368.4 📋 章末速蚘 Summary

368.4.1 🔑 䞀句話瞜結

Dizziness = nonspecific — clinically distinguish 4 types: vertigo (illusion of motion — vestibular peripheral or central) + presyncope (near-faint, cardiovascular) + disequilibrium (off-balance without rotation, often gait — cerebellar/sensory ataxia/parkinsonian/peripheral neuropathy) + lightheadedness/anxiety/hyperventilation/hypoglycemia; vertigo divided into peripheral (vestibular labyrinth or nerve) vs central (brainstem/cerebellum); peripheral causes — more common, less dangerous: BPPV (most common, brief < 1 min, positional, otoconia in semicircular canal, posterior most common) — Dix-Hallpike + Epley maneuver; vestibular neuritis (sudden sustained days, viral prodrome, no hearing loss) — steroids + early vestibular rehab; labyrinthitis (vestibular neuritis + hearing loss); Meniere disease (recurrent attacks 20 min-hours, tetrad: vertigo + tinnitus + sensorineural hearing loss + aural fullness; endolymphatic hydrops) — diet low salt + diuretics + betahistine + intratympanic steroid or gentamicin; vestibular migraine (recurrent vertigo + migraine features) — migraine prevention β-blocker/topiramate/TCA/CGRP mAbs; central causes (dangerous!) — brainstem/cerebellar stroke (PICA Wallenberg, AICA can mimic labyrinthitis with hearing loss!) + cerebellar hemorrhage + MS + posterior fossa tumor (vestibular schwannoma) + vertebrobasilar insufficiency; HINTS exam for acute vestibular syndrome — Head Impulse (peripheral abnormal/catch-up saccade vs central normal) + Nystagmus (peripheral unidirectional horizontal-torsional vs central direction-changing or vertical/pure torsional) + Test of Skew (peripheral absent vs central present vertical misalignment) — HINTS more sensitive than early MRI within 48 hr for posterior stroke; peripheral vs central nystagmus — peripheral reduced by visual fixation vs central not changed; workup — history (4 types), exam (HINTS + neuro + Romberg + orthostatic + cardiac), MRI brain DWI for suspected central, vestibular function tests (caloric, VNG, rotational, VEMP); treatment — Epley (BPPV), steroids (vestibular neuritis), diet + diuretics + betahistine (Meniere), migraine prevention (vestibular migraine), treat underlying for central; special — PPPD chronic > 3 months SSRIs + CBT + vestibular rehab; mal de débarquement persistent rocking after travel; cerebellar stroke can cause obstructive hydrocephalus → suboccipital craniectomy decompression。

368.4.2 💊 治療粟芁

  • BPPVEpley maneuver (canalith repositioning) 95%+ effective — Patient supine head turned 45° toward affected, lower head 20° below horizontal, then series of head turns; Brandt-Daroff exercises home; avoid vestibular suppressants (delay recovery); Semont/Gufoni/Yacovino for other canals
  • vestibular neuritismethylprednisolone 100 mg PO taper × 3 weeks + vestibular suppressants short-term ≀ 72 hr (meclizine 25 mg q6-8h, dimenhydrinate, diazepam) + antiemetics + early vestibular rehabilitation therapy (key)
  • Meniere diseasediet low salt < 1500 mg/d + caffeine/alcohol/nicotine avoidance + hydrochlorothiazide-triamterene + betahistine 16-48 mg TID (Europe) + acute vestibular suppressants; refractory intratympanic steroid (methylprednisolone or dexamethasone) or intratympanic gentamicin (vestibulotoxic, ablates affected ear, preserves hearing); endolymphatic sac decompression + labyrinthectomy + vestibular nerve section
  • vestibular migraineas migraine prevention β-blocker (propranolol) + topiramate + TCA (amitriptyline) + venlafaxine + CGRP mAbs (emerging evidence); acute as migraine
  • cerebellar strokesuboccipital craniectomy decompression for mass effect with brainstem compression or obstructive hydrocephalus
  • PPPD (persistent postural-perceptual dizziness)SSRIs (sertraline, escitalopram) + CBT + vestibular rehabilitation
  • vestibular paroxysmiacarbamazepine 200-1200 mg/d or oxcarbazepine (vascular loop compression CN VIII)

368.4.3 🎯 盧醫垫的考前提醒

  1. Four types of dizziness (memorize): vertigo (spinning) + presyncope (near-faint) + disequilibrium (off-balance) + lightheadedness (vague); each has different etiology category
  2. Peripheral vs central vertigo distinction: peripheral (unidirectional horizontal-torsional nystagmus + reduced by fixation + hearing symptoms common + no other neuro) vs central (direction-changing or vertical/pure torsional + NOT reduced by fixation + other neuro signs + dangerous!)
  3. HINTS exam for acute vestibular syndrome (key skill): Head Impulse (peripheral abnormal/catch-up saccade vs central normal) + Nystagmus + Test of Skew (peripheral absent vs central present vertical misalignment) — more sensitive than early MRI within 48 hr for posterior fossa stroke
  4. BPPV (most common vertigo): brief < 1 min + positional + Dix-Hallpike + Epley maneuver 95%+ effective; posterior canal most common
  5. Vestibular neuritis: sudden sustained days + viral prodrome + no hearing loss (vs labyrinthitis = with hearing loss) → methylprednisolone taper + vestibular suppressants short-term ≀ 72 hr + early vestibular rehab
  6. Meniere tetrad (memorize): vertigo (recurrent 20 min-hours) + tinnitus + sensorineural hearing loss (fluctuating, low-frequency) + aural fullness; endolymphatic hydrops → low salt diet + diuretic + betahistine + intratympanic steroid/gentamicin refractory
  7. Vestibular migraine: recurrent vertigo + migraine features (may not have headache during episode) → treat as migraine prevention β-blocker/topiramate/TCA/CGRP mAbs
  8. AICA stroke can mimic labyrinthitis (peripheral pattern with hearing loss) — use HINTS exam + MRI to distinguish; PICA (Wallenberg) lateral medullary — vertigo + ipsilateral face/contralateral body sensory + dysphagia + hoarse + ataxia + Horner
  9. Cerebellar stroke EMERGENCY: posterior fossa mass effect → brainstem compression + obstructive hydrocephalus → suboccipital craniectomy decompression; 5 Ds (dizziness, diplopia, dysarthria, dysphagia, dystaxia)
  10. Chronic dizziness syndromes: PPPD (persistent postural-perceptual dizziness, > 3 months, worse upright/visual/motion → SSRIs + CBT + vestibular rehab); mal de débarquement (persistent rocking after travel); superior canal dehiscence (sound/pressure-induced vertigo Tullio phenomenon + autophony + CT confirms)