44. Differential diagnosis of seizures. Epilepsy Flashcards
The seizure definition?
The Seizure
DEFINITIONS
Myoclonus: Sudden, brief & involuntary muscle contraction
Clonic: Repetitive myoclonus
Seizure: Any sudden, short-lasting & transient event
Epileptic seizure: Transient occurrence of signs and/or symptoms
due to abnormal synchronous neuronal activity in the brain
Epilepsy: Disorder of the brain characterised by and enduring
preposition to generate epileptic seizures; 2 or more unprovoked
seizures >24hrs apart
Clinical examination of seizures?
CLINICAL EXAMINATION
Not during seizure
§ Signalment
§ Full clinical exam
§ Neurological exam
§ Further workup
During seizure
§ Description
§ Video analysis
§ Ask the owner to examine the patient during seizure
Problem-oriented approach: VITAMIND
What could be causing the seizure
§ Vascular (Stroke; Hypoxia; Ischaemia; Anaesthesia)
§ Inflammatory (Limbic encephalitis; FIV)
§ Trauma/Toxic (Jodoxychinolin; Kainic acid)
§ Anomaly (inherited) (Dentate gyrus dysgenesis)
§ Metabolic
§ Idiopathic
§ Neoplastic (Brain neoplasia)
§ Degenerative
Reccomended diagnostic approaches to seizures?
Clinical signs?
CLINICAL SIGNS
Pre-ictal phase
1 – 24 hours long
§ Nervousness; Seeking the owner
Ictal phase
10 seconds – 1 hour long
§ Convulsions § Clonic
§ Impaired consciousness § Vegetative
§ Complex behavioural changes § Tonic
§ Hallucination § Automatism
Post-ictal phase
<2 hours long
§ Todd’s paralysis § Weakness
§ Compulsive walking § Paresis
§ Blindness § Ataxia
§ Deafness § Circling
§ Salivation § Barking
§ Disorientation § Panting
Treatment of status epilepticus(active seizures)?
Treatment Of Status Epilepticus (Active Seizure)
- Insert an IV catheter
- Administer Diazepam (rectally if there is no IV access);
1mg/kg; Repeat every 2 minutes if unsuccessful (Max. 4
doses) ; Maybe consider a Diazepam CRI
3. Administer a loading dose of Phenobarbital; Repeat every 6
hours
- If patient doesn’t respond – Administer Propofol,
maintaining a patent airway and monitoring carefully
Causes for Paroxysmal events?
Causes For Paroxysmal Events
Paroxysmal events: Sudden outburst/attack in a particular motion
EXTRACRANIAL CAUSES
§ Hypoglycaemia § Toxicosis
§ Liver origin § Uraemia
§ Hyperviscosity § Hypocalcaemia
§ Severe ascariasis § Hypokalaemia
§ Diabetic ketoacidosis § Hypoxia
§ Hypernatraemia §
INTRACRANIAL CAUSES
§ Hydrocephalus § Encephalitis
§ Idiopathic epilepsy § Ischaemia
§ Lissencephalopathia § Neoplasia
§ Brain oedema § Infectious
§ Thromboembolus § Trauma
Diagnosing seizures?
Diagnosing Seizures
LAB.D
§ Haematocrit § Glucose
§ Leukocytes § Ca2+
§ Azotaemia § Na+
§ Hyperosmolarity § Acid-base
§ Hypoosmolarity
§ Urinalysis
§ Hepatic parameters
§ Liquor: Meningitis; Meningoencephalitis; Neoplasia;
Bleeding
IMAGING
§ CT; MRI
§ Anomalies: Hydrocephalus; Chiari-malformation (see
§ topic 41)
§ Lesions: Granuloma; Neoplasia; Bleeding; Ischaemia; Cyst
OTHER DIAGNOSTIC TOOLS
§ EEG (Electroencephalogram)
§ Genetic testing
Differential diagnoses for seizures in dogs?
Differential Diagnoses For Seizures In Dogs
NARCOLEPSY/CATALEPSY
Emotion/excitation-induced
Congenital/acquired
Congenital: Doberman; Labrador; Dachshund
Acquired: Autoimmune
Treatment: Amitriptyline; Selegiline
EXERCISE-INDUCED COLLAPSE
Predisposed: Labrador; Clumber spaniel; Corgi
Clinical signs: Ataxia & paresis; Hyperthermia
Diagnosis: Genetic testing
Treatment: Diazepam; Buscopan; Clorazepate
CANINE EPILEPTIC CRAMPING SYNDROME
“Spike’s disease”
Predisposed: Border terrier
Clinical signs
§ Ataxia § Falling
§ Borborygmi § Stiffness
§ Tremor § Diarrhoea
§ Vomiting
Treatment: Diazepam; Buscopan; Clorazepate
EPISODIC FALLING (HYPEREKPLEXIA)
In Cavalier King Charles Spaniel; Stress/exercise-induced
Clinical signs: Episodic stiffness & falling
Treatment: Clonazepam; Acetazolamide
SCOTTIE CRAMP
Predisposed: Scottish terrier; Stress/exercise-induced
Clinical signs: Episodic stiffness; Kyphosis; Rigidity
Treatment: Diazepam; ACP; Fluoxetine
CHINOOK SEIZURE
Congenital idiopathic paroxysmal dyskinesia
Clinical signs: Limbs in flexion; Mild movement; Convulsive episodes
OTHER DIFFERENTIAL DIAGNOSES
§ Myasthenia gravis
§ Syncope
§ Flea biting
§ Head bobbing (Bulldog; Doberman)
§ Degenerative encephalopathy in Nova Scotia Duck Tolling
Retriever
§ Increased startle reaction
§ Chiari-like malformation
Differential diagnoses for seizures in cats?
Differential Diagnoses For Seizures In Cats
FEPSO
Feline partial seizure with orofacial involvement
Epileptic activity within the temporal lobe due to different aetiology
Clinical signs
§ Episodic facial twitching
§ Mastication
§ Swallowing
§ Lip-smacking
FOPS
Feline orofacial pain syndrome
Predisposed: Burmese cats (any age)
May be associated with oral lesions
Clinical signs
§ Episodic oral discomfort
§ Tongue mutilation
§ Triggered mouth movements
§ Stress
Treatment
§ Dental care
§ Phenobarbital; Diazepam; NSAIDs; Glucocorticoids
§ Reduce environmental stressors
FHS
Feline hyperaesthesia syndrome
Clinical signs
§ Episodic twitching
§ Rolling skin
§ Agitation
§ Aggression
§ Licking/biting of the flank
Treatment:
§ Glucocorticoids; NSAIDS; Amitriptyline; Antiepileptics
§ Flea control
FARS
Feline audiogenic reflex seizures
Predisposed: Older cats (15 years)
Clinical signs: Myoclonic episodes triggered by high-frequency
sounds
Treatment: Levetiracetam; Phenobarbital
Prevention of epilepsy?
Prevention Of Epilepsy
Aim: ↓ Seizure severity, frequency & duration; ↓ Adverse effects
PHENOBARBITAL
GABA agonist; Ca2+ channel blocker
Antiepileptic (within the therapeutic range)
Adverse effects: Sedation; Ataxia; Paraparesis; PU/PD
IMEPITOIN
BZD agonist; New experimental drug with ↓ adverse effects
IMEPITOIN + PHENOBARBITAL
KALIUM BROMIDE
If the seizures are resistant to phenobarbital & imepitoin
Adverse effects: Vomiting; Paraparesis; Pancreatitis; Pruritis
