What is the appropriate work‑up and treatment for focal seizures in a 2‑year‑6‑month‑old girl with no prior medical history?

Management of Focal Seizures in a 2.5-Year-Old Girl

Obtain urgent MRI brain with dedicated epilepsy protocol and initiate levetiracetam as first-line antiseizure medication, given the 94% recurrence rate for focal seizures and high likelihood (50%) of detecting structural pathology. 1, 2

Immediate Diagnostic Workup

Neuroimaging - Primary Modality

• MRI brain with dedicated epilepsy protocol is the mandatory first imaging study, detecting 55% of abnormalities in children with focal seizures compared to only 18% with CT 1
• The epilepsy protocol should include 3T scanner with T1-weighted volumetric acquisition (1mm isotropic voxels) and high-resolution coronal slices optimized for hippocampal pathology 2
• MRI identifies 47% of abnormalities that CT misses in children with focal seizures 2
• Approximately 4% of children with first-time afebrile focal seizures have urgent intracranial pathology (infarction, hemorrhage, thrombosis) 1, 2

When to Use CT Instead

• If MRI is not immediately available or the child is unstable, obtain non-contrast CT head first to rapidly identify acute hemorrhage, mass effect, or surgically treatable lesions 1
• CT identified 100% of acutely treatable lesions requiring urgent surgical intervention (7% of cases) 1
• However, MRI must still follow even if CT is negative, as 29% of abnormal findings are not seen on initial CT 1

EEG Evaluation

• EEG is recommended as part of the neurodiagnostic evaluation and will show ictal discharges originating from one hemisphere in focal seizures 3, 2
• EEG helps distinguish focal from generalized seizures and guides treatment selection 2, 4

Laboratory Testing

• Check serum glucose immediately, as hypoglycemia can present with focal neurologic deficits 2
• Electrolytes (particularly sodium) should be obtained, as hyponatremia is among the most frequent abnormalities in patients with focal features 2
• Consider toxicologic screening if any question of drug exposure exists 3

Lumbar Puncture Considerations

• LP is of limited value in first non-febrile seizure and should be used primarily when there is concern about meningitis or encephalitis 3
• Consider LP if the child has not returned to baseline alertness several hours after the seizure 3

Pharmacological Management

First-Line Antiseizure Medication

• Initiate levetiracetam immediately given the 94% recurrence rate for focal seizures (compared to 72% for generalized seizures) 1, 2
• Do not delay medication while awaiting imaging results 1
• The high recurrence rate and focal nature with potential for secondary generalization justify immediate treatment 1

Alternative First-Line Options

• Carbamazepine and valproic acid are considered first-line therapies for children with partial seizures based on controlled trials 5, 6
• Oxcarbazepine, topiramate, gabapentin, and lamotrigine have sufficient data supporting use as adjunctive or first-line monotherapy 5
• Avoid phenobarbital and phenytoin as they are considered last-choice drugs due to adverse event profiles 5

Treatment Duration

• Treatment period should be as short as possible, possibly within 2 years after initiation, without waiting for EEG normalization 7
• The goal should be complete freedom from seizures 8

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, 2
• Do not delay imaging – 7% of mild trauma patients have lesions requiring urgent surgical intervention 1
• Do not withhold antiseizure medication pending imaging results given the 94% recurrence rate 1
• Do not use CT as the only imaging modality – MRI must follow to identify structural causes 1, 2

Mandatory Follow-Up Actions

Neurology Referral

• Neurology referral is mandatory for ongoing epilepsy management and medication optimization 1
• If seizures prove intractable to adequate medical intervention, surgical resection should be considered, especially if structural abnormality is detected 8

Seizure Precautions

• Educate caregivers to activate EMS for seizures lasting >5 minutes, multiple seizures without return to baseline, or seizures with complications 1
• Implement appropriate safety measures given the high recurrence risk 1

Repeat Imaging Considerations

• Repeat MRI may be indicated at an interval to better identify sequelae including gliosis and volume loss that evolve over time 1
• If initial MRI is negative but seizures continue, optimized epilepsy protocol MRI with 3T scanner may be needed 1

Prognosis Context

• Most children with focal seizures will not "grow out of their seizures" and only 50% will have seizures adequately controlled with medication 8
• The considerably higher recurrence rate (94%) compared to generalized seizures (72%) justifies aggressive early intervention 1, 2
• Neuroimaging yields are substantially higher (50% positive findings) in focal seizures compared to generalized seizures (6%), supporting the likelihood of structural pathology requiring treatment 1, 2