Veena Pani M. K1, Leela Tejaswini R. M2, Prakash S. B3, Geetha4
ABSTRACT: The most common peripheral vestibular disorder generally is agreed to be BPPV. The hallmark of the disease is brief spells (lasting seconds) of often severe vertigo that are experienced after specific movements of the head.
ï?· The head movements that most commonly cause symptoms are rolling over in bed and extreme posterior extension of the head as if looking under a sink.
ï?· Current understanding of this disease has evolved such that specific therapies based on accepted theories have been developed and proved successful in controlling symptoms.
HISTORY:
ï?· This disorder was first described by Barany in 1921. He documented the various components of this disorder as 1. Nystagmus, 2. Fatiguability of the nystagmus and 3. Vertigo. He failed to correlate the onset of nystagmus with specific positions of the head.
ï?· Dix & Hallpike 1952 described the Dix Hallpike maneuver for eliciting the nystagmus. They also described the unique features of nystagmus accompanying this disorder. These features were 1. Very short latency, 2. Directional features, 3. Brief duration and 4. Reversibility on returning the patient to a seated position.
ï?· Schuknecht postulated that BPPV was caused by loose otoconia from the utricle which in certain positions displaced the cupula of the posterior canal. (Schuknecht theory). He later modified his theory and proposed that it was due to the deposition of otoconia on the cupula of the posterior semi-circular canal. He termed this theory as cupulolithiasis. The cupulolithiasis theory proposes that calcium deposits become embedded on the cupula making the posterior semi-circular canal sensitive to gravity.
ï?· Hall & Ruby suggested that BPPV could result from deflection of the posterior canal cupula caused by debris within the posterior canal. This theory became known as the canal lithiasis theory. In this theory the calcium debris doesnot become adherent to the cupula but float freely within the canal. Head movements like looking up, down, or rolling over to the affected ear may result in the displacement of the sludge causing the classic symptoms.
ï?· Hall & Ruby described 2 types of BPPV: 1. BPPV with a fatiguable nystagmus, where the deposits are freely mobile within the cupula of the posterior canal,
ï?· BPPV with a non-fatiguing nystagmus where the calcium deposits are fixed on the cupula of the posterior canal.
