Transcript Cold
Vertigo
&
Its Management
By Dr.H.T.Lathadevi
M.S(ENT) Shree B.M.Patil Medical College Hospital & Research Centre Bijapur
What is Vertigo
Giddiness /dizziness
Light headedness.
Sensation of floating in space.
Unstable or uncertain gait.
Loss of balance
Ringing in the ears.
Vertigo
Vertigo is a hallucination of self environmental movement , a feeling of spinning or
Vertigo is a symptom and not a disease.
Body Balance System
Maintenance of balance is a function of nervous system
Balance is achieved by integrating information from 3 sources
Vestibular labyrinth
Eyes
Proprioceptors located in muscles and joint
Harmonious integration of these inputs in the brain is essential for maintenance of balance
Disorder of Balance System
Disorder may occur in one or more organs of the balance system
Commonest site is labyrinth
Labyrinth is susceptible to damage by numerous factors -
Medicines ( e.g.gentamycin,streptomycin )
Infections
Degenerative changes of aging Head trauma
Vertigo - Prevalence
Present in about 5% of all patients consulting general practitioners
Seen in 10-15% of patients seen by ENT specialist or neurologist
The reasons for high prevalence -Vertigo is a symptoms which accompanies large number of diseases -More than described 80 possible causes have been
Vertigo- symptoms
Giddiness /dizziness
Light headedness.
Sensation of floating in space.
Unstable or uncertain gait.
Loss of balance
Ringing in the ears.
Vestibular System
Vestibular Function and Anatomy
System of balance Membranous and bony labyrinth embedded in petrous bone 5 distinct end organs – 3 semicircular canals: superior, lateral, posterior – 2 otolith organs: utricle and saccule
Semicircular canals are orthogonal to each other Lateral canal inclined to 30 degrees Superior/postereor canals 45 degrees off of sagittal plane
Utricle is in horizontal plane Saccule is in vertical plane
Anatomy
There are five openings into area of utricle Saccule in spherical recess Utricle in elliptical recess
45% from AICA 24% superior cerebellar artery 16% basilar Two divisions: anterior vestibular and common cochlear artery
Superior vestibular nerve: superior canal, lateral canal, utricle Inferior vestibular nerve: posterior canal and saccule
Membranous labyrinth is surrounded by perilymph Endolymph fills the vestibular end organs along with the cochlea
Perilymph – Similar to extracellular fluid – K+=10mEQ, Na+=140mEq/L – Unclear whether this is ultrafiltrate of CSF or blood – Drains via venules and middle ear mucosa
Endolymph – Similar to intracellular fluid – K+=144mEq/L, Na+=5mEq/L – Produced by marginal cells in stria vascularis from perilymph at the cochlea and from dark cells in the cristae and maculae – Absorbed in endolymphatic sac which connected by endolymphatic, utricular and saccular ducts
Sensory structures
Ampulla of the semicircular canals Dilated end of canal Contains sensory neuroepithelium, cupula, supporting cells
Cupula is gelatinous mass extending across at right angle Extends completely across, not responsive to gravity Crista ampullaris is made up of sensory hair cells and supporting cells
Sensory cells are either Type I or Type II Type I cells are flask shaped and have chalice shaped calyx ending One chalice may synapse with 2-4 Type I cells Type II cells – cylinder shaped, multiple efferent and afferent boutons
Hair cells have 50-100 stereocilia and a single kinocilium.
stereocilia are not true cilia, they are graded in height with tallest nearest the kinocilium.
Kinocilium is located on one end of cell giving each cell a polarity Has 9+2 arrangement of microtubule doublets Lacks inner dynein arms, and central portion of microtubules not present near ends – may mean they are immobile or weakly mobile
Each afferent neuron has a baseline firing rate Deflection of stereocilia toward kinocilium results in an increase in the firing rate of the afferent neuron Deflection away causes a decrease in the firing rate
kinocilia are located closest to utricle in lateral canals and are on canalicular side in other canals Ampullopetal flow (toward the ampulla) excitatory in lateral canals, inhibitory in superior/posterior canals Ampullofugal flow (away from the ampulla) has opposite effect
Semicircular canals are paired – Horizontal canals – Right superior/left posterior – Left superior/right posterior – Allow redundant reception of movement – Explains compensation after unilateral vestibular loss
Otolithic organs
Utricle and saccule sense linear acceleration Cilia from hair cells are embedded in gelatinous layer Otoliths or otoconia are on upper surface
Calcium carbonate or calcite 0.5-30um Specific gravity of otolithic membrane is 2.71-2.94
Central region of otolithic membrane is called the striola
Saccule has hair cells oriented away from the striola Utricle has hair cells oriented towards the striola Striola is curved so otolithic organs are sensitive to linear motion in multiple trajectories
Central connections
Scarpa’s ganglion is in the internal auditory canal Contains bipolar ganglion cells of first order neurons Superior and inferior divisions form common bundle which enters brainstem No primary vestibular afferents cross the midline
Afferent fibers terminate in the vestibular nuclei in floor of fourth ventricle – Superior vestibular nucleus – Lateral vestibular nucleus – Medial vestibular nucleus – Descending vestibular nucleus
Vestibular nuclei project to – Cerebellum – Extraocular nuclei – Spinal cord – Contralateral vestibular nuclei
Senses and controls motion Information is combined with that from visual system and proprioceptive system Maintains balance and compensates for effects of head motion
Vestibulo-ocular reflex – Membranous labyrinth moves with head motion to right – Endolymph moves utriculopetally – Cupula on right canal deflected towards utricle causing increase in firing rate, left deflects away causing a decrease in firing rate.
– Reflex causes movement of eyes to the left with saccades to right – Stabilizes visual image
Vestibulospinal Reflex
Senses head movement and head relative to gravity Projects to antigravity muscles via 3 major pathways: – Lateral vestibulospinal tract – Medial vestibulospinal tract – Reticulospinal tract
How do calorics work?
Patient is lying down with horizontal canals oriented vertically (ampulla up) Cold water irrigation causes endolymph in lateral portion to become dense and fall causing deflection of cupula away from utricle with a decrease in the firing rate This causes nystagmus with fast phase (beat) away from the stimulus
With warm water irrigation column of endolymph becomes less dense, rises and causes deflection of cupula toward the utricle Results in increase firing rate and nystagmus which beats towards the stimulation COWS (cold opposite, warm same)
Investigations for vertigo
Caloric Test
Audiometry
Electronystagmography (ENG)
Craniocorpography (CCG)
Brain -Stem Evoked Response Audiometry (BERA)
Pendular Or Phasic Spontaneous Or Induced Horizontal Or Vertical
Electronystagmography (ENG)
Basic test for balance system
Assesses the integrity of - vestibular labyrinth & its connections with the eyes and certain parts of the brain which are concerned with the maintenance of balance
Gives an idea of functional integrity of vestibulo-ocular reflex system
It comprises tests like test for spontaneous nystagmus, the gaze nystagmus, pendulum tracking test & caloric test
Caloric Test
Caloric test involves instillation of hot or cold water into ear canal
When labyrinth is stimulated, either by heat or cold, caloric nystagmus generally results
Nystagmus produced by left & right eyes are assessed
Brain Stem Evoked Response Audiometry (BERA)
A method of plotting electrical activities in response auditory or vestibular stimuli
Electrical activities are measured by keeping the electrode on the scalp
In BERA wave-form obtained from one particular site on the scalp (vertex), over specified duration of time of 10 milliseconds
Investigations - for structural integrity
Tests to asses structural integrity of the system
– X rays – CT scan – MRI
Newer imaging ethnologies - for visualization of functional or metabolic activity occurring in brain
– Positron emission tomography (PET) – Single photon emission computed tomography
(SPECT)
Vertigo - Possible circulatory causes
Increased vascular resistance
Increased blood viscosity due to -
Reduced flexibility of RBCs
Increased blood viscosity
Reduced micro-circulation
Vertigo : Peripheral
V/S
PERIPHERAL CENTRAL Occurrence : Episodic . May be constant Severity Axis : Proportionate . Disproportionate : Horizontal . Variable Nyst. Type : Slow & Fast . Irregular phases Latency : 10 to 20 sec. . None Direction Duration Fatigue Hearing loss : Single . Changing : Brief . Long : Yes . No /Tinitus : Possible . No
Central
O .
ANATOMY OF BALANCE AND VERTIGO
Meniere’s syndrome
Sudden onset & recurring episodes of vertigo
Tinnitus
Progressive deafness.
Ischaemia of the inner ear.
The cause is unknown - may be associated with dilation of the endolymphatic system due to increase in the amount of endolymph.
Clinical Features
Deafness Tinnitus Episodic vertigo Autonomic –Nausea, vomiting, Diaphoresis Aural pressure 57
Managrment
Medical-Vestibular sedatives Vascular-Increase blood supply-Betahistine Carbogen Alter electrolytic balance-Frusemide,Glycerol Hydrochlorothiadize Surgical-Endolymphatic sac decompression, Vestibular neurectomy, Ultrasonic destruction Reassurance Vestibular rehabilitation exercises 58
Benign Paroxysmal Positional Vertigo
BPPV results from freely moving crystals of calcium carbonate (Otoconia) usually within the semicircular canals
BPPV develop with change in position
This type of vertigo can be sequelae of head trauma or vestibular neuritis
Most common in age group of 60-70 years
DIX-HALL-PIKE’S TEST
EPLEY’S MANEUVER
General management of
vertigo
Management of patients suffering from vertigo or vertiginous syndrome should consist of….
Elimination of the underlying cause
Symptomatic relief.
Methods:
Drug treatment
Vestibular rehabilitation exercises
Surgical
Drug treatment
Labyrinthine suppressant/ Ca++ entry blocker
– Cinnarizine
Vasodilators
– Betahistine
Antihistaminics
– Meclizine, Promethazine – Sedatives / tranquilizers – Diazepam
Cinnarizine Selective Antivasoconstrictant, Ca
++
entry blocker
Antivertiginous activity due to
– Suppressant action on vestibular labyrinth. – Anti-vasoconstrictant activity. – Lowering of blood viscosity by improving the
flexibility of the RBC’s.
Cinnarizine
Presentation: Tablet of 25 mg / 75 mg Dosage : 1-2 tablets of 25 mg two to three times a day or as directed by the physician.
Children (5 - 12 yr.) : 1/2 tablet three times a day
Betahistine
Histamine analogue.
Vasodilator-increases blood flow
Indicated for vertigo.
Side effects : headache, rash, g.i. disturbances.
Steal effect
Contraindicated in asthma, peptic ulcer
Dose : 8 to16 mg. tid
Vestibular Rehabilitation Exercises
Co-ordinated head, body & eye movement helps to ameliorate the patient’s symptoms Exercises should be performed 5 - 10 minutes twice or thrice daily.
– Exercises of eye movement – Exercises in sitting position like
Shrugging & rotating shoulders
Bending forward & picking up the objects from the floor
– Exercises in standing position like
Changing from sitting to standing initially with eyes open & then eyes shut repeatedly for 15 times with
Vestibular Rehabilitation Exercises (contd.)