Febrile Seizures

•       A febrile seizure, also known as a fever fit or febrile convulsion, is a convulsion associated with a significant rise in body temperature. They most commonly occur in children between the ages of 6 months and 5 years of age.  They are more common in boys than girls.

•       Since early in the 20th century, people have debated about whether these children would benefit from daily anticonvulsant therapy.

•       Epidemiologic studies have led to the division of febrile seizures into   3 groups, as follows:

–      simple febrile seizures,

–      complex febrile seizures, and

–      symptomatic febrile seizures.

v  Simple febrile seizure

•                      The setting is fever in a child aged 6 months to 5 years.

•                      The single seizure is generalized and lasts less than 15 minutes.

•                      The child is otherwise neurologically healthy and without neurological abnormality by                             examination or by developmental history.

•                       Fever (and seizure) is not caused by meningitis, encephalitis, or other illness affecting the brain.

•                      "Simple febrile seizures" last <15 minutes, are generalized, and occur only once per 24 hours.

v  Complex febrile seizure

•                       Age, neurological status before the illness, and fever are the same as for simple febrile seizure.

•                       This seizure is either focal or prolonged (ie, ³15 min), or multiple seizures occur in close                       succession.

•                      "Complex febrile seizures" last ³ 15 minutes, have a focal onset, or occur more than once per 24              hours.

v  Symptomatic febrile seizure

•                        Age and fever are the same as for simple febrile seizure.

•                        The child has a preexisting neurological abnormality or acute illness.

CAUSES OF FEBRILE SEIZURES

•       Infection — Febrile seizures can occur as a result of the fever that accompanies bacterial or viral infections, especially human herpesvirus-6 (also called roseola or sixth disease).

•       Immunizations — Fever can occur as a side effect of certain vaccines, particularly after measles mumps rubella (MMR) vaccination. The fever typically occurs 8 to 14 days after the injection.

•       Risk factors — A family history of febrile seizures increases a child's risk of febrile seizures.

Pathophysiology

•       The exact mechanism by which fever causes seizures is not known. But there are various theories put forward to explain it.One theory states that respiratory alkalosis which accompanies fever is the cause for seizures. Fever can cause hyperventilation especially in children. This causes increase in the pH within the brain. The increased pH increases the excitability and causes seizures. This also explain why febrile seizures occur in children – they are more prone for hyperventilation.Another theory states that increased temperature causes down regulation of GABA ( gamma-aminobutyric acid ) a receptors on the neuronal cell membrane. The inhibition of neuronal firing is removed and this results in increased excitability an seizures.

Epidemiology

•       Febrile seizures occur in 2-5% of children aged 6 months to 5 years in industrialized countries.  Among children with febrile seizures, about 70-75% have only simple febrile seizures, another 20-25% have complex febrile seizures, and about 5% have symptomatic febrile seizures. Children with a previous simple febrile seizure are at increased risk of recurrent febrile seizures;  this occurs in approximately one third of cases. Children younger than 12 months at the time of their first simple febrile seizure have a 50% probability of having a second seizure. After 12 months, the probability decreases to 30%.Children who have simple febrile seizures are at an increased risk for epilepsy.  The rate of epilepsy by age 25 years is approximately 2.4%, which is about twice the risk in the general population.The literature does not support the hypothesis that simple febrile seizures lower intelligence (ie, cause a learning disability) or are associated with increased mortality .Sex: Males have a slightly (but definite) higher incidence of febrile seizures.Age: Simple febrile seizures occur most commonly in children aged 6 months to 5 years.

Clinical Presentation

•       The general approach the patient with febrile seizures is delineated in Figure 1.Each child who presents with a febrile seizure requires a detailed history and a thorough general and neurologic examination.These are the cornerstones of the evaluation. Febrile seizures often occur in the context of otitis media, roseola and human herpesvirus 6 (HHV6) infection, shigella, or similar infections, making the evaluation more demanding. Several investigations need to be considered.

7.1-History

•       Children with simple febrile seizures are neurologically and developmentally healthy before and after the seizure.They do not experience a seizure in the absence of fever.The seizure is described as either a generalized clonic or a generalized tonic-clonic seizures.Signs of a focal seizure during the onset or in the postictal period (eg, initial clonic movements of 1 limb or of the limbs on 1 side, a weak limb postictally) would rule out a simple febrile seizure.Similarly, simple febrile seizure activity does not continue for more than 15 minutes, although a postictal period of sleepiness or confusion can extend beyond the 15-minute maximum.Simple febrile seizures often occur with the initial temperature elevation at the onset of illness. The seizure may be the first indication that the child is ill. While no clear cutoff is known, a rectal temperature under 38°C should raise concern that the event was not a simple febrile seizure.

7.2- Physical Exam

•       Physical examination findings reveal a neurologically and developmentally healthy child.It is especially important that the child have no signs of meningitis or encephalitis (eg, stiff neck or persistent mental status changes).

Simple febrile seizures:

•        are the most common. Typically, the child loses consciousness and has a convulsion or rhythmic twitching of the arms or legs.Most seizures do not last more than one to two minutes, although they can last up to 15 minutes.After the seizure, the child may be confused or sleepy, but does not have arm or leg weakness.

Complex febrile seizures

•       are less common and can last more than 15 minutes (or 30 minutes if in a series).The child may have temporary weakness of an arm or a leg after the seizure

6.3- Laboratory Studies

•       No specific studies are indicated for a simple febrile seizure.Physicians should focus on diagnosing the cause of fever.Other laboratory tests may be indicated by the nature of the underlying febrile illness. For example, a child with severe diarrhea may benefit from blood studies for electrolytes.

7.4-Lumbar Puncture (LP)

•       LP is recommended in children <12 mo of age after their first febrile seizure to rule out meningitis.It is especially important to consider if the child has received prior antibiotics that would mask the clinical symptoms of the meningitis.The presence of an identified source of fever, such as otitis media, does not eliminate the possibility of meningitis. Seizures are the major sign of meningitis in 13-15% of children presenting with this disease, and 30-35% of such children have no other meningeal signs.

7.4-Lumbar Puncture

•       According to the American Academy of Pediatrics (AAP) practice parameter, it is strongly recommended in infants <1 yr of age because other signs of the infection might not be present.A child between 12 and 18 mo of age should also be considered for lumbar puncture because the clinical symptoms of meningitis may be subtle in this age group. For the well-appearing child after a febrile seizure, the yield of lumbar puncture is very low.For children >18 mo of age, a lumbar puncture is indicated in the presence of clinical signs and symptoms of meningitis (e.g., neck stiffness, Kernig sign, Brudzinski sign) or if the history and/or physical examination otherwise suggest intracranial infection.

7.5- Imaging Studies

•       Neither computed tomography (CT) nor magnetic resonance imaging (MRI) is indicated in patients with simple febrile seizures.According to the AAP practice parameter, a CT or MRI is not recommended in evaluating the child after a first simple febrile seizure.

7.6- Other Tests

•       EEG is not indicated in children with simple febrile seizures. Published studies demonstrate that the vast majority of these children have a normal EEG.In addition, some of those with an abnormal EEG have remained free of seizures for the duration of their follow-up. On the other hand, some of the children with a normal initial EEG have experienced 1 or more afebrile seizures subsequent to the EEG.Finally, no evidence indicates that beginning anticonvulsant therapy for a child with simple febrile seizures and an abnormal EEG will alter the child's eventual outcome.In general, antiepileptic therapy, continuous or intermittent, is not recommended for children with one or more simple febrile seizures. Parents should be counseled about the relative risks of recurrence of febrile seizures and recurrence of epilepsy, educated on how to handle a seizure acutely, and given emotional support.If the seizure lasts for >5 min, then acute treatment with diazepam, lorazepam, or midazolam is needed.Rectal diazepam is often prescribed to be given at the time of recurrence of febrile seizure lasting >5 min:

–      <5ys:                             Rectal 0.5mg/kg

–      6-11 ys:                        Rectal 0.3mg/kg

–      >12 ys:                         0.2mg/kg

–      IV:                  0.2- 0.5mg/kg

Some authors recommend 0.3 to 0.5 mg/kg (not to exceed 10 mg) per rectum.

Treatment

•       If the parents are very anxious concerning their child's seizures, intermittent oral diazepam can be given during febrile illnesses (0.33 mg/kg every 8 hr during fever) to help reduce the risk of seizures in children known to have had febrile seizures with previous illnesses. Intermittent oral nitrazepam, clobazam, and clonazepam (0.1 mg/kg/day) have also been used.Other therapies have included intermittent diazepam prophylaxis (0.5 mg/kg administered as a rectal suppository every 8 hr), phenobarbital (4-5 mg/kg/day in 1 or 2 divided doses), and valproate (20-30 mg/kg/day in 2 or 3 divided doses).In the vast majority of cases it is not justified to use these medications owing to the risk of side effects and lack of demonstrated long-term benefits, even if the recurrence rate of febrile seizures is expected to be decreased by these drugs.

•       Antipyretics can decrease the discomfort of the child but do not reduce the risk of having a recurrent febrile seizure, probably because the seizure often occurs as the temperature is rising or falling.

•       Chronic antiepileptic therapy may be considered for children with a high risk for later epilepsy. Currently available data indicate that the possibility of future epilepsy does not change with or without antiepileptic therapy.

•       Iron deficiency has been shown to be associated with an increased risk of febrile seizures, and thus screening for that problem and treating it appears appropriate.

RECURRENT FEBRILE SEIZURE

•       Children who have a febrile seizure are at risk for having another febrile seizure; this occurs in approximately 30 to 35 percent of cases. Recurrent febrile seizures do not necessarily occur at the same temperature as the first episode, and do not occur every time the child has a fever. Most recurrences occur within one year of the initial seizure and almost all occur within two years.


•       The risk of recurrent febrile seizures is higher for children who:

–      Are young (less than 15 months)

–      Have frequent fevers

–      Have a parent or sibling who had febrile seizures or epilepsy

–      Have a short time between the onset of fever and the seizure

–      Had a low degree of fever before their seizure

•       Home treatment — Parents who witness their child's febrile seizure should take a number of steps to prevent the child from harming him or herself.Place the child on their side but do not try to stop their movement or convulsions. Do not put anything in the child's mouth.Keep an eye on a clock or watch. Seizures that last for more than five minutes require immediate treatment. One parent should stay with the child while another parent calls for emergency medical assistance, available by dialing 911 in most areas of the United States.Parents of a child who is at risk of having a recurrent febrile seizure can be taught to give treatment at home for seizures that last longer than five minutes. Treatment usually involves giving one dose of diazepam gel (Diastat®) into the rectum. One dose is generally all that is required to stop a seizure.Preventive treatment — In most cases, treatment to prevent future seizures is not recommended; the risks and potential side effects of daily antiseizure medications outweigh their benefit. In addition, giving medication (eg, acetaminophen or ibuprofen) to prevent fever is not recommended in a child without fever (eg, if the child has a cold but no fever) because it does not appear to reduce the risk of future febrile seizures.Treatment for fever (temperature greater than 100.4ºF or 38ºC) is acceptable but not always required; parents should speak with their healthcare provider for help in deciding when to treat a child's fever. Prognosis for normal neurologic function is excellent.About one third of children who experience a single simple febrile seizure will have another. The lifetime rate of epilepsy in these children is slightly above that of the general population.A Danish population-based study by Norgaard et al found little association between febrile seizures and cognitive function. Data linked from health-care databases and conscript records of Danish men born from 1977-1983 showed that, of the 18,276 eligible conscripts, 507 (2.8%) had a record of hospitalization with febrile seizures and no known history of epilepsy. Compared with conscripts with no record of febrile seizures, the adjusted prevalence ratio for having a Boerge Prien intelligence test score in the bottom quartile was 1.08 (95% confidence index [CI], 0.94-1.25). The adjusted prevalence ratios were 1.38 (95% CI, 1.07-1.79) for febrile seizures with an onset age of 3 months to < 1 year, 0.98 (95% CI, 0.80-1.18) for febrile seizures with an onset age of 1-2 years, and 1.14 (95% CI, 0.79-1.66) for an onset age of 3-5 years.

FOLLOW-UP

•       Intelligence and other aspects of brain development do not appear to be affected by a febrile seizure, whether the seizure was simple, complex, or recurrent or whether it occurred in the setting of infection or after immunization.Epilepsy occurs more frequently in children who have had febrile seizures. However, the risk that a child will develop epilepsy after a single, simple febrile seizure is only slightly higher than that of a child who never has a febrile seizure.

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Neurological Diagnostic Tests and Procedures

•   Diagnostic tests and procedures are vital tools that help physicians confirm or rule out the presence of a neurological disorder or other medical condition.  A century ago, the only way to make a positive diagnosis for many neurological disorders was by performing an autopsy after a patient had died. 

•  But decades of basic research into the characteristics of disease, and the development of techniques that allow scientists to see inside the living brain and monitor nervous system activity as it occurs, have given doctors powerful and accurate tools to diagnose disease and to test how well a particular therapy may be working.

•    Researchers and physicians use a variety of diagnostic imaging techniques and chemical and metabolic analyses to detect, manage, and treat neurological disease. 

•   Some procedures are performed in specialized settings, conducted to determine the presence of a particular disorder or abnormality. 

•    Many tests that were previously conducted in a hospital are now performed in a physician’s office or at an outpatient testing facility, with little if any risk to the patient.  Depending on the type of procedure, results are either immediate or may take several hours to process.

What are some of the more common screening tests?

•   Laboratory screening tests of blood, urine, or other substances are used to help diagnose disease, better understand the disease process, and monitor levels of therapeutic drugs.  Certain tests, ordered by the physician as part of a regular check-up, provide general information, while others are used to identify specific health concerns. 

•   For example, blood and blood product tests can detect brain and/or spinal cord infection, bone marrow disease, hemorrhage, blood vessel damage, toxins that affect the nervous system, and the presence of antibodies that signal the presence of an autoimmune disease. 

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Neurologic Evaluation

    Neurological disease may produce systemic signs and systemic disease may affect nervous system.A comprehensive neurologic evaluation-including:

1- history,

2- physical examination, and

3- the judicious use of ancillary studies/ Tools for test

allows the clinician to localize and determine the etiology of central and peripheral nervous system pathology.A detailed history is the cornerstone of any neurologic assessment. Although parents may be the primary informants, most children older than 3-4 yr are capable of contributing to their history and should be questioned directly.The history should begin with the chief complaint, as well as a determination of the complaint's relative significance within the context of normal development.The latter step is critical because a 13 month old who cannot walk may be perfectly normal, whereas a 4 yr old who cannot walk might have a serious pathology.Next, the history of present illness should provide a chronological outline of the patient's symptoms, with attention paid to location, quality, intensity, duration, associated features, and alleviating or exacerbating factors.It is essential to perform a review of systems, because abnormalities of the central nervous system (CNS) often manifest with vague, nonfocal symptoms that may be misattributed to other organ systems (e.g., vomiting, constipation, urinary incontinence).A detailed history might suggest that vomiting is due to increased intracranial pressure (ICP) rather than gastritis or that constipation and urinary incontinence are due to a spinal cord tumor rather than behavioral stool withholding.Following the chief complaint and history of present illness, the physician should obtain a complete birth history, particularly if a congenital disorder is suspected. The birth history should begin with a review of the pregnancy, including specific questions about common complications, such as pregnancy-induced hypertension, preeclampsia, gestational diabetes, vaginal bleeding, infections, and falls. It is important to quantify any cigarette, alcohol, or drug (prescription, herbal, illicit) use. Inquiring about fetal movement might provide clues to an underlying diagnosis, because decreased or absent fetal activity can be associated with chromosomal anomalies and CNS or neuromuscular disorders. Finally, any abnormal ultrasound or amniocentesis results should be noted.The most important component of a neurologic history is the developmental assessment.Careful evaluation of a child's social, cognitive, language, fine motor, and gross motor skills is required to distinguish normal development from either isolated or global (i.e., in two or more domains) developmental delay. An abnormality in development from birth suggests an intrauterine or perinatal cause, but a loss of skills (regression) over time strongly suggests an underlying degenerative disease of the CNS, such as an inborn error of metabolism.The social history should detail the child's current living environment, as well as his or her relationship with other family members.It is important to inquire about recent stressors, such as divorce, remarriage, birth of a sibling, or death of a loved one, because they can affect the child's behavior. If the child is in daycare or school, one should document his or her academic and social performance, paying particular attention to any abrupt changes.

   

      The neurologic examination begins at the outset of the interview. Indirect observation of the child's appearance and movements can yield valuable information about the presence of an underlying disorders.For instance, it may be obvious that the child has dysmorphic facies, an unusual posture, or an abnormality of motor function manifested by a hemiparesis or gait disturbance. The child's behavior while playing and interacting with his or her parents may also be telling. A normal child usually plays independently early in the visit but will rapidly engage in the interview process. A child with attention-deficit/hyperactivity disorder might display impulsive behavior in the examining room, and a child with neurologic impairment might exhibit complete lack of awareness of the environment. Finally, note should be made of any unusual odors about the patient, because some metabolic disorders produce characteristic scents (e.g., the “musty” smell of phenylketonuria or the “sweaty feet” smell of isovaleric acidemia). If such an odor is present, it is important to determine whether it is persistent or transient, occurring only with illnesses.The examination should be conducted in a nonthreatening, child-friendly setting. The child should be allowed to sit where he or she is most comfortable, whether it be on a parent's lap or on the floor of the examination room. The physician should approach the child slowly, reserving any invasive or painful tests (e.g., measurement of head circumference, gag reflex) for the end of the examination. In the end, the more that the examination seems like a game, the better the child will cooperate. Because the neurologic examination of an infant requires a somewhat modified approach from that of an older child, the two groups are considered separately.

Common or Concerning Symptoms of the Nervous System

•       Observing mental status, speech, and language

•       Observing sensorium, memory, abstract thinking ability, speech, mood, emotional state, perceptions, thought processes, ability to make judgments

•       Headache

•       Dizziness or vertigo

•       Weakness

•       Numbness

•       Loss of sensations

•       Loss of consciousness

•       Seizures

•       Tremors or involuntary movements

 Correct measurement of the head circumference is important. It should be performed at every visit for patients younger than 3 yr and should be recorded on a suitable head growth chart.The average rate of head growth in a healthy premature infant is 0.5 cm in the 1st 2 wk, 0.75 cm in the 3rd wk, and 1.0 cm in the 4th wk and every week thereafter until the 40th wk of development. The head circumference of an average term infant measures 34-35 cm at birth, 44 cm at 6 mo, and 47 cm at 1 yr of age If the brain is not growing, the skull will not grow; therefore, a small head reflects a small brain, or microcephaly. Conversely, a large head may be associated with a large brain, or macrocephaly, which is most commonly familial but may be due to a disturbance of growth, neurocutaneous disorder (e.g., neurofibromatosis), chromosomal defect (e.g., Kleinfelter syndrome), or storage disorder. Alternatively, the head size may be increased secondary to hydrocephalus or chronic subdural hemorrhages.An infant has two fontanels at birth: a diamond-shaped anterior fontanel at the junction of the frontal and parietal bones that is open at birth, and a triangular posterior fontanel at the junction of the parietal and occipital bones that can admit the tip of a finger or may be closed at birth.If the posterior fontanel is open at birth, it should close over the ensuing 6-8 wk; its persistence suggests underlying hydrocephalus or congenital hypothyroidism.A very small or absent anterior fontanel at birth might indicate craniosynostosis or microcephaly, whereas a very large fontanel can signify a variety of problems.Inspection of the head should include observation of the venous pattern, because increased ICP and thrombosis of the superior sagittal sinus can produce marked venous distention.Palpation of a newborn's skull characteristically reveals molding of the skull accompanied by overriding sutures—a result of the pressures exerted on the skull during its descent through the pelvis. Marked overriding of the sutures beyond the early neonatal period is cause for alarm, because it suggests an underlying brain abnormality.Auscultation of the skull is an important adjunct to the neurologic examination.Cranial bruits may be noted over the anterior fontanel, temporal region, or orbits and are best heard using the diaphragm of the stethoscope.Soft symmetric bruits may be discovered in normal children <4 yr of age or in association with a febrile illness.Demonstration of a loud or localized bruit is usually significant and warrants further investigation, because they may be associated with severe anemia, increased ICP, or arteriovenous malformations of the middle cerebral artery or vein of Galen.It is important to exclude murmurs arising from the heart or great vessels, because they may be transmitted to the cranium.Deep tendon reflexes are readily elicited in most infants and children. In infants, it is important to position the head in the midline when assessing reflexes, because turning the head to one side can alter reflex tone.Reflexes are graded from 0 (absent) to 4+ (markedly hyperactive), with 2+ being normal. Reflexes that are 1+ or 3+ can be normal as long as they are symmetrical. Sustained clonus is always pathologic, but infants <3 mo old can have 5-10 beats of clonus, and older children can have 1-2 beats of clonus provided that it is symmetrical.The ankle jerk is hardest to elicit, but it can usually be obtained by passively dorsiflexing the foot and then tapping on either the Achilles tendon or the ball of the foot. The knee jerk is evoked by tapping the patellar tendon. If this reflex is exaggerated, extension of the knee may be accompanied by contraction of the contralateral adductors (crossed adductor response). Hypoactive reflexes reflect lower motor neuron or cerebellar dysfunction, whereas hyperactive reflexes are consistent with upper motor neuron disease. The plantar response is obtained by stimulation of the lateral aspect of the sole of the foot, beginning at the heel and extending to the base of the toes.The Babinski sign, indicating an upper motor neuron lesion, is characterized by extension of the great toe and fanning of the remaining toes. Too vigorous stimulation may produce withdrawal, which may be misinterpreted as a Babinski sign.Plantar responses have limited diagnostic utility in neonates, because they are mediated by several competing reflexes and can be either flexor or extensor, depending on how the foot is positioned. As with adults, asymmetry of the reflexes or plantar response is a useful lateralizing sign in infants and children.

6-1: Primitive reflexes appear and disappear at specific times during development (Table), and their absence or persistence beyond those times signifies CNS dysfunction. Although many primitive reflexes have been described, the Moro, grasp, tonic neck, and parachute reflexes are the most clinically relevant.The Moro reflex is elicited by supporting the infant in a semierect position and then allowing his or her head to fall backwards onto the examiner's hand. A normal response consists of symmetric extension and abduction of the fingers and upper extremities, followed by flexion of the upper extremities and an audible cry. An asymmetric response can signify a fractured clavicle, brachial plexus injury, or hemiparesis. Absence of the Moro reflex in a term newborn is ominous, suggesting significant dysfunction of the CNS.The grasp response is elicited by placing a finger in the open palm of each hand; by 37 wk of gestation, the reflex is strong enough that the examiner can lift the infant from the bed with gentle traction.The tonic neck reflex is produced by manually rotating the infant's head to one side and observing for the characteristic fencing posture (extension of the arm on the side to which the face is rotated and flexion of the contralateral arm).The parachute reflex, which occurs in slightly older infants, can be evoked by holding the infant's trunk and then suddenly lowering the infant as if he or she were falling. The arms will spontaneously extend to break the infant's fall, making this reflex a prerequisite to walking.Healthy is more important than money. Money cannot buy healthy and happiness. But a Healthy person remains in a very state of satisfaction and happiness.A healthy person sings your glory of life and works hard to understand his dreams. They never complains. They are always happy along with cheerful. He may be poor, he might have to work very tough to earn the living, but even your richest man would likely envy him for his  Healthy good.

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