Atypical PC-BPPV - Cupulolithiasis and Short-Arm Canalithiasis: A Retrospective Observational Study.

Background And Purpose: Atypical posterior canal (pc) benign paroxysmal positional vertigo (BPPV) may be caused by cupulolithiasis (cu), short arm canalithiasis (ca), or jam. The purpose of this study was to describe the clinical presentation and differential diagnosis of pc-BPPV-cu and short arm canalithiasis.

Methods: This retrospective observation study identified persons with atypical pc-BPPV based on history and findings from four positional tests.

When, where, and why should we look for vestibular dysfunction in people with diabetes mellitus?

The biochemistry of diabetes mellitus results in multi-system tissue compromise that reduces functional mobility and interferes with disease management. Sensory system compromise, such as peripheral neuropathy and retinopathy, are specific examples of tissue compromise detrimental to functional mobility. There is lack of clarity regarding if, when, and where parallel changes in the peripheral vestibular system, an additional essential sensory system for functional mobility, occur as a result of diabetes.

Case report: Atypical patterns of nystagmus suggest posterior canal cupulolithiasis and short-arm canalithiasis.

Background: Atypical posterior canal (PC) positional nystagmus may be due to the changes in cupular response dynamics from cupulolithiasis (cu), canalithiasis of the short arm (ca-sa), or a partial/complete obstruction-jam. Factors that change the dynamics are the position of the head in the pitch plane, individual variability in the location of the PC attachment to the utricle and the position of the cupula within the ampulla, and the location of debris within the short arm and on the cupula. The clinical presentation of PC-BPPV-cu is DBN with torsion towards the contralateral side in the DH positions and SHHP or no nystagmus in the ipsilateral DH position and no nystagmus upon return to sitting from each position.

Reliability of two dissociating tests of phoria in artificially created phoria in normal adults.

Background: The ability of physical therapists (PTs) to accurately identify and reliably measure phoria/tropia is critical in the differential diagnosis of individuals with acute vestibular syndrome and concussion/mild traumatic brain injury.

Objectives: To determine if PTs may reliably measure phoria and to determine the reliability of two dissociating tests of phoria, the prism neutralized Maddox rod test and modified Thorington method, in normal adults with artificially created phoria.

Methods: Thirty adults (mean age 24.

Horizontal semicircular canal jam: Two new cases and possible mechanisms.

Introduction: Benign paroxysmal positional vertigo (BPPV) of the horizontal semicircular canal (hSCC) can present with otoconia blocking its lumen (canalith jam), with signs and symptoms that make it difficult to distinguish from central nervous system pathology.

Objective: Here we report two cases of canalith jam affecting the hSCC and offer a theoretical mechanism based on known vestibular neurophysiology.

Methods: We use video-oculography to document the canalith jam and show the moment the otoconia loosen.

Peripheral Downbeat Positional Nystagmus: Apogeotropic Posterior Canal or Anterior Canal BPPV.

Background And Purpose: Downbeat nystagmus (DBN) during the Dix-Hallpike test (DHT) suggests excitation of the anterior canal (AC) or inhibition of the posterior canal (PC) underlying benign paroxysmal positional vertigo (BPPV). This case series describes 2 individuals presenting with DBN in positional testing suggestive of a PC BPPV variant termed apogeotropic PC-BPPV and due to inhibition of the PC.

Case Descriptions: Case 1 illustrates a DBN during positional testing (PC inhibition) that changes to an upbeating nystagmus (PC excitation) representing the otoconial material changing location and direction of movement within the PC.

Test-retest and Interrater Reliability of the Video Head Impulse Test in the Pediatric Population.

Objective: Determine reliability of horizontal and vertical video head impulse test (vHIT) and effect of maturation on angular vestibular ocular reflex (AVOR) gain estimations and peak head velocities of individual canals in typically developing children and adolescents.

Design: Reliability study.

Setting: University research laboratory

Subjects: : Two normal adults mean age 51.

Daily exercise does not prevent recurrence of benign paroxysmal positional vertigo.

Objective: The purpose of this study was to analyze if a daily routine of self-canalith repositioning procedure (CRP) will increase the time to recurrence and reduce the rate of recurrence of benign paroxysmal positional vertigo (BPPV).

Study Design: Prospective study, nonrandomized control group.

Setting: Outpatient clinic.

Strategies to prevent recurrence of benign paroxysmal positional vertigo.

Objective: To determine if a daily routine of Brandt-Daroff exercises increases the time to recurrence and reduces the rate of recurrence of benign paroxysmal positional vertigo (BPPV).

Design: Random sample of convenience and retrospective case review.

Setting: Tertiary referral center and outpatient clinic.

Macaque frontal eye field input to saccade-related neurons in the superior colliculus.

Extracellular recordings were made simultaneously in the frontal eye field and superior colliculus in awake, behaving rhesus monkeys. Frontal eye field microstimulation was used to orthodromically activate the superior colliculus both to locate the depth of the strongest frontal eye field input to the superior colliculus and to identify superior colliculus neurons receiving direct frontal eye field input. The activity of orthodromically driven colliculus neurons was characterized during visuomotor tasks.