A review on epilepsy in the horse and the potential of Ambulatory EEG as a diagnostic tool.

The research article discusses the challenges faced in diagnosing epilepsy in horses, and explores the potential of using Ambulatory electroencephalography as a diagnostic tool.

Epilepsy in Horses

• Epilepsy is a brain disorder in horses, characterized by recurrent episodes of involuntary abnormal behavior. The cause can originate from within the brain, outside the brain, or could be idiopathic i.e., have an unknown cause.
• Diagnosing this condition in horses can be challenging, especially in the absence of grand mal seizures. The future prospects of the horse and potentially the safety of the owner depend on getting an accurate diagnosis.

Seizure Categories

• The review identified two main categories of seizures (aside from their etiology) – generalized seizures, which affect the whole brain, and partial seizures which only affect certain parts of the brain.
• A typical generalized tonic-clonic seizure (a type of grand mal seizure) is characterized by three distinct phases – the prodrome phase (pre-seizure symptoms), the ictus (the seizure itself), and the post-ictal phase (recovery phase).

Electroencephalography (EEG)

• The EEG is a tool used to graphically record rhythmic bioelectric activity, which is predominantly produced by the brain’s cerebral cortex. This tool can aid in diagnosing epilepsy and other brain disorders.
• In human medicine, the 10/20 basis system is used for electrode placement, making comparisons more reliable and consistent.
• In epilepsy patients, both human and equine, the EEG shows characteristic patterns, such as spikes, spike-and-wave discharges, and rhythmical multi-spike activity.

Ambulatory Electroencephalography (AEEG)

• AEEG is seen as having advantages over short-duration EEG in diagnosing epilepsy or intracranial pathology. It is a wearable technology that records brain activity over longer periods of time and under more natural circumstances. This offers prospects for recording brain signals in awake horses expressing their behavior under natural circumstances.
• The authors suggest more research is required to understand normal EEG signals in horses and to develop ways to interpret EEG signals from horses using AEEG.

The review highlights the need for improved diagnostic tools in veterinary neurology, particularly for conditions like equine epilepsy, and hints at the potential of Ambulatory EEG to fulfill this role in the future.