Overview
Definition:
Seizures are transient occurrences of abnormal, excessive, or synchronous neuronal activity in the brain
In children, they are broadly classified as focal (starting in one area of the brain) or generalized (affecting both hemispheres from onset)
Differentiating these types is crucial for diagnosis, management, and prognosis.
Epidemiology:
Epilepsy is a common neurological disorder in childhood, with incidence rates varying by age and geographic region
Approximately 0.5-1% of children experience epilepsy by age 16
Focal seizures are more common in older children and adolescents, while generalized seizures are more frequent in younger children, especially those with developmental delays.
Clinical Significance:
Accurate classification of seizure types guides appropriate antiepileptic drug (AED) selection, influences the choice of further investigations, and impacts long-term outcomes
Misclassification can lead to ineffective treatment or even worsen seizure control
Understanding EEG findings is paramount for objective diagnosis and classification.
Clinical Presentation
Symptoms:
Symptoms vary widely based on seizure type and location
Focal seizures may involve motor symptoms like clonic movements, tonic posturing, or automatisms (e.g., lip-smacking, fumbling), or non-motor symptoms such as altered awareness, strange sensations (epigastric rising), or visual/auditory disturbances
Generalized seizures often present with loss of consciousness and bilateral motor symptoms like tonic-clonic activity, absence spells, or myoclonic jerks
Postictal confusion or somnolence is common.
Signs:
Physical examination may reveal focal neurological deficits, developmental delay, or dysmorphic features
During a seizure, observe motor activity (tonic, clonic, atonic, myoclonic), autonomic signs (pupillary changes, pallor, sweating), and altered consciousness
Postictally, assess for focal neurological deficits or posturing.
Diagnostic Criteria:
International League Against Epilepsy (ILAE) classification provides a framework for classifying seizure types
The 2017 ILAE classification emphasizes seizure onset (focal, generalized, unknown) and awareness (retained or impaired)
Diagnosis relies on a thorough clinical history, detailed seizure description, and corroborated by EEG findings
Imaging (MRI brain) is essential to identify underlying structural causes, especially in focal epilepsy.
Diagnostic Approach
History Taking:
Detailed history from eyewitnesses is critical
Elicit: precise description of events (onset, duration, character of movements/sensations), precipitating factors, frequency, developmental milestones, family history of epilepsy or neurological disorders, and response to any previous treatments
Red flags include prolonged seizures, status epilepticus, developmental regression, and clusters of seizures.
Physical Examination:
Perform a comprehensive neurological examination, including assessment of mental status, cranial nerves, motor strength, sensation, coordination, and reflexes
Look for any signs of underlying neurological conditions such as dysmorphic features, birthmarks, or focal neurological deficits
Thorough examination of the skin for neurocutaneous markers like café-au-lait spots is also important.
Investigations:
Electroencephalography (EEG) is the cornerstone of diagnosis and classification
it records electrical activity of the brain and can detect characteristic patterns like generalized spike-and-wave discharges (absence seizures) or focal epileptiform abnormalities (focal seizures)
Video-EEG monitoring offers continuous recording and simultaneous video capture for detailed correlation
MRI brain is crucial to identify structural lesions like tumors, malformations of cortical development, or hippocampal sclerosis, especially in focal epilepsy
Metabolic screening (serum electrolytes, glucose, calcium, magnesium) and genetic testing are important in specific contexts.
Differential Diagnosis:
Conditions to consider include syncope (vasovagal, cardiac), psychogenic non-epileptic seizures (PNES), benign paroxysmal torticollis, benign paroxysmal vertigo, infantile spasms (now termed generalized epilepsy with spasms), breath-holding spells, and movement disorders
Distinguishing features include the absence of EEG abnormalities during PNES, and specific triggers for non-epileptic events.
Seizure Classification And Eeg Interpretation
Focal Seizures:
Focal seizures originate in a limited area of one cerebral hemisphere
EEG may show focal interictal epileptiform discharges (spikes, sharp waves) in the affected region, or continuous rhythmic delta activity (CRDA) during a seizure
Ictal EEG can demonstrate evolving focal high-amplitude rhythmic activity or flattening
Focal aware seizures have retained awareness, while focal impaired awareness seizures involve impaired consciousness.
Generalized Seizures:
Generalized seizures involve both cerebral hemispheres from the outset
EEG patterns are typically bilateral and symmetric
Absence seizures show generalized 3-4 Hz spike-and-wave discharges
Myoclonic seizures present with generalized, brief, high-amplitude, polyspike-and-wave discharges
Tonic-clonic seizures show an initial widespread generalized fast activity or flattening followed by diffuse slowing and postictal depression.
Eeg Patterns And Significance:
Interictal EEG can reveal epileptiform discharges (spikes, sharp waves, spike-and-wave complexes) that are not present during normal brain activity
Ictal EEG patterns, recorded during a seizure, are crucial for localization and classification
Background activity assessment is also vital
generalized slowing may indicate an underlying encephalopathy
Normal EEG does not rule out epilepsy, especially if the recording is brief or occurs between seizures.
Eeg Artifacts:
Recognizing artifacts is essential for accurate interpretation
Common artifacts include muscle activity (EMG), eye movements (EOG), electrode pop, and electrical interference
These can mimic or mask epileptiform discharges, requiring careful differentiation.
Management
Initial Management:
For a first-time seizure, ensure airway patency, breathing, and circulation (ABCs)
Protect from injury
If a seizure lasts longer than 5 minutes or recurs without full recovery, administer benzodiazepines (e.g., intravenous lorazepam 0.1 mg/kg, maximum 4 mg, or rectal diazepam 0.5 mg/kg) as first-line treatment for status epilepticus.
Medical Management:
Pharmacological management is guided by seizure type and epilepsy syndrome
For focal epilepsy, first-line AEDs include levetiracetam, carbamazepine, or oxcarbazepine
For generalized epilepsy, options include valproic acid, lamotrigine, or levetiracetam
Dosing is age- and weight-dependent, with specific protocols for neonates and infants
Titration of AEDs is crucial to achieve seizure freedom with minimal side effects
Monitor drug levels and for adverse effects.
Surgical Management:
Epilepsy surgery may be considered for intractable focal epilepsy unresponsive to multiple AEDs
Pre-surgical evaluation involves detailed EEG (including video-EEG), MRI, and sometimes functional imaging (PET, SPECT)
Surgical options include resective surgery (removing the seizure focus) or palliative procedures like corpus callosotomy for severe generalized epilepsies with disabling drop attacks.
Supportive Care:
Provide education and counseling to families regarding the child's condition, medication adherence, and safety precautions (e.g., avoiding heights, swimming unsupervised)
Regular follow-up with a neurologist is essential for monitoring seizure control, medication side effects, and neurodevelopmental progress
Consider ketogenic diet or vagus nerve stimulation for refractory epilepsy.
Complications
Early Complications:
Status epilepticus, injury during seizures (falls, burns), respiratory compromise, and aspiration pneumonia
SUDEP (Sudden Unexpected Death in Epilepsy) is a rare but serious complication.
Late Complications:
Cognitive impairment, behavioral problems, learning difficulties, psychosocial challenges, and medication-related side effects
In severe cases, prolonged uncontrolled seizures can lead to neuronal damage.
Prevention Strategies:
Adherence to prescribed AEDs, timely management of status epilepticus, appropriate safety measures, regular medical follow-up, and addressing underlying etiologies where possible are key preventive strategies.
Prognosis
Factors Affecting Prognosis:
Prognosis depends on the underlying cause, seizure type and frequency, epilepsy syndrome, response to treatment, and presence of comorbidities
Early diagnosis and appropriate management improve outcomes
Idiopathic epilepsies often have a better prognosis than those with structural or metabolic causes.
Outcomes:
Many children with epilepsy achieve seizure freedom with appropriate AEDs, allowing for normal development and schooling
However, a significant proportion may have refractory epilepsy, requiring advanced therapies or continuing to experience seizures
Long-term neurodevelopmental and psychosocial outcomes are influenced by seizure control and underlying etiology.
Follow Up:
Regular follow-up appointments are essential to monitor seizure control, assess for AED side effects, and track neurodevelopmental progress
The frequency of follow-up is tailored to the individual child's needs, typically more frequent initially and then annually or semi-annually once seizure control is established.
Key Points
Exam Focus:
Distinguish focal vs generalized seizures based on clinical presentation and EEG findings
Understand first-line and second-line AEDs for common pediatric epilepsy syndromes
Recognize EEG patterns of absence, myoclonic, and tonic-clonic seizures
Know the management of status epilepticus in children.
Clinical Pearls:
Always elicit a detailed seizure description from multiple observers
Suspect epilepsy in any child with recurrent unexplained paroxysmal events
EEG is a tool, not a definitive diagnosis
clinical correlation is paramount
Early intervention and consistent medication adherence are vital for optimal outcomes.
Common Mistakes:
Mistaking other episodic events (syncope, PNES) for seizures
Inadequate history taking
Prescribing AEDs that exacerbate generalized epilepsies (e.g., carbamazepine in absence seizures)
Delaying management of status epilepticus
Over-reliance on normal EEG findings to rule out epilepsy.