Post-Gliotic Seizures Following TB Meningitis
Yes, seizures occurring after recovery from tuberculous meningitis are appropriately classified as post-gliotic (or structural) epilepsy, resulting from permanent brain injury including gliosis, infarction, hydrocephalus, and tuberculomas that develop during the acute infection.
Understanding the Mechanism
Seizures in TB meningitis patients fall into two distinct categories based on timing 1:
- Early seizures (within 1 month): Occur in 29.6% of cases and are typically provoked by acute processes including cerebral edema, meningeal irritation, hyponatremia (SIADH), and active inflammation 1, 2
- Late seizures (>1 month after onset): Occur in 70.4% of cases and are associated with structural brain damage including tuberculomas, cerebral infarctions, and hydrocephalus 1
The structural brain damage that causes late seizures includes 2:
- Tuberculomas (27% of cases)
- Cerebral infarctions (13% of cases)
- Hydrocephalus (32% of cases)
- Meningeal enhancement and gliosis (55% of cases)
Clinical Significance
Seizures are common in TB meningitis, occurring in 30-34% of patients, and are associated with significantly worse outcomes 3, 1:
- Higher mortality rates (27.6% vs 13.4% in non-seizure patients) 3
- Poor functional outcomes at 6 months (mRS >2) 1
- Late-onset seizures specifically indicate permanent structural damage rather than acute provoked seizures 1
Diagnostic Approach
When evaluating a patient with prior TB meningitis presenting with seizures 4:
- Contrast-enhanced MRI is essential to identify structural lesions including tuberculomas, infarctions, gliosis, and hydrocephalus 4, 2
- EEG abnormalities are present in 75% of cases and include focal spike-wave patterns (15%), interhemispheric asymmetry (23%), and generalized dysrhythmia (38%) 2
- CT findings show meningeal enhancement (55%), hydrocephalus (32%), tuberculomas (27%), and infarctions (13%) 2
Treatment Implications
These patients require long-term antiseizure medication 3, 5:
- Common first-line agents include phenytoin, valproate, and levetiracetam 3
- 60% may develop refractory epilepsy requiring multiple ASMs 5
- 20% may develop super-refractory status epilepticus 5
Key Clinical Pitfall
Do not assume all seizures in TB meningitis patients are simply "provoked" by the acute infection 1. Late seizures (>1 month) represent structural epilepsy from permanent brain injury and require ongoing epilepsy management, not just treatment of the acute infection 1. The median time to status epilepticus after initial meningitis symptoms is 65 days, well into the recovery phase 5.