epilepsy%20(pediatric)
EPILEPSY (PEDIATRIC)
Epileptic seizure is a transient occurrence of signs or symptoms that is due to abnormal excessive or synchronous neuronal activity in the brain.
Epilepsy is a disorder that is characterized by a persistent predisposition of the brain to generate epileptic seizures.
This condition may cause neurobiologic, cognitive, psychological and social disturbances.
It is recommended that all patients having a first seizure be referred to a specialist as soon as possible.

Diagnosis

Three Levels of Diagnosing Epilepsy

  • Seizure type
    • Focal onset
    • Generalized onset
    • Unknown onset
  • Epilepsy type
    • Focal
    • Generalized
    • Combined generalized and focal
    • Unknown
  • Epilepsy syndrome wherein specific syndromic diagnosis can be made


Seizure Description

  • Pertinent details to be obtained from patient: Frequency of attacks, triggering factors, symptoms before, during and after the attacks, duration of symptoms, injury incurred and incontinence
  • Pertinent details to be obtained from witness: Frequency of attacks, detailed observations before and during the attacks (eg physical symptoms, psychic symptoms and level of consciousness) and symptoms following the attacks


Investigate Triggering Factors

  • Visual stimulation (eg photic stimulation), drug-induced (eg alcohol), sleep deprivation or metabolic causes (eg hyponatremia, hypoglycemia or hypocalcemia)

Classification

Seizure Types

May be self-limited type, as focal, generalized, or unknown, or continuous type, as in status epilepticus; precipitating factors should also be determined

Focal Onset

  • Affects only a portion of the brain, typically involving part of 1 lobe of 1 hemisphere
  • Can be subcategorized to Aware and Impaired Awareness
  • Can also be subgrouped to with motor and nonmotor signs and symptoms
  • When a patient is aware of self and his surroundings during a seizure, this is referred to as retained awareness
  • Impaired awareness is the presence of any significant impairment of awareness during a seizure episode
  • Focal aware seizure replaces the term “simple partial seizure”
  • Focal impaired awareness seizure corresponds to the prior term “complex partial seizure”
  • Focal to bilateral tonic-clonic is a special type of seizure that was previously termed partial onset with secondary generalization
  • Classification of seizures should be based on the earliest prominent motor onset or nonmotor onset feature
  • New focal onset seizure types include automatisms, autonomic, behavior arrest, cognitive, emotional, hyperkinetic, sensory and focal bilateral tonic-clonic seizures

Generalized Onset

Consciousness is lost at onset except in myoclonic seizures; motor features bilateral

  • Nearly always consciousness is lost except in myoclonic seizures and clinical features together with electroencephalographic changes indicate involvement of bilateral hemispheres of the brain at the onset of seizure
  • Divided into motor and nonmotor (absence) seizures
  • Further subdivisions:
    • Absence (last for seconds; with or without automatism)
    • Myoclonic (simple or multiple jerks, often upper limbs)
    • Tonic
    • Tonic-clonic
    • Clonic
    • Atonic (sudden loss of head posture, limbs and/or body)

Unknown Onset

  • Onset of seizure may be missed or obscured
  • Subgroup of motor unknown onset seizure is are epileptic spasms (includes infantile spasm) and tonic-clonic
  • Behavior arrest

Epilepsy Types

Generalized Epilepsy

  • EEG shows generalized spike-wave activity
  • May have a range of seizure types including absence, myoclonic, atonic, tonic and tonic-clonic seizures
  • Idiopathic/Genetic Generalized Epilepsy
    • Well-recognized and common subgroup that encompass 4 well-established epilepsy syndromes: Childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy and generalized tonic-clonic seizures alone

Focal Epilepsy

  • Diagnosis is made on clinical grounds supported by EEG findings of focal epileptiform discharges
  • Include unifocal and multifocal disorders as well as seizures involving one hemisphere
  • Range of seizure types that can be seen include focal aware seizures, focal impaired awareness seizures, focal impaired awareness seizures, focal motor seizures, focal non-motor seizures, focal to bilateral tonic-clonic seizures

Combined Generalized and Focal Epilepsy

  • Patients who have both generalized and focal seizures
  • Diagnosis is made on clinical grounds supported by EEG findings of both generalized spike-wave and focal epileptiform discharges but epileptiform activity is not required for diagnosis

Unknown Epilepsy

  • For patients who have epilepsy but the clinician is unable to determine if the epilepsy type is focal or generalized due to insufficient information available

Epilepsy Syndrome
  • A cluster of features incorporating seizure types, EEG and imaging features that present together
  • Often with age-dependent features such as age at onset and remission, seizure triggers, diurnal variation and prognosis
  • No correlation with an etiologic diagnosis and may only serve as a guide in therapeutic decisions
  • With well-recognized syndromes such as childhood absence epilepsy, West syndrome, Dravet syndrome

Physical Examination

  • Detect signs of disorder associated with epilepsy (eg sign of head trauma, ear or sinus infection, congenital abnormalities, focal or diffuse neurologic abnormalities, diseases in other organ systems)

Evaluation

  • This condition may cause neurobiologic, cognitive, psychological and social disturbances
  • It is recommended that all patients having a first seizure be referred to a specialist as soon as possible
  • Diagnosis of epilepsy should be made by a pediatric neurologist or a child physician with expertise in childhood epilepsy
  • History should include but is not limited to: Age of onset, family history, social history, alcohol and drug use, and past medical history including head injury, febrile convulsions, diseases in other organ systems

Laboratory Tests

  • Blood glucose level
  • Creatinine and electrolytes
  • Liver function tests (LFTs)
  • Serum Ca and Mg levels
  • Serum prolactin (PRL) level
    • Obtained at 10-20 minutes after a suspected seizure may differentiate generalized tonic-clonic seizures or complex partial seizures from psychogenic non-epileptic seizures among older children
    • Serum PRL determined more than 6 hours after a suspected seizure should represent the baseline PRL level

Imaging

Electroencephalography (EEG)

  • Presence of abnormal electric activity
  • Location of seizure focus
  • Type of seizure disorder
  • Must be performed only after clinical evaluation by an expert in epileptic disorders
  • Limitations
    • Abnormalities are common in migraine patients and patients with psychotic illness, psychotropic medication
    • Abnormal EEG should therefore not be interpreted as confirming a diagnosis of epilepsy
    • May be normal in a number of epileptic patients
    • A normal result should not be interpreted as excluding a diagnosis of epilepsy
    • Should be performed in all children with recurrent epileptic seizure
    • A repeat EEG and a sleep EEG should be done in children with recurrent epileptic seizures and normal standard EEG
    • An ictal EEG should be performed when diagnosis is uncertain
  • In children, an initial work up of presumed ‘idiopathic generalized epilepsy’ syndrome should include an EEG
  • Consider video EEG for refractory epilepsy with “normal EEG”

Brain Imaging

  • Computed tomography (CT) scan, magnetic resonance imaging (MRI)
    • MRI is brain imaging of choice in patients with epilepsy
    • CT may be used if urgent assessment of seizures is necessary or MRI is contraindicated

Recommended Diagnostic Testing in Patients <25 years old

  • EEG should be performed to assist in classification of seizures and epilepsy
  • Most children with epilepsy should have an elective MRI scan
  • Brain imaging is not required if firm diagnosis of ‘idiopathic generalized epilepsy syndrome’ is made based on clinical history and EEG, there is complete and rapid response to 1st-line anticonvulsant medication
  • If firm diagnosis of ‘idiopathic generalized epilepsy syndrome’ is not made, both EEG and brain imaging are necessary
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