Upload
bhuvaneshwari-babu
View
199
Download
1
Embed Size (px)
Citation preview
CLINICAL EXAMINATION
OF VERTIGO
DR.B.BHUVANESHWARI
NYSTAGMUS
IT IS INVOLUNTARY OSCILLATION OF ONE OR BOTH EYE S ABOUT ONE OR MORE
AXES.
IT IS EITHER PHYSIOLOGICAL OR PATHOLOGICAL
PHYSILOGICAL
a)congenital
b)induced(OKN)
PATHOLOGICAL
In heath,to maintain a steady gaze these mechanisms are important
,VOR and gaze holding mechanism,problem in any of these will lead to
nystagmus.
NYSTAGMUS
PERIPHERAL CENTRAL
TYPE COMBINED HORIZONTAL
AND TORSIONAL
PURELY VERTICAL(MOST
COMMON),HORIZONTAL
OR TORSIONAL
DIRECTION ONE DIRECTION MAY CHANGE DIRECTION
VISUAL FIXATION INHIBITS NO CHANGE
FATIGABLE YES NO
LATENCY PRESENT ABSENT
LAWS OF NYSTAGMUS
ALEXANDER’S LAW
The first element says that spontaneous nystagmus after an acute vestibular
impairment has the fast phase directed toward the healthy ear. The direction
of the nystagmus, by convention, is named for the fast phase, so the
spontaneous nystagmus is directed toward the healthy ear.
the second element says nystagmus is greatest when gaze is directed toward
the healthy ear, is attentuated at central gaze and may be absent when gaze
is directed toward the impaired ear.
The third element says that spontaneous nystagmus with central gaze is
augmented when vision is denied. This became apparent with the
implementation of electrographic testing.
EWALD’S LAW
Ewald's first law: "The axis of nystagmus parallels the anatomic axis of the
semicircular canal that generated it".
Ewald's second law: "Ampullopetal endolymphatic flow produces a stronger
response than ampullofugal flow in the horizontal canal".
EAVLUATION OF VERTIGO
EXAMINATION OF EYE MOVEMENTS
SPONTANEOUS AND GAZE EOKED NYSTAGMUS
CONVERGENCE
SMOOTH PURSUIT
SACCADE
VESTIBULO-OCCULAR REFLEXS
POSITIONAL MANOEUVRES
SPONTANEOUS NYSTAGMUS
CONGENITAL SQUINT
NYSTAGMUS APPEARS DURING CONVERGENCE
WHILE IN PRIMRY GAZE SPONTANEOUS LATENT NYSTAGMUS SHOULD BE ELICITED WITH COVER TEST.
THESE SUBJECTS ARE ASSYMPTOMATIC WITH LATENT NYSTAGMUS
WHILE SPONTANEOUS NYSTAGMUS IN PRIMARY GAZE IN ACUTE SYMPTOMATIC PATIENTS(WITH ACUTE VERTIGO,SEVERE UNSTEADINESS,NAUSEA) INDICATES SOME PERIPHERAL VESTIBULAR PATHOLOGY LIKE VESTIBULAR NEURITIS,MENIERES,RECENT LABYRINTHINE SURGERY,TRAUMA.
THESE PERIPHERAL NYSTAGMUS ARE PREDOMINANTLY HORIZONTAL WITH MINOR TORSIONAL COMPONENT.FAST PHASE TOWARDS CONTRALATERAL SIDE OFLESION
WHILE THESE KIND OF NYSTAGMUS CAN OCCUR IN CENTRAL LESIONS IN THE 8TH
NERVE ROOT ENTRY ZONE OR VESTIBULAR NUCLEI BUT THEY HAVE ASSOCIATED
BRINSTEM SYMPTOMS AND SIGNS.
THE CENTRAL NYSTAGMUS DIFFERS FROM PERIPHERAL IN THAT
WAVEFORMS(PENDULAR,QUASI-SINUSOIDAL)
CENTRAL LESIONS PREDOMINANTLY HAVE DOWNBEATING NYSTAGMUS
GAZE EVOKED NYSTAGMUS
IN PERIPHERAL LESIONS AFTER ACUTE PHASE NYSTAGMUS CANNOT BE ELICITED
IN PRIMARY GAZE
IN SUCH CASES NYSTAGMUS CAN BE ELICITED ONLY BY GAZE DEVIATION TO THE
OPPOSITE SIDE OF LESION i.e in the direction of fast phase
GAZE PARETIC NYSTAGMUS
This occurs in central lesion where patient unable to hold gaze in the
eccentric position of the orbit , this nystagmus is usually of larger amplitude
nystagmus usually results from ipsilateral brainstem and cerebellar lesion
Smooth pursuit
The slow phase eye movement on a moving target (<10-15*per second) is
smooth pursuit.
When the target moves at velocities of 40-50 degree per second or more
pursuit becomes abnormal or broken pursuit.
Abnormal pursuit indicates central vestibular disorder
EXAMINATION
examiner should hold a solid target like pen,key that is visible to the
subject
The target has to b moved slowly taking 4 to 5 seconds to travel from left
to right and vice versa
INTERPRETATION
WHEN THE PURSUIT IS BROKEN TO THE RIGHT,THE LESION IS LIKELY TO
BE IN THE IPSILATERAL CEREBELLUM OR PARIETAL LOBE.
IN BRAINSTEMLESIONS IPSILATERAL ABNORMAL PURSUIT NOTED.IF VESTIBULAR
NUCLEUS INVOLVES THIS CAUSES NYSTAGMUS.
LIMITATIONS
AGE
VISUAL PROBLEMS
Saccadic eye movement
Saccades are fast movement of eyes (200-500 degree per second) which
allows us to shift the gaze from one object to another.
Unlike smooth pursuit target need not be necessarily moving they can be
generated with commands
Properties of saccade
saccadic velocity
saccadic accuracy
saccadic conjugacy
Saccadic velocity
Saccadic slowing takes longer time to travel from one object to another.
Saccadic slowing is intermediate staging between normal saccade and absent
saccade (i.e gaze palsy)
Saccadic slowing indicates some neurodegenerative disorder that reduces
saccadic velocity
Saccadic accuracy
Saccadic hypometria
Here where the patient takes two or three corrective saccades to
fix the target.these occurs in lesions of cortex ,basal
ganglia,brainstem,cerebellum,oculomotor nucleus.
SACCADIC HYPERMETRIA
Here patients saccade too large initially and travels past the target
so patient makes corrective saccade in opposite direction.this indicates
cerebellar abnormality.
SACCADIC CONJJUGACY
It is the conjugate movement of eyes to fix the target
Patient should not have any 3,4,6 cranial nerve palsy to demonstrate this.
Abnormal saccadic conjugacy in horizontal plane indicates internuclear
opthalmoplegia due to lesion in medial longitudinal fasciculus.
OPTOKINETIC NYSTAGMUS
PROCEDURE
A ROATING STRIPED DRUM PLCED IN FRONT OF THR PATIENT THE SLOW
IPSILATERAL EYE MOVEMENT(SMOOTH PURSUIT) AND FAST CONTRALATERAL EYE
MOVEMENT (SACCADES) PRODUCES OKN.
ABNORMALITY IN OKN INDICATES CORTICAL AND SUBCORTICAL LESION.SS
Vestibular ocular reflex
It is reflex to maintain gaze stability during head movements, this function is
responsible for gaze stability during walking, running, while turning our head.
Clinical manoeuvers available to detect VOR
a)DOLL’S EYE MANOEUVRE
b)HEAD IMPULSE OR HEAD THRUST MANOEUVRE
DOLLS EYE MANOEUVRE
THIS CAN BE ASSESD BY
a) direct observation of eyes
b)measurement of visual acuity
c) opthalmoscope
Observation of eyes
Procedure
Patient made to sit in front of the examiner, pt asked to fixate a
feature in examiners face. the examiner then oscillates the head from side to
side at a frequency of 0.5 to 1 Hz.
In the absence of VOR pt eye movements will not be smooth and interrupted
by a catch-up saccade.
This occurs because at 0.5 -1 Hz frequency head oscillation produces peak
velocities of 94-188 degree per second this velocity is too high for the pursuit
to compensate so catch-up saccades occurs.
This test is positive in bilateral vestibular loss (gentamycin toxicity, meningitis
or idiopathic)
DYNAMIC VISUAL ACUITY
Patient visual acuity is noted priorly eg(6/6).patient is made to read the
visual acuity chart while examiner behind the patient oscilates the head at a
frequency of 1Hz.
Normal persons visual acuity does not changes with the test or one line
difference is fond(eg 6/9)
Patient VOR is said to b abnormal when two or three line detoriation noted.
False positive in patients with spontaneous nystagmus.
False negative if the patient themselves control the head movement
HEAD IMPULSE TEST
Principle of head impulse test:
It is based on the fact that excitation of canal can shoot up the
discharge rate in sensory epithelium from resting rate of 90 to sudden spike of
300.
Whereas inhibition of primary and secondary vestibular neurons cannot produce
these spikes
So when a normal scc is stimulated it can produce enough discharge to carry out
the VOR,disinhibition by the contralateral semicircular cannal for the excited
side type 1 vestibular neurons constitutes minimal for VOR.
procedure
Patient asked to fixate a target across the room. The head is turned in
discrete steps 10-15degree across midline , briskly, By the examiner this
produces velocity of several hundred degrees per second.
A fast right side thrust will produce one or more catch-up saccade towards
left to the target in acute unilateral vestibular loss ( vestibular neuritis,
labyrinthitis)
Head thrust test
VESTIBULO-OCCULAR REFLEX
SUPRESSION
PATIENT ASKED TO FIXATE THE FIXATE THE OBJECT AND HAS TO MOVE HIS HEAD
SIDE TO SIDE HIMSELF OR BY THE EXAMINAER ANY BREAKTHROUGH NYSTAGMUS
INDICATES CENTRAL PATHOLOGY.IT IS NORMAL IN PERIPHERAL LESION.
POSITIONAL MANOEUVRES
TEST FOR POSTERIOR CANNAL AND ANTERIOR CANNAL BPPV
DIX-HALPIKE MANOEUVRE
TEST FOR HORIZONTAL CANNAL BPPV
SUPINE HEAD ROLL TEST
DIX HALPIKE TEST
SUPINE ROLL TEST
REPOSITIONING MANOEUVERS
FOR P-BPPV
EPLEY’S MANOEUVRE
BRANDT DAROFF POSITIONAL EXERCISE
SEMONT’’S LIBERATORY MANOEVURE
FOR H-BPPV
BBQ ROLE TEST
GUFONI TEST
YAW ROTATION
FORCED PROLONGED POSITION ON HEALTHY SIDE
EPLEY’S MANOEUVRE
SEMONTS TEST
BBQ ROLL TEST
GUFONI TEST
CALORIC TEST
PRINCIPLE: CHANGES IN THE TEMPERATURE OF EAC influences the vestibular
activity
Procedure
patients head end elevated to 30 degree to make the horizontal
semicircular cannal vertical.
Water irrigation at 30 and 44 degree celcius in the order left cold,right
cold,left warm,right warm.
Normal response: nystagmus for cold water occurs on the opposide side of
irrigation.nystagmus due to warm water occurs on the same side (COWS)
INTERPREATION
B/L absence of caloric nystagmus in case of aminoglycoside toxicity or
postmeningitis.
U/L absence in U/L vestibular schwannoma or vestibular neuritis
Directional preponderance in case of peripheral lesions for eg left vestibular
neuritis causes right directional preponderance ie right beatin nystagmus is
stronger than the left beating nystagmus.
Perverted nystagmus:this indicates nystagmus occurring in all planes instead
of normal horizontal plane this indicates central pathology
ROTATIONAL TESTS
VELOCITY STEP OR IMPULSIVE ROTATIONAL TEST
THE STIMULUS CONSIST OF SUDDEN INCRESSE IN CHAIR VELOCITY FROM 0 TO 60 OR 90 DEGREE.THE TIME TAKEN TO REACH THIS VELOCITY IS CALLED ACCELERATIN TIME IT IS BOUT 1 TO 2 SECONDS.TE TEST IS CARRIED OUT IN A DARK ROOM.
THIS ELICITS PER-ROTATIONAL NYSTAGMUS WHICH SLOWLY DECAYS AND EVENTUALLY STOPS.FULL CHAIR VELOCITY TO BE MAINTAINED FOR 60-90SECONDS OR UNTIL NYSTAGMUS DISAPPEARS.AT THIS POINT CHAIR IS SUDDENLY STOPPED AND SIMILAR NYSTAGMIC RESPONSE APPEARS IN OPPOSITE DIRECTION.THIS NYSTAGMUS IS TERMED S POS ROTATIONAL NYSTAGMUS.
CLOCKWISE OR RIGHTWARDS ROTATION INDUCES RIGHT BEATING NYSTAGMUSBASED ON THE PRINCIPLE THAT EYEMOVEMENT IS OPPOSITE TO HEAD ROTATION.POST ROTATIONAL NYSAGMUS OCCURS TOWARDS LEFT
Sinusoidal rotation test
In this test chair is sinusoidally modulated.usually,a range of frequencies from
0.005-1 Hz while peak velocity is kept constant.
The results are given as gain (ratio of slow phase eye velocity to chair
velocity) strength of vestibular response and
Phase(difference in degrees between maxima and minima pf chair and eye
velocity waveforms) measures degree of asymmetry.
INTERPRETATION
B/Lreduction or absence of response in case of B/L vestibular failure.
Assymetry indicates vestibular system disorder.
Loss of VOR suppression,investigated by chair-fixed target indicative of
central disease.
EXAMINATION OF POSTURE, BALANCE
AND GAIT
POSTURE
ABNORMAL TITLTS ROTATION-DYSTONIA,
FLEXED- PARKINSONISM
HYPEREXTENDED-PROGRESSIVE SUPRANUCLEAR PALSY
TITUBATION – CEREBELLAR DISEASE
IPSILATERAL EAR DOWN HEAD TILT,WITH SKEW EYE DEVIATION,IPSILATERAL
BODY PULSION– WALLENBERG SYNDROME (LESION OF VESTIBULAR NUCLEI)
ROMBERGS’S TEST
PATIENT SHOWS A TENDENCY TO FALL ON THE IPSILESIONAL SIDE ON EYE
CLOSURE.
ONLY IN ACUTE PHASE OF VESTIBULAR DISEASE THIS BECOMES POSITIVE.
POSTURAL REFLEXES ARE EXAMINED BY GENTLE PUSHING AND PULLING OF
UPPER TRUNK.
IN AKINETIC PATIENTS LIKE PARKINSONISM THIS RESPONSE IS COMPLETELY
ABSENT.
IN PERIPHERAL VESTIBULAR LESIONS THIS RESPONSE IS PESERVED.
WALKING
Drsal column lesion – tabeic gait
Sensory ataxia – raises the feet high from the ground and places the feet on
the ground under intense visual control.
Cerebellar lesion- drunken gait
Parkinsonian disease- gait stuck with loss of arm swing on the same side.
Utenbergs test- in unilateral pheripheral when patient is asked to walk on the
spot with eyes closed.patient turns towards the hypoactive side.
POSTUROGRAPHY
Computer dynamic posturography is a test for vestibule-spinal tract.it evaluates
overall balance function and the capacity of the body to maintain erect [osture
and gait.
METHODS OF POSTUROGRAPHY
a)Sensory organisation test –this tests capacity of patient to maintain equilibrium
during variety of changing sensory inputs
b)Motor co-ordination
SENSORY ORGANISATION TEST
THIS TESTS DEMONSTRATES CNS FUNCTION IN CORRECTLY PICKING THE
CONTRADICTORY INPUTS AND INDENTIFYING THE CORRECT INPUT FOR
MAINTAING EQUILIBRIUM.
IN THE ABOVE TESTABNORMALITY IN SITUATION 5,6 SUGGEST DISORDER OF
VESTIBULAR INPUT.
4,5,6 SUGGEST DISORDER OF VISUAL AND VESTIBULAR INPUTS.
THANK YOU