Many families of children with medically refractory epilepsy are choosing to use medicinal cannabinoids (MCBD) as an adjunctive alternative treatment option. The safety, tolerability and efficacy of these products are not known. The primary objective of this study is to determine how the use of MCBD affects children with medically refractory epilepsy in an observational study. Measures of evaluation to be used will include: laboratory values, developmental measures, seizure diaries and serial electroencephalographic (EEG) recordings.

This is an observational study of a family's choice to use MCBD and the effect of this substance on medically refractory epilepsy in children. The risks associated with this use are not well known. There have recently been reports of stroke, liver dysfunction and altered anticonvulsant levels. In addition, there have been long term risks reported of decreased memory function, cognitive problems and executive function abnormalities. This study does not condone or advocate the use of the substance but merely seeks to document the short term effects of the use in this population. It should be noted that providers at Children's Hospital Colorado are not registered providers for medicinal cannabis; therefore, this will be an observational study of effects of this substance as prescribed by other physicians outside of our institution.

Inclusion Criteria:

1. Male or Female >1 month of age

2. Documentation of a diagnosis of medically refractory epilepsy as evidenced by medical records, genetic testing and/or the following clinical features:

   • Failure to control seizures despite an appropriate trial of two anticonvulsant medications at therapeutic doses

3. Baseline seizure frequency of at least 2 per week of the any of the following types:

   • Generalized tonic-clonic
   • Clonic
   • Tonic
   • Hemiconvulsive
   • Drop attacks
   • Focal motor
   • Epileptic spasms

4. 1-3 baseline anti-seizure medications at stable doses for a minimum of 4 weeks prior to enrollment.

5. Written informed consent obtained from the patient or the patient's legal representative.

Exclusion Criteria:

1. Epilepsies associated with rapidly progressing neurodegenerative diseases ex: Rasmussen encephalitis, and tumors.
2. Epilepsies associated with treatable inborn errors of metabolism
3. Presence of a condition or abnormality that in the opinion of the Investigator would compromise the safety of the patient or the quality of the data.
4. Non-epileptic events.
5. Current use of MCBD products (Note: Patient is eligible if currently using MCBD but will be switching to a different product).

Pediatric epilepsy patients who are followed at Children's Hospital Colorado with medically refractory epilepsy, and whom the family has decided to treat with medicinal cannabis. Children who have not been treated with medically accepted standard treatment for their epilepsy condition will not be accepted into this study as the researchers do not want to be misperceived as condoning the use of medical marijuana in lieu of standard treatment.