UMEM Educational Pearls - Neurology

• About 15% of strokes are preceded by TIA.
• Within 90 days after a TIA, 10.5% will suffer a stroke.
• Of these, 21% will be fatal, 64% will be disabling, and half will occur within 1 to 2 days of the patient's emergency department visit.

• Multiple Sclerosis (MS) is a relapsing condition caused by the destruction of myelin sheaths.
• Ninety percent of MS-related lesions can be detected on T2 MRI images.
• These lesions are typically para-ventricular, sometimes ovoid in shape (referred to as "Dawson's Fingers"), and often located on medullary veins.

• Calcium channel blockers, such as nicardipine, play an important role in treating arterial hypertension and cerebral vasospasm, both of which are associated with intracranial hematoma and increased intracranial hypertension.

• Many consider nicardipine to be an excellent choice for treating an acute hypertensive emergency in the setting of intracranial hemorrhage.

• Dosing should start at an infusion of 5 mg/hr.  Titrate by 2.5 mg/hr every 5 to 15 minutes to desired effect, up to a maximum dose of 15 mg/hr. 

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Once you've punctured the spinal canal space during lumbar puncture, the following tips can be used to improve the rate of cerebrospinal fluid (CSF) flow, should it be suboptimal:

1. Ask the patient to cough or bear down as in the Valsalva maneuver.
2. Ask an assistant to intermittently press on patient's abdomen.
3. Turn the spinal needle 90 degrees such that the bevel is cephalad.
4. Use a larger diameter spinal needle (increases risk of post-lumbar puncture headache).

• Acute optic neuritis (ON) must be considered in any patient presenting with vision loss, especially if unilateral and associated with discomfort on eye movement.

• ON is a finding often (50%) associated with Multiple Sclerosis (MS), with or without other classic MS abnormalities such as transverse myelitis, internuclear ophthalmoplegia, and paresthesias. 

• A normal fundoscopic examination does not rule out ON, as 50% of acute cases affect the retrobulbar space.

• Positive pertinent clinical findings may include an afferent pupillary defect in the affected eye and/or visual acuity abnormality, ranging from subtle deficit to total blindness. 

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• There are over 6 million stroke survivors in the United States, many of whom participate in helpful support groups, along with their loved ones and caregivers.

• Stroke recovery is often a lifelong journey.

• Prognosis and outcomes significantly improve with early, stroke rehabilitation at stroke-focused units.

• Stroke rehabilitation consists of several areas of focus such as physical, occupational, and visual therapies.

Stroke strikes F.A.S.T. and must be recognized quickly for optimized management.

The following Face, Arms, Speech test, known as F.A.S.T., is an easy and quick bedside teaching tool that can be used to spread awareness about how to recognize and respond to stroke symptoms:

F = Ask person to smile. Does one side of face droop down?

A = Ask person to raise both arms. Does one arm drift downward?

S = Ask person to say a simple phrase. Does speech sound slurred or strange?

T = If any of the above findings are observed, it's time to call 911 immediately.

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• May is Stroke Awareness Month;  Health care provider and patient education about how to prevent stroke is at least as important as treating it with cutting-edge therapies.
• Studies have shown that up to 80% of strokes could be prevented through recognition and management of risk factors, lifestyle changes, and compliance with recurrent stroke prevention treatments.
• Even in the emergency department, the opportunity to educate patients about the following stroke risk factors should be seized when possible:

              --  Hypertension                        

              --  Diabetes

              --  Atrial Fibrillation

              --  Hypercholesterolemia

              --  Physical Inactivity

              --  Tobacco Use

              --  Alcohol Use

              --  Obesity

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• May is National Stroke Awareness Month.  It is an important opportunity to foster education of the public and health care providers, which is a key component of stroke management.  Awareness hastens recognition and optimized management.

• Clinicians can take part in public health initiatives by educating patients about the following signs and symptoms of acute stroke:

              1.  Walk; Is their balance off?
              2.  Talk; Is their speech slurred or face droopy?
              3.  Reach; Is one side weak or numb?
              4.  See; Is their vision all or partly lost?
              5.  Feel; Is their headache severe?

• This month, public education campaigns, through mechanisms such as billboard and mass transit advertisement, will be heightened, and can be used as additional tools for patient education.

• The terms pseudotumor cerebri, benign intracranial hypertension, and idiopathic intracranial hypertension (IIH), are all synonymous terms which describe a condition of elevated intracranial pressure (ICP), but the latter is the preferred term of use.
• IIH almost ubiquitously presents with a generalized headache and papilledema (i.e. fundoscopic examination imperative!).  Visual disturbance and non-specific symptoms such as dizziness may also be present.
• Elevated ICP and papilledema are clinical emergencies until the presence or absence of an intracranial mass is confirmed. 
• The following conditions must be met in order to diagnose IIH:

1. Non-focal neurologic examination (except for 6th nerve palsy in some cases)
2. Elevated opening pressure on lumbar puncture, > 20 to 25 mmH2O (perform only after risk for herniation assessed!)
3. Normal cytologic and chemical cerebrospinal fluid analysis
4. Small, symmetric brain ventricles on neuroimaging
5. Exclusion of other sources of IH such as venous sinus thromboses by obtaining an MRI/venographic study of the head

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• The Brachial Plexus is a bundle of nerve roots arising from C5, C6, C7, C8, and T1.
• Brachial plexus injuries (BPI) result from severe traction forces on the limb.
• The most common sources of BPI are motorcycle accidents and birth palsy (i.e. Erb or Duchenne Palsy) affecting the upper part of the plexus (C5, C6) and causing shoulder and biceps muscle weakness.
• Injury to C7 >>> wrist weakness.
• Injury to C8 and T1 >>>  forearm and intrinsic hand muscle weakness.
• Injury to stellate ganglion or cervical sympathetic trunk >>> Horner's Syndrome.
• MRI of the upper extremity is the standard imaging modality used to make the diagnosis.

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• Bitemporal hemianopsia ("tunnel vision") is a type partial blindness affecting the lateral halves of vision in both eyes (see attached diagram), and is usually associated with lesions or compression of the optic chiasm.
• Always assess visual fields in patients presenting with neurologic complaints, particularly when associated with visual abnormality, headache, focal deficit, and endocrine-related symptoms.
• One of the simplest ways of assessing visual fields is to (1) stand directly in front of the patient, (2) instruct them to stare straight at your nose, (3) laterally extend both your arms to 2/3 of full capacity (i.e. elbows slightly bent), and (4) ask them where they see your wiggling fingers (i.e. left or right).  
• Bitemporal hemianopsia commonly results from pituitary microadenomas (< 1 cm) and macroadenomas (> 1 cm), which are sometimes associated with acromegaly and Cushing's Disease.

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• Nonspecific brain atrophy is a common finding on Head CT's, sometimes without any clearly articulated clinical significance for the emergency physician.
• Generally speaking, brain atrophy is the manifestation of the effects of atherosclerosis.
• Radiographically, it typically presents as widened sulci and dilated ventricles.
• In patients with vague mental status abnormalities and limited access to medical history, consider the following brain atrophy clues in your management:

              --  Multiple areas of local cortical brain atrophy (wedge-shaped

                   appearance) suggests multi-infarct dementia.

              --  Disproportionate atrophy in the frontal and temporal lobes may be a 

                   sign of Alzheimer's Disease.

• The thalamus is a major relay center of the brain locaed between the cerebral cortex and the midbrain.
• It regulates motor and sensory function as well as sleeping and waking states. 
• It is supplied by 4 arterial systems (3 from the vertebrobasilar system; 1 from the posterior communicating system) such that strokes within these territories result in 4 distinct clinical syndromes, including syndromes consisting of pure sensory, arousal, and memory deficits.
• Thalamic strokes are thought to be more common in young people, associated with smoking and hypertension, and of poorer prognosis when presented with loss of consciousness.

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• Etiologic causes of hearing loss can be categorized into three groups:  (1) Sensorineural, (2) Conductive, and (3) Sensorineural and Conducitve.
• Sensorineural hearing loss results from problems with the vestibulocochlear nerve (cranial nerve VIII), inner ear, or central processing centers of the brain.
• When performing the Weber Test on patients with sensorineural hearing loss (tuning fork touched to midline of skull), sound localizes to the normal ear (i.e. sound conducts normally through bone, which measures sensorineural function, on the side without the abnormality).
• Examples of conditions that cause sensorineural hearing loss include:  Acoustic neuroma and other cerebellopontine angle tumors, perilymph fistula, noise trauma, and ototoxic medications.     

• The majority of epilepsies (60%) are partial-onset or focal, such that a single, isolated part of the body is affected.
• Seizures arising from the temporal lobe of the brain are the most common type of partial-onset epilepsy and have been associated with childhood febrile seizures.
• Simple temporal lobe seizures, which do not result in a loss of consciousness, typically present as a sensation such as: 

              -- Deja' vu (feeling of familiarity)     -- Jamais vu (feeling of unfamiliarity)

              -- Specific or single set of memories     --  Amnesia

             -- Auditory        --  Gustatory       --  Visual       --  Disphoric     -- Euphoric 

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•  Focal seizures, such as those due to frontal lobe epilepsy (FLE), are not always easy to recognize and may be erroneously attributed to peripheral or psychiatric sources.
• FLE seizures may present as abnormal body posturing, sensorimotor tics, and/or other abnormal motor skills, and rarely may be associated with uncontrollable laughing and/or crying.
• Post-seizure confusion >may occur, but typically does not last as long as the post-ictal states associated with other types of epilepsy.

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• Frontal Lobe Epilepsy (FLE) is characterized by recurrent, brief, focal seizures arising from the frontal lobe of the brain, often occuring during sleep.
• FLE is the second most common form of epilepsy, behind Temporal Lobe Epilepsy (TLE).
• FLE presents in 2 forms:  (1) simple partial (focal) seizures (no affect on awareness or memory), or (2) complex partial (focal) seizures (affects awareness and memory before, during, and/or after the seizure).
• FLE seizures are often misdiagnosed as psychiatric disorders, non-epileptic convulsions, or sleep disorders, due to the unusual symptoms that they often produce.

• The 7-day risk of completed ischemic stroke after TIA is 5%.
• The use of reliable stroke prediction tools are potentially invaluable in guiding the degree of urgency that one applies to the management of TIA patients.
• Accuracy of the ABCD² Score, considered to be the most-refined tool of its kind, was recently again evaluated.
• This 7-point scale assigns risk based on 5 factors: Age > 60 (1 pt.), BP > = 140/90 (1 pt), Clinical features - weakness (2 pts), speech impairment w/o weakness (1 pt); Duration  >=60 min (2 pts), 59 to 10 min (1 pt); Diabetes (1 pt).
• The study found that the discriminatory power of the ABCD² Score may best be applied when used in patients at low risk for an early, disabling ischemic stroke.     

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• For many years the recommendations for managing new-onset seizure (NOS) in the emergency department did not include any specific instruction for such patients with HIV/AIDS.
• A study done by Pesola and colleagues found that, infact, AIDS patients with NOS require additional vigilence in terms of their management.
• This study found that over 15% of AIDS patients with NOS would have erroneously been sent home without appropriate treatment had the standard recommendation for NOS management been followed; these patients were found to have intracranial lesions related to toxoplosmosis and lymphoma, and did not necessarily have focal neurologic deficits.
• It is therefore recommended that all AIDS patients with NOS undergo neuroimaging with lumbar puncture, as indicated.

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