How do you diagnose seizures?
Since seizures can be caused by any process that alters the normal neurological function, the goal of the clinician is to distinguish between primary and secondary causes of seizures through examination, the taking of a thorough client history, and further medical and/or advanced imaging diagnostics if necessary. With this information, the clinician can then create a plan for the management and treatment of the patient’s seizures.
The first step in the diagnosis of epilepsy (repetitive seizure over time) is to determine whether the patient’s neurological episodes are, in fact, seizures. Syncope, narcolepsy/catalepsy, and most commonly vestibular spells or other medical scenarios which owners frequently misinterpret as “seizures.”
Types of Seizures
There are three types of epilepsy:
Idiopathic (or primary) epilepsy. Typically manifesting in young animals between 6 months and 5 years of age, these are seizures for which no underlying pathology or abnormality can be identified. Certain breeds, including (but not limited to) Beagles, Standard Poodles, Labrador Retrievers, German Shepherd Dogs, German Pointers, Golden Retrievers, Keeshonds, Irish Wolfhounds, and the Belgian Sheepdog family of
breeds, seem to be predisposed to idiopathic epilepsy.
Symptomatic (or secondary) epilepsy. In these cases, the epilepsy is secondary to a disease process such as an intracranial mass (benign or neoplastic), congenital brain malformation (such as hydrocephaly), infectious or non-infectious inflammation of the central nervous system (CNS), cerebrovascular disease or cranial trauma. Causes of symptomatic epilepsy also include those of metabolic origin such as hepatic encephalopathy, toxin ingestion, and glucose or electrolyte imbalances.
Probable symptomatic (cryptogenic) epilepsy, which we also refer to as non-active disease, is the most esoteric of the three categories. This classification is used when a secondary condition is suspected but cannot be proven using current diagnostic and advanced imaging (CT or MR) techniques. Such patients may have partial seizures, a history of suspected trauma or infection, and/or may be resistant to traditional seizure pharmacotherapy.
Following the information given by the client such as age at onset, number of seizures at onset, response to the treatment and neurological status of the patient, we will make a tentative diagnosis and establish a diagnostic plan. For patients highly suspected of suffering from idiopathic epilepsy, blood analysis, urinalysis, serum levels of the antiepileptic drug administered, and an ophthalmologic evaluation are usually performed.
For patients suspected of suffering from secondary epilepsy, such as those with multiple seizures at onset, lateralized seizures and abnormal neurological status, or those that are older than five years, we strongly encourage the following diagnostic procedures: Complete Blood Count biochemistry analysis, urinalysis, ophthalmologic consultation, thoracic radiographs, MRI, Cerebrospinal Fluid analysis (CSF), and specific serum titers if indicated (such as toxoplasmosis and neospora) when infectious conditions are suspected.
The treatment of a specific condition should now be considered; in fact, trial therapy is sometimes the only way of determining if certain episodes are true seizures. But, certainly, the diagnostic evaluation remains the most important step in the understanding of the origin of the seizures.
Learn more about this disease by contacting our Neurology service at your nearest BluePearl veterinary hospital. Here are our hospital locations.
© BluePearl Veterinary Partners 2011