ESM 6.7 A flowsheet approach to the patient with acute onset prolonged vertigo from Neuro-Ophthalmology and Neuro-Otology Textbook

: A vascular etiology should always be on the differential diagnosis of the acute onset prolonged vertigo, especially in the older population and when vascular risk factors are present. However, young patients can suffer from vascular events too - be especially concerned in patients with recent onset head/neck pain and vertigo. Unfortunately, the evaluation and management of this population is not one size fits all, but this flowchart offers a framework to the approach of acute onset prolonged vertigo when the diagnosis is unknown and a vascular etiology is possible. First, is spontaneous nystagmus present? If so, this is the acute vestibular syndrome (AVS), and the ‘HINTS Plus' examination should be applied (HIT=head impulse test; Bi/Vertical=bidirectional in lateral gaze or spontaneous vertical nystagmus; Uni=unidirectional nystagmus). If the pattern is that of a "peripheral" HINTS exam, vestibular neuritis is almost always the cause, but at least a cursory neurologic examination should always be performed as well, especially evaluation of gait, stance and coordination (e.g., if the patient can't sit and stand independently, this is very worrisome…most vestibular neuritis patients will be able to take a few steps independently at least, although imbalance may be severe in others). Also, look closely at the function of the cranial nerves, in addition to sensation and strength in the arms and legs. Finally, 15 cycles of 2-3 Hz horizontal head-shaking is a valuable bedside maneuver to evaluate for peripheral (increased contralesional nystagmus) or central (reversal of horizontal nystagmus or "cross-coupling" where horizontal head-shaking causes vertical [usually downbeat] nystagmus) patterns of head-shaking-induced nystagmus. If the symptomatic patient does not have spontaneous nystagmus, this is a more difficult situation. In addition to the ocular motor/vestibular exam, a comprehensive neurologic evaluation becomes even more important in this scenario. Symptomatically, the presence of head motion intolerance, nausea and imbalance is suggestive of a vestibular etiology (although this by itself doesn't tell you whether you're dealing with a central disorder like stroke, vestibular migraine, or a peripheral disorder like Meniere's) as compared to a non-vestibular etiology (e.g., severe anemia). Look closely for truncal, limb or gait ataxia, evaluate sensory and motor function in the limbs as well as on the face with emphasis on the cranial nerve exam. Perform the HINTS Plus exam, but realize that the rules of HINTS cannot be applied to triage the patient who does not have spontaneous nystagmus (e.g., symmetric acute onset bilateral vestibular loss may not cause nystagmus, although a bilaterally abnormal head impulse test will be seen). Assess saccades looking specifically for dysmetria (e.g., with a lateral medullary [Wallenberg] syndrome, ipsilesional hypermetria [and ocular lateropulsion] and contralesional hypometria) and impaired smooth pursuit, which can be significantly impaired with certain stroke syndromes (e.g., flocculus/paraflocculus, middle cerebellar peduncle). If there are any neurologic abnormalities, assume that the etiology is central until proven otherwise. If the neuro-vestibular examination and history is normal, is there a medical explanation (e.g., toxicity from lithium, benzodiazepines, anti-seizure medication; severe anemia) or a vestibular explanation (e.g., long and strong migraine history, and the patient is experiencing a prolonged attack with associated photophobia and phonophobia) - while a stroke is unlikely in these examples, urgent neuroimaging may still be warranted. If the neuro-vestibular history (including no Dangerous D's(1) and no new head/neck pain) and exam are unremarkable, risk stratify using the ABCD2 score.(2, 3) While there is no specific benign/dangerous cut-off for this score, a score of 3-4 or more should be enough to initiate the stroke work-up expeditiously. However, a patient with a vestibular stroke or TIA can still have a score of 2 or less! Finally, don't forget about non-neurologic/non-vestibular etiologies, and be especially concerned by cardiorespiratory symptoms or transient loss of consciousness. A head CT scan is insufficient to evaluate for stroke unless there are focal findings on exam, a severe headache or change in mental status (e.g., posterior fossa hemorrhage), or if the patient is in a thrombolytic window. Brain MRI and MR angiogram head and neck (or MRI and CT angiogram) is preferable as the initial neuroimaging modality. - - : A flowsheet approach to the patient with acute onset prolonged vertigo1. Newman-Toker DE, Edlow JA. TiTrATE: A Novel, Evidence-Based Approach to Diagnosing Acute Dizziness and Vertigo. Neurol Clin. 2015;33(3):577-99, viii. 2. Newman-Toker DE, Kerber KA, Hsieh YH, Pula JH, Omron R, Saber Tehrani AS, et al. HINTS outperforms ABCD2 to screen for stroke in acute continuous vertigo and dizziness. Acad Emerg Med. 2013;20(10):986-96. 3. Saber Tehrani AS, Kattah JC, Kerber KA, Gold DR, Zee DS, Urrutia VC, et al. Diagnosing Stroke in Acute Dizziness and Vertigo: Pitfalls and Pearls. Stroke. 2018;49(3):788-95