What antiepileptics (AEDs) are recommended for hyperglycemia-induced focal seizures?

Management of Hyperglycemia-Induced Focal Seizures

For hyperglycemia-induced focal seizures, the primary treatment is insulin therapy and rehydration to correct the underlying hyperglycemia, with antiepileptic drugs (AEDs) reserved for refractory cases or when seizures persist despite glucose normalization. 1

Understanding Hyperglycemia-Induced Seizures

• Hyperglycemia-induced seizures most commonly present as focal seizures, in contrast to the generalized seizures typically seen in hypoglycemia 2
• These seizures often occur in the context of nonketotic hyperglycemia (NKH), which presents with profound hyperglycemia, hyperosmolality, and dehydration 2
• Seizures may be the first manifestation of hyperglycemia, particularly in previously undiagnosed diabetes 1

First-Line Management

• Insulin therapy and rehydration are the primary treatments for hyperglycemia-induced seizures, with most cases responding well to correction of the underlying metabolic disturbance 1
• These seizures are often resistant to antiepileptic medications when used alone, highlighting the importance of addressing the underlying hyperglycemia first 1
• Seizures typically resolve completely within an average of 4 days once proper glucose management is initiated 1

Role of Antiepileptic Drugs

• The role of antiepileptic drugs in hyperglycemia-induced seizures is controversial 2
• Consider adding antiepileptic medication only when:
  • Seizures are refractory to insulin therapy and glucose normalization 2
  • Seizures persist despite correction of hyperglycemia 2
  • There is epilepsy partialis continua (continuous focal motor seizures) 1

Antiepileptic Drug Selection

• For focal seizures (including those induced by hyperglycemia), monotherapy with standard antiepileptic drugs should be offered 3
• When an AED is required, carbamazepine should be preferentially offered for focal-onset seizures 3
• Other options include:
  • Phenobarbital (if cost/availability is a concern) 3
  • Phenytoin (for acute management) 3
  • Valproate (may be considered, but use with caution due to potential for encephalopathy) 3, 4
  • Levetiracetam (better tolerated than phenytoin in acute settings) 3

Important Considerations and Cautions

• Avoid antiepileptic drug polytherapy as it increases the risk of adverse effects and drug interactions 3
• Be aware that some AEDs may paradoxically worsen seizures in certain contexts:
  • Carbamazepine and phenytoin may exacerbate generalized seizures 4
  • Valproate can cause encephalopathy, particularly in patients with complex focal seizures 4
• Monitor for drug side effects, which may include drowsiness, dizziness, ataxia, and cognitive impairment 3
• AEDs should not be routinely prescribed after a first unprovoked seizure, but hyperglycemia-induced seizures represent a provoked seizure with an identifiable cause 3

Monitoring and Follow-Up

• EEG monitoring may be helpful to detect subclinical seizures and guide therapy 2
• Brain imaging (MRI) may show characteristic findings in hyperglycemia-induced seizures, including T2 FLAIR hyperintensities 2
• Once seizures are controlled and hyperglycemia is corrected, consider discontinuation of antiepileptic drugs after an appropriate seizure-free period 3
• Long-term management should focus on optimal diabetes control to prevent recurrence 5

Special Situations

• In cases of epilepsy partialis continua (EPC) associated with hyperglycemia, more aggressive antiepileptic therapy may be required alongside metabolic correction 1
• For refractory seizures in the context of generalized illness, combination therapy may be necessary 3
• If seizures are exclusively triggered by specific movements or postures in the context of hyperglycemia, they may resolve completely with glucose regulation alone 5