Lecture 24

Question 1

What is an epileptic seizure?

Answer 1

hyper-synchronous epileptic activity of neurons in the brain

Question 2

What are the charactersitics of an epileptic seizure?

Answer 2

-very organized firing of the neurons all at once
-usually self-limiting
-typically around 90 seconds long (or less)
-can be motor, autonomic, or behavioral

Question 3

What are the characteristics of a reactive seizure?

Answer 3

-response of normal brain to transient disturbance
-metabolic or toxic in nature
-reversible when disturbance is rectified
-can occur in any animal

Question 4

What is the definition of epilepsy?

Answer 4

-disease characterized by predisposition to generate epileptic seizures
-at least 2 unprovoked epileptic seizures more than 24 hours apart

Question 5

what are the characteristics of the prodrome period?

Answer 5

*long-term change in disposition
*occurs before the seizure
*signs include:
-restlessness
-anxiety
-aggression
-attention-seeking

Question 6

What are the characteristics of the postictal period?

Answer 6

-where normal brain function is restored
-cannot do accurate neuro. exam in this phase; any neuro sign could be related to seizure
-lasts minutes to days
-deficits more likely to be permanent if lasting more than 3 days
-commonly see disorientation, behavior changes, ataxia, hunger, and blindness

Question 7

What are the types of ictus/seizure activity?

Answer 7

-generalized epileptic seizure (tonic-clonic)
-focal epileptic seizure
-focal seizure evolving into generalized

Question 8

What is the pathology of seizures?

Answer 8

-decreased GABA and glycine
-increased glutamate and aspartate
-high frequency burst of AP combined with hyper-synchronization of neuronal population leads to seizure

Question 9

What are the characteristics of focal epileptic seizures?

Answer 9

-lateralized and/or regional signs
-ictal onset consistent between seizures
-activity arises in localized groups of neurons
-can be motor, autonomic, or behavioral

Question 10

What are the characteristics of generalized epileptic seizures?

Answer 10

-bilateral involvement/entire forebrain involved
-tonic, clonic, or tonic-clonic
-patient loses consciousness
-autonomic effects (urination, salivation, defecation) are common

Question 11

What are characteristics of focal evolving into generalized epileptic seizures?

Answer 11

-spread from initial region to bilateral
-most common type in dogs
-focal component lasts seconds to minutes; easy to miss

Question 12

What are cluster seizures?

Answer 12

-two or more seizures within a 24 hour period
-recovery or post-ictal phase between the seizures

Question 13

What is status epilepticus?

Answer 13

-greater than 5 minutes of continuous epileptic seizures OR
-2 or more discrete seizures with incomplete recovery of consciousness

Question 14

What are the characteristics of non-convulsive status epilepticus?

Answer 14

-status lacking outward manifestation
-body is limp/comatose but brain is still firing
-can only be definitively diagnosed via EEG

Question 15

What toxin is likely to be causing seizures in a pig that walks backwards during the seizure?

Answer 15

salt intoxication

Question 16

What are the possible vascular causes of seizures?

Answer 16

-acute onset
-secondary to infarct or hemorrhage
-feline ischemic encephalopathy due to cuterebra
-anesthesia-induced; especially when using mouth gags in cats
-comorbidities: HCM, vegetative endocarditis, hypothyroidism, CKD, liver dz hypertension

Question 17

What are the possible infectious/inflammatory causes of seizures?

Answer 17

-usually progressive
-toxoplasmosis/neospora
-fungal
-tick-borne
-FIP
-abscess (ear infection, post-bite wound)
-meningoencephalitis of unknown origin

Question 18

What are the characteristics of traumatic and toxic causes of seizures?

Answer 18

-trauma cases will often have external injuries and other neuro. signs in addition to seizures
-toxic cases often have acute onset (exception is lead) and other associated signs

Question 19

What are potential anomalous causes of seizures?

Answer 19

-hydrocephalus
-porencephaly/brain not developing and filling in with CSF
-meningocele/meningoencephalocele

Question 20

what are the possible metabolic causes of seizures?

Answer 20

-hypoglycemia
-electrolyte abnormalities (hypoNa, hyperNa, hypoCa)
-hypertensive encephalopathy
-hepatic encephalopathy
-thiamine deficiency
-polycythemia/thickened blood

Question 21

What are the characteristics of idiopathic epilepsy?

Answer 21

-onset between 6 months and 6 years of age
-no inter-ictal neurologic deficits
-metabolic causes must be excluded

Question 22

Which neoplasms can cause seizures?

Answer 22

-meningioma
-glioma
-lymphoma
-pituitary macroadenoma
-any tumor with forebrain involvement

Question 23

Which neoplastic cause of seizures has the best prognosis in cats?

Answer 23

meningioma: great prognosis with surgical removal