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Flashcards in James - Neurology Deck (69):
1

VITAMINN D - what do the letters stand for?

• Vascular accidents
• Immune-­‐mediated / infecTous encephaliTs
• Trauma
• Anomaly: congenital malformaTon (parenchyma, meninges) • Metabolic: hepaTc, renal encephalopathies
• Idiopathic: geneTc (idiopathic) epilepsy
• Neoplasia: brain tumours
• NutriTon: thiamine deficiency
• DegeneraTve: storage diseases

2

What can cause encephalitis (inflammation of the brain)?
Infectious(6)/non-infectious

1. Inflammatory/infectious
a) Viral: CDV, FIP, rabies
b) Rickettsial (very tiny gram -ve, obligate intracellular bacteria): Ehrlichia canis, RMS
c) Bacterial(3): Staph, strep, coliforms
d) Fungal(5): blastomycosis, Histoplasmosis, cryptococcus, coccidioides, aspergillosis
e) Protozoal: Toxoplasma, neospora
f) Parasititc: verminous, larval migrans, cysticercosis
2. Non-infectious (immune-mediated) - approx 99% in Ontario

3

What structures are affected with GME? (Granulomatous meningoencephilitis)

Brain, spinal cord, meninges, can be optical (CN II)

4

What is the breed disposition for necrotizing encephalitis?

Small breeds, younger age (2-5 y)
e.g. pugs, maltese, chihuahua for NME
yorkshire terriers for NLE (Necrotizing Leukoencephalitis)

5

What is the difference between NME and NLE

Necrotizing meningoencephalitis
Necrotizing Leukoencephalitis

NME - immune-mediated against astrocytes, cerebrum/leptomeninges involved.
NLE - brainstem commonly involved (sometimes the cerebrum/leptomeninges)
Both affect grey & white matter

6

What is Necrotizing encephalitis?

NME - Cerebral & white matter + meningitis
NLE - Brainstem, cerebral white matter
--> eating away from mild edema

7

Necrotizing encephalitis - Diagnostic tests

CBC/profile/UA
Thoracic rads, abdominal ultrasound
MRI (brain +/- spinal cord
CSF analysis -> inc. nucleated cells/inc TP
Titres, PCRs
HIstopathology (definative)

8

Necrotizing encephalitis - Diagnostic tests for infectious cause suspected

Titres, PCRs

9

Brain tumours - signalment

Older dogs & cats

10

Brain tumours - primary (5)? Secondary (2)?

Primary(5): neurons, glial cells(supportive, form myelin), choroid plexus, ependymal (thin membrane lining the ventricles), meninges
Secondary: local extension, metastases

11

Most common primary brain tumour? Other common ones?

Meningoma
Glioma (astrocytoma, oligodendroglioma, glioblastoma)
Choroid plesus tumour (papilloma vs. carcinoma)
Ependymoma

12

Secondary Brain tumours - local extension (4)

Local extension:
• Calvarial (osteosarcoma, MLO)
• Nasal carcinoma
• Pituitary tumour
• PNST (CN V)

13

Secondary Brain tumours - metastatic (4)

Metastatic:
• HSA (hemangiosarcoma)
• LSA (lymphosarcoma)
• Carcinoma – mammary, pulmonary, prostatic
• Malignant melanoma

14

Brain Tumours Treatment
Factors for choice
4 options with details

• Factors: tumour type, location, morbidity/mortality, cost
• Corticosteroids
• Chemotherapy: lomustine, hydroxyurea, cytosine arabinoside
• Radiation therapy: linear accelerator, gamma knife
• Surgery

15

Metabolic Encephalopathies - what parts of the body cause these?

Cerebrocortical neurones are most susceptible to metabolic disrutpion (high energy demands, litter reserve)
Hepatic encepalopathy (congenital PSS, microvascular dysplasia, acutehepatotoxicity)
Renal encephalopathy (aka uremic encephalopathy)
Others:
Hypoglycemia
Electrolyte imbalances (e.g. sodium)
Hypoperfusion

16

Metabolic Encephalopathies - clinical signs

Clinical Signs:
• Symmetrical (whole system affected)
• ThalamocorTcal
• Depression, disorientaTon • Pacing, head pressing
• Menace response deficits • Seizures

17

Examples of congenital disorders

• Hydrocephalus
ly means a smooth brain without evidence
eopallium.
rtical fo•l diAngratochpnrooduidcecgysritsa,ndlysuslcei.nIct eispahaly, etc.

18

Circling to the right?

Thalamo-cortex, right (Direction they circle in is not *contra*)

19

Neurological exam

• MentaTon
• Gait & Posture
• Cranial Nerves
• Postural ReacTons
• Spinal Reflexes
• PalpaTon (Spinal Pain)

20

Depressed/obtunded - what is it & where is the lesion?

• Drowsiness, inattention, less responsive to environment
• Brainstem (ARAS)
• Thalamocortex

21

Stuporous - what is it & where is the lesion

• Unconsciousness +êresponsiveness • Can be aroused with noxious sTmulus • ParTal disconnecTon
• Brainstem (ARAS)

22

Comatose - what is it & where is the lesion

• Unconsciousness + NO responsiveness • Total disconnecTon
• Reflexes may be intact
• Brainstem (ARAS)

23

Disoriented - where is the lesion

• Thalamocortex &/or vestibulocerebellar

24

Thalamocortex: NE

• Mentation: depression / delirium / disorientation / Δ behaviour
• Head pressing, compulsion, wandering, pacing
• Gait & Posture: circling (ipsi), body turn (ipsi pleurothotonus)
• Mild hemiparesis (contra)
• Cranial Nerves: menace & nasal septum responses (contra)
• Postural Reactions (contra, almost normal gait)
• Spinal Reflexes
• PalpaTon (Spinal Pain): possible neck pain

25

Cranial Nerves: Tests

• Menace response (II, VII, cortex, cerebellum) • PLRs (II, III)
• Physiological nystagmus (VIII, MLF, III, IV, VI) • Nasal septum response (Vs, cortex)
• Muscles of masTcaTon (Vm) • Palpebral reflexes (Vs, VII)
• Facial symmetry (VII)
• Head Tlt (VIII)
• Swallow (IX, X, XII) • Voice (X)
• Tongue tone (XII)

26

Brainstem: NE

• Mentation: depression / stupor / coma
• Gait & Posture:
• UMN tetra/hemiparesis/plegia
• Decerebrate rigidity / opisthotonus
• Vestibular ataxia
• Cranial Nerves:
• Deficits III -­‐ XII
• Postural ReacTons:
• Deficits all limbs (ipsi)
• Spinal Reflexes: NAF
• PalpaTon (Spinal Pain): possible neck pain

27

Encephalopathy: Clinical Signs

• Thalamocortex ± Brainstem ± Cerebellum
• Lesion localizaTon: diffuse vs mulTfocal
• Beware the focal lesion:
• Extensive mass invading mulTple CNS regions
• Focal lesion w/ extensive 2nd surrounding edema • Focal obstrucTon of CSF flowèhydrocephalus

28

EncephaliTs: Differentials

• Vascular accidents
• Immune-­‐mediated / infecTous encephaliTs
• Trauma
• Anomaly: congenital malformaTon (parenchyma, meninges) • Metabolic: hepaTc, renal encephalopathies
• Idiopathic: geneTc (idiopathic) epilepsy
• Neoplasia: brain tumours
• NutriTon: thiamine deficiency
• DegeneraTve: storage diseases

29

EncephaliTs: Clinical Signs

MulTfocal / diffuse CNS • Acute / subacute
• Progressive

30

What areas are there problems in for the following:
encephalitis
Brain
MyeliTs

Spinal Cord
Meningitis
Meninges

31

Infectious Encephalitis

• Viral: CDV, FIP, rabies...
• RickeOsial: Ehrlichia canis, RMS
• Bacterial: Staph, Strep, coliforms
• Fungal: blasto, histo, crypto, coccidioides, aspergillosis • Protozoal: Toxoplasma, Neospora
• ParasiTc: verminous, larval migrans, cysTcercosis...

32

What is a seizure?

Seizure: A transient occurrence of signs due to abnormal excessive or synchronous neuronal acRvity in the thalamus & cerebral cortex (thalamocortex)
NeurolocalizaRon: Thalamocortex

33

What is epilepsy?

Epilepsy: A condiRon of recurrent seizures due to a chronic brain disorder

34

Prodrome:

Period preceding seizure, consisRng of a change in sensorium of paRent exhibited in behaviour; ~ hrs – days

35

Aura:

IniRal motor or sensory signs of a seizure; ~ seconds

36

Ictus:

Seizure itself

37

Post-­‐ictus:

Recovery period with transient abnormaliRes, e.g. mentaRon, menace, gait; ~ minutes – days

38

Timing of seizures

Singles (self-limited) - Isolated
Cluster - >= 2 in 24, recover in between
Status Epilepticus - continuous

39

Generalized Seizure (previously Grand mal)

• Originates at some point within & rapidly engaging bilateral networks
• LocaRon & lateralizaRon not necessarily consistent
• Usually symmetric (may be asymmetric)
• Consciousness oben impaired
• Previously known as “grand mal”

40

Focal Seizures

• Originate w/in networks limited to 1 hemisphere (unilateral)
• Ictal onset consistent between seizures
• PreferenRal propagaRon paeerns may include other hemisphere (“secondarily generalized”)
• ± Impairment of consciousness
• Previously known as:
• Petit mal
• Partial
• Simple partial
• Complex partial

41

Types of generalized seizures

• Generalized seizures • Tonic-­‐clonic
• Absence
• Myoclonic
• Clonic • Tonic • Atonic

42

• Tonic-­‐clonic
• Absence
• Myoclonic
• Clonic
• Atonic

Tonic - increased tone
Clone - repetative
Absence - forget where they are
Myoclonic - small motor twitch
Atonic - limp & collapse

43

Types of focal seizures

• Sensory
• Altered consciousness
• Motor / autonomic signs
• “Secondary generalizaRon”

44

Things mistaken for seizures

• Syncope: Transitory loss of consciousness, short, no pre-­‐/post-­‐ ictus; cardiac vs respiratory
• Cataplexy/narcolepsy
• Neck Pain
• VesRbular dysfuncRon
• Metabolic encephalopathy
• Idiopathic head tremor
• Generalized tremor syndromes
• Exercise-­‐induced weakness
• Compulsive disorders
• Stereotypy
• Feline estrus behaviours
• Myoclonus

45

Genetic epilepsy - what is it? cause? who?

Genetic Epilepsy
• Direct result of a known or presumed geneRc defect • Intracranial cause
• Generalized tonic-­‐clonic seizures
• Dogs >> cats / horses

46

Genetic Epilepsy - breeds?

• Australian Shepherd
• Beagle
• Belgian Shepherd (Tervueren)
• Bernese Mountain Dog
• Border Collie
• DalmaRan
• English Springer Spaniel
• German Shepherd Dog (AlsaRan)
• Golden Retriever
• Irish Woljound
• Keeshond
• Labrador Retriever
• PeRt Basset Griffon Vendeen • Lagoeo Romagnolo
• Shetland Sheepdog
• Standard Poodle
• Viszla

47

Prognosis for Genetic Epilepsy

• First seizure: 1-­‐5 years of age
• Normal interictal neurologic exam & diagnosRc tests
• Prognosis (efficacy of therapy)
• Breed related
• Border Collies & Australian Shepherds worse

48

Progressive Myoclonic Epilepsy

• Genetic epilepsy syndromes with progressive neurologic decline over Rme (abnormal interictal neurologic exam)
• Autosomal recessive

49

Structural/Metabolic Epilepsy

• Signalment does not fit geneRc epilepsy • Breed
• Age of seizure onset
• Interictal abnormaliRes found on diagnosRc tests, including neurologic exam

50

What are toxic causes for structural/metabolic epilepsy

Extracranial DDx
• Toxic: • Lead
• Organophosphates • Ethylene glycol
• Chocolate
• Xylitol

51

What are metabolic causes for structural/metabolic epilepsy?

• Hypoglycemia: iatrogenic, young/toy, insulinoma • Organ failure: hepaRc/uremic encephalopathy
• Electrolyte abnormaliRes: Na+, H2O, K+, Ca2+
• Hypoxemia
• Hyperlipidemia
• Hyperthermia

52

What are intracranial causes for structural/metabolic epilepsy?

• Vascular: hypertension, hyper/hypothyroidism (cats/dogs)
• Inflammatory/Infec@ous: encephaliRdes: GME, FIP
• (Bacterial, viral, fungal, protozoal, rickeesial, larval migrans)
• Trauma@c: head trauma
• Anomaly: hydrocephalus, cortical dysplasia (e.g. lissencephaly)
• Idiopathic: geneRc epilepsy
• Neoplasia:
• Primary (e.g. meningioma)
• MetastaRc (e.g. hemangiosarcoma)
• Degenera@ve:
• Mitochondrial encephalopathies / storage diseases / organic acidurias
• Thiamine deficiency (polioencephalomalacia)

53

Unknown epilepsy

Truly idiopathic
Signalment does not fit genetic epilepsy
No cause identified on diagnostic tests
How?
* Lesion is beyond the level of detecRon by current technology
• Genetic, just don’t know it yet
• Old trauma (birth? Previous encephalitis?)

54

Signalment for epilepsy causes
Causes based on age (< 1 year, 1-5, > 5 y)

Breed
Age
5y
• Neoplasia (primary >> secondary)

55

How does history help with determining if it is a seizure?

Seizure or not?
• Good descripRon of pre-­‐ictal, ictal, post-­‐ictal behaviour (VIDEO)
• Consciousness?
• DuraRon/frequency/Rme of day (seizures most common
when drowsy)
• Interictal mentaRon, personality

56

5 things in a basic biochem panel to say that the liver is working

Liver:
1. Protein (albumin)
2. BUN (makes urea from ammonia in the gut)
3. Bilirubin
4. Glucose: glycogenolysis (glucose will drop)
5. Cholesterol: (LDL, HDL etc)
Clotting factors - but not in a routing biochem

57

Seizure Exam (diagnosis

• Physical Exam:
• Rule out non-­‐epilepRc events (cardiac arrhythmia? Neck pain?) • Rule in extracranial causes (lymph nodes? CyanoRc mm?)
• Neurologic Exam:
• DO THE WHOLE EXAM
• 4 tests specific to thalamocortex?
NAF
• GeneRc (idiopathic) epilepsy • (Early neoplasia)
Deficits
• PosRctal
• Drugs (therapy)
• Structural/metabolic epilepsy

58

Seizure diagnosis minimum database

• CBC
• Serum biochemistry profile • 5 tests of liver funcRon?
• Electrolytes

59

Seizure diagnosis expanded database

• Thyroid panel: TT4, TSH, fT4
• Blood pressure (note machine, cuff, limb, recumbency, x3) • Toxicology
• Titres / PCR
• Thoracic radiographs
• Abdominal ultrasound

60

Seizure diagnosis advanced database (only if the previous tests are normal)

Only if previous tests are normal • EEG: if not sure seizure
• MRI vs CT
• CSF analysis (“spinal tap”)
• Biopsy?

61

EEG

Electro encephalogram

62

Treatment - when do you treat?

• Frequent seizures
• é frequency
• é severity
• Status epilepRcus or clusters
• Structural/metabolic epilepsy: treat the cause

63

Goals of treatment/commitment

• Practical goals of therapy: not seizure eradicaRon
• decreased frequency & severity
• Expected adverse effects
• Commitment
• Lifestyle: Dosing requirements
• Cost: Drugs + routine monitoring bloodwork
• Organization: Seizure dietary to monitor efficacy

64

Treatment - drug choices

Phenobarbital ***
Potassium ***
Bromide
Levetiracetam
Gabapentin/Pregabalin
Zonisamide
Topiramate (not common)
Phenytoin (not common)
Felbamate (not common)
Diazepam: too short-­‐acRng, tolerance builds up, emergency only

65

When should you monitor how the treatment is working?

When to check serum [drug] is within therapeutic range:
• @ steady-­‐state aber starRng Tx or dose Δ
• Uncontrolled seizures despite apparently adequate dose
• @ signs of dose-­‐related toxicity
• Every 6-­‐12 months (to check for pharmacokineRc Δ causing drib)

66

Status epilepticus

≥ 30 mins conRnuous/intermieent seizure acRvity • Start Tx ≥ 5 mins conRnuous/intermieent seizures

67

Potential physiologic complicaRons?

• Respiratory, cardiovascular, renal, autonomic, metabolic, neurologic
• Treatment: supporRve care +

68

Treatment in status epilepticus

Start with top & go down
Diazepam
Phenobarbitol
Propofol
Inhalants

69

Refractory Epilepsy

• QoL compromised by seizure severity or frequency, or medicaRon adverse effects
• ConsideraRons:
• Lack of response to 2 drugs
• ≥1 seizure/mo
• Duration ≥1yr