Neurology Flashcards
1
Q
Signs of forebrain dysfunction
A
- Altered mental status
- Behavioural change
- Blindness (central) w/ decreased/absent menace reflex
- Loss of smell
- Abnormal movements and posture
- Altered postural reactions
2
Q
Signs of brainstem dysfunction
A
- CN deficits
- Proprioceptive deficits
- Hemi/tetraparesis
- Stupor or coma w/ abnormal pupil size
- Abnormalities in resp. and CDV function
3
Q
Signs of cerebellum dysfunction
A
- Unaltered (normal) mental status
- Intention tremors (head and eye) and hypermetria w/ preservation of strength
- Ataxia, wide base stance (ie. vestibular signs)
- Loss of menace response
4
Q
4 segments of the spinal cord
A
C1-C5
C6-T2
T3-L3
L4-S3
5
Q
List the order in which spinal functions (4) are lost
A
- CP
- Voluntary motor function
- Superficial pain sensation
- Deep pain sensation
6
Q
What is the motor function of UMN lesions?
A
reduced
7
Q
What is the motor function of LMN lesions?
A
reduced
8
Q
What is the muscle tone of UMN lesions?
A
increased
9
Q
What is the muscle tone of LMN lesions?
A
reduced
10
Q
contrast the muscle atrophy of UMN and LMN lesions?
A
UMN: slow and mild
LMN: rapid and severe
11
Q
increased reflexes are associated with UMN or LMN lesions?
A
UMN
12
Q
why might a dog with forebrain disease have a decrease in appetite?
A
due to loss of smell
13
Q
most common congenital cause of forebrain disease
A
hydrocephalus
14
Q
ddx for acquired forebrain disease
A
D A: epilepsy M: metabolic disorders (seizures) N: brain tumours I: inflammatory diseases (meningoencephalitis) T: hydrocephalus V: vascular accidents
15
Q
why is congenital hydrocephalus usually asymptomatic?
A
because the CPP is normotensive
16
Q
surgical management of hydrocephalus includes
A
insertion of a ventriculoperitoneal shunt
17
Q
how do prednisolone/omeprazole help hydrocephalus cases?
A
they decrease CSF production
18
Q
when are mannitol +/- frusemide indicated in hydrocephalus cases?
A
emergencies!
19
Q
3 types of metastatic brain cancer
A
- haemangiosarcoma
- melanoma
- mammary carcinoma
20
Q
tumors arising from meninges or supportive structures
A
- meningioma
- gliomas
- choroid plexus tumours
21
Q
describe the palliative care plan of a dog with a brain tumour
A
- dexamethasone then prednisolone = glucocorticoids reduce the peri-neoplastic inflam and oedema and can be surprisingly effective
- manage seizures w/ anti-epileptic drugs
22
Q
list 4 underlying disease states that could cause a ‘stroke’ in dogs
A
- renal disease
- hyperA
- hypertension
- hypercoagulable states
23
Q
treatment of a ‘stroke’ in a dog
A
no specific treatment - episodes usually resolve over time (hrs to days)
24
Q
the presence of an ‘aura’ indicates
A
that the cause of the seizure is intracranial
25
the most common type of seizure is
a generalised motor seizure - clonic-tonic muscle activity
26
describe the appearance of a partial/focal seizure
limited to a single region of motor activity - movement of a single limb/'fly catching'
27
describe the concept of kindling
The understanding that seizure frequency worsens over time and the seizure focus expands and enlarges to involve other regions of the brain. (like kindling a fire)
Thus best reason to be proactive in tx. of seizures
28
Generalisations of extracranial caused seizure presentation
- sudden in onset, generalised/cont (status) as caused by sudden exposure to toxin/metabolic crisis
29
Generalisations of intracranial caused seizure presentation
- tend to be isolated or clusters
- worsen (freq + severity) over wks - months
- focal or general
- usu have all three phases
30
what are the 3 phases of seizures
1. aura
2. seizure
3. post-ictal
31
DDx for intracranial causes of seizures
D: hydrocephalus
A: meningoencephalitis of unknown aetiology (necrotizing encephalitis, GME), idiopathic epilepsy
M
N: neoplasia
I: viral (CDV, FIP), parasite (neospora), fungal (cryptococcus)
T
V: cerebrovascular accidents (+ underlying disease)
32
when would you strongly advise seizure investigation?
If >1 seizure/cluster/status or residual neurological abnormalities between seizures
33
what infectious diseases do you want to rule out early in seizure investigations?
Toxoplasma
Neospora (dogs)
Cryptococcus
FIP (cats)
34
Rough cost of CSF tap and analysis
1k
35
CT scan estimated cost
1.5-2k
36
MRI cost
>2k
37
idiopathic epilepsy is unusual in cats (T/F?)
true - more likely to have primary disease
38
age of onset of idiopathic epilepsy
1-5yrs
39
two initial choices of AED
1. Phenobarbitone
| 2. Imepitoin
40
add potassium bromide to initial treatment of idiopathic epilepsy if:
1. Young GSD
| 2. Dogs w/ particularly severe seizures
41
Phenobarbitol dose
2-4mg/kg q12h PO
42
main side effects of phenobarbitol
drowsiness, ataxia -- once tolerance develops this usu. wears off
43
less common side effect of phenobarbitol
PU/PD, polyphagia, biochemical hepatopathy
44
what is your aim phenobarbitol serum concentration?
15-30ug/ml
45
MOA of imepitoin
partial GABA agonist
46
Imepitoin dose
10mg/kg q12h PO
| can increase by 10mg weekly to maximum dose 30mg/kg q12 PO if seizures not controlled
47
Potassium bromide dose w/ pheno
20-30mg/kg/day (single or divided) PO w/ phenobarbitol
48
Potassium bromide dose alone
40-50mg/kg/day (max 80mg/kg)
49
how long should you be seizure free before considering to stop AED?
at least 12months --> still risk of recurrence
50
reasons for refractory epilepsy
1. Disease related: undiagnosed underlying disease/cause
2. Drug related: not efficacious - inadequate dose/serum levels
3. Patient/client related: poor compliance
51
List 4 AED you can add to PB
1. Imepitoin
2. Levetiracetam (Keppra)
3. Gabapentine (Neurontin)
4. Zonisamide
52
Levetiracetam dose
20mg/kg q8h IV/PO
53
Gabapentin dose
20mg/kg q8h IV/PO
54
Common extracranial causes of seizures
Hypoglycaemia
| Hypocalcaemia
55
Less common extracranial causes of seizures
1. Toxins (most cause SE - some recurrent)
2. Electrolyte derangement (esp. Sodium)
3. Hyperlipidaemia
4. Thiamine deficiency
5. Polycythemia
6. Hypoxaemia (advanced resp. or cardiac disease) differentiate from syncope
56
List 6 toxins that cause seizures
1. OPs and carbamates: snail baits/ sprays
2. Metaldehyde
3. Rodenticides (1080, strychnine)
4. Mouldy food (penetrem mycotoxin)
5. Lead (paint, fishing sinkers)
6. Bufo toxins (toads
7. Pyrethrins (cats)
8. Naphthalene (cats)
57
What drug + dose can you use to stop SE?
1. diazepam 0.5-1mg/kg IV bolus
2. Midazolam 0.2mg/kg IV bolus
Rpt up to two more times
58
If seizures do not stop after 2 boluses of diazepam at 1mg/kg IV what drug can you use next?
1. Phenobarbitol 2-4mg/kg IV to effect
2. Levetiracetam IV
3. Propofol 1-3.5mg/kg IV bolus OR 6-12mg/kg/h CRI
59
what are two relatively common complications of prolonged seizure activity?
1. Cerebral oedema
| 2. Hyperthermia
60
Abnormalities of eye position can be caused by dysfunction in which CNs?
CN III, IV and VI
61
How can you test CN VII?
- menace reflex
| - palpebral reflex
62
what nerves does the menace reflex test?
CN II and VII
63
what nerves does the palpebral reflex test?
CN V and VII
64
DDx of CN VII paralysis?
```
D: myasthenia gravis
A: idiopathic
M: hypoT (debated)
N: neoplasia of CN VII or assoc. structures
I: otitis media/interna
T: trauma (to side of head)
V
```
65
causes of temporal muscle atrophy
- Trigeminal nerve disease
- MMM
- corticosteroid use
- old age
66
what are the two functions of the CN V?
Trigeminal nerve
- sensory nerve of the face
- motor nerve (LMN) to muscles of mastication
67
Treatment for idiopathic trigeminal neuritis
there is none
| - assist eating/nutrition - tube/hold mouth closed
68
DDx for unilateral CN V disease
nerve sheath tumour
69
Dx of MMM
CS and serum [anti-2M fibre antibodies]
70
damage to the oculomotor nerve (CN III) results in
lateral strabismus
71
damage to the trochlear nerve (CN V) results in
rotated strabismus?
72
damage to the abducens nerve (CN VI) results in
medial strabismus
73
4 signs of horner's syndrome
- miosis
- enopthalmus
- prolapse of third eyelid
- ptosis
74
what are the three neural components that when damaged result in horner's?
1. UMN midbrain to T1-3
2. LMN vagosympathetic trunk to cranial cervical ganglion
3. LMN cranial cervical ganglion to eye
75
DDx for horner's syndrome
50% idiopathic vs other.
T: brachial plexus nerve root injury/avulsion, neck injuries (choker chains, needle stick, bite wounds), otitis externa/media, skull fractures and retrobulbar lesions, cervical spinal injury, anterior mediastinal lesions, brainstem injury
76
define syncope
sudden, transient loss of consciousness and postural tone - a secondary neuro event to an extracranial disease
77
3 causes of ataxia
1. vestibular disease
2. cerebellar disease
3. sensory (proprioceptive) deficit (dt disruption of sensory pathways) - loss of sence of limb/body position. Any lesion of sensory pathways in peripheral nerves or central in spine (most common) or brain.
78
4 neuro signs of vestibular disease
- ataxia
- head tilt
- nystagmus
- falling/circling
79
the disease process of central vestibular system occurs in..
the vestibular nuclei in brainstem
80
the disease process of peripheral vestibular system occurs in..
- the inner ear (semicircular canals)
| - cranial nerve VII
81
differentiate peripheral and central vestibular disease based on CS
P: often has Horner's and CN VII/V signs
C: often has nystagmus changes direction, vertical nystagmus, CP and postural deficits and paresis, but RARELY horners/CN V/VII signs
82
Causes of peripheral vestibular disease
- otitis externa (externa/media)
- ototoxic drugs
- trauma to lateral skull
- tumours of middle ear
- idiopathic (geriatric)
83
causes of central vestibular syndrome
- brain tumours (meningiomas, choroid plexus papillomas)
- GME
- meningoencephalitis - cryptococcus, toxoplasma, neospora, viral CDV
- metronidazole toxicity
- head trauma
- cerebrovascular accidents
84
management of idiopathic peripheral vestibular syndrome
- remove from owners 24-48hrs
- keep in quiet/dark
- maropitant 1-2mg/kg q24h SC (motion sickness) OR ACP judicious dose
- should improve over 24-48hs and gradually recover over 1-4wks
85
congenital and acquired cerebellar disease results in severe ataxia with preservation....
of strength and normal mentation (unless multifocal cause)
86
DDx for generalised LMN disease
D: Drugs (vincristine, cisplatin), myasthenia gravis
A:
M: hyperglycaemia (cats w/ diabetic neuropathy), hypoglycaemia, lytes (Na, K, Ca), hypothyroidism
N: paraneoplastic syndromes, lymphoma
I: polyradiculoneuritis, toxoplasma or neospora polyneuritis
T: envenomation (Ixodes holocyclus/cornuatus, snakes), poisons (tetrodotoxin, botulism)
V: hypoxaemia/ischaemia (FATE)
87
diseases of the NMJ
- tick paralysis
- botulism
- myasthenia gravis
88
What is idiopathic polyradiculoneuritis?
aka Coonhound paralysis --> immune-mediated inflm of the spinal nerves causing ascending tetraparesis/plegia for 2-4d
89
recovery period of idiopathic polyradiculoneuritis?
weeks to months
90
management actions of prolonged recumbency
1. Good nursing care + proactive rehab
2. Hydration via IVFT
3. Nutrition: hand feeding/tube
4. Freq. turning
5. Physio
6. Cushions/padded support
7. Bladder/bowel care - U-cath, shave hair + barrier creams, mild laxatives, nappies?
91
Complications of recumbency
1. Progressive muscle atrophy
2. Pressure sores and necrosis
3. UTI
4. Pneumonia
92
what AB for toxoplasmosis/neospora?
clindamycin
93
Most common causes of meningoencephalitis
1. Granulomatous meningoencephalitis (GME)
| 2. Aseptic meningitis-arteritis (‘steroid-responsive meningitis arteritis’ SRMA)
94
Causes of infectious meningoencephalitis
1. Fungal -cryptococcosis and aspergillus (in GSD)
2. Protozoal – neosporosis and toxoplasmosis
3. Bacterial – very low incidence. Any bacteria (Brucella canis overseas)
4. Viral – very low incidence in dogs AUS. Distemper and rabies overseas. FIP in cats.
95
GME diagnosis requires
CSF collection --> Mononuclear pleocytosis (lymphocytes and macrophages), increased protein (but normal CSF has also been recorded occasionally)
96
GME tx
1. Immunosuppressive medication:
- Pred 2-4mg/kg/day divided
- Cytarabine 50mg/m2 q12h for 4 doses rpt q3wks for 4 cycles
97
survival time for GME
1-2.5yrs
98
what type of dog usu. gets GME?
small/minis, geriatric
99
Prognosis of SRMA
good prognosis, tx/ w prd for 6-12months
100
Detrusor muscle is innervated by
the pelvic nerve (parasymp) (S1-S3) and hypogastric nerve (L1-L4) (symp)
101
Internal urethral sphincter (smooth m.) is innervated by
the hypogastric n (L1-L4)
102
Anal sphincter and external urethral sphincter are innervated by
pudendal nerve (S1-S3)
103
UMN bladder signs
Increased tone to external urethral sphincter: urethral obstruction, full bladder that is difficult to express
104
what segment of the spinal cord results in UMN bladder signs
cranial to segment L7 ( = L5 vertebrae)
105
LMN bladder signs
Decreased tone to external urethral sphincter: incontinence, bladder that is easy to express
106
Define neurapraxia
Mildest form of nerve injury from blunt trauma or compression. Transient conduction block w/out nerve degeneration recovery in weeks to months
107
Define axonotmesis
Disruption of nerve cell axon, w/ Wallerian degeneration occuring below and slightly proximal to the site of injury. Axons and their myelin sheath are damaged, but Schwann cells, the endoneurium, perineurium and epineurium remain intact --> loss of conduction but recovery is possible at ~1mm/day.
108
Define neurotmesis
Both nerve and nerve sheath disrupted (eg. Severance) --> regeneration will not occur, no recovery
109
Immune-mediated polymyositis can often see very elevated CK - what values?
2,000-20,000+
110
tx of immune-mediated polymyositis
corticosteroids + other immunsuppresives
1. Prednisolone +
2. Azathioprine OR cyclosporine OR mycophenolate
111
if immune-mediated polymyositis is not treated what happens?
fibrosis and stiffness of muslces
