Neurology Pearls

  1. Where do lacunar infarcts commonly occur and is the prognosis good or bad?
    They affect the deep penetrating vessels of the middle cerebral artery and carry the best prognosis of all strokes.
  2. There are 4 classic syndromes characteristically caused by lacunar infarcts, with which the emergency physician should be familiar and able to recognize. They are:
    • 1. Pure motor hemiparesis.
    • 2. Pure sensory syndrome.
    • 3. Ataxic hemiparesis (ipsilateral cerebellar and motor symptoms).
    • 4. Clumsy hand dysarthria syndrome (ipsilateral hand weakness, patient may say their hand "feels awkward," dysarthria more pronounced than the weakness).
  3. You are evaluating a patient with the sudden onset of a severe headache and order a CT scan of the head. The radiologist's report makes note of the presence of a delta sign. What is the significance?
    The "delta sign" is the classic CT finding of cerebral venous thrombosis - a dense triangle within the superior sagittal sinus that is created by thrombosis within the sinus (JEM, Vol. 36, pg. 132-137).
  4. Migraine with Aura Diagnostic Criteria
    • Migraine with aura (MA) diagnostic criteria
    • A. At least two attacks with at least 3 of the following:1. One or more fully reversible aura symptoms (indicates focal cerebral cortical and/or brain stem functions).2. At least 1 aura symptom develops gradually over greater than 4 minutes, or 2 or more symptoms occur in succession.3. No aura symptom lasts greater than 60 minutes.4. Headache follows aura with free interval of at least 60 minutes.

    B. At least 1 of the following aura features establishes a diagnosis of migraine with typical aura:1. Homonymous visual disturbance.2. Unilateral paresthesias and/or numbness.3. Unilateral weakness.4. Aphasia or speech difficulty.

    ReferencesInternational Headache Society Diagnostic Criteria for Headaches
  5. It is sometimes stated that a single acute administration of glucose can precipitate Wernicke's encephalopathy. Is this true?
    Wernicke's encephalopathy can occur with prolonged glucose or carbohydrate loading in the absence of thiamine. However, a single acute administration of glucose does not appear to cause this effect (Ann of EM, Vol. 50, pg. 715).
  6. Information about cervicogenic headaches:
    Cervicogenic headaches are a syndrome of chronic, hemicranial pain that is referred to the head from bony structures or soft tissue of the neck.

    Adequate treatment of these headaches is often difficult to achieve, particularly from the emergency department, as a multi-faceted approachincluding pharmacologic, physical, anesthetic nerve block, psychological and sometimes surgical therapy, is often required.

    The emergency physician may prescribe simple agents such as acetaminophen and ibuprofen, with or without muscle relaxants to treat cervicogenic headaches.

    When close follow up is ensured, low doses of tricyclic anti-depressants or anti-epileptics such as gabapentin, divalproex sodium, carbamazepine, and topiramate may be utilized; while these are not FDA approved for the treatment of cervicogenic headaches, they have been shown to be effective for some headache types and neurogenic pain syndromes.

    ReferencesBiondi, DM. Cervicogenic Headaches: A Review of Diagnostic and Treatment Strategies. JAOA. Volume 105. No. 4. Suppl; 16-22. April 2005.
  7. Treatment of Dural Sinus Thrombosis
    Treatment of Cerebral Venous and Sinus ThrombosisThrombosis of the cerebral venous system, also known as cerebral venous and sinus thrombosis and dural sinus thrombosis, is an uncommon condition encountered in the emergency department.

    The diagnosis may be stumbled upon by various CT findings or by MRI and/or a high opening pressure on lumbar puncture.

    The treatment of choice is full dose anticoagulation with heparin. Available studies looked at unfractionated heparin, but many experts now consider LMWH (like Lovenox) an acceptable alternative.

    Despite the risk of hemorrhagic transformation of a venous infarct, heparin therapy is considered the standard treatment for this condition.

    ReferencesCouthino JM, et al. How to treat cerebral venous and sinus thrombosis. J Thromb Haemost 2010;8:877-83
  8. Guillain-Barre syndrome is a known complication of Campylobacter jejuni infection, a common cause of enteritis. How does Guillain-Barre occur as a result of Campylobacter infection?
    Most cases occur as a result of molecular mimicry, with antibodies directed to campylobacter lipooligosaccharides and peripheral nerve gangiliosides (NEJM, Vol.362 , pg. 1567).
  9. Definition of Cluster Headaches:
    Cluster headaches are defined as a group of at least five headache attacks causing unilateral orbital, supraorbital and/or temporal pain, with at least one of the following simultaneous associated findings on the affected side:

    • conjunctival injection
    • lacrimation
    • nasal congestion
    • rhinorrhea
    • ptosis
    • miosis
    • sweating on the forehead

    Cluster headaches can occur at a frequency of one every other day to eight episodes per day.
  10. What percent of transient ischemic attack patients who present to the ED will have a stroke within 90 days? Of these strokes, how many will occur within 2 days?
    10.5% of TIA patients who present to the ED will have a stroke within 90 days.

    Of these strokes, half will occur within 2 days, 64% will be disabling, and 5% of patients will die or have a major adverse cardiac event (Annals of EM, Vol. 50, pg. 109).
  11. Guillain-Barré syndrome has become regarded as a spectrum of immune-mediated acute neuropathies. When does the classic ascending paralysis and areflexia peak after onset?
    The classic acute inflammatory demyelinating polyradiculoneuropathy presenting as ascending paralysis and areflexia peak within 4 weeks

    (JEM, In Press, Online 7/16/10).
  12. What is the significance of the finding of loss of gray-white differentiation on noncontrast CT of the head?
    It is a significant early sign of cerebral ischemia, occurring within the first few hours after symptom onset, because there is an increase in the relative water concentration of ischemic tissues

    (Circulation, Vol. ;40:3646).
  13. Idiopathic Intracranial Hypertension, previously known as pseudotumor cerebri, can be treated with medications such as carbonic anhydrase inhibitors (i.e. acetazolamide), corticosteroids, indomethicin, loop diuretics, and analgesics used to treat migraine headaches. While removing excess cerebrospinal fluid (CSF) via lumbar puncture (LP) is sometimes considered to be an appropriate therapeutic intervention for IIH in the emergency department, it is generally not recommended for the following reasons:
    • 1. CSF reforms within 6 hours, making its removal short-term, unless there is a CSF leak.
    • 2. LP can be challenging in obese patients and uncomfortable for patients, in general.

    3. LP complications such as low pressure headaches, CSF leak, CSF infection, and intraspinal epidermoid tumors.
  14. Bell's palsy rarely recurs. Recurrent or bilateral facial palsy should prompt consideration of what diagnoses?
    • Recurrent or bilateral facial palsy should prompt consideration of myasthenia gravis or lesions where the facial nerve exits the pons; such types of palsy occur in lymphoma, sarcoidosis, and Lyme disease
    • (NEJM, Vol. 351, pg. 1323).
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Neurology Pearls
Neurology Pearls