NEW YORK--With good management, brain tumor patients at risk for
seizures can control their seizures and regain control of their
lives, a UCLA neuro-oncologist reassured brain tumor patients during
a Cancer Care, Inc. teleconference.
Timothy Cloughesy, MD, director of the Neuro-Oncology Program at UCLA
Medical Center, reviewed some important points of seizure control and
had some tips for physicians as well.
First and foremost, he said, the patient and physician must recognize
that seizures are occurring, and they are not always easy to identify.
The most obvious seizures are the generalized tonic-clonic type in
which the person becomes unconscious, shakes, and may have frothing
at the mouth or other symptoms, he said.
On the other hand, a simple seizure, one that is very focal, can
manifest more subtly--as a strange smell, a sense of rising in the
stomach, or a feeling of impending doom. The more common symptoms of
focal seizures are twitching, visual changes, or abnormal sensations
in the arms or legs.
If a focal seizure spreads to the temporal lobes, it becomes a
complex partial seizure, which is also hard to diagnose, Dr.
Cloughesy noted. Patients may lose contact with the environment and
develop automatic behaviors. They may be able to get up and walk and
look like they are doing something appropriate, but actually they are
not in control and are unresponsive.
Seizures Are Stereotyped
Something to look for when making a diagnosis, Dr. Cloughesy said, is
that seizures are stereotyped. If twitching happens during one
seizure, it will occur the next time rather than some other symptom.
But symptoms can change during one event if the seizure spreads.
Seizures cannot always be documented by an EEG, Dr. Cloughesy warned,
so the physician may have to rely on symptomatology alone. "The
physician has to realize that what is going on is actually a seizure
and that it is coming from the brain and not from something in the
stomach or the nose," he said.
The physician also has to be very astute to make an early diagnosis
of a brain tumor based on seizures, he added, stressing the need for
magnetic resonance imaging (MRI). "Many times a physician will
order a CT scan," he said, and then tell the patient--well, you
are having some event, but actually we dont see a tumor or even
a lesion there--but when an MRI scan is obtained, the lesion becomes
The top part of the brain is most susceptible to seizures, Dr.
Cloughesy said, and patients with tumors in that area will likely be
given antiseizure agents prophylactically after surgery. Patients
with a more mid-line tumor, one that is not out at the cortex, have a
decreased risk of seizure and will not usually be treated prophylactically.
People with gliomas have about a 70% chance of having seizures, he
said, and are usually given antiseizure agents prophylactically.
Generally, patients with meningiomas are not treated unless they
actually have seizures.
Individuals with metastatic brain tumors are not thought to be at
risk for seizures, unless the metastatic tumor arises from a melanoma
or renal cell cancer, in which case prophylactic antiseizure
medication is often prescribed, Dr. Cloughesy said.
He urged brain tumor patients who are prone to seizures or taking
antiseizure medication to inform their doctor before any surgery
requiring general anesthesia. The physician should then make sure
that the anticonvulsant the patient is taking can be given
intravenously if necessary in the surgical setting. If not, it should
be changed to a medication that can be given intravenously.
The serum level of the antiseizure drug must also be carefully
monitored before and after surgery, he said, particularly in settings
where the patient may develop nausea.
Tumors That Cause Seizures
Even after a tumor that is causing seizures is resected, the
antiseizure medicine must be continued for 1 to 2 years, Dr.
Cloughesy said. After that, it can be tapered off if there have not
been any more seizures.
Patients will also be put on antiseizure medication after resection,
even if they have never had a seizure, in order to prevent a reactive
seizure. These patients usually remain on the medication for 6 weeks
to 6 months.
Conventional radiation for brain tumors does not lead to an increase
in seizure frequency and often leads to an improvement in seizure
control, especially in the case of low-grade tumors, Dr. Cloughesy
said. But stereotactic radiation, because of the high amount of
radiation being delivered, does bring increased risk of seizures and
necessitates temporarily increasing the antiseizure medication dose.
Chemotherapy, because of the way it interacts with antiseizure
medicine, may increase seizure risk by decreasing serum drug levels.
Also, if a patient vomits because of the chemotherapy, and does so
less than an hour after ingesting anti-seizure medicine, the patient
will need to take more of the anticonvulsant, Dr. Cloughesy said.
Although all of the anticonvulsants have similar side effects, people
react to each differently, and may do better with one than another,
Side effects can include lethargy, cognitive changes, or even double
vision or difficulty in walking and talking. What is important, Dr.
Cloughesy cautioned, is that the side effects of an antiseizure
medication not be mistaken for the effects of a tumor.
In general, anticonvulsants work better when used as a single agent,
because there will be fewer side effects and, therefore, better
compliance. However, a newer anticonvulsant, such as gabapentin
(Neurontin), is usually added when first-line drugs, such as
carbamazepine (Tegretol and others), phenytoin (Dilantin), valproic
acid (Depakene, Depakote), and phenobarbital, do not work. He added
that gabapentin needs to be given at a higher dose and can cause sedation.
Once a seizure has started, there are different ways to control it,
he said. One way is to take more of the medicine the patient is
already using, but that may not work because of the time it takes for
the medicine to be absorbed.
In the emergency room, patients can be given an intravenous form of
their current medicine if it is available, or intravenous diazepam
(Valium) or lorazepam (Ativan), Dr. Cloughesy commented.
Diazepam Gel Formulation
If someone has a simple seizure that lasts a couple of minutes and
feels that a bigger seizure is coming on, the new diazepam gel
formulation delivered rectally is very effective in aborting a larger
seizure, Dr. Cloughesy said. "It actually empowers the patient
quite a bit. It keeps people from going to the emergency room, when
they can control the situation in the confines of their own home."
Oral lorazepam is also valuable, he said. "When it is crushed
and placed under the tongue, it actually has fairly good and rapid
absorption." Dr. Cloughesy recommends that patients take a
crushed form of oral lorazepam in a bag with them when they go out.
"It is just so critical that you have control over your
situation," Dr. Cloughesy told his audience. "Seizures can
be incredibly frightening and dangerous as you all know, and I hope
you have learned that you can take control."