What is the diagnosis and management for a 2-year-old male with a history of fall 1 month ago, now presenting with focal seizures and impaired awareness?

Post-Traumatic Focal Seizure with Impaired Awareness: Diagnosis and Management

Diagnosis

This 2-year-old presents with post-traumatic focal seizures with impaired awareness (formerly called complex partial seizures), requiring urgent neuroimaging to identify treatable intracranial pathology from the fall one month ago. 1

Key Diagnostic Features

• Focal seizures with impaired awareness are characterized by seizure onset limited to one hemisphere with loss of awareness during the event, distinguishing them from focal aware seizures where consciousness is retained 1, 2

• The one-month interval between trauma and seizure onset is consistent with post-traumatic epilepsy, as subdural hematoma and young age are independent predictors for developing post-traumatic seizures in children 1

• Approximately 4% of children with first-time afebrile focal seizures have urgent intracranial pathology, most commonly infarction, hemorrhage, and thrombosis 1, 3

• The recurrence rate for focal seizures is up to 94%, considerably higher than generalized seizures (72%), making this a high-risk situation requiring aggressive workup 1, 3

Clinical Features to Document

• Motor manifestations may include jerking of one extremity or one side of the body, abnormal facial movements, or small repetitive movements 2

• Non-motor manifestations include staring spells indicative of focal impaired awareness 2

• Post-ictal state characteristics, including duration of confusion, focal deficits (hemiparesis, aphasia, visual field defects), and recovery time 3

• Seizure duration and any progression patterns, as seizures lasting >5 minutes require emergency activation 2

Immediate Management

Neuroimaging Protocol

MRI brain with dedicated epilepsy protocol is the primary imaging modality and should be obtained urgently, as it detects 55% of abnormalities in children with focal seizures compared to only 18% with CT. 1

• In the acute post-traumatic setting, if MRI is not immediately available or the child is unstable, obtain non-contrast CT head first to rapidly identify acute intracranial hemorrhage, mass effect, or surgically treatable lesions 1

• CT identified 100% of acutely treatable lesions in mild trauma patients, with 7% requiring urgent surgical intervention 1

• MRI should follow CT even if CT is negative, as 29% of abnormal intracranial findings in children with focal seizures are not seen on initial CT 1

• MRI sequences should include susceptibility-weighted imaging and diffusion-weighted imaging to identify diffuse axonal injury, microhemorrhage, gliosis, and volume loss from prior traumatic brain injury 1

Electroencephalography

• Obtain EEG to confirm focal seizure activity, looking for ictal discharges originating from one hemisphere 3

• A normal interictal EEG cannot rule out epilepsy and must be interpreted in clinical context 2

• EEG helps differentiate focal seizures from generalized seizures and guides treatment selection 3, 4

Laboratory Evaluation

• Check serum glucose immediately, as hypoglycemia can present with focal neurologic deficits and seizures 3

• Electrolytes including sodium, as hyponatremia is among the most frequent abnormalities in patients with focal neurologic deficits 3

• Additional laboratory tests should be guided by clinical presentation, particularly if fever or altered mental status beyond the post-ictal period is present 3

Pharmacological Management

Initiate antiseizure medication with levetiracetam as first-line therapy given the high recurrence rate (94%) of focal seizures and the post-traumatic etiology. 1, 5

Levetiracetam Dosing and Monitoring

• Levetiracetam is FDA-approved for focal seizures and has a favorable safety profile in pediatric patients 5

• Monitor for behavioral adverse effects, including irritability (most common), aggression, mood changes, and somnolence, which occur more frequently than in placebo-treated patients 5

• 5% of levetiracetam-treated patients require dose reduction or discontinuation due to behavioral or psychiatric events 5

• Gradual withdrawal is essential if discontinuation is considered, as abrupt cessation increases seizure frequency risk 5

Treatment Rationale

• The post-traumatic etiology and focal nature with impaired awareness indicate high risk for recurrence and potential for secondary generalization 1, 3

• Neuroimaging yields are considerably higher (50% positive findings) in focal seizures compared to generalized seizures (6%), supporting the likelihood of structural pathology requiring treatment 1, 3

Critical Pitfalls to Avoid

• Do not assume CT is sufficient imaging – 47% of children with focal seizures have MRI abnormalities not detected by CT 1, 3

• Do not delay imaging – 7% of mild trauma patients have lesions requiring urgent surgical intervention 1

• Do not dismiss subtle post-ictal signs – abrupt change in motor activity and resumption of contact with the environment mark seizure ending, which can be very subtle 6

• Do not withhold antiseizure medication pending imaging results, given the 94% recurrence rate for focal seizures 1

• Do not use ultrasound or PET/CT – there is no evidence supporting these modalities in post-traumatic seizure workup 1

Follow-Up Considerations

• Neurology referral is mandatory for ongoing epilepsy management and medication optimization 2

• Repeat MRI may be indicated at an interval after trauma to better identify sequelae including gliosis and volume loss that evolve over time 1

• Seizure precautions should be implemented, with caregivers educated to activate EMS for seizures lasting >5 minutes, multiple seizures without return to baseline, or seizures with complications 2

• Optimized epilepsy protocol MRI with 3T scanner, T1-weighted volumetric acquisition with 1mm isotropic voxels, and high-resolution coronal slices may be needed if initial MRI is negative but seizures continue 3