Canna~Fangled Abstracts

Antiseizure effects of the cannabinoids in the amygdala-kindling model

By July 12, 2021July 15th, 2021No Comments
. 2021 Jul 12.

doi: 10.1111/epi.16973.

Online ahead of print.
Merrick S Fallah 1 2, Lukasz Dlugosz 2, Brian W Scott 2, Miles D Thompson 3 4, W McIntyre Burnham 2
Affiliations 

Abstract

Objective: Focal impaired awareness seizures (FIASs) are the most common seizure type in adults and are often refractory to medication. Management of FIASs is clinically challenging, and new interventions are needed for better seizure control. The amygdala-kindling model is a preclinical model of FIASs with secondary generalization. The present study assessed the efficacy of cannabidiol (CBD), ∆9-tetrahydrocannabinol (THC), and a combination of CBD and THC in a 15:1 ratio at suppressing focal and secondarily generalized seizures in the amygdala-kindled rat.

Methods: Fully kindled, male Sprague Dawley rats, with bipolar electrodes implanted in the right amygdala, were given either CBD (0-320 mg/kg), THC (0-40 mg/kg), or a combination of CBD and THC (15:1 ratio, multiple doses) intraperitoneally. Suprathreshold kindling stimulation was administered 1 h (THC) or 2 h (CBD) after drug injection, and outcomes were assessed using focal electroencephalographic recording and the Racine seizure scale.

Results: CBD alone produced a partial suppression of both generalized seizures (median effective dose [ED50 ] = 283 mg/kg) and focal seizures (ED40 = 320 mg/kg) at doses that did not produce ataxia. THC alone also produced partial suppression of generalized (ED50 = 10 mg/kg) and focal (ED50 = 30 mg/kg) seizures, but doses of 10 mg/kg and above produced hypolocomotion, although not ataxia. The addition of a low dose of THC to CBD (15:1) left-shifted the CBD dose-response curve, producing much lower ED50 s for both generalized (ED50 = 26 + 1.73 mg/kg) and focal (ED50 = 40 + 2.66 mg/kg) seizures. No ataxia or hypolocomotion was seen at these doses of the CBD + THC combination.

Significance: CBD and THC both have antiseizure properties in the amygdala-kindling model, although THC produces suppression of the amygdala focus only at doses that produce hypolocomotion. The addition of small amounts of THC greatly improves the effectiveness of CBD. A combination of CBD and THC might be useful for the management of FIASs.

 

Keywords: CBD, THC, amygdala kindling, cannabinoids, epilepsy, focal onset seizures, temporal lobe

References

REFERENCES

    1. Chen Z, Brodie MJ, Liew D, Kwan P. Treatment outcomes in patients with newly diagnosed epilepsy treated with established and new antiepileptic drugs: a 30-year longitudinal cohort study. JAMA Neurol. 2018;75(3):279-86.
    1. French JA, Kanner AM, Bautista J, Abou-Khalil B, Browne T, Harden CL, et al. Efficacy and tolerability of the new antiepileptic drugs II: treatment of refractory epilepsy: report of the Therapeutics and Technology Assessment Subcommittee and Quality Standards Subcommittee of the American Academy of Neurology and the American Epilepsy Society. Neurology. 2004;62(8):1261-73.
    1. French JA, Kanner AM, Bautista J, Abou-Khalil B, Browne T, Harden CL, et al. Efficacy and tolerability of the new antiepileptic drugs, I: treatment of new-onset epilepsy: report of the TTA and QSS Subcommittees of the American Academy of Neurology and the American Epilepsy Society. Epilepsia. 2004;45(5):401-9.
    1. Kanner AM, Ashman E, Gloss D, Harden C, Bourgeois B, Bautista JF, et al. Practice guideline update summary: efficacy and tolerability of the new antiepileptic drugs I: treatment of new-onset epilepsy. Epilepsy Curr. 2018;18(4):260-8.
    1. Hauser WA. Questioning the effectiveness of newer antiseizure medications. JAMA Neurol. 2018;75(3):273-4.

LinkOut – more resources

  • Full Text Sources

Leave a Reply