The Vestibular System · why the room spins, and why it's rarely your neck

cofactor · 2

• →Calcium

  Otoconia are calcium carbonate crystals. Being denser than the fluid around them, gravity pulls the gelatinous membrane they sit on, which drags the hair-cell bundles to one side — that is how the body knows its orientation to gravity.

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• →Nervous

  The semicircular canals register rotation, not translation: turn your head and the fluid lags by inertia, bending the cupula and with it the hair bundles, which fire down the nerve at once. In a lift going straight up, the push is equal on both sides and they stay quiet.

  TEXT · OPINION

regulates · 2

• →Osteoporosis

  Vertigo causes falls, especially in older people, and one fall can cost far more than the dizziness did. Repositioning manoeuvres are not just symptom relief — they remove the first link in the fall-to-fracture chain.

  GUIDE · AREVIEW · A

• →Vitamin D

  Vitamin D shaves a little off BPPV recurrence but is nowhere near a cure — repositioning is still the treatment; D at most discounts the relapse rate. Do not carry this over to vitamin D and falls or fractures, which large trials have substantially revised in the past decade.

  TEXT · OPINIONREVIEW · A

contrast · 1

• ≠Stroke

  The first job in acute vertigo is telling a benign inner-ear cause from a posterior-circulation stroke: early imaging misses a sizeable share, while bedside HINTS is more sensitive in trained hands.

  TEXT · OPINIONCOHORT · B