Seizures in childhood
Seizure ( convulsion, fit):- paroxysmal time-limited change in motor activity and/or
behavior that results from abnormal electrical activity. Seizures are common in the
pediatric age group and occur in approximately10%.
Most Seizures are provoked by infection, fever, head trauma, hypoxia, toxin fatigue,
hyperventilation alkalosis and drugs like ( INH, penicillin, theophylline …etc).
Epilepsy:- Two or more unprovoked seizures occur at an interval greater than 24 hr
apart . The incidence of epilepsy is 3% and more than 50% of cases begin in
childhood.
Classification of epileptic seizures:1) Partial seizures ( 40%):-
Motor
a) Simple partial seizures ( SPS)
Sensory
b) Complex partial seizures ( CPS).
Autonomic
Psychic
2) Generalized seizures:-
Typical
a) Absence seizures
A typical
Tonic
Clonic
b) Generalized tonic – clonic seizures
Myoclonic
A tonic
Infantile spasms
3) Unclassified seizures.
This classification is important because it gives a clue to the cause, prognosis and
treatment, for ( e.g) :- a child with generalized tonic- clonic epilepsy is usually
controlled with anticonvulsant, while isn’t in the partial seizures. Clinical
classification may be difficult because the manifestation of different seizures may
be similar ( absences seizures with CPS), so EEG is used in addition to the clinical
finding. 50% of childhood seizures can be classified into specific syndromes
(e.g):- West syndrome and lennox – Gastaut syndrome.
Partial seizures
SPS :- The average duration is ( 10-20) seconds, no loss of consciousness and may
verbalize during seizure, postictal (Todd's) paralysis that can last minutes or hours,
and sometimes longer, no automatism. Aura seen in some cases as ( felling funny,
some thing crawling inside me, chest pain, head ache… ). Versive seizures consisting
of head turning and conjugate eye movements are particularly common. It may be
confused with tics, which can be briefly suppressed.
CPS:- The average duration is (1-2) minutes. Impaired consciousness. Aura seen in
1/3 of cases which indicate a focal onset of seizure, it consist of vague, unpleasant
feelings, epigastric discomfort or fear. Automatism is seen in 50-75% of patients
which follow the loss of consciousness, in infants it is characterized by alimentery
type (lip smacking. Chewing, swallowing and excessive salivation), these movements
can represent a normal infant behavior but in CPS it is associated with blank stare or
lack of responsiveness. In older children, the automatism consists of picking and
pulling of clothing, walking or running in non-directive repetitive and often fearful
fashion.
CPS may begin with a SPS followed by impaired consciousness or it starts with
altered state of consciousness.
CT scanning and MRI are most likely to identify temporal abnormality in a child with
CPS.
Benign Childhood Epilepsy with Centro temporal spikes (BECTS) :It is a common type of partial epilepsy in childhood with good prognosis, it occur
between (2-14)y and peaked at (9-10)y. It occur in normal children with often positive
F.H of epilepsy, the signs and symptoms are often confined to the face as tonic
contraction and parasthesia of the tongue, unilateral numbness of the cheek,
dysphagia, excessive salivation and frequently there is unilateral tonic- clonic
contraction of the lower face. The consciousness is intact or impaired and the seizure
may progress to generalization. It occur during sleep in 75% of patients. The EEG is
diagnostic and characterized by repetitive spike focus localized in centro temporal or
rolandic area with normal background activity.
Treatment : carbamazepine for at least 2y. or until (14-16)y of age when spontaneous
remission occur.
Generalized seizures
Typical absence seizures:- Characterized by flutter or upward rolling of the eyes.
Usually start at 5-8 yr of age, never associated with aura, rarely persist longer than 30
sec and no post ictal state, no loss of body tone, Can have simple automatisms like
lip-smacking or picking at clothing and the head can minimally fall forward
Hyper ventilation for (3-4) min, produce this seizure. EEG→ typical 3/ sec- spikes.
Atypical absence seizures: - Have associated myoclonic components and tone
changes of the head and body. It is more difficult to treat. They are precipitated by
drowsiness and are usually accompanied by 1-2 Hz spike–and–slow wave discharges.
Generalized tonic – clonic seizures ( grand mal epilepsy ):They are extremely common and may follow a partial seizure with a focal onset. They
may be associated with aura suggesting a focal origin of the epileptic discharge. There
is sudden loss of consciousness and some times emit a shrill cry, eyes role back with
tonic contraction of the body and rapidly become cyanotic with apnea, then develop
rhythmic clonic
contraction alternating with relaxation of all muscle groups. This clonic phase persist
for few minutes. During seizure, the child may bite his tongue, loss of sphincters
control especially the bladder. Tight clothing and jewelry around the neck should be
loosened and put patient onside and gently hyperextend the neck and jaw to enhance
breathing, don’t open the mouth by force to avoid dislodgment and aspiration of his
teeth. Postictally the child is semi comatose and then go in deep sleep for ( 30 min –
several hours ). If the patient examined during seizure or immediately post ictally we
may find truncal ataxia, hyperactive deep tendon reflexes, clonus and babinski reflex .
The post ictal phase often associated with vomiting and intense bifrontal headache.
Petit mal epilepsy: Typically starts in mid-childhood. Most patients outgrow it before
adulthood. Approximately 25% of patients also develop generalized tonic-clonic
seizures
Myoclonic epilepsy :- Repetitive seizures consist of brief, often symmetrical
muscular contraction with loss of body tone and falling for ward with tendency to
cause injury of the face and mouth.
1) Benign myoclonic Epilepsy of infancy:- normal EEG, good prognosis,
stopped by 2y. it may be confused with infantile spasm, no need for treatment.
2) Juvenile myoclonic epilepsy (Janz syndrome): The most common
generalized epilepsy in young adults, accounting for 5% of all epilepsies. It
begins between ( 12-16)y .Frequently occur upon a wakening which make hair
– combing and tooth – brushing difficult, it abate later in the morning. It may
respond to Na. valproate which is required lifelong.
West Syndrome: It starts between the ages of 2 and 12 mo. It consists of a triad
of:
1- Infantile spasms that usually occur in clusters (particularly in drowsiness or
upon arousal).
2- Developmental regression.
3- Typical EEG picture called hypsarrhythmia.
It is classified into 2 groups :A: Cryptogenic (idiopathic): Patients have normal development before onset. It
is a medical emergency because diagnosis may be delayed for 3 weeks or longer
and can affect long-term prognosis. The spasms are often being mistaken for
startles due to colic or for other benign paroxysmal syndromes.
B- Symptomatic: Patients have preceding developmental delay owing to perinatal
encephalopathies, malformations, underlying metabolic disorders, or other
etiologies. In boys, West syndrome often associated with ambiguous genitalia.
Treatment:
1- ACTH gel
2- Vigabatrin: Its principal side effect is its retinal toxicity.
3- Valproate, nitrazepam, clonazepam, pyridoxine, ketogenic diet, and
(IVIG).
Lennox – Gastaut syndrome: Typically starts between the age of 2 and 10 yr. It
consists of a triad of :
1- Developmental delay.
2- Multiple seizure types.
3- Characteristic EEG findings ( 1-2 Hz spike–and-slow waves, polyspike bursts
in sleep, and a slow background in wakefulness).
Most patients are left with long-term mental retardation and intractable seizures
despite multiple therapies.
Landau – Kleffner Syndrome :- rare, unknown cause, more common in boys, mean
onset at 5 1/2 y, often confused with autism because of language loss in a previously
normal child. 70% have different types of seizures, aphasia, auditory agnosia may be
so severe so the hearing is normal but have behavioral problems like irritability and
poor attention span. EEG examination should be done during sleep if the a wake
record is normal.
Treatment :1)
Valproic acid alone or in addition to clobazam.
2)
If no response give prednisolone 2 mg/kg/24h for 1 mo, tapered to
1mg/kg/24h for 1 mo, then reduce the dose to 0.5 mg/kg/24h for 6-12 mo.
3)
Speech therapy for several years.
4)
Surgery ( sub – pial transaction ) when medical treatment fails.
5)
Methylphenidate for severe hyperactivity and inattention, but it may
potentate the seizure.
6)
IV IG :- may be helpful.
Prognosis :1) If it starts < 2y. It will have poor prognosis.
2) Most children have a significant speech abnormality during adulthood.
3) Some children have a recurrence of aphasia and seizures
Febrile Seizures
It occurs between the age of 6 and 60 months, when the temperature is 38C or
higher, and is not the result of CNS infection or any metabolic imbalance, with no
history of prior afebrile seizures. In most cases the disorder appears polygenic, but
in many families the disorder is inherited as an autosomal dominant trait.
Simple febrile seizure: is a primary generalized, usually tonic-clonic, attack
associated with fever, lasting for a maximum of 15 min, and not recurrent within a
24-hour period, do not have an increased risk of mortality
Complex febrile seizure is more prolonged (>15 min), focal, and/or recurs within
24 hr, may have an approximately 2-fold long-term increase in mortality.
Febrile seizures recur in 30% of those experiencing a first episode, in 50% after 2
or more episodes, and in 50% of infants <1 year old at febrile seizure onset.
About 15% of children with epilepsy have had febrile seizures.
Risk factors for recurrence of febrile seizures
Major: (Age <1 year, Duration of fever <24 hr, and Fever 38-39C)
Minor: (Family history of febrile seizures, Family history of epilepsy, Complex
febrile seizure, Day care, Male gender, and Lower serum sodium).
No risk factors:
recurrence risk
12%.
1 risk factor:
recurrence risk
25-50%.
2 risk factors:
recurrence risk
50-59%.
3 or more risk factors:
recurrence risk
73-100%.
Risk factors for epilepsy:
Risk Factor
Simple febrile seizure
Recurrent febrile seizures
Complex febrile seizure
Fever <1 hour before febrile seizure
Family history of epilepsy
Focal complex febrile seizure
Neurodevelopmental abnormalities
Investigations:
Risk for Epilepsy
1%
4%
6%
11%
18%
29%
33%
1- Lumbar puncture (LP): is recommended in children <12 months of age after
their first febrile seizure to rule out meningitis. A child between 12 and
18 months of age should also be considered for LP because the clinical
symptoms of meningitis may be subtle in this age group. For children
>18 months of age LP is indicated in the presence of clinical signs and
symptoms of meningitis or if the history and/or physical examination
otherwise suggest intracranial infection.
2- EEG: is indicated if epilepsy is highly suspected.
3- Blood studies: (serum electrolytes, Ca, PO4, Mg, and CBC) are not routinely
recommended with a first simple febrile seizure. Blood glucose should be
determined only in children with prolonged postictal obtundation or those with
poor oral intake.
4- CT or MRI: is indicated if the child is neurologically abnormal and in patients
with febrile status epilepticus
Treatment:
1- Parents emotional support.
2- Antiepileptic therapy is not recommended for children with one or more
simple febrile seizures.
3- If the seizure lasts for >5 min, then acute treatment with diazepam, lorazepam,
or midazolam is needed.
4- Rectal diazepam is given at the time of recurrence of febrile seizure lasting
>5 min. Alternatively, buccal or intranasal midazolam may be used and is
often preferred by parents.
5- Intermittent oral diazepam can be given during febrile illnesses (0.3 mg/kg
every 8 hr). Intermittent oral nitrazepam, clobazam, and clonazepam
(0.1 mg/kg/day) have also been used.
6- Antipyretics do not reduce the risk of having a recurrent febrile seizure.
7- Iron deficiency has been shown to be associated with an increased risk of
febrile seizures, and thus screening for that problem and treating it.
Diagnosis of seizures
1) History :- full description of the seizure and the post ictal state including the
timing, duration, precipitating factors, aura, personality changes or intellectual
deterioration which may suggest a degenerative disease of CNS where as
vomiting and FTT might indicate a metabolic disorder or a structural lesion.
2) Physical examination :- to search for organic cause, B.P, wt, length and H.C
should be recorded and plotted on a growth chart. Look for any unusual facial
features or associated hepato – splenomegaly which may indicate a metabolic
or storage disease. Search for cutaneous lesion ( neurocutaneous syndromes),
eye examination for ( retinal phakoma, papillodema, retinal hemorrhage,
chorio retinitis ), hyper ventilation for ( 3-4) min produce absence seizure.
3) Investigation :- in the first a febrile seizure we must do
a) ( FBS, Ca ++, mg++ and electrolyte ) estimations.
b) EEG ( normal EEG seen in 40% of patients ), so we may do activation
procedures. (hyperventilation, eye closure, photic stimulation and sleep
deprivation), which will ↑the positive results. Seizures discharges are
more likely to be recorded in infants and children than in the adolescent
or adult.
c) CT and MRI : indicated if there is suspicion of intra – cranial lesion,
prolonged partial seizure, focal neurological deficit, no response to
anticonvulsant and evidence of ↑ I.C. P.
d) CSF examination :- if there is suspicion of infection, sub- archnoid
hemorrhage or demyelination diseases.
e) Specific metabolic tests.