Language recovery after left hemispherotomy for Rasmussen encephalitis.

Area of Science:

• Neuroscience
• Pediatric Neurology
• Epileptology

Background:

• Rasmussen encephalitis (RE) is a rare neurological disorder causing progressive inflammation of one cerebral hemisphere.
• Hemispherotomy (H), a surgical disconnection of a cerebral hemisphere, is the established treatment for medically intractable epilepsy in RE.
• Assessing long-term linguistic outcomes after H, particularly when the dominant hemisphere is affected, remains a critical concern.

Purpose of the Study:

• To delineate the long-term linguistic profile of the right hemisphere following left-sided hemispherotomy (H) in children with Rasmussen encephalitis (RE).
• To investigate the functional reorganization of language in the right hemisphere after surgical intervention for RE.

Main Methods:

• A longitudinal study followed 6 children (ages 8.4–14.6 years) who underwent left H for RE.
• Preoperative and postoperative neuropsychological evaluations assessed intellectual efficiency and detailed language functions (receptive and expressive) using computerized tasks.
• Follow-up duration averaged 5.6 years, with age at surgery ranging from 4.1 to 8.4 years.

Main Results:

• Rasmussen encephalitis significantly impacted cognitive and linguistic functions preoperatively, with decreased verbal comprehension index (VCI) in 4/6 patients.
• Postoperatively, all children achieved sufficient VCI (above 70) for regular schooling, with 5/6 attending normal or adapted schools.
• A specific linguistic profile emerged: normal verbal comprehension but persistent weaknesses in grammar, word repetition, statement production, semantic fluency, and metaphonological abilities. Working Memory Index correlated with language recovery.

Conclusions:

• The right hemisphere demonstrates a significant capacity for functional language reorganization long-term after left H for RE.
• Persistent deficits in syntactic and phonological abilities support the hypothesis of early left hemispheric specialization for these functions.
• Lexico-semantic processes recover well, suggesting a potential for both hemispheres. These findings support proceeding with H in RE and inform postoperative rehabilitation.