Corpus Callosotomy - Following the Progress of a 'Brain Splitting' Patient

Dr. Fiona Bateman

10 July 2006

The procedure known as a corpus callosotomy involves the surgical severing of the connection between the left and right cerebral hemispheres. It is designed to localise the abnormal electrical activity in the brain and hence stop or lessen seizures in patients with epilepsy. In this case study we review the progress of ‘Penny’ the Fox Terrier, two months after such a surgery at the Southern Animal Referral Centre, Melbourne, Australia. The accompanying image shows the corpus callosum through an endoscopic 'keyhole camera'.

‘Penny’ is a 5 year old Fox Terrier who presented to SARC for uncontrolled epilepsy. She was receiving medications from her regular veterinarian to control her seizures and was on the maximum safe dose for these medications. However, this medication was not sufficient to stop her having anywhere from 4 to 8 seizures per day. The side-effects of these medications included moderate to heavy sedation and Penny was becoming increasingly more sedated as the dose of the medications increased.

Penny’s owners had heard about a procedure known as corpus callosotomy, where the connection between the left and right cerebral hemispheres is surgically disrupted in an attempt to localise the abnormal electrical activity in the brain.

This surgery has been used in human medicine for more than 50 years, however Dr. Charles Kuntz of the Southern Animal Referral Centre is one of only a few surgeons in Australia to attempt this procedure in small animals. Many epileptics can be successfully controlled on medications and do not require surgery. However, in severe cases surgery is offered as a last resort. The surgery itself is not without risk, but in many cases the benefits far outweigh the potential complications of the procedure.

The decision for surgery

Penny’s owners elected to proceed with the surgery, which takes around 30-45 minutes and is performed endoscopically using a small camera inserted through the top of the skull. The corpus callosum is then severed using a small blade introduced through the same hole. The procedure proceeded as planned, and after a short recovery, Penny returned home to recuperate over several weeks with seemingly no ill effects after her initial recovery.

Although the procedure itself had been performed according to plan, only time would tell if Penny continued to seizure with the same frequency or intensity as before surgery. Over the next few months Penny was observed closely for seizure activity. Penny returned home on the same medication level of medication as she was receiving prior to surgery, and had her dose reduced by 25% after one month. The ultimate goal would be to wean her completely from her medication, but this would need to be done incrementally, and there was always the chance that Penny would continue to experience seizures at any medication dose.

Two months after surgery

Penny revisited her SARC family nearly two months after her surgery. She has been completely seizure-free since surgery and has begun to scale down her medications. She is running around, responsive to her owners and is now ‘a completely different dog’. Her owners describe her as being 100% of what she was before she was diagnosed with epilepsy. While her recovery took several weeks, with dedicated owners, and the combined efforts of her referring veterinarian and the team at SARC, Penny is now a normal dog. The long term outlook for Penny is unknown - this procedure is far too new to evaluate the long term effects and prognosis, but for now she is enjoying a happy, healthy life with her loving owners.

If your dog is experiencing uncontrolled seizures despite medication, you may wish to discuss the possibility of surgery with your regular veterinarian.

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