Pearls and important clues from the Neurological Exam
• Goals for lecture–Emphasize 3 components of the
neurological exam that YOU canhelp your doctor
Seizure disorders
Approach to Chronic Seizure Patient
Jay McDonnell, DVM, MS, DACVIM-N
Seizures and Status epilepticus
Seizures killSeizures make new seizuresStop the seizuresSupport the patient
Guiding Principles:
Seizure disorders
Definitions
• Epilepsy– Idiopathic– Symptomatic
Seizure disorders
Seizure disorders
The unseen seizure – cortical activity during a seizure
Seizure disorders
The unseen seizure – cortical activity during a seizure
Seizure disorders
Metabolism
Glucose req
O2 consumption
The unseen seizure – cortical activity during a seizure
• Uncontrolled seizures and status epilepticus result in permanent brain damage within 20-30 minutes due to anoxia and ischemic necrosis
• Limbic structures, thalamus and cortical layers 3 and 5 particularly susceptible
Seizure disorders
Metabolism
Glucose requirements
O2 consumption
Mariani et al 2005, Podell et al 2003, Holliday et al 1999
Neurology-Neurosurgery
Mirror Focus-Kindling Theories
Seizures and Status epilepticus
Seizures killSeizures make new seizuresStop the seizuresSupport the patient
Guiding Principles:
Seizure disorders
Some considerations for the “perfect anticonvulsant• Efficacy- 99%• Side-effects – none• Toxicity - none• Cost – low cost
Some choices
Seizure disorders
Seizure disorders
Pharmacokinetic considerations
T ½ (half-life) time required for the [drug] to be reduced by one-half
Seizure disorders
Pharmacokinetic considerations
Seizure disorders
Diazepam (Valium®)
• T1/2 3.2 hours (oral)• Tolerance rapidly
develops in dogs• In dogs, primarily used
for status as IV, PR or IN
In dogs and cats, 0.5-2 mg/kg IV, PR, IN
Seizure disorders
Diazepam
• In cats, 2-5 mg TID• caution with
idiosyncratic hepaticnecrosis
• not recommended
Seizure disorders
Phenobarbital
• 1st choice drug• Effective (80-85%)• Expense $$• Good experience• ease of dosing-typically start at 2 mg/kg BID
Seizure disorders
Phenobarbital
• 1st choice drug (?)• serious hepatoxic effects at high blood
concentrations
• monitor [PB], liverenzymes and liverfunction
Seizure disorders
Potassium bromide
• 1st choice drug• Effective (80-85%)• Expense $• Good experience• Ease of dosing-liquid or chew tab once daily
Seizure disorders
Potassium bromide • 25-45 mg/kg/day w phenobarbital• 60 mg/kg/day if monotherapy• Give w food to prevent GI upset• long t1/2= long time to steady state• Loading dose: 400-600 mg/kg
divided over 24-48 hours withfood
• pelvic limb weakness -discontinue for 2-4 days toevaluate
• associated with pancreatitis
Seizure disorders
Sodium bromide • With intractable
vomiting, try NaBr (dosereduce by 15%)
• Omeprazole• Increase dose frequency,
decrease amt/dose• Precautions
Seizure disorders
Zonisamide
• Sulfonamide-based drug• Effective (~60-65%)• Expense $$$• Well tolerated, good experience• T1/2 15 hours• 5-10 mg/kg q 12 hours• Use – secondary or tertiary add-on drug
Seizure disorders
Levetiracetam
• Effective (65% 🐶, 70% 😸)• Expense $$$• Well tolerated, good experience• T1/2 3 hours• 15-35 mg/kg q 8 hours• Use – secondary or tertiary add-on drug
Decision making
• Situation – single seizure vs knownmultiple, prolonged seizures
• Goals of treatment• Client compliance
Seizure disorders
Some choices
Seizure disorders
known multiple, prolonged seizures
Seizure disorders
Phenobarbital and bromide - a good marriage?
Seizure disorders
Phenobarbital and bromide - a good marriage?• Effective in controlling most dogs with
intractable seizures, cluster seizures orfrequent seizures (> 95%)
• ataxia, PU/PD and PP(!)
Seizure disorders
Other options
•
Conclusions
• Rational use of PB and Br• Judicious blood monitoring• If complications, consider
adding levetiracetam orzonisamide
Other treatments
• Acupuncture/herbs• Chiropractic• Diets• CBD oil
Seizure disorders
Acupuncture
Seizure disorders
Thanks to North America Veterinary Health Center, Jupiter FL
Chiropractic and Homeopathy
Seizure disorders
Diets
• Keto diet• Eliminar diet• MCT/ diet
Seizure disorders
CBD oil and seizures
Seizure disorders
Seizure disorders
Topriamate (Topomax®)
• T1/2 4 hours but effectlikely lasts longer
• 10 mg/kg TID
• cost $305
Seizure disorders
Gabapentin (Neurotin®)
• T1/2 3-4 hours• efficacy unknown but some
control as a 2nd or 3rd add-on drug
• No effective monitoring• 25-60 mg/kg divided
TID/QID
Seizure disorders
Felbamate (Felbatol®)
• T1/2 8 hours• effective 2nd or 3rd add-on
drug• aplastic anemia in humans• 15 mg/kg TID with
subsequent of 15 mg/kg every 2 weeks until seizure control adequate
Seizure disorders
Felbamate
• Hepatotoxicity– ALT and SAP
• Monitor liver functionas well
