HiNTS exam

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What

Series of three quick, bedside, physical exam maneuvers that can potentially rule out a central cause of vertigo

 

Hi for head impulse testing, or head thrust testing.
N for nystagmus to remind you to look for direction-changing or vertical nystagmus
TS for test of skew.

 

HINTS1.png




 

Why

  • Nearly two-thirds of patients with stroke lack focal neurologic signs that would be readily apparent to a nonneurologist

  • Presence of all three “reassuring” exam findings suggests it can be ruled out with a 100% sensitivity for ischemic stroke in AVS while an initial MRI with diffusion-weighted imaging (DWI) had a 88% sensitivity





 

Who

Maneuvers used to help distinguish between central and peripheral vertigo in patients experiencing an acute vestibular syndrome (AVS) which is best defined as: rapid-onset vertigo, nausea and/or vomiting, gait unsteadiness, head motion intolerance, and nystagmus.

 

When

The patient must be experiencing continuous vertigo for the results to be reliably interpreted.

How

Head Impulse Test

HINTS2.png







  • Ask the patient to relax his/her head and maintain his/her gaze on your nose. Gently move the patient’s head to one side, then rapidly move it back to the neutral position. The patient may have a small corrective saccade. The head impulse test is positive (consistent with peripheral vertigo) if there is a significant lag with corrective saccades. If you can see the correction, it is abnormal. Compare this to the contralateral side; a difference in the speed of correction should be noted.

  • In acute vestibular syndrome, an abnormal result of a head impulse test usually indicates a peripheral vestibular lesion, whereas a normal response virtually confirms a stroke.

  • Abnormal exam rules in peripheral vertigo and thus rules out central vertigo if only unilateral

  • Video- https://www.youtube.com/watch?v=XpghlvnrREI&feature=youtu.be&t=665

 

Nystamus

  • Note if it is present in primary gaze (i.e. looking straight ahead) and or in lateral gaze. Unidirectional, horizontal nystagmus is reassuring for peripheral vertigo where as purely bidirectional, vertical or torsional can be consistent with central cause

  • The most common peripheral nystagmus, BPPV, in the posterior semicircular canal consists of a unidirectional horizontal nystagmus with a torsional component.

 

Test of Skew

  • Have the patient maintain his/her gaze on your nose. Alternate covering each of the patient’s eyes

  • Positive result will be the deviation of one eye while it is being covered, followed by correction after uncovering it.

https://www.youtube.com/watch?v=WAPaIMMsV_A

 

Summary

  • If the HiNTs exam is entirely consistent with peripheral vertigo (positive head impulse test, unidirectional and horizontal nystagmus, negative test of skew), then, according to the derivation paper, it is 100% sensitive and 96% specific for a peripheral cause of vertigo.

  • Use of HiNTs exam in the ED is currently controversial as the primary study was performed by neurologists in a partially differentiated patient population

  • likely has higher utility in the patient population in whom the clinician suspects a peripheral cause of their vertigo to rule out central cause and limit needless imaging

 

 

Limitations

  • Do not perform on any patient that has head trauma, neck trauma, an unstable spine, or neck pain concerning for arterial dissection.

  • Do not perform in patients with known severe carotid stenosis as it may embolize unstable plaque

  • Challenging to differentiate between catch up saccade and nystagmus

  • Patients with acute active AVS likely to not tolerate the testing

  • Patient must be awake and cooperative.

  • Essentially an awake “doll’s eye” that requires conscious fixation on an object. Cannot perform on mentally impaired or sedated patients

  • Not yet been validated by a large external group, let alone a large external group of emergency medicine providers.

  • In the study, exam performed by ophtho neurologists

 

References

 

NUEMBlog

Tamingthesru

Nelson, James A., and Erik Viirre. "The clinical differentiation of cerebellar infarction from common vertigo syndromes." Western Journal of Emergency Medicine 10.4 (2009): 273.

Kattah, Jorge C., et al. "HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging." Stroke 40.11 (2009): 3504-3510.

Tarnutzer, Alexander A., et al. "Does my dizzy patient have a stroke? A systematic review of bedside diagnosis in acute vestibular syndrome." CmAJ 183.9 (2011): E571-E592.




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POTD: Idiopathic Intracranial Hypertension

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POTD: Idiopathic intracranial hypertension

 

Idiopathic intracranial hypertension (IIH) aka pseudotumor cerebri and benign intracranial hypertension

·      rare condition

·      presents with gradual onset and chronic headache, vision changes, nausea, vomiting, and tinnitus

·      + papilledema/ swelling of the optic disc on fundoscopy

potd eye papill.jpg

·      optic sonography

potd us eye.jpg

  • ONSDs should be measured 3 mm behind the papilla, an average of less than 5 mm is considered normal.

  • ONSD > 5 mm has been shown to be 90% sensitive and 85% specific for ICP > 20.

·      Classic presentation: young, obese female

·      + association has been found with this diagnosis and the use of oral contraceptive medications, tetracycline, anabolic steroids, and vitamin A

·      Pathophysiology is not well understood but thought to be caused by an imbalance in CSF production and reabsorption

·      Diagnostic criteria include an alert patient with either a normal neurologic examination or findings consistent with papilledema, visual field defect, or an enlarged blind spot

·      Definitive dx: Lumbar puncture

  • done in a recumbent position reveals an elevated CSF opening pressure of more than 20 mm Hg in an obese patient (normal being up less than 20 mm Hg).

  • normal CSF analysis.

·      CT head may show “slit like” or normal ventricles without mass effect

·      DDx: glaucoma, venous sinus thrombosis, ICH, IC mass.

·      Treatment

  • Repeat LPs  

  • Acetazolamide

  • Surgical shunt if severe and refractory

  • offending agents such as oral contraceptive medications should be discontinued.

·      Permanent loss of vision can occur in up to 10% of patients, and higher if left untreated

 

Sources:

 

  • Dubourg J, Javouhey E, Geeraerts T, Messerer M, Kassai B. Ultrasonography of optic nerve sheath diameter for detection of raised intracranial pressure: a systematic review and meta-analysis. Intensive Care Med. 2011;37(7):1059-68. [pubmed]

  • Blaivas M, Theodoro D, Sierzenski PR. Elevated intracranial pressure detected by bedside emergency ultrasonography of the optic nerve sheath. Acad Emerg Med. 2003;10(4):376-81. [PDF]

  • https://www.ultrasoundoftheweek.com/uotw-5-answer/

  • Peer IX

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POTD: Straight leg test. A leg up on clinical testing!

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A little background:

Lumbar disc herniation is the most common cause of lumbar radiculopathy, or sciatica, a shooting or burning pain from the low back radiating down the posterior leg distal to the knee.

Two tests used to evaluate these symptoms are

The straight leg raise.

·       The straight leg raise test is highly sensitive but not very specific for disc herniation.

·       This is performed by lifting the leg affected by the radiating pain.

·       The patient lies supine with one leg either straight or flexed at the knee with the sole of the foot flat on the stretcher.

·       The examiner then raises the affected leg up, extended, to 30 to 70 degrees.

·       Reproduction of low back pain that radiates down the posterior affected leg at least past the knee is considered a positive result. Not just pain to the lower back, which is a common misconception.

·       The SLR test can also be performed with the patient in a sitting position, by stretching the sciatic nerve by extending the knee; the test is positive if pain radiates to below the knee.

 

The crossed straight leg raise.

·       It is highly specific (90%) for disc herniation

·       You perform the same test as the straight leg but on the unaffected leg.

·       A positive test: reproducing both the back pain + the radiation down the affected leg.

Sources: Peer IX, Tintinelli’s, Dr. Sergey Motov, Uptodate

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