Cognition & Senses 2: Vestibular Dz Flashcards
FUNCTION of the VESTIBULAR system?
= MAINTAIN POSTURE/BALANCE of the HEAD, TRUNK, LIMBS & HEAD during REST & IN MOTION
VESTIBULAR DZ DESCRIBES A ___ ___, not a ____, meaning:
VESTIBULAR DZ DESCRIBES A NEUROANATOMICAL LOCALIZATION, not a DIAGNOSIS, meaning:
vestibular dz just tells us WHERE the problem is, NOT WHAT IT IS
CLINICAL SIGNS for DYSFUNCTIONAL VESTIBULAR SYSTEM?
signs are on the IPSILATERAL/CONTRALATERAL side for EACH?
- DECREASED EXTENSOR TONE of LIMB, TRUNK & NECK MUSCLES –> IPSILATERAL/SAME
- HEAD TILT, CIRCLING & ROLLING –> IPSILATERAL/SAME
- RESTING PATHOLOGICAL NYSTAGMUS –> goes towards CONTRALATERAL/OPPOSITE
projections to the ___ ___ provides _____ ___ of the body’s ____ in ___ via the ____
projections to the CEREBRAL CORTEX provides CONSCIOUS AWARENESS of the body’s POSITION in SPACE via the THALAMUS
projections to the VOMITING CENTER are located in the ____ ____
RETICULAR FORMATION
projections to the ____ can result in DECREASED ___ ___ on ONE SIDE and INCREASED _____ on the OTHER SIDE, causing ____
CEREBELLUM, EXTENSOR TONE, TONE, LEANING
projections via the ____ ___ to the ___, ____ & ____ allow for APPROPRIATE ___ or ___ POSITION relative to ____, and if dysfunctional causes ____ or ____
VESTIBULOSPINAL TRACT, NECK, TRUNK, LIMBS, HEAD, NECK, GRAVITY, LEANING, CIRCLING
what 3 CNs control EXTRAOCULAR EYE MUSCLES?
what do they project through? (3 words)
CN III, IV, VI
project through MEDIAL LONGITUDINAL FASCICULUS
CENTRAL vestibular system vs. PERIPHERAL vestibular system?
which one tends to have more BENIGN lesions?
CENTRAL vestibular = BRAINSTEM or CEREBELLUM
PERIPHERAL vestibular = EAR & EXTERNAL VESTIBULAR NERVES BEFORE they enter BRAINSTEM
PERIPHERAL = MORE BENIGN
PARADOXICAL VESTIBULAR DZ…
= where is the lesion?
causes what 2 clinical signs? TOWARDS or OPPOSITE from lesion?
look for UNILATERAL/BILATERAL ___ DEFICITS to CONFIRM
= lesion is in the CAUDAL CEREBELLAR PEDUNCLE in the ROSTRAL & MEDIAL VESTIBULAR NUCLEI
causes 2 what 2 clinical signs?
1. HEAD TILT/CIRCLING ON OPPOSITE SIDE OF LESION
2. FAST PHASE OF NYSTAGMUS TOWARDS SIDE OF LESION
look for UNILATERAL PROPRIOCEPTIVE DEFICITS
HORNER’S SYNDROME
tend to see PTOSIS on the AFFECTED/UNAFFECTED side
tend to see MIOSIS (define) on the AFFECTED/UNAFFECTED side
tend to see EXOPHTHALMOS/ENOPHTHALMOS on the AFFECTED/UNAFFECTED side
PERIPHERAL vs. CENTRAL VESTIBULAR SYSTEM affected?
PTOSIS, MIOSIS (PUPIL CONSTRICTS) & ENOPHTHALMOS on AFFECTED side
PERIPHERAL
CONGENITAL PERIPHERAL VESTIBULAR DZ
cause?
tends to present UNILATERAL/BILATERAL
can be caused by WHAT PRIMARY disease? what happens in this dz?
EXACT cause unknown
tends to be UNILATERAL, BILATERAL is RARE
can be caused by PRIMARY SECRETORY OTITIS MEDIA where MUCOID EFFUSION in TYMPANIC BULLA compromises NORMAL DRAINAGE
IDIOPATHIC PERIPHERAL VESTIBULAR DZ
tends to occur in WHAT AGE SA?
causes ACUTE/CHRONIC signs
severity is ___
often will RESOLVE in WHAT TIMELINE?
tends to occur in OLDER DOGS & CATS
causes ACUTE SIGNS
severity is VARIABLE
often will RESOLVE WITHIN 3 DAYS OF ONSET, but can be up to 3 WEEKS
INFECTIOUS PERIPHERAL/CENTRAL VESTIBULAR DZ
caused by WHAT INFECTION?
diagnosed via…
1 unique clinical sign?
common in ANIMALS with WHAT DZ? 2 species? (2)
treatment? (2, which is more effective?)
caused by OTITIS MEDIA/INTERNA that can ASCEND via AUDITORY TUBE; can be PERIPHERAL or VESTIBULAR
diagnosed via ADVANCED IMAGING (MRI/CT)
1 unique clinical sign? = FACIAL NERVE PARALYSIS ON SIDE OF LESION, aka HORNER’S SYNDROME
common in…
1. ANIMALS W/ SKIN ALLERGIES
2. BULLDOGS & CATS
treatment?
1. MEDICAL = ANTIBIOTICS, sometimes ANTIFUNGAL
- SURGICAL = SLIGHTLY more EFFECTIVE
what is the MOST COMMON INFLAMMATORY CAUSE of PERIPHERAL VESTIBULAR DZ in CATS?
what LESIONS do we see?
what AGE cats are affected?
treatment?
MOST COMMON INFLAMMATORY CAUSE = NASOPHARYNGEAL POLYPS
what LESIONS = SMALL BENIGN MASSES that OCCLUDE NORMAL DRAINAGE of NOSE & AUDITORY TUBE
AGE cats = 1-5 YEARS
Tx? = REMOVE POLYP via SURGERY or ENDOSCOPY
MOST COMMON CAUSE of PERIPHERAL VESTIBULAR DZ in DOGS?
dogs with this often have CONCURRENT DZ ___ ___
patients usually present with WHAT 3 CLINICAL SIGNS?
treatment? why?
MOST COMMONMOST COMMON CAUSE of PERIPHERAL VESTIBULAR DZ in DOGS? = CHOLESTEATOMA
dogs with this often have CONCURRENT DZ OTITIS MEDIA
patients usually present with WHAT 3 CLINICAL SIGNS?
1. PAIN OPENING MOUTH
2. PAIN ON PALPATION OF EAR
3. +/- PERIPHERAL VESTIBULAR SIGNS
treatment? why?
–> SURGICAL INTERVENTION because RISK OF RECURRENCE IS HIGH
what DRUG is MOST COMMONLY REPORTED for OTOTOXICITY & PERIPHERAL VESTIBULAR DZ?
name 3 other drugs that can cause OTOTOXICITY & PERIPHERAL VESTIBULAR DZ?
MOST COMMON = AMINOGLYCOSIDES
3 others?
1. DIURETICS
2. ANTISEPTICS
3. PROPYLENE GLYCOL
what METABOLIC DZ is POSSIBLY LINKED w/ PERIPHERAL VESTIBULAR DZ?
HYPOTHYROIDISM
TRUE/FALSE
TRAUMA is a COMMON CAUSE OF PERIPHERAL VESTIBULAR DZ
FALSE, it’s UNCOMMON cause
CONGENITAL CENTRAL VESTIBULAR DZ pathophys?
OCCIPITAL BONE is MALFORMED and PRESSES ONTO CEREBELLUM, causing OBSTRUCTIVE HYDROCEPHALUS and VESTIBULAR SIGNS
what 2 INFECTIOUS diseases in SA most COMMONLY cause CENTRAL VESTIBULAR DZ?
- FIP in cats
- DISTEMPER in dogs
MENINGIOENCEPHALITIS of UNKNOWN ETIOLOGY can cause ____ VESTIBULAR DZ
CENTRAL
VASCULAR CENTRAL VESTIBULAR DZ
aka?
diagnostics?
prognosis?
aka = STROKE
diagnostics = do MRI SEQUENCES
prognosis = FAIR
NEOPLASIA in the VESTIBULAR SYSTEM is MOST COMMONLY FOUND AT THE… (3 words)
CEREBELLAR PONTINE ANGLE
DEFICIENCY in WHAT NUTRIENT can cause ____ VESTIBULAR DZ?
look for WHAT on diagnostics?
DEFICIENCY in THIAMIN (B1) can cause CENTRAL VESTIBULAR DZ
look for BILATERAL SYMMETRICAL CHANGES on MRI
what ANTIBIOTIC can cause ____ VESTIBULAR DZ?
this occurs when… (2)
METRONIDAZOLE can cause CENTRAL VESTIBULAR DZ
this occurs when..
1. medication given AT HIGH DOSES
2. medication given OVER A LONG TIME
what 2 CLINICAL SIGNS are KEY to DETERMINING AFFECTED SIDE in VESTIBULAR DZ?
- PRESENCE OF PROPRIOCEPTIVE DEFICITS
- HYPERMETRIA
