“Sitting-up vertigo as an expression of posterior semicircular canal heavy cupula and posterior semicircular canal short arm canalolithiasis”

Background:Vestibular symptoms on sitting-up are frequent on patients seen by vestibular specialists.Recently,a benign paroxysmal positional vertigo(BPPV)variant which elicits vestibular symptoms with oculomotor evidence of posterior semicircular canal(P-SCC)cupula stimulation on sitting-up was described and named sitting-up vertigo BPPV.A periampullar restricted P-SCC canalolithiasis was proposed as a causal mechanism.Objective:To describe new mechanisms of action for the sitting-up vertigo BPPV variant.Methods:Eighteen patients with sitting-up vertigo BPPV were examined with a pre-established set of positional maneuvers and follow-up until they resolved their symptoms and clinical findings.Results:All patients showed up-beating torsional nystagmus(UBTN)and vestibular symptoms on coming up from either Dix-Hallpike(DHM)or straight head-hanging maneuver.Sixteen out of 18 patients presented a sustained UBTN with an ipsitorsional component to the tested side on half-Hallpike maneuver(HH).A slower persistent contratorsional down-beating nystagmus was found in eleven out18 patients tested on nose down position(ND).Conclusions:Persistent direction changing positional nystagmus on HH and ND positions indicative of PSCC heavy cupula was found in 11 patients.A sustained UBTN on HH with the absence of findings on ND,which is suggestive of the presence of P-SCC short arm canalolithiasis,was found on 5 patients.All patients were treated with canalith repositioning maneuvers without success,but they resolved their findings by means of Brandt-Daroff exercises.We propose P-SCC heavy cupula and P-SCC short arm canalolithiasis as two new putative mechanisms for the sitting-up vertigo BPPV variant.

Affected-Ear-Up 90°Maneuver Proves That Nystagmus Does Not Occur by the Stimulation to the Macula of the Utricle

Background: The utricular macula is located on the floor of the utricle, approximately in the plane of the lateral semicircular canal, and is oriented to respond best to lateral tilts and side-to-side or fore-and-aft translations of the head. However, the details of the otolith ocular reflex are unknown. Pathophysiology of transient direction-changing geotropic positional nystagmus is a canalolithiasis in the lateral semicircular canal. The principle of affected-ear-up 90° maneuver is moving debris from a long arm to the utricle, therefore debris stimulates the utricular macula in the sitting position after the treatment. Objective: To clarify whether nystagmus occurs by the stimulation to the macula of the utricle. Methods: The subjects were 10 patients with lateral semicircular canal canalolithiasis. After the diagnosis, we performed affected-ear-up 90° maneuver immediately. We observed eye movements in the sitting position (chin-down 30°) just after the treatment. Results: No one showed nystagmus in the sitting position after the treatment. In all patients, positional nystagmus disappeared within 7 days after the treatment. Conclusion: Nystagmus does not occur by the stimulation to the macula of the utricle. Hence, we cannot assess the function of the utricle by the analysis of eye movements, and ocular counter-rolling is considered to be a semicircular canal ocular reflex.

良性阵发性位置性眩晕的手法复位治疗

良性阵发性位置性眩晕（benign paroxysmal positional vertigo,BPPV）是头部运动或身体姿势变动诱发的、短暂的眩晕发作,在临床上很常见。2006年中华医学会耳鼻咽喉科学分会组织专家制定了BPPV的诊断依据和疗效评估标准，为BPPV的诊断和治疗提供了依据。