Paroxysmal Disorders Flashcards
What are paroxysmal disorders?
constellation of conditions whose common clincial denominator is the association with episodic, transient, and generally self limiting abnormalities in behavior, movement, or consciousness in an animal that appears normal in between episodes
What is a paroxysm?
A sudden recurrence, outburst, or intensification of symptoms
What is the most important step in classifying a paroyxsmal disorder?
Obtaining a thorough history from someone that witnessed the event
Paroxysmal disorders can result from _ or _ etiologies
epileptogenic or nonepileptogenic
Non-epileptogenic causes can result from what diseases?
neurological or cardiovascular
What are some examples of neurologic non-epileptogenic etiologies
narcolepsy, cataplexy, movement disorders, neuromuscular weakness, behavioral stereotypes
What is an example of a cardiovascular nonepileptogenic etiology
syncope
What are examples of epiletpgenic causes
idopathic/ genetic, structural, or unknown epilepsides
What is narcolepsy/ cataplexya
rare disease affecting the neuronal circuit in brain that regulates the sleep/wake cycle. Specifically involves abnormalities of the hypocretin/orexin neurotransmitter.
Narcolepsy can be inherited or genetic, what is this caused by?
a mutation in the HCRTR2 gene resulting in abnormality hypocrin/orexin receptors in the brain
-this is autosomal recessive in dobermans, dachunds and lab retrievers
The acquired form of narcolepsy occurs due to?
hypocretin/orexin deficiency in the brain , affects older animals
What are the CS of narcolepsy?
cataplectic attacks are the primary manifestation of the disease. Sudden and complete atonia causing collapse lasting several seconds to minutes
What are cataplexy triggers?
feeding, excitement/stress, concurrent disease
Do the animals remain conscious during a narcoleptic attack?
Yes, particullary at the beginning . Episode can usually be interrupted with petting or interacting with the animal
How quickly do animasl recover from a narcoleptic episode?
quickly. can experience dozens of episodes throughout the day
How do we diagnose narcolepsy?
Uusually based on CS +/- a genetic test where applicable.
-episodes can be induced using food induced cataplexy test or pharmacologically induced with physotiigimine.
What does an EEG show during a cataplexy or narcolepsy episode?
low amplitude, fast waves consistnet with paradoxial sleep
How can we test for the acquired form of narcolepsy?
Genetic testing for the HCRTR2 mutation or measurement of CSF hypocretin/orexin concentrations
How do we treat narcolepsy?
Imaprimaine, clomipramine, yohimbine
-treatment of excessive sleepiness can be done with stimulants
-some cases of acquired can have resolution if the stimulus disappears
Describe behavioral disorders that are characterized as episodic stereotypies
-aggression or compulsive disorder
-many manifest as continous rhythmic pacing, oral facial autism (lip smacking) or tail chasing
How are animals in between behavioral episodes?
usually normal
-there is no alteration in consciousness or muscular tone during these episodes but there is usually an identifiable trigger
what are transient vestibular attacks?
A rare syndrome that is characterized by recurrent, transient signs of vestibular disease (head tilt, nystagmus, vestibular ataxia) that resolves spontaneously within 24 hours
What has transient vestibular attacks been associated with in dogs?
systemic hypertension, hypothyroidism, otitis media/interna, and cerebellar malformations/ degernative disease
How are animals in between vestibular attacks?
they are normal , do not have impaired consciousness during episode
In cases with vestibular attacks that have cerebellar malformations or neurodegenerative disease how can vestibular designs be induced?
by manipulating the head position
How can transient vestibular attacks resolve?
if underlying etiology can be identified and successfully managing and treating hypertension, hypothryoidis
What is paroxysmal dyskinesias?
Dyskinesias is a general term referring to a heterogenous group of CNS disorders that impair normal posture muscle tone or locomotion without affecting consciousness.
Cramp or hypertonocity in scottish terriers
-trigger is stress or excitement, exerise
Cramp age of onset
most are less than 1 year of age
-autosomal recessive inheritance
Describe CRAMP
-duration of episode -> less than 30 minutes
-frequency of episodes depends on trigger
pehnotype -> stiffness or bunny hopping of pelvic limbs, kyphotic posture ], stiffness may also involve thoracic limbs
How do we treat CRAMP
How does it progress
diazapam and fluoxetine.
severeity and frequency decrease with age, treatment and behavioral modification
Canine epileptoid cramping syndrome of the border terrier (spike’s diseas)
trigger -> stress, excitement, waking up, temperature extremes
-age of onset -> majority less of 3 years of age
durationg of episodes -> 1 minutes to 3 hours
frequency of episodes -> multiple per day, month or per year
How does spikes disease look?
-treatment
inability to stand or walk, involuntary flexion or extension of multiple limbs , dysotonia or vomiting
-may resolve with gluten free diet
Paroxysmal nonkinesogenic dyskinesias of the Chinook
trigger -> unknown
age of onset -> most cases less than 3 years of age
duration of episodes -> less than 1 hour
frequency of episodes ->several per day, per year to per lifetime
Chinook phenotype
treatment/progression
sustained limb flexion, flailing or kicking of the limbs, ocassionally head tremor
-unknown
Episodic, postural or tremor syndromes
tremors are involuntary, rhythmic oscillatory movements of a body part with symmetric velocity in both directions of movement
-postural tremors actional related tremors that occur when muscles are supporting the body against gravity
Episodic, postural tremor of the head and neck (head tremor or head bobbers)
Signalment
triggers
phenotype
diagnosis
treatment
prognosis
-boston terrior, bulldog, bocer, doberman predisoposed, usuually mean age less than 4 years
-can be triggered by illness, surgery or other stressors
-focal tremors of the head that can results in horizontal or vertical head excersions . they can last seconds to hours. Episodes can be interrupted in a majority of dogs
-signalement history and CS
-various anticonvulsant medications have been tried but dont seem to work
-non progressive disease
neuromuscular weakness
Myathesnia gravis and polymyositis may cause paresis that may eventually cause collapse. THe collapse is usally associated with historical or clincial evidence an excerise associated exacerbation of weakness and the animal often has other CS of disease . Typically do not recover rapidly or completely after collapse
What is syncope
udden, transient loss of consciousness and
postural tone. During the syncopal attack, the animals will have flaccid
muscle tone, but some will display myoclonic jerks of the limbs or head at the
episode onset, and some animals will display autonomic signs (urinate
How do animals with syncope appear before and after an attack?
Animals with syncope do not typically show any pre- or post-episodic signs;
exercise and stress may precipitate syncopal events; and recovery from an
episode is nearly instantaneous.
How often can animals with syncope have episodes?
There can be multiple episodes/day, and episodes frequently occur in rapid
succession
What are other non-epileptogenic causes of paroxysms?
Pain
-Several disorders are classically characterized by clinical signs of episodic
discomfort with intervening periods of relative normalcy. These include
Chiari-like malformation and syringohydromyelia, feline orofacial pain
syndrome (FOPS), and intermittent claudication. In addition to their
paroxysmal nature, these conditions can be accompanied by abnormal body
postures, stereotypical behaviors, or reluctance to move in the absence of
more classical signs of associated with pain.
Epileptic seizures
ecurrent, transient, and sudden, often stereotypical motor, sensory,
autonomic, or psychic disturbance that results of excessive or abnormal synchronous
electrical activity in the brain. Epileptic seizures can result from a genetic predisposition to
seizures (genetic/idiopathic epilepsy), secondary to many brain diseases (structural
epilepsy), or for unknown reasons.
How can we differentiate seizures from other paroxysmal events?
Many seizures will have an identifiable premonitory event, the aura,
in which the animal displays abnormal behaviors, such as attention
seeking, hiding, etc that occur a few minutes prior to the ictus
Seizures are the most common paroxysmal event aoscciated with _ signs
-are they conscious?
autonomci
-their consciouness is impaired
Seizures very commonly _ muscle tone.
What is the most common semiology of a seizure?
-increased
-generalized tonic-clonic seizure. the animal first goes stiff (tonic phase), becomes recumbent, and then develops rhythmic alternating muscle contractions (tonic-clonic phase) which may progress to running type movement
Seizures first often manifest how?
in the face/head as eyelid twitching movements and then secondarily generalize
When do seizures most often occur
at rest or when the animal is sleeping
What are most common for focal or generalized seizures?
rhythmic alternating or muscle contractions
Most animals with epilepsy will look how?
each seizure will look the same
How long does the typical ictal event last
less than 1-3 minutes
What are common after a seizure
post ictal abnromalitesi and can last hours to day
-fear, aggression blindness, increased appetite and ataxis
