Brainstem Disease Flashcards
1
Q
What is Pontomedullary syndrome?
A
- Lesion of the nucleus (intra-axial lesion) or the nerve (extra-axial lesion)
- Multiple cranial nerve deficits
- 5, 6, 7, 8 (Central vestibular)
- 9, 10, 12 (nucleus ambiguus)
- 7, 9, 10, 11, 12 are closely associated in the skull
- Hemiparesis to tetraparalysis
- ipsilateral limb deficits
- UMN to all limbs
- Mass lesions may impact brainstem and cerebellum concurrently
2
Q
What is Midbrain syndrome?
A
- Depression, coma
- hemiparesis to tetraplegia
- Contralateral limb deficits with UMN signs
- Massive lesion ⇢ decerebrate rigidity (opisthotonos)
- CN3 deficits (ophthalmoplegia, mydriasis)
- Hyperventilation (respiratory alkalosis)
- Cavernous sinus syndrome: CN 3, 4, 5, 6
3
Q
What is Hypothalamic syndrome
A
- Behavior changes
- CN2 deficits (variable)
- Abnormal temperature regulation
- Abnormal appetite
- Central diabetes insipidus
- Normal gait
4
Q
What are the components of the vestibular system?
A
- Peripheral
- Vestibulocochlear nerve (CN8)
- Vestibular apparatus (semicircular canals, utriculus, sacculus of inner ear)
- Central
- Brainstem: vestibular nucleus (4 on each side)
- Cerebellum: caudal cerebellar peduncle, ipsilateral flocculonodular lobe
5
Q
What is Vestibular Syndrome?
A
- Head tilt, falling, rolling
- Walking in tight circles
- Nystagmus
- Ventrolateral strabismus on ipsilateral side
- Motion sickness (vomiting, salivation)
- Must differentiate peripheral vs. central
- Increased extensor tone on side opposite of lesion
6
Q
What is Peripheral Vestibular syndrome?
A
- Loss of balance, head tilt, falling, VL strabismus
- Nystagmus can be:
- horizontal or rotary
- Rarely is it vertical, on occasion it can be induced
- Constant when present
- Slow phase toward lesion
- Faster than central vestibular nystagmus
- Possible CN7 deficits, Horner’s
7
Q
What is Central Vestibular Syndrome?
A
- Loss of balance, head tilt, falling VL strabismus
- Nystagmus
- Horizontal, rotary, or vertical
- inducible in different position (upside down)
- Changing nystagmus
- Conscious proprioceptive deficits confirms CVS
- Cranial nerve deficits:
- Possible CN 5, 6, 7 (or 9, 10, 12)
- Deficits other than 7 confirm CVS
8
Q
What diseases are common in the Peripheral Vestibular System?
A
- Congenital vestibular disease
- Lymphocytic labyrinthitis
- Hypothyroidism
- Neoplasia
- peripheral nerve sheath tumor
- Ceruminous gland ACA
- Otitis media/interna
- Most common cause
- Otoscopic exam, CT, MRI
- Culture if possible
- Bulla osteotomy
- Otic medications
9
Q
What is Idiopathic Vestibular Disease? etiology? treatment?
A
- Acute to peracute onset head tilt, nystagmus, rolling
- No evident structural, metabolic or inflammatory disease
- Affects old dogs, cats of any age
- Rapid Recovery
- Noticeable improvement in 24-48 hours
- Normal within 2-3 weeks
- Residual head tilt
- Supportive Care
- Maropitant, Diphenhydramine, Meclizine, Diazepam
10
Q
What are some diseases of the Central Vestibular System?
A
- Neoplastic: any type of CNS neoplasia
- Infectious disease
- Canine distemper virus encephalomyelitis
- Rocky Mountain Spotted fever (other rickettsials)
- Bacterial and fungal meningoencephalitis
- Primary systemic vasculitis
- Granulomatous meningoencephalitis and other MUE
- Metronidazole toxicity
11
Q
What are the signs of Cerebellar Syndrome?
A
- Dysmetria (hypermetria)
- Truncal ataxia
- Intention tremors
- Broad based stance
- Ataxia with preserved strength
- Abnormal postural reactions
- Menace deficits with intact vision and PLR
12
Q
Where are the lesions in cerebellar syndrome?
A
ipsilateral to abnormality
13
Q
What are some diseases of the Cerebellum?
A
- Cerebellar cortical atrophy
- Cerebellar abiotrophy
- Neuroaxonal dystrophy
- Cerebellar hypoplasia
- Hereditary
- Congenital
- Caudal occipital malformation syndrome
- Neoplasia
- Infectious
- Canine herpes virus
- Feline panleukopenia
- Canine distemper virus
- FIP
- Fungal, rickettsial, protozoal, algal
- Primary systemic vasculitis
- Lysosomal storage disease
- Vascular accident
