures, orthostatic, blood pressure (PubMed Search)

Posted: 5/10/2017 by Danya Khoujah, MBBS
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"Neurally mediated syncope" is the most common cause of syncope in all age groups, and includes various overlapping entities, such as neurocardiogenic syncope, vasovagal syncope, and vasodepressor syncope. These are distinctly different from orthostatic hypotension and seizures. 
A careful history is the most important “test” to diagnose neurally mediated syncope. It is frequently preceded by a characteristic prodrome with symptoms such as nausea, dizziness, feelings of warmth or coldness, visual dimming or blurring, clammy skin, facial pallor, general weakness, decreased hearing, or fecal urgency. Symptoms last 30 seconds to several minutes prior to syncope. 
Differentiating syncope from seizures:
Brief, multifocal,arrhythmic, myoclonic jerks are observed in up to 90% of patients at the time of syncope. These are caused by brainstem hypoperfusion and may be mistaken for seizures. The jerks follow the LOC (rather than immediate) and the eyes deviate upward (rather than lateral). If tongue biting occurs, it’s the tip (rather than the side, which is what occurs with seizures).
 

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Category: Neurology

Title: Vasogenic Cerebral Edema

Keywords: vasogenic cerebral edema, white matter, blood-brain-barrier, steroids (PubMed Search)

Posted: 4/26/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 
Vasogenic Cerebral Edema
  • Vasogenic cerebral edema is most commonly seen with brain tumors and cerebral abscesses.
  • It mainly involves the white matter.
  • Gray-white differentiation is maintained, so the edema has a finger-like pattern on CT (see Figure).
  • It is caused by disruption of the blood-brain-barrier, thus responds to treatment with steroids.

 

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Attachments

1704262312_20170426_Figure.jpg (60 Kb)



Category: Neurology

Title: Simplified GCS vs. Full GCS? Which One To Use?

Keywords: Glasgow Coma Scale, GCS, motor GCS, mGCS, Simplified Motor Scale, SMS (PubMed Search)

Posted: 4/12/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 
Simplified GCS vs. Full GCS?  Which One To Use?

  • The Glasgow Coma Scale (GCS) is an instrument widely used to assess level of consciousness by EMS.
  • The motor GCS (mGCS) and Simplified Motor Scale (SMS) have been proposed to simplify EMS triage.
  • A number of retrospective studies have compared these scales.
  • Chou et al. performed a systematic review and meta-analysis of 18 studies with a total number of 1.7 million patients to compare the predictive utility of these scales for identification of patients with severe traumatic injury.
  • The total GCS was slightly better than the mGCS or SMS on predicting mortality, neurosurgical intervention, severe traumatic brain injury, and emergent intubation.

Bottom Line:  The motor GCS and Simplified Motor Scale (SMS) have similar discrimination when compared with the total GCS, and may be easier to use.

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Category: Neurology

Title: Stroke and Pregnancy: What's Different?

Keywords: CT, MRI, tPA, peripartum, PRES (PubMed Search)

Posted: 3/22/2017 by Danya Khoujah, MBBS (Updated: 11/1/2024)
Click here to contact Danya Khoujah, MBBS

  • The incidence of stroke (both ischemic and hemorrhagic) in pregnant and peripartum women is three times age-matched controls. This increased risk is mostly in the 3rd trimester and up to 16 weeks postpartum. 
  • Consider other causes of stroke:  posterior reversible encephalopathy syndrome (PRES), reversible cerebral vasoconstriction syndrome, cerebral venous sinus thrombosis and cardioembolic stroke from peripartum cardiomyopathy.
  • CTs carry some risk due to the ionizing radiation, but with abdominal and pelvic shielding the exposure to the fetus is very low. MRIs do not carry that risk, but Gadolinium is absolutely contraindicated in pregnancy as it deposits in fetal tissue. 
  • Pregnancy is a relative (not absolute) contraindication for tPA.

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Category: Neurology

Title: IV Fluids for Headache?

Keywords: headache, migraine, intravenous fluids, IVF (PubMed Search)

Posted: 3/8/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 
IV Fluids for Headache?
  • Headache is the 4th most common ED visit in the US.
  • Clinical experience suggests that IV fluids (IVF) are commonly used as adjunctive treatment for headaches, however, the efficacy is unknown.
  • A retrospective study using the National Hospital Ambulatory Medical Care Survey (NHAMCS) found that ED length of stay was significantly greater in patients who received IVF than in those who did not (202 min vs. 131 min, p<0.001) even after adjusting for initial pain score, sex, age, and mode of arrival. 
  • A post-hoc analysis of data collected from 4 ED-based migraine trials found that IVF was not associated with improvement of pain score or sustained headache freedom.
  • There is no current evidence to suggest a direct analgesic effect of IVF in the treatment of headaches.

 

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Category: Neurology

Title: Strokes in Young Adults

Keywords: stroke, alcohol, substance abuse, mimics (PubMed Search)

Posted: 2/22/2017 by Danya Khoujah, MBBS (Updated: 11/1/2024)
Click here to contact Danya Khoujah, MBBS

  • 15% of all cases of ischemic strokes occur in patients less than 45 years old.
  • To put things into perspective, incidence of stroke in this age group is twice that of multiple sclerosis.
  • Delayed diagnosis is due to several factors:
    • The relative rarity of the diagnosis in comparison to stroke mimics at this age, the 3 most common being: migraines, seizures, and Bell's palsy. 
    • Atypical presentations, such as acute vestibular syndrome. 
    • Although “typical" risk factors (such as smoking, diabetes and hypertension) are present in young patients with strokes, other factors to be considered are high-risk alcohol consumption, cocaine use (especially smoked), physical inactivity, sleep 6 hours or less a night, and known thrombophilia. 

 

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Category: Neurology

Title: Back to the Basics: Aphasia

Keywords: aphasia, fluency, comprehension, repetition, Broca's aphasia, Wernicke's aphasia, conduction aphasia (PubMed Search)

Posted: 2/8/2017 by WanTsu Wendy Chang, MD
Click here to contact WanTsu Wendy Chang, MD

 
Back to the Basics: Aphasia
  • Aphasia is an impairment of language
  • 3 important assessments in an aphasic patient are fluencycomprehension, and repetition (see attached figure)
  • Patients with fluent speech are able to generate speech spontaneously, though the content of their speech may have errors
  • Patients with non-fluent speech have difficulty initiating speech
  • Patients who have fluent speech but are unable to repeat have a problem with comprehension or a disconnect between the sensory and motor components of language
    • In Wernicke’s aphasia, patients cannot comprehend what they read and hear 
    • In conduction aphasia, patients can comprehend what they read and hear

 

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Attachments

1702082322_20170208_Figure.jpg (84 Kb)