Vestibular seminar exam semi final

• VESTIBULAR SYSTEM DYSFUNCTION

  BPPV - is a biomechanical disorder and mc cause of vertigo
• VESTIBULAR SYSTEM DYSFUNCTION

  cupulolithiasis - indicates otoconia adhering to the cupula

  Canalithiasis - indicates free floating otoconia within the SCC
• VESTIBULAR SYSTEM DYSFUNCTION SX

  • nystagmus
  • Vertigo
  • Nausea
  • Vomiting
  • Dysequilibrium
• VESTIBULAR SYSTEM DYSFUNCTION

  vertigo and nystagmus occur within 15sec once the head is in the provoking position
• VESTIBULAR SYSTEM DYSFUNCTION

  Duration - <60sec
• VESTIBULAR SYSTEM DYSFUNCTION

  schuknecht - 1st therorized that fragments of otoconia break away and adhere to the cupula of one of the SCCs
• VESTIBULAR SYSTEM DYSFUNCTION

  UVH - decreased or eliminated receptor input and an experience of direct impairments of vertigo, spontaneous nystagmus, oscillopia during head movements, postural instability and dysequilibrium
• VESTIBULAR SYSTEM DYSFUNCTION

  Duration of UVH - 3-7days
• VESTIBULAR SYSTEM DYSFUNCTION

  vertigo revolves within 7days, persistent sx beyond 2weeks considered chronic
• VESTIBULAR SYSTEM DYSFUNCTION MC causes of UVH

  • viral insults
  • Trauma
  • Vascular events
• VESTIBULAR SYSTEM DYSFUNCTION MC cause of BVH

  • OTOTOXICITY
• VESTIBULAR SYSTEM DYSFUNCTION less common cause of BVH

  • menigitis
  • Autoimmune disorder
  • Head trauma
  • Tumors on 8cn
  • Transient ischemic
  • Sequential unilateral vestibular neuroritis
• VESTIBULAR SYSTEM DYSFUNCTION Primary complaint pt c BVH

  • dysequilibrium
• comon clinical signs c BVH

  • oscillopia
  • Gait ataxia
• Affect the vestibular system, including cerebrovascular insults involving the:

  • AICA
  • PICA
  • VERTEBRAL ARTERY
• VERTIGO

  • can be caused by these infarcts
  • Hearing loss mc c AICA infarcts
• Cerebellar lesions - mimic peripheral vestibular hypofunction, c associated signs like dysdiadochokinesea or past pointing
• vertebrobasilar insufficiency(VBI) - Doesnt involve vestibular pathology and common sx including visual field cuts, drop attakcs and unsteadiness.
• VBI MC CAUSES:

  • MVA
• MENIERE'S DISEASE - low frequency hearing loss and episodic vertigo
• perilymphatic fistula - is mc caused by a rupture of the oval or round windows, membranes that separate the middle and inner ears.
• vestibular schwannoma - are benign tumors arising from the schwann cell of the 8cn often in the IAC and historically known as ACOUSTIC NEUROMAS
• MOTION SICKNESS - a normal sensation that in some people becomes debilitating
• migraine related dizziness - can be deceptively similar to a peripheral vestibular lesion, BPPV or UVH
• MULTIPLE SLCEROSIS - affect 8cn where it enters the brainstem and causes identical sx to UVH
• multiple system atrophy - a progressive degenerative disease of the nervous system involving cerebellar ataxia,autonomic dysfunction, parkinson's disease and corticospinal dysfunction
• cervicogenic dizziness - a term meant to imply the cause of sx such as dizziness or imbalance
• dizziness - to describe a vague sensation of lightheadedness or a feeling that they have a tendency to fall.
• Most complaints of being “dizzy” can be categorized as:

  • ​vertigo
  • lightheadedness
  • Dysequilibrium
  • ​oscillopsia (targets in visual field appear to move during head motion).
• Vertigo is defined as an illusion of movement.
• Lightheadedness is often defined as a feeling that fainting is about to occur and can be caused by nonvestibular factors such as hypotension, hypoglycemia, or anxiety.
• Dysequilibrium is defined as the sensation of being

  off balance.
• Oscillopsia is the subjective experience of motion of

  objects in the visual environment that are known to be

  stationary.
• Tests and Measures

  Visual analogue scale - is an effective technique to obtain intensity ratings of vertigo, lightheadedness, dysequilibrium, and oscillopsia.
• Tests and Measures

  dizziness handicap inventory - is a popular tool used to measure a pt's self-perceived handicap as a result of vestibular disorder.
• Tests and Measures

  Motion Sensitivity Quotient (MSQ) - was developed

  to provide a subjective score of an individual’s sensitivity to motion.
• Observation for Nystagmus

  Nystagmus - is the primary diagnostic indicator used in

  identifying most peripheral and central vestibular lesions.
• Head Impulse Test - is a widely accepted clinical

  tool used to examine semicircular canal function.
• head-shaking induced nystagmus (HSN) - test is a

  useful aid in the diagnosis of a unilateral peripheral

  vestibular defect.
• Positional testing - is commonly used to identify whether

  otoconia have been displaced into the SCC, causing a

  condition referred to as benign paroxysmal positional

  vertigo (BPPV).