Authors :
Presenting Author: Nived Jayaraj Ranjini, MBBS – University of Missouri, Columbia, MO
Ajay Gupta, MD – Cleveland Clinic
Ahsan Moosa Naduvil Valappil, MD, FAES – Cleveland Clinic
Rationale:
Large infarcts in the perinatal period and early childhood are known to shift the language dominance entirely to the opposite hemisphere [Rattani et al. Pediatr Neurol. 2019;90:44-55.]. Dissociation of language areas with expressive and receptive functions in different hemispheres is rare, reported mostly in patients with mesial temporal epilepsy [Kurthen et al. Brain Lang. 1992;43(4):694-712; Lee et al. Epilepsy Behav. 2008;13(2):350-356.]. Recognition of such dissociation of language centers has a significant impact on treatment in patients being considered for epilepsy surgery.
Methods:
We describe a case of drug-resistant epilepsy secondary to perinatal stroke in the left temporoparietal region with interhemispheric dissociation of language centers.
Results:
A 15-year-old left-handed female was evaluated for drug-resistant epilepsy. She had seizures with impaired awareness, head deviation to the right, with frequent secondarily generalized asymmetric tonic-clonic seizures. She had mild developmental delay, right arm monoparesis since early infancy, while maintaining age-appropriate speech abilities. She underwent pre-surgical evaluation. Clinical features and seizure semiology supported left hemispheric epilepsy. Video EEG data showed continuous left hemispheric slowing with multiregional epileptiform discharges, predominantly left-sided, supporting a left hemispheric epilepsy. Ictal EEG showed left hemispheric localization in most seizures; ictal patterns had an apparent better organization over the right hemisphere in a minority of seizures. Brain MRI revealed encephalomalacia involving the left posterior temporal, parietal, and occipital lobes. [Figure 1] During functional MRI, expressive speech tasks showed activation in the left frontal lobe, while comprehension tasks showed activation in the right posterior temporal lobe. [Figure 2, A and B] She underwent a left temporo-parieto-occipital resection. [Figure 2 C] Postoperatively, she had transient right leg weakness but no changes to her speech. She has remained seizure-free at the latest follow-up, 12 years after surgery.
Conclusions:
The age at brain injury, along with the extent and severity of brain injury, determines effective language transfer. Our patient had a perinatal stroke in the left temporo-parietal region without involvement of the frontal regions. In such cases, an interhemispheric dissociation of language centers may occur, as shown here. Organization of the language comprehension areas in the right posterior temporal regions allowed for a successful left temporo-parieto-occipital resection. Recognition of the clinical setting for such potential dissociation of language centers assists in appropriate preoperative evaluation, surgical planning, and preoperative counseling.
Funding: No funding received for this report.