Odd episodes: when is a seizure not a seizure?: Dogs and cats presenting with abnormal episodes provide some of the most challenging and frustrating cases for veterinarians of all abilities. In veterinary neurology these episodes can be defined as ‘paroxysmal episodes’ with a defined start, defined end and relatively short duration. There are relatively few causes of paroxysmal episodes in dogs and cats including: seizures, syncope, vestibular syndrome, paroxysmal dyskinesia (movements disorders), narcolepsy/cataplexy, neuromuscular disease and idiopathic head tremors. Accurately classifying the paroxysmal episode is dependent on taking a thorough and systematic history that includes: a description of the event, the clinical status between episodes, asking if there is impairment or loss of consciousness, presence or absence of autonomic signs, description of muscle tone a lateralisation of presenting clinical signs. Where possible videos of the events should be reviewed with the owner. This lecture uses case examples and videos to review common paroxysmal episode presentations. Particular attention is given to seizures, syncope, vestibular syndrome and paroxysmal dyskinesia. We investigate the diagnostic approach to these conditions including genetic testing for certain breed associated conditions. Cases review the appropriate use of pharmacological or dietary treatments and highlight how the provision of accurate information to owners is critical in ensuring the optimal management of these varied conditions.

Other causes: Patients presenting with a history of paroxysmal episodes or ‘fits’ can be a challenge for even the most experienced clinician. First, the patient presents usually in your practice when it is normal. Second, the identification of the nature of episode is heavily dependent on a good description from the person who witnessed the episode or a home-style video. Third, most of these paroxysms appear unpredictable and uncontrollable for the owner so their view of what has happened might be clouded. A meticulous history is essential before embarking on a diagnostic investigation. Syncope, narcolepsy/cataplexy, pain, compulsive behaviour disorders, vestibular attacks, certain movement disorders, neuromuscular weakness and seizures are paroxysmal events, which share commonalities in their clinical presentation. The inter-paroxysmal (inter-episodic) clinical examination can be completely unremarkable. If the animals present with inter-episodic deficits then this will guide your clinical reasoning and help you determine the body system involved. If you are ‘lucky’ then the patient will present during a ‘strange’ episode at your clinic, e.g. prolonged seizure activity (status epilepticus [>10min], cluster seizures [≥2 seizure/day]) or vestibular attack. This lecture covers the ins and outs of how best to differentiate the wonderful bouquet of paroxysmal neurological episodes.