Epileptic seizures: Classification and diagnostic approach

Question 1

Definition of seizures

Answer 1

Transient + involuntary change in behaviour/neurological status due to the abnormal activity of populations of CNS neurons

Question 2

clinical signs - Focal seizures - Simple focal

Answer 2

no loss of consciousness

Question 3

clinical signs - Focal seizures - Complex focal

Answer 3

impairment of consciousness

Question 4

clinical signs - generalized seizures

Answer 4

convulsive or non-convulsive

Question 5

Status Epilepticus

Answer 5

Prolonged seizure activity
≥ 5mins (clinical)
≥ 30mins (basic science) -> brain damage
Life-threatening emergency

Question 6

Cluster Seizures

Answer 6

≥ 2 seizures in a 24hrs period

Serious

Question 7

prodrome - define

Answer 7

Behaviour changes that occur hours or days before the seizure

Question 8

aura - define

Answer 8

Sensory/focal onset seizures may start with a sensory experience
hard to prove in animals
owners often report a behaviour change of their dog minutes before the ictus

Question 9

ictus - define

Answer 9

The seizure event itself

Question 10

post-ictal - define

Answer 10

Neurological status alterations hours or days after the seizure
v.important

Question 11

Syncope - define

Answer 11

Partial or complete loss of consciousness
Lack of motor activity
No post-ictal signs
Shorter in duration

Question 12

events that can mimic seizures

Answer 12

syncope
Narcolepsy
Stimulated often by excitement, food, pharmacologically
Pain
Vestibular syndrome

Question 13

classification of seizures by aetiology

Answer 13

symptomatic/secondary seizure
reactive seizure
idiopathic/primary epilepsy
possible symptomatic/cryptogenic seizure

Question 14

symptomatic/secondary seizure - aetiology

Answer 14

structural brain lesion

Question 15

reactive seizure - aetiology

Answer 15

metabolic/toxic causes

Question 16

idiopathic/primary epilepsy - aetiology

Answer 16

suspected genetic cause

Question 17

possible symptomatic/cryptogenic seizure - aetiology

Answer 17

rule out only via PME

Question 18

extracranial epilepsy - causes

Answer 18

electrolyte disturbance (Hypernatraemia, Hyponatraemia, Hypocalcaemia)
energy deprivation (Thiamine deficiency, Hypoglycaemia) 
organ dysfunction (Uraemic/Hepatic encephalopathy)

Question 19

epilepsy/seizures in horses

Answer 19

Arab foals – congenital
Foals with perinatal asphyxia
Adults - structural or metabolic brain disease (migrating parasite, previous trauma, intra-carotid injection)

Question 20

Inter-ictal neuroexam findings - normal

Answer 20

idiopathic epilepsy
metabolic
neoplasia

Question 21

Inter-ictal neuroexam findings - abnormal - symmetrical

Answer 21

metabolic
toxic
hydrocephalus - degenerative disease

Question 22

Inter-ictal neuroexam findings - abnormal - asymmetrical

Answer 22

neoplasia
infl/infectious
anomalies

Question 23

Symmetrical – generalized onset

Answer 23

idiopathic epilepsy
metabolic
neoplasia
hydrocephalus
degenerative
trauma
midline structural problems

Question 24

Asymmetrical – focal onset

Answer 24

infl/infectious
neoplasia
anomalies
trauma
cryptogenic and idiopathic

Question 25

diagnostics - extracranial

Answer 25

``` Minimum data-base Complete blood count and cytology Biochemistry Ammonia if indicated resting bile acids Urinalysis (not common in horses) Blood pressure in mature small animals ```

Question 26

diagnostics - intracranial

Answer 26

``` Advanced imaging of the brain (MRI, CT) Cerebrospinal fluid analysis (CSF) White blood cell count Differential cell count Protein content Positive brain imaging or inflammatory CSF ```