Abstracts

Atypical Posterior Onset Rasmussen Encephalitis Treated with Temporal Parietal Occipital Disconnection

Abstract number : 1.34
Submission category : 9. Surgery / 9C. All Ages
Year : 2023
Submission ID : 271
Source : www.aesnet.org
Presentation date : 12/2/2023 12:00:00 AM
Published date :

Authors :
Presenting Author: Anuranjita Nayak, MD – Baylor College of Medicine

Howard Weiner, MD, FACS, FAAP, FAANS, FAES – Professor and Vice Chair of Neurosurgery, Neurosurgery, Baylor College of Medicine and Texas Children's Hospital; Carrie Mohila, MD, Phd – Associate Professor, Pathology, Baylor College of Medicine and Texas Children's Hospital; Jonathan Yarimi, MD – Resident PGY5, Pediatric Neurology, Baylor College of Medicine and Texas Children's Hospital; Cristina Trandafir, MD – Assistant Professor, Pediatrics and Neurology, Baylor College of Medicine and Texas Children's Hospital

Rationale:

Atypical Rasmussen encephalitis cases risk a delayed diagnosis due to later onset of presentation, different clinical presentation and clinical course than typical disease.1,2 Early identification is beneficial and could be aided by recognizing key features. We tried a different treatment approach with temporal parietal occipital (TPO) disconnection instead of conventional hemispherectomy in our patient to achieve palliation. Effect of bilingualism on right sided hemispheric surgery outcomes is also identified.



Methods:
Our patient presented at age 11 years with features suggestive of right occipital cerebritis with quadrantonopsia (Fig:1). Later on developed medically refractory focal seizures (treated with Levetiracetam, Oxcarbazepine, Lacosamide, Topiramate, Perampanel, Clobazam, Brivaracetam, Zonisamide, Cenobamate). An autoimmune process was suspected as the patient showed initial response to steroids. However, IVIg and Rituximab were not helpful rather were perceived as worsening his condition. New regions of involvement continued to appear over time on brain MRI (fig:2) in the ipsilateral temporal, parietal then eventually frontal region. About six years after onset, MRI did show atrophy,( fig:3) meeting criteria for Atypical Rasmussens. Patient did not have motor deficits except during the post ictal state. Family was offered hemispherectomy but elected for a motor sparing procedure to avoid any motor deficit. Due to high burden of lesions in the temporal parietal occipital regions a TPO disconnection was planned with counselling family that leaving the frontal region behind will result in incomplete seizure control. Additionally, though language deficit is common in left hemispheric surgeries,3 in a bilingual patient some language deficit can be expected with a right TPO disconnection or which our patient was counselled.

Results:

Following surgery, the patient had significant reduction in motor seizure burden to none at two month follow up, though the visual and sensory seizure burden had a modest reduction. One antiseizure medication was weaned off. Patient was more alert, however he had mild aphasia, English more than Spanish and a left hemianopia. Surgical pathology showed features of an inflammatory process consistent with Rassmussen’s encephalitis. There was minor left sided motor deficit that patient is recovering fast.



Conclusions:

Our case is another example of atypical Rasmussen’s encephalitis with late onset (adolescence) and occipital involvement which has been reported to have an indolent clinical evolution1 and poor response to immunomodulatory therapy.2 TPO disconnection, a technically difficult surgery, could be considered in cases with predominant involvement and seizure burden from the posterior region, instead of hemispherectomy, specifically in later onset cases like ours. This case also illustrates pitfalls of hemispheric surgeries in bilingual patients.



Funding: None

Surgery