ENGLISH 183 – READING PRACTICE – SEIZURES
Read the following article and answer the questions that follow. To
check your answers, see the answer key below.
Seizures
are brief malfunctions of the brain’s electrical system resulting from cortical
neuronal discharge. The manifestations
of seizures are determined by the site of origin and may include
unconsciousness or altered consciousness, involuntary movements, and changes in
perception, behaviors, sensations, and posture. Seizures are the most frequently observed neurological
dysfunction in children and can occur with a wide variety of conditions
involving the central nervous system.
Once it is determined that the child has a seizure, it is important to
distinguish whether the episode was an epileptic or a nonepileptic
seizure. Seizures are the indispensable characteristic of
epilepsy; however, not every seizure is epileptic.
Epilepsy is a chronic seizure
disorder marked by recurrent and unprovoked seizures. Up to 20% of children have been misdiagnosed as having
epilepsy. It is, therefore, extremely
important to differentiate between an epileptic seizure and a nonepileptic
seizure as the therapeutic implications and methods of treatment vastly differ
between the two cases.
A simple seizure event should not be
classified as epilepsy and is generally not treated with long-term
antiepileptic drugs. Some seizures may
result from an acute medical or neurological illness and cease once the illness
is treated. In other cases, children
may have a single seizure without the cause ever being known.
Seizures in children have many
different causes and histories.
However, most seizures occur due to idiopathic epilepsy. Although the word idiopathic refers to
unknown causes, it may indicate genetic factors that in some way alter the
seizure threshold to influence normal neuronal discharge. Congenital defects and some genetic
disorders, like tuberous sclerosis,
also have seizures as a manifestation.
Febrile and breath-holding seizures are related to a lowered seizure
threshold and this tends to have a higher incidence in certain families. Hereditary abnormalities have been detected
in some families and there is a higher incidence of seizures among relatives of
children with idiopathic seizure disorders.
A seizure disorder can also be
acquired as a result of brain injury during prenatal, perinatal, or postnatal
periods. This may be caused by trauma, hypoxia, infections, as well as
a variety of other factors.
Furthermore, biochemical events, like hypoglycemia, can also produce
seizure activity.
The incidence of causative factors
associated with childhood seizures is frequently related to the age of the
child. Seizures are more common during
the first 2 years of life than during any other period of childhood. In very young infants the most
frequent
causes are birth injuries. Acute
infections are a frequent cause of seizures in late infancy and early
childhood, but become an infrequent cause in middle childhood. In children older than 3 years, the most
common cause is idiopathic epilepsy.
Regardless of the type of seizure,
the basic causative mechanism is the same. Electrical discharges that may arise from central areas in
the brain affect the
consciousness
immediately. These electrical charges
may be restricted to one area of the cerebral cortex, or they may begin in a
localized area of the cortex and spread to other portions of the brain, which,
if sufficiently extensive, produce generalized neurological manifestations. Seizure activity is believed to be caused by
a spontaneous electrical discharge initiated by a group of hyperexcitable cells
referred to as the epileptogenic focus. They
usually display increased electrical excitability, but may remain quiescent over a period of time, reacting
only once in a while. Normally, these
reactions are restrained from spreading beyond the focal area by normal
inhibitory mechanisms.
The objective of treatment of
seizure disorders is to control the seizures or to reduce their frequency and
severity, discover and correct the cause when possible, and help the child who
has recurrent seizures to live as normal a life as possible. Seizures of a recurrent nature are treated
as soon as the diagnosis is established.
If the seizure activity is a manifestation of an infectious, traumatic,
or metabolic process, then seizure therapy is instituted as part of the general
therapeutic regimen. Seizure control is
also considered to prevent secondary brain cell injury from the neuronal
discharge and hypoxia.
1. Seizures are identified according to
____________.
a. their
severity
b. the
location of their occurrence
c. involuntary
movements
d. the
behavior of sufferers
2. Idiopathic epilepsy is caused by
_____________.
a. hereditary
abnormalities
b. idiopathic
seizures
c. unknown
causes
d.
congenital defects
3. Tuberous
sclerosis is an example of ______________.
a. a
seizure
b. a
congenital defect
c. a genetic disorder
d. idiopathic
epilepsy
4. During a seizure, neurological activity
in the brain ____________.
a. makes
the person unconscious
b. spreads
all over the brain
c. produces
an electrical discharge
d. initiates
hyperexcitable cells
5. Treatment of seizures is mostly related
to __________.
a. controlling
seizures
b. giving
medication
c. maximizing
the frequency and severity of seizures
d. both
a. and c.
6. Age determines the cause of childhood
seizures.
a. True
b. False
7. A majority of children are misdiagnosed
as having epilepsy.
a. True
b. False
8. The cause of seizures is not always
identifiable.
a. True
b. False
9. ‘this’ (para. 5, line 2) refers to
______.
a. a
period
b. seizure
disorder
c. trauma
d.
brain injury
10. ‘they’ (para. 7, line 8) refers to
______.
a. reactions
b. electrical discharges
c. hyperexcitable
cells
d. inhibitory
mechanisms
11. ‘indispensable’ (para. 1, line 8) means
_________.
a. unnecessary
b. trivial
c. basic
d. none of the above
12. ‘quiescent’ (para. 7, line 8) means
_________.
a. normal
b. balanced
c. excited
d. motionless
1.
b 2. d 3. c 4. a 5. a
6. b 7. b 8. a
9. d 10. c 11. c
12. d