Seizures Flashcards
What is an epileptic seizure? What is epilepsy?
manifestation of excessive and/or synchronous activity in the brain -> transient signs
Epilepsy = a brain disorder that causes unprovoked seizures
What is a reactive seizure? What causes it?
Seizure occurring as a NATURAL response from the NORMAL BRAIN from transient disturbance (metabolic, toxic), which is REVERSIBLE when disturbance is removed
3 Terms for Seizure Semiology
- Focal epileptic seizures
- Generalized epileptic seizures
- Focal epileptic seizures evolving to generalized
Generalized: Tonic-clonic, tonic, clonic, myoclonic
3 different etiologies of epileptic seizures, and most common? Average life span?
idiopathic - MOST COMMON, GENETIC; Avg lifespan = 7 years, tx extends 2.3 years
structural
epilepsy of unknown cause (Cryptogenic = old term!)
Cryptogenic epilepsy is defined as epilepsy of presumed symptomatic nature in which the cause has not been identified. The key difference between idiopathic and cryptogenic epilepsy is that idiopathic epilepsy is an inherited type with predominantly genetic or presumed genetic origin.
MRI - what type of epilepsy?
Idiopathic epilepsy
Characteristics of focal seizure
hyper-salivation, fly-biting, facial tremors
Characteristics of generalized seizure and the 3 phenotypes
Autonomic signs (hypersalivation), lateral recumbency, all 4 limbs involved
1. Myoclonic
2. Clonic
3. Tonic
Pre-ictal period - describe two parts
Prodromal: hours-days, abnormal compulsive behaviors
Aura: minutes-to-seconds before seizure, abnormal posture, hypertonia of facial structures
Ictus period
the epileptic seizure itself
Post-ictal period
transient, brain restores its normal function -> can last hours to days
Interictal period
time between resolution of post-ictal period and the next ictal period
Clonic phenotype (generalized seizure)
Convulsions: paddling, jerking/twitching
Tonic phenotype (of generalized seizure) - define
hypertonia / abnormal posture
Define a Cluster seizure vs. Status Epilepticus
Cluster: ≥ 2 seizures within 24 hours. Should regain consciousness b/w each!
Status Epilepticus: 20-30 mins of continuous seizure activity (≥ 5 mins in duration, > 2 seizures w/out recovery in b/w)
Myoclonic phenotype (generalized seizure)
“HICCUPS” - brief, shock-like jerks of a muscle / muscle groups
- Doesn’t look as severe as convulsion (clonic) seizure, but still considered a generalized seizure
What is syncope? How does this differ from epileptic seizures?
Decreased blood flow to the brain -> “fainting”
syncope usually triggered by exercise and excitement with sudden collapse that is much more brief than seizures, lasting only seconds
- DDX WITH A SEIZURE -> difference = a eplieptic seizure lasts ≥ 90 seconds, and with syncope RELAXATION occurs shortly afterwards
What typically triggers narcolepsy?
Excitement (from getting ready to eat)
Presentation of vestibular disease (non-seizure activity)
Nystagmus
Presentation of Paroxysmal Dyskinesia (non-seizure activity)
Episodic, Abnormal, involuntary movements that occur as spasms without loss of consciousness and lasting minutes to hours
Some Labradors with these atypical seizures simply stagger and look dazed or confused for a few seconds or minutes and then recover, without ever falling over. Others have a 2 to 5 minute episode (occasionally longer) where they appear anxious and are unable to stand erect and walk but they will attempt to crawl to their desired location. Some dogs will experience either uncontrollable trembling or increased muscle tone during an episode and a few simply develop a head tremor or trembling while they remain abnormally quiet and recumbent.
Affected dogs maintain consciousness and appear to be visual, able to recognize their owners and can even obey commands during the episodes. Episodes are most likely to occur when the dog is drifting off to sleep or when awaking from sleep in many dogs but exercise and excitement are common triggers in others. Affected dogs are normal between these episodes which occur suddenly, without warning. Systemic evaluation for metabolic, neoplastic and infectious causes of seizures is negative and repeated toxin exposure is unlikely. Related dogs may be similarly affected.
SOURCE https://vetmed.umn.edu/research/research-labs/canine-genetics-lab/canine-genetics-research/atypical-seizures-paroxysmal-dyskinesia#:~:text=An%20episodic%20movement%20disorder%20that,especially%20retriever%20crosses%20and%20poodles)
Presentation of head tremors (non-seizure activity)
30s-1 min, head shaking, animal is responsive // tremors end when owner calls animal
