One of the
abstract presentations at the ASET 2013 Annual Conference in Reno last month
was particularly of interest to me as a dog lover and owner of two Labrador retrievers. The title of the presentation was “Electroencephalographic and Clinical
Findings in 37 dogs and 4 cats.” The
author of the abstract was Dr. William Bush, V.MD, DACVIM, and his presentation
was fascinating!
He showed
videos of some of his canine and feline patients having clinical spells that
could very well be seizures. The
confirmation of seizure activity has been a challenge in veterinary medicine,
and for the most part, is done by clinical observation and pathology affecting
the brain may be detected with MRI, and lab studies of the cerebral spinal
fluid. Dr. Bush explained that when
these tests are positive, there is a greater chance that the EEG recording will
be abnormal as well. But in cases where
there is no structural or infectious process to cause seizures, an EEG
recording can be done and is very helpful.
His study included three patients who were diagnosed with non-convulsive
status epilepticus based upon their EEG findings.
It is also
interesting to contemplate exactly how an EEG can be done on cats and
dogs. Dr. Bush discussed the use of
sedation and a small number of needle electrodes.
I actually
have some experience with recording an ambulatory EEG on a dog. In the past, when I was working at Children’s
Hospital in Boston, I was contacted by a veterinary behavioral specialist from
Florida, who was a consultant for a show dog: a standard poodle, living in New
Hampshire, who had frequent spells which may represent seizures. Since the animal was a show dog, the owner
did not want to start prescription anticonvulsants unless the seizures could be
documented. She was seeking a
neurodiagnostic technologist who would be willing to work with the dog to
record an ambulatory EEG at the nearby state-of-the-art facility, “Angell
Memorial Animal Center”. That person
would be me!
We
coordinated a dedicated exam room at the veterinary hospital, a flight to
Boston for the specialist, and the use of the ambulatory EEG equipment donated
for the session by Digitrace. We knew
that the dog would need to wear a backpack with the ambulatory recorder so for
a few weeks prior to the recording session, the owner placed a harness and
backpack on the dog for several hours per day, to acclimate the dog to the
device he would be wearing.
A team of
helpers met the dog, Flair, the owner and the behavioral specialist on the
appointed day. Our team included a
clinical applications specialist from Digitrace, a veterinary neurologist from
Angell and myself and another tech from Children’s. We were prepared to administer a sedative for
lead placement. I had brought disk
electrodes, collodion, and an air compressor with me. We decided to try applying electrodes without
sedation first. The owner held the dog’s
muzzle still, made eye contact with the dog, and calmed him verbally, while I
placed leads. No problem! Frankly, the dog was easier to work with than
most 2 year olds!
The dog wore
the equipment for 48 hours and stayed with the owner in a pet-friendly hotel
nearby. Once a day, she brought the dog
to a Digitrace office to have the leads checked and regelled. It took a while but eventually typical clinical
events were recorded which correlated to EEG activity that could be
electrographic seizures.
We
videotaped the patient set-up and the owner videotaped the clinical
events. I presented this case study as
an abstract at the ASET annual conference in New Orleans in 2002.
A picture of me with my poodle patient:
It is
interesting to speculate that in the future, there will be more utilization of
clinical EEG in veterinary practice. My
thanks to Dr. Bush for sharing this fascinating topic with us. Many of the techs in the audience agreed with
me and would like to hear more from him in the future.