SEIZURES

Although the occurrence of a seizure in a child without a provocative stimulus such as high fever is often considered a harbinger of a chronic seizure disorder or epilepsy, less than half of these children go on to develop a 2nd seizure. A careful history is warranted to ascertain a potential family history of epilepsy, a prior neurologic disorder, or history of seizure with fever, which may increase the likelihood of recurrence. Laboratory testing of serum electrolytes, toxicology screening, or urine and serum metabolic testing should be chosen based on individual clinical circumstances rather than on a routine basis. Serum glucose should be evaluated with the 1st afebrile seizure. In the child with a 1st nonfebrile seizure, a lumbar puncture is of limited value and should be used primarily when there is concern about possible meningitis, encephalitis, sepsis, subarachnoid hemorrhage, or a demyelinating disorder. An EEG is recommended as part of the neurodiagnostic evaluation of the child with an apparent 1st unprovoked seizure because it is useful for diagnosis of the event, prediction of recurrence risk, and identification of specific focal abnormalities and/or epileptic syndromes. Neuroimaging is generally not recommended after a 1st unprovoked seizure unless there is an indication for it on neurologic examination (focal neurologic deficits). If it is obtained, however, MRI of the brain is recommended over CT scanning. Anticonvulsant medication is generally not recommended after a single seizure. MRI may also be indicated in infants and adolescents with their 1st seizure
RECURRENT SEIZURES.
Two unprovoked seizures >24 hr apart suggest the presence of an epileptic disorder within the brain that will lead to future recurrences. It is important to perform a careful evaluation to look for the cause of the seizures as well as to assess the need for treatment with antiepileptic drugs and estimate the potential for response to treatment and remission of seizures in the future.
The history can provide important information about the type of seizures. Some parents can precisely act out or recreate a seizure. Children who have a propensity to develop epilepsy may experience the 1st convulsion in association with a viral illness or a low-grade fever. Seizures that occur during the early morning hours or with drowsiness, particularly during the initial phase of sleep, are common in childhood epilepsy. In retrospect, irritability, mood swings, headache, and subtle personality changes may precede a seizure by several days. Some parents can accurately predict the timing of the next seizure on the basis of changes in the child's disposition. The physical portrayal of the convulsion by the parent or caregiver is often surprisingly similar to the actual convulsion and is much more accurate than the verbal description
CLASSIFICATION OF SEIZURES.
It is important to classify the type of seizure ( Table 593-2 ). The seizure type may provide a clue to the cause of the seizure disorder. Precise delineation of the seizure may allow a firm basis for making a prognosis and choosing the most appropriate treatment. Anticonvulsants may readily control generalized tonic-clonic epilepsy in a child, but a patient with multiple seizure types or partial seizures may fare less well with the same type of therapy. Infants with benign myoclonic epilepsy have a more favorable outlook than patients with infantile spasms. Similarly, a school-aged child who has benign partial epilepsy with centrotemporal spikes (rolandic epilepsy) has an excellent prognosis and is unlikely to require a prolonged course of anticonvulsants. Clinical classification of seizures may be difficult because the manifestations of different seizure types may be similar. The clinical features of a child with absence seizures may be almost identical to those of another patient with complex partial epilepsy. An EEG is a useful adjunct to the classification of epilepsy because of the variability of seizure expressivity in this age group
TABLE 593-2 -- International Classification of Epileptic Seizures
PARTIAL SEIZURES
Simple partial (consciousness retained)
Motor
Sensory
Autonomic
Psychic
Complex partial (consciousness impaired)
Simple partial, followed by impaired consciousness
Consciousness impaired at onset
Partial seizures with secondary generalization
GENERALIZED SEIZURES
Absences
Typical
Atypical
Generalized tonic-clonic
Tonic
Clonic
Myoclonic
Atonic
Infantile spasms
UNCLASSIFIED SEIZURES

2.1. A seizure is considered generalized when clinical
symptomatology provides no indication of an
anatomic localization and no clinical evidence of
focal onset. When possible, three main seizure subtypes
may be categorized:
Generalized convulsive seizures with predominantly
tonic, clonic, or tonicoclonic features
Generalized nonconvulsive seizures represented
by absence seizures
Myoclonic seizures
In patients who have experienced several types
of generalized seizure each seizure type must be
categorized.
2.2. A seizure should be classified as partial when
there is evidence of a clinical partial onset, regardless
of whether the seizure is secondarily generalized.
The first clinical signs of a seizure, designated
for too long by the misleading term of “aura,” have
a highly localizing value and result from the anatomic
or functional neuronal activation of part of
one hemisphere.
When alertness and ability to interact appropriately
with the environment is maintained, the seizure
is classified as a simple partial seizure.
When impairment of consciousness, amnesia, or
confusion during or after a seizure is reported, the
seizure is classified as a complex partial seizure.
When the distinction between simple and complex
partial seizure cannot be made, from information
provided by history or medical records, the
seizure is classified as partial epileptic seizure of
unknown type.
When a patient has several types of partial seizure,
each should be separately categorized.
When a seizure becomes secondarily generalized,
the seizure is classified as partial seizure, secondarily
generalized (simple or complex).