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(!)

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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