UMEM Educational Pearls

Today's joint conference with the UMMS' Neurology Department was quite beneficial and applicable to our daily practice in the Emergency Department (ED).

The topics discussed included:

• Third Nerve Palsy (aneurysmal versus vasculopathic)
• Painful Post-ganglionic Horner's Syndrome
• Cluster Headache
• Carotid Dissection
• Pituitary Apolplexy

While the information provided for each of these clinical topics was comprehensive, be sure to review these disorders in the near future, in order to commit them to memory and increase your comfort level with diagnosing and treating them in the ED.  If you'd like a copy of the handouts, just let me know.

Today's pearl will highlight pituitary apoplexy.

Take Home Points about Pituitary Apoplexy:

• Defined as hemorrhage or infarction of a pituitary tumor.
• Neurologic emergency that can be fatal, usually due to hemorrhage.
• Typically presents with acute onset of headache +/- meningeal irritation, altered mental status,  photophobia, and  ophthalmoplegia (usually 3rd cranial nerve palsy, followed by 6th and 4th cranial nerve dyfunction).
• CT head (dry) may appear normal.  MRI typically makes the diagnosis.
• Ophthalmoplegia (of 3rd CN) + CSF with significant red cells may prompt an angiogram in search of a PCOM (posterior communicating artery) aneurysm, when an MRI is acutally all that's needed.
• Treatment:  high dose steroids (hydrocortisone 100 mg IV q 6-8 h) +/- decompressive surgery via Neurosurgery.

 

• Fever in the setting of acute ischemic stroke is associated with increased mortality and morbidity.

• These effects are possibly due to increased metabolic demands, neurotransmitter release, and free radical production.

• Use of antipyretics to achieve normothermia may improve outcome.

• Studies have shown that hypothermia is neuroprotective.

• Look for a potential source of fever, which may have caused or prompted the stroke (i.e. infective endocarditis, complications of pneumonia).

 

Adams, et al.  Guidelines for the Early Management of Adults with Ischemic Stroke.  AHA/ASA Guidelines.  2007.

 

• Apraxia = Inability to carry out physical acts despite intact motor function.

• Agnosia = Inability to recognize and identify objects and/or sounds despite intact sensory function.

 

What should I do about this finding on the MRI I ordered

Now tha ta lot of EDs are getting MRIs on a more urgent basis, we will need to know what to do with the resutls.  However, the natural history of findings on MRI has not been well studied, so what should we do with that small meningioma you find.  Well some researchers in the Netherlands have attempted to address your question. In a population-based study [Rotterdam Study] , 2000 adults aged 45 or older underwent a brain MRI.

Some of the common findngs were:

• Asymptomatic brain infarcts were observed in 7%.
• Aneurysms and benign tumors (mostly meningiomas) were each found in nearly 2%.
• The two most urgent findings were a chronic subdural hematoma and a 12-mm aneurysm. Both required surgey.
• Only two out of the 2000 (0.001%) people had symptoms related to their MRI findings (hearing loss in both).
• The prevalence of asymptomatic brain infarcts and meningiomas increased with age, as did the volume of white-matter lesions, whereas aneurysms showed no age-related increase in prevalence.

Most of the study patients were white and middle class so these results may not be generalized to the general public.  I am sure more studies are in the works, but for now don't be two suprised if you find an asympomatic infarct or meningioma.

Vernooji MW, Ikram MA, Tanghe HL. Incidental Findings on Brain MRI in the General Population. NEJM. 2007;357(18):1821-1828.

• Xanthochromia is the result of metabolized hemoglobin in cerebrospinal fluid (CSF), which suggests intracranial bleed.
• It helps differentiate traumatic lumbar puncture results from true intracranial bleeding.
• It causes the CSF to have a yellowish color which can be detected with the naked eye or analyzed with a machine (done visually at UMMS).
• It typically takes at least 6 hours for xanthochromia to manifest itself. 

 

Don't forget to do  thorough assessment of deep tendon reflexes on physical examination when appropriate.  DTR assessment can help localize a lesion and determine a diagnosis (i.e. thyroid disease, Guillain Barre, spinal cord and peripheral nerve lesions).

DTR Assessment Scale:

• 4+ - very brisk, hyperactive with clonus<
• 3+ - brisker than normal
• 2+ - average, normal
• 1+ - somewhat diminished, low normal
• 0 - no response

Major DTR Assessment Locations:

• Triceps (C6, C7)
• Supinator or Brachioradialis (C5, C6)
• Knee (L2, L3, L4)
• Ankle (mainly S1)
• Plantar (L5, S1)

• The most common (80%) cause of non-traumatic subarachnoid hemorrhage (SAH) = ruptured saccular (berry) aneurysm.
• Saccular aneuryms are thought to be present in up to 5% of the population.
• There is a strong familial association with cerebral aneurysms, and prevalence is increased in people with Marfan Syndrome and Polycystic Kidney Disease.
• Other causes of non-traumatic SAH include:  AV malformation, cavernous angioma, mycotic aneurysm, and blood dyscrasia. 

Horner's Syndrome Deficit in descending sympathetic pathways Miosis + Ptosis + Anhidrosis Associated with lateral medullary infarctions, which are caused by disrupted flow to the posterior inferior cerebral artery (PCA) (i.e. Wallenberg Syndrome)

Common causes of stroke in young patients: --> Arterial dissection (most commonly involving the carotids, often trauma related) --> Cardioembolic events (most commonly via a patent foramen ovale (PFO) associated with an atrial septal aneurysm; also atrial septal anuerysms and myxomatous mitral valve prolapse; most common amongst our patient population is likely endocarditis) --> Large vessel disease (typically in 5th decade of life) --> Small vessel disease (typically in 5th decade of life) --> Coagulopathies (i.e. Sickle cell anemia) --> Vasculopathies/Vasculitis Cerrato, et al. "Stroke in young patients: Etiopathogenesis and risk factors in different age classes." Cerebrovascular Diseases 2004;18:154-159.

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.

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.

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.

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.

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.

-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

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.

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.

*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.

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

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.