Epileptic seizures

Question 0

When in the day do seizures occur more often and why?

Answer 0

At night as the brain is less active and has less inputs from sensory organs

Question 1

Define a seizure

Answer 1

Hypersynchronicity of neuron firing where all nerves fire at the same time
Transient and involuntary change in behaviour or neurological status due to the abnormal activity of populations of CNS neurons

Question 2

How are seizures named?

Answer 2

By clinical signs

Question 3

How are seizures treated?

Answer 3

Increase inhibition not to decrease excitation as a way to do this hasn’t been discovered yet

Question 4

What are the different methods of classifying seizures?

Answer 4

By clinical signs
By duration/timing of seizure
By aetiology

Question 5

How are focal seizures classified?

Answer 5

Simple focal = no loss of consciousness
Complex focal = impairment of consciousness
Focal seizure with secondary generalisation
And then also by sensory/motor/autonomous

Question 6

How are generalised seizures classified?

Answer 6

Convulsive - further by type of convulsion

Non-convulsive

Question 7

Define status epilepticus

Answer 7

Prolonged seizure activity which requires treatment if longer than five minutes as at this point it becomes a clinical case

Question 8

What happens when a seizure lasts a long time?

Answer 8

If its longer than 30 minutes then it results in brain damage
The longer a seizure lasts the more difficult they are to treat

Question 9

Define cluster seizures

Answer 9

More than 2 seizures in a 24 hour time period

Question 10

What do cluster seizures indicate?

Answer 10

That it is a serious case that is likely to be more difficult to treat

Question 11

What are the four stages of a seizure?

Answer 11

Prodrome = behavioural changes that occur hours/days before 
Aura = sensory/focal onset seizures start with a sensory experience such as a perceived smell/feeling of deja vu
Ictus = seizure onset
Post-ictal = neurological status alterations hours or days after the seizure

Question 12

What types of seizures can be focal and self-limiting?

Answer 12

Sensory
Motor
Automatisms (orofacial/chewing gum)

Question 13

What types of generalised seizure can be self-limiting?

Answer 13

Tonic-clonic
Clonic
Myoclonic
Atonic

Question 14

What types of focal seizure can be clustered or continuous?

Answer 14

Epilepsia partialis continua = motor

Aura continua = sensory and difficult to classify in dogs

Question 15

Which types of generalised seizure can be clustered or continuous?

Answer 15

All of them

Question 16

What are reflexive seizures?

Answer 16

Seizures that have a precipitating stimulus

Question 17

What events can mimic seizures?

Answer 17

Syncope, narcolepsy, pain (esp cervical), vestibular syndrome, movement disorders

Question 18

What are the features of a tonic-clonic seizure?

Answer 18

Tonic phase 1st where all the muscles tense

Clonic phase follows which is seen as the limbs jerking rapidly and rhythmically

Question 19

What is the appearance of a clonic seizure?

Answer 19

Repeated jerking movements of limbs caused by rapidly alternating contraction and relaxation of muscles

Question 20

What do myoclonic seizures look like?

Answer 20

Brief shock like jerks of a muscle/group of muscles

Question 21

What do atonic seizures look like?

Answer 21

Abrupt loss of muscle tone resulting in a drop to the floor

Question 22

How can seizures be classified by aetiology?

Answer 22

-> Functional -> Idiopathic epiliepsy
-> Intracranial -> Structural -> (possible) Symptomatic
Seizures
-> Extra-cranial -> Intrinsic (metabolic -> Reactive
-> Extrinsic (toxic) -> Reactive

Question 23

What are some differential diagnoses of extra-cranial seizures?

Answer 23

Electrolyte imbalances (hyper/hyponatraemia, hypocalcaemia)
Energy deprivation due to thiamine deficiency or hypoglycaemia
Organ dysfunction such as uraemic encephalopathy (kidneys) or hepatic encephalopathy (liver)

Question 24

What are some differential diagnoses of intra-cranial seizures?

Answer 24

Cryptogenic epilepsy (head trauma from years ago with normal imaging)
Symptomatic epilepsy

Question 25

What are the DDx for symptomatic epilepsy?

Answer 25

Anomalous (hydrocephalus/lissencephaly/arachnid cyst)
Neoplastic (meningioma/ependyoma/choroid plexus tumour/astrocytoma/oligodendroglioma)
Infectious or inflammatory ( various meningio-encephalomyelitis)
Traumatic
Vascular (ischaemic or haemorrhagic secondary to hypertension)

Question 26

What are the characteristics of idiopathic epiliepsy?

Answer 26

Ion channel genetic mutation or other genetic abnormality
Found in dogs aged 6 months to 6 years
Generalised seizures or partial seizures depending on breed

Question 27

What breeds are affected by generalised idiopathic epilepsy?

Answer 27

Beagles, GSD, Labradors, Golden Retrievers, Bermese Mountain Dogs, Belgian Terwerens, Keeshounds, Irish Wolfhounds

Question 28

What breeds are affected by partial idiopathic epilepsy?

Answer 28

Vislas, English Springer Spaniels, Danish Labradors, Lagotlo Romagnolo, Standard Poodles and Finnish Spitz

Question 29

How can signalment help refine the problem list?

Answer 29

< 6 months = metabolic, infectious, congenital, toxic, trauma
6 months - 6 years = idiopathic, inflammatory/infectious, metabolic, neoplastic, toxic, traumatic
> 6 years = neoplastic, idiopathic late onset, inflammatory/infectious, metabolic, toxic, trauma

Question 30

How do you define disease onset and progression?

Answer 30

DAMNITV

Degenerative, anomalous, metabolic, neoplastic, inflammatory/infectios, trauma/toxic, vascular

Question 31

How do inter-ictal neuro-exam findings narrow down the problem list?

Answer 31

Normal = idiopathic, metabolic, neoplastic, toxic
Abnormal symmetrical = metabolic, toxic, hydrocephalus, degenerative, midline structural
Abnormal asymmetrical = neoplastic, inflammatory/infectious, anomalies

Question 32

What does a minimum data base include?

Answer 32

CBC and cytology, Biochemistry, Ammonia, Resting bile acids, Urinalysis, Blood pressure in mature animals

Question 33

What additional diagnostic methods can be used?

Answer 33

Imaging using MRI/CT
CSF analysis for WBC, differential cell count, protein content
Positive brain imaging/inflammatory CSF