UMEM Educational Pearls - Neurology

Category: Neurology

Title: Acute MCA Infarcts

Keywords: infarct, stroke, MCA (PubMed Search)

Posted: 9/20/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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The majority of large cerebral artery infarcts take place in the Middle Cerebral Artery (MCA) because it supplies the largest territory. The MCA supplies most of the temperol, anterolateral frontal lobe, and parietal lobes. Perforating branches supply the posterior limb of the internal capsule and the head and body of the caudate and globus pallidus. Clinical findings can include: ipsilateral facial, upper, and lower extremity deficit/weakness (arm > leg); dysarthria; dysphagia; global aphasia if lesion on left (i.e. dominant hemisphere); neglect.

Category: Neurology

Title: Post-Dural Puncture Headache

Keywords: Lumbar Puncture, Lumbar Puncture headache, headache, dural puncture (PubMed Search)

Posted: 9/12/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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Post-dural Puncture Headache (PDPH) PDPH = typically occurs within 3 days after a lumbar puncture (LP), improves when supine, worsens when upright and by any movement that increases intracranial pressure (i.e. sneezing, coughing), most subside within 24 hours. The pain typically distributes to the frontal-occipital region and is usually throbbing or dull. The incidence of PDPH after an ED LP ranges from 5% to 10%. While optimal operator experience, minimizing the amount of CSF removed, and having the patient lie in the recumbent position for at least 30 minutes after the procedure have all traditionally been associated with decreasing the risk of PDPH, only minimizing the bore size of the needle used has consistently been proven to decrease the risk. Treatment options: 1) Opiates, IV fluids, anti-emetics. 2) Caffeine 500 mg in 1 L of NS, IV over 1 hour (80 - 90% effective). 3) Cosyntropin (ACTH analog) 0.25 - 0.75 mg IV (~ 56% success rate). 4) Epidural blood patch, epidural fibrin glue, epidural crystalloid/colloid infusion, caudal saline infusion. Younggren, Merchant. "Post-Dural Puncture Headache." ACEP News, 26:8.

Category: Neurology

Title: Transient Global Amnesia

Keywords: amnesia, TIA, memory (PubMed Search)

Posted: 9/5/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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Transient Global Amnesia (TGA) is a rare (5 to 11 cases per 100,000 persons per year), but clinically well-defined disorder defined as an acute episode of short-term memory loss, in the absence of any neurologic signs or symptoms, which resolves within 24 hours. TGA is typically triggered by an event such as valsalva, exercise, emotional stress, sexual intercourse, immersion in cold water, painful stimuli, and severe exertion. While there are widely used diagnostic criteria, TGA is primarily a clinical diagnosis and one of exclusion. While TGA is benign, self-limiting, and there is no specific treatment other than reassurance, it is important to recognize and differentiate TGA from TIA, which has different prognostic implications. Agrawal, et al. "Transient Global Amnesia: An Uncommon Differential Diagnosis of Transient Ischemic Attack." Hospital Physician 43:8.

Category: Neurology

Title: Cheyne Stokes Respirations

Keywords: Cheyne Stokes, stroke, increased intracranial pressure (PubMed Search)

Posted: 8/29/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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Cheyne-Stokes (CS) respirations, also known as "periodic breathing," results from the inability of the respiratory center of the brain, the brain stem (i.e. pons and medulla oblongata), to rapidly compensate for changing serum partial pressure of oxygen and carbon dioxide. CS is characterized by respirations of gradually increasing and decreasing tidal volumes, with interspersed periods of apnea. Conditions associated with CS: - Increased ICP (i.e. space occupying brain lesions such as hemorrhage and tumors) - Congestive heart failure - Altitude sickness - Toxic-metabolic encephalopathy - Carbon monoxide poisoning - High-dose morphine administration CS was first described by physicians John Cheyne and William Stokes. Wikipedia Encyclopedia. The Diagnosis of Stupor and Coma by Plum and Posner.

Category: Neurology

Title: Cushings Reflex and Triad

Keywords: increased intracranial pressure, cushings triad, cushings reflex, intracranial hemorrhage (PubMed Search)

Posted: 8/22/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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Cushings reflex = a hypothalamic response to brain ischemia wherein the sympathetic nervous system is activated which causes increased peripheral vascular resistance with a subsequent increase in BP. The increased BP then activates the parasympathetic nervous system via carotid artery baroreceptors, resulting in vagal-induced bradycardia. The brain ischemia that leads to cushings reflex is usually due to the poor perfusion that results from increased ICP due to head bleeds or mass lesions. Cushings reflex leads to the clinical manifestation of Cushings triad. Cushings triad = hypertension, bradycardia, and irregular respirations (Cheyne-Stokes breathing). Some sources describe widened pulse pressure (increasing difference between systolic and diastolic BP) as the 3rd component of the triad, rather than irregular respirations. Cushings triad signals impending danger of brain herniation, and thus, the need for decompression. Consider administering mannitol, hyperventilation, and elevation of the head of bed as temporizing measures. Cushings triad was first described in 1902 by Harvey Williams Cushing, an American neurosurgeon. -Physiology, 2nd Edition, Saunders, 2002, page 150. -Ayling, J (2002). "Managing head injuries". Emergency Medical Services31 (8): 42.

Category: Neurology

Title: Coagulation Disorders Causing Ischemic Stroke

Keywords: coagulopathy, stroke (PubMed Search)

Posted: 8/15/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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-polycythemia rubra vera -sickle cell disease -essential thrombocytosis - TTP - Heparin-induced thrombocytopenia -Antithrombin III deficiency - Protein C or S deficiency - Factors V, VII, XII, or XIII deficiency -heparin cofactor II deficiency - dysfibrinogenemias -antiphospholipid/anticardiolipin antibodies -nephrotic syndrome -malignancy -pregnancy -oral contraceptives -dehydration

Category: Neurology

Title: TIA

Keywords: TIA, stroke (PubMed Search)

Posted: 8/8/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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While TIA has historically been defined as lasting less than 24 hours, recent data clearly demonstrates that ischemic attack lasting longer than one hour is often associated with actual brain infarction. Most TIA's last less than 5 minutes. Evidence of acute infarction can be identified by MRI in up to 50% of patients who meet the 24 hour criteria for TIA. Diffusion MRI in patients with transient ischemic attacks. Kidwell CS; Alger JR; Di Salle F; Starkman S; Villablanca P; Bentson J; Saver JL. Stroke 1999, Jun;30(6):1174-80. Transient ischemic attack--proposal for a new definition. Albers GW; Caplan LR; Easton JD; Fayad PB; Mohr JP; Saver JL; Sherman DG. New England Journal of Medicine 2002, Nov 21;347(21):1713-6.

Category: Neurology

Title: Stroke Mimics

Keywords: stroke, stroke mimics, complex migraine (PubMed Search)

Posted: 8/1/2007 by Aisha Liferidge, MD (Updated: 8/17/2022)
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One study found that the top 4 stroke mimics confused for a true stroke are: 1) Unrecognized seizure with post-ictal phase 2) Systemic infections 3) Brain tumor 4) Metabolic disturbances Complex migraine, specifically hemiplegic migraine, is also a common stroke mimic. This diagnosis is especially difficult to make on initial presentation and should be a diagnosis of exclusion. The hemiparesis associated with the migraine can actually outlast the actual headache. Libman RB, Wirkowski E, Alvir J, Rao TH. Conditions that mimic stroke in the emergency department. Implications for acute stroke trials. Archives of Neurology. 1995;52:1119-1122.

Category: Neurology

Title: Migraine Headaches

Posted: 7/29/2007 by Michael Bond, MD (Emailed: 7/30/2007) (Updated: 8/17/2022)
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*Hormone-related migraine headaches are largely related to changes in levels of estrone glucuronide (EIG). *Studies have shown that in addition to an increase in symptoms for female migraneurs during the menstrual phase (during first 3 days of menses), there are also 3 distinct midcyle (around day 14) phases during which migraines are most prevalent. They are: 1) Late follicular phase (LF) (rapid rise in estrodiol level) 2) Early follicular 1 phase (rapid drop in estrodiol level) 3) Early follicular 2 phase (rapid rise in progesterone level) American Headache Society 49th Annual Scientific Meeting: Abstract 150. June 7-10, 2007.

Category: Neurology

Title: Stroke

Keywords: Stroke, Carotid Artery Lesion, CVA (PubMed Search)

Posted: 7/29/2007 by Michael Bond, MD (Emailed: 7/30/2007) (Updated: 8/17/2022)
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Learn the Lingo for Stroke Manangement: Patients with acute stroke due to a carotid artery thrombotic lesion that then embolizes to a cerebrovascular artery, have two problems that can be addressed with one coordinated intervention. * "Triple Play" = (1) Carotid artery lesion stenting followed by (2) retrieval of the embolic clot from the cerebrovascular artery via the Merci device followed by (3) intra-arterial tPA (the latter prevents complications that could result from removal of embolic clot). * "Double Play" = (1) Retrieval of the clot from the cerebrovascular artery via the Merci device followed by (2) intra-arterial tPA. Merci Device information: http://www.concentric-medical.com/products_retrieval.html

Category: Neurology

Title: Migraine Headache Diagnosis

Keywords: Migraine, Headache, Diagnostic Criteria (PubMed Search)

Posted: 7/29/2007 by Michael Bond, MD (Emailed: 7/30/2007) (Updated: 8/17/2022)
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Diagnostic Criteria for Migraine Headaches: * Migraine w/o aura- A. At least five headache attacks lasting 4 - 72 hours, with at least two of the four following characteristics: 1. Unilateral location. 2. Pulsating quality. 3. Moderate or severe intensity (inhibits or prohibits dailyactivities). 4. Aggravated by walking stairs or similar routine physical activity. B. During headache, at least one of the two following symptoms occur: 1. Phonophobia and photophobia. 2. Nausea and/or vomiting. * Migraine w/ aura (remember: aura is not always visual) - A. At least two attacks with at least three of the following: 1. One or more fully reversible aura symptoms indicating focal cerebralcortical and/or brain stem functions. 2. At least one aura symptom develops gradually over more than four minutes,or two or more symptoms occur insuccession. 3. No aura symptom lasts more than 60 minutes; if more than one aura symptomis present, accepted duration is proportionally increased. 4. Headache follows aura with free interval of at least 60 minutes (it mayalso simultaneously begin with the aura). B. At least one of the following aura features establishes a diagnosis ofmigraine with typical aura: 1. Homonymous visual disturbance. 2. Unilateral paresthesias and/or numbness. 3. Unilateral weakness. 4. Aphasia or unclassifiable speech difficulty. Headache 44(5):426-435, 2004. Headache classification committee of the IHS. Classification and diagnostic criteria for headache disorders, cranial neuralgias and facial pain. Cephalalgia 1988 8: 1-96.

Category: Neurology

Title: Phantoms in EMS

Keywords: Stroke, EMS, prehospital care, tPA, emergency medical services, fibrinolysis (PubMed Search)

Posted: 5/15/2014 by Ben Lawner, DO (Emailed: 8/17/2022) (Updated: 7/3/2014)
Click here to contact Ben Lawner, DO

The Prehospital Acute Neurological Treatment and Optimization of Medical Care in Stroke Study (PHANTOM-S) was a randomized prehospital  clinical trial. On certain days, a dedicated Stroke Emergency Mobile (STEMO) responded to possible ischemic stroke incidents. Outcomes measured included time to thrombolysis and adverse events such as intracerebral hemorrhage. As opposed to usual prehospital care, a STEMO ambulance was equipped with a CT scanner, point of care laboratory, and a neurologist. According to the study, STEMO use resulted in reduced time to treatment (tPA) without adverse events. 

Though this trial did not specifically measure clinical endpoints, it addresses issues central to the delivery of specialized prehospital care:

1) Are there certain conditions which might warrant a tailored, super-specialized EMS response?
2) Are EMS systems capable of delivering definitive care to the patient as opposed to delivering the patient to definitive care? 

Stateside study has already started.  The Houston Fire Department, in partnership with UTHeath, has already loosed a "Mobile Stroke Unit" on the streets. Like the STEMO, the specialized ambulance will be University hospital based, carry a neurologist, and have the capability to administer tPA. 

STEMO pictures courtesy of the "NeuroEMS Blog"
http://www.neuroems.com/2014/05/14/tpa-in-the-truck-results-of-the-phantom-s-trial/

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