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    Poster

    Spontaneous Convulsions and Tremors in Control Animals from Regulatory Toxicology Studies: A Multi-Site Retrospective Analysis Comparing Nonhuman Primates, Dogs, Minipigs, Rabbits, Rats, and Mice (P426)

    Monday, November 18, 2024
    5:00 PM - 6:30 PM CT
    Convulsions are life threatening events that can be test article related or spontaneous background. The incidence of convulsions differs between species and the interpretation of toxicology and safety pharmacology studies relies on the availability of robust historical control data. This is paramount for low incidence observations such as convulsions. Tremors are commonly observed but can be considered as a premonitory sign to seizure. We aimed to characterize and compare the incidence of spontaneous convulsions and tremors in control non-human primates, dogs, minipigs, rabbits, rats and mice. A retrospective analysis was conducted with data from GLP facilities in North America and Europe including non-human primates (n=8805), dogs (n=24553, minipigs (n=2359), rabbits (n=21476), rats (n=312261) and mice (n=131272). For rats and mice, the incidence of convulsions was lowest at less than 6 weeks of age, was stable from 6 to 26 weeks of age and then increased progressively for older animals reaching 0.66% in rats and 0.60% in mice above 38 weeks. When comparing species, the incidence of spontaneous convulsion was lowest in minipigs (0%) followed by mice (0.03%), rats (0.06%), rabbits (0.07%), dogs (0.11%) and non-human primates (0.17%). While tremors can be monitored as a premonitory sign of seizures, the incidence of tremors in normal healthy animals is generally high and this observation is most often considered physiological. Consequently, other premonitory clinical signs such as myoclonus present higher specificity than tremors to predict test article related seizurogenic effects.