Seizures

Question 1

Seizure

Answer 1

Manifestation of excessive or hypersynchronus electrical activity in the cerebral cortex

Question 2

Epilepsy

Answer 2

Clinical sign (not specific dz)
Recurrent seizures over a long period of time

Question 3

Reactive seizures

Answer 3

Seizures secondary to systemic disorder or brain insult
Stops when condition resolves, toxins

Question 4

Idiopathic epilepsy

Answer 4

Recurrent seizures with no other brain abnormality
Genetic in most patients

Question 5

Structural/ metabolic epilepsy

Answer 5

Seizures caused by identifiable lesions
Structural: degenerative, neoplasia, inflamm, infections, ischemic
Metabolic: HE, hypoglycemia, toxins

Question 6

Cryptogenic epilepsy (geriatric)

Answer 6

Seizures that start >7y of age
Underlying pathologic change in brain (can’t ID)

Question 7

Kindling

Answer 7

Recruitment over time of previously non-hyperexcitable neurons into a near by group of stimulating hyperexcitable neurons

Question 8

Mirroring

Answer 8

Recruit neurons from the opposite cerebral hemisphere via corpus callosum

Question 9

Why do seizures happen?

Answer 9

Inadequate neuronal inhibition
Excessive neuronal excitation

Question 10

Stages of a seizure

Answer 10

1. prodrome
2. aura
3. Ictus**
4. Post-ictal stage

Question 11

Prodrome

Answer 11

Long term indication of a forthcoming seizure
Restless, clingy, vocalization
Normal EEG (electroencephalogram)

Question 12

Aura

Answer 12

Initial sensation of seizure before observable signs
Caused by abnorm. electrical activity
Hiding, seeking owners, being agitated

Question 13

Ictus

Answer 13

The seizure

Question 14

Post-ictal stage

Answer 14

Transient abnormalities in brain function after ictus
Disorientation, restlessness, ataxia, blindness, deafness, behavior change
Minutes to days

Question 15

Generalized seizures

Answer 15

MC in dogs and cats

Question 16

Generalized tonic-clonic seizures

Answer 16

Tonic phase: sustained contraction of all muscles
Loss of consciousness then opisthotonos with limbs extended
Clonic: paddling/ jerking of limbs/ chewing

Question 17

Tonic seizures

Answer 17

Motor activity of only generalized muscle rigidity

Question 18

Clonic seizures

Answer 18

padding and jerking with no tonic component

Question 19

Atonic seizures

Answer 19

Rare
Sudden, brief, loss of muscle tone (drop of head or sudden collapse)
Looks like syncope or narcolepsy (dobermans)

Question 20

Myoclonic seizures

Answer 20

Brief, shock like contractions generalized or continued to individual muscle groups

Question 21

Focal (partial) seizures

Answer 21

Simple: doesn’t impair consciousness
Complex: consciousness impaired (bizarre behavior)

Question 22

Focal seizures with motor signs

Answer 22

Rhythmic contraction of facial or masticatory muscles
Abnorm movement of one limb
Turning head to one side

Question 23

Focal siezures with autonomic signs

Answer 23

Hypersalivation, vomiting, gagging, diarrhea, apparent abdominal pain

Question 24

Focal seizure with secondary generalization

Answer 24

Starts focal then spreads to entire brain and becomes tonic-clonic

Question 25

Cluster seizures

Answer 25

>2 in a 24 hours period (3+)

Question 26

Status epilepticus

Answer 26

EMERGENCY Single seizure lasting >5 min or multiple seizures without return to normal consciousness between events Can lead to neuronal death

Question 27

Generalized seizure criteria

Answer 27

Must meet 3/4: Autonomic signs (salivation, defecation, urination, lacrimation) Tonic or tonic-clonic movements or rhymical contraction fo face or limbs ↓ responsiveness/ unconsciousness Post-ictal response

Question 28

Lab work

Answer 28

CBC/Chem Liver function tests (ammonia, BAs) Toxin screening Thyroid screening (complicates seizures)

Question 29

Indications for advanced testing

Answer 29

Neuro deficits between seizure episodes Refractory seizures (don’t respond to AEDs) Onset <6m-1y or >5-6yr

Question 30

Ancillary tests (advanced)

Answer 30

MRI: gold standard CSF analysis: inflamm not seen on MRI (normal: <5 WBC, <25 protein) EEG: epilepsy

Question 31

Infectious disease testing

Answer 31

Toxoplasma gondii, neospora canis, tick panel, fugal titers Distemper: paired serum/ CSF Abs Viral PCR test

Question 32

When should you start AEDs?

Answer 32

Known/ suspected structural disease, prior hx of brain disease Cluster seizures Status epilepticus Having 1 seizures more than once every 3m Prolonged, severe or atypical postictal periods

Question 33

Guidelines of AED therapy

Answer 33

Maximize one drug before adding Don't start one then stop another Monitoring (serum levels and bloodwork)