|
absence seizure: (also know as "dialeptic seizure," or the
older term "petit mal seizure") a seizure that causes a brief
loss of awareness. During an absence seizure, the patient stops any activity and
stares blankly. Rarely, there may be some blinking.
anticonvulsant: an antiepileptic drug used to control
both convulsive and nonconvulsive seizures.
atonic seizure: a seizure that causes a sudden loss of muscle tone,
particularly in the arms and legs, and often causes the patient to fall
aura: a warning or initial symptom at the beginning of a
seizure, experienced by the patient, but not visible to observers. Auras may
progress to become focal or even generalized seizures, or they may exist alone.
clonic seizure: repetitive, rhythmic jerks that involve all or part of
the body
complex partial seizure: a seizure that includes impairment of awareness,
i.e., patients seem to be "out of it" or "staring into
space." Automatisms or other movements are frequently a part of the
seizure, such as in automotor seizures.
corpus callosum: a band of nerve fibers located deep in the brain that
connects the two halves (hemispheres) of the brain. The corpus callosum helps
the hemispheres share information.
corpus callosotomy: an operation that cuts the corpus callosum and
interrupts the spread of seizures from one hemisphere of the brain to the other.
Callosotomies may be complete, or may involve only a portion of the corpus
callosum. Although seizures generally do not completely stop after this
procedure, they usually become less severe.
EEG-video monitoring: Continuous simultaneous recording
of brainwaves and video observation of the behavior accompanying the EEG. This
technique, carried out at comprehensive epilepsy centers, is employed to
diagnose epilepsy and localize the seizure focus. The results are useful to
determine therapy--medical or surgical.
electrode: a conductive disk (usually metal) attached to the scalp which
conveys the electrical activity of the brain through a wire to an EEG machine.
During an electroencephalogram, typically 21 electrodes are temporarily pasted
to the scalp.
electroencephalogram (EEG): a diagnostic test that measures brainwaves,
the electrical impulses in the cerebral cortex. This test helps a physician to
diagnose epilepsy.
epilepsy: a chronic medical condition marked by recurrent epileptic
seizures. Patients may have single seizures as a result of fever, medication
withdrawal, etc., but are not labeled as having epilepsy if seizures do not
recur.
epileptogenic zone: the region of the brain responsible for the abnormal
electrical signals that cause seizures
epilepsy surgery: a neuro-surgical procedure to prevent further seizures,
usually accomplished by resecting the epileptogenic zone. Successful in
eliminating seizures in a large majority of patients, depending on the type of
epilepsy identified during EEG-video monitoring.
extratemporal cortical resection:
an operation to cut out (resect) brain tissue that contains a seizure
focus. "Extratemporal" means the tissue is located in an area of the
brain other than the temporal lobe, most often the frontal lobe.
functional hemispherectomy: a procedure in which portions of one
hemisphere of the brain which is not functioning normally are removed, and the
corpus callosum is split. This interrupts the communications among the various
lobes and between the two hemispheres and prevents the spread of seizures.
generalized seizure: a seizure that occurs all through the brain
grand-mal seizure: an older term for a seizure in which the patient
loses consciousness and collapses. The patient also has body stiffening and
violent jerking, and then goes into a deep sleep. Also known as a generalized
convulsion.
hemisphere: one half of the cerebrum, the largest part of the brain.
ketogenic diet: a treatment for epilepsy intended to maintain the
starvation or fasting metabolism for a long period in order to create ketones,
byproducts of fat-burning metabolism. (Seizures often
lessen or disappear during periods of fasting.) The diet is very high in fat and
low in carbohydrates and is most often recommended for children ages 2 through
12 who have been diagnosed with a generalized type of epilepsy, and who have
failed to respond to a variety of medications.
lesionectomy: surgery to remove isolated brain lesions that are
responsible for seizure activity
lobe: one of the sections of the cerebrum, the largest part of the brain.
The lobes are divided into four paired sections (frontal, parietal, occipital,
and temporal). The seizure focus is usually located in one of the lobes.
lumbar puncture: a diagnostic procedure in which the fluid surrounding
the spinal cord (cerebrospinal fluid) is withdrawn through a needle and examined
in a laboratory. Also known as a spinal tap.
multiple subpial transection: a surgical procedure to help control
seizures that begin in areas of the brain that cannot be safely removed (areas
that control movements or speech). The surgeon makes a series of shallow cuts (transections)
in the brain tissue to interrupt the movement of seizure impulses.
myoclonic seizure: a seizure that consists of sporadic jerks, usually on
both sides of the body. Patients with these seizures
may drop or involuntarily throw objects.
neurologist: a physician who specializes in the treatment of disorders of
the brain and nervous system (such as epilepsy)
neuron: a single nerve cell. The brain is made up of billions of neurons.
Many neurons malfunctioning together are necessary to produce a seizure.
nonepileptic event: an event that resembles a seizure but is actually
produced by another condition, such as Tourette syndrome and heart rhythm
disturbances (arrhythmias). Certain psychological conditions can also bring on a
nonepileptic event.
partial seizure: (also know as a "focal seizure") a seizure
that occurs in a limited area in only one hemisphere of the brain. This type of
seizure is more amenable to treatment with surgery than are generalized
seizures.
seizure: an event of altered brain function caused by abnormal or
excessive electrical discharges in the brain. Most seizures cause sudden changes
in behavior or motor function.
seizure focus: the area of the brain in which a seizure starts
status epilepticus: a prolonged seizure (usually
defined as lasting longer than 30 minutes) or a series of repeated seizures
without regaining consciousness. Status epilepticus is a medical emergency, and
medical help should be obtained immediately.
temporal lobe resection: a surgical procedure in which brain tissue in
the temporal lobe is cut away (resected) to remove the seizure focus.
tonic seizure: a seizure that is characterized by stiffening of the
muscles, sustained for more than a few seconds
tonic-clonic seizure: a seizure marked by loss of
consciousness, falling, stiffening, and jerking. This is the hallmark of a
generalized motor seizure, which used to be called a "grand mal
seizure."
vagus nerve stimulation: a surgical treatment for epilepsy involving
implantation in the neck of an electrode on the vagus nerve. The electrode is
connected to a pacemaker that is placed under the skin in the chest. While the
VNS is usually programmed to cycle continuously, the patient can turn the
stimulator on, using a small magnet placed over the pacemaker, if he or she
feels a seizure coming on.
vagus nerve: a small cranial nerve that passes through the neck and is
connected to various areas of the brain
|
