Abstract Details

Title Longitudinal FreeSurfer Volumetric Analysis as a High-sensitivity Radiographic Tool for Disease Progression in Rasmussen Syndrome

Topic Autoimmune Neurology

Presentation(s) P3 - Poster Session 3 (11:30 AM-12:30 PM)

Poster/Presentation
Number 1-043

Objective

N/A

Background

Rasmussen syndrome (RS) is an immune-mediated, refractory epilepsy characterized by progressive unilateral cortical atrophy. Standard radiological surveillance relies on qualitative assessment and does not quantify volume loss as part of clinical care. Longitudinal analysis pipelines such as FreeSurfer (FS) use machine learning approaches to generate biologically meaningful metrics of disease progression by quantifying regional brain volume loss. The FS longitudinal pipeline constructs an unbiased within subject template across all time points, minimizing session to session variability and avoiding over regularization.

Design/Methods

We conducted a single-center retrospective case series of two patients with confirmed Rasmussen syndrome who underwent serial brain MRI. All imaging time points were processed using the Standard FreeSurfer 8.1 longitudinal pipeline.

Results

Results: Patient 1 (10.2-month follow-up) demonstrated cumulative ipsilateral volume loss involving the thalamus (−32.2%; 5,376 → 3,645 mm³), hippocampus (−22.7%), caudate (−15.8%), and putamen (−13.8%), with relative contralateral thalamic stability (−0.7%). The thalamic asymmetry index (TAI) increased from −11.7% to −29.9%. During two intervals qualitatively reported as “no interval change” on standard radiology reports, FS 8.1 detected ipsilateral thalamic atrophy of −6.5% and −3.2%, along with caudate (−8.6%) and putaminal (−7.4%) volume loss.

Patient 2 (39.3-month follow-up) exhibited ipsilateral thalamic volume loss of −18.0% compared with −9.7% contralaterally and caudate loss of −17.7%. In a similarly reported “no-change” interval on conventional MRI interpretation, FS 8.1 identified thalamic (−2.3%) and caudate (−2.8%) volume loss with contralateral stability. Across both cases, three radiology reports did not mention progression despite quantitatively demonstrable volume loss detected by FS analysis.

Conclusions

Longitudinal FS volumetric analysis detected progressive brain volume loss and identified disease progression at three independent time points earlier to conventional radiological reporting. Incorporation of longitudinal quantitative volumetric analysis into routine imaging workflows may facilitate earlier detection of disease progression and inform medical and surgical decision making.

Authors/Disclosures
Prabhumallikarjun Patil, MD (Childrens health care of atlanta) PRESENTER	Dr. Patil has nothing to disclose.
Ekta G. Shah, DO, MS (Washington University in St. Louis)	Dr. Shah has nothing to disclose.
Madeleine H. McLaughlin, MD (Emory)	Dr. Hebert has nothing to disclose.
Grace Gombolay, MD, FAAN (Emory University/Children'S Healthcare of Atlanta)	Dr. Gombolay has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Genentech. The institution of Dr. Gombolay has received research support from CDC. The institution of Dr. Gombolay has received research support from NIH. Dr. Gombolay has a non-compensated relationship as a Board of Trustee with National MS Society -Georgia chapter that is relevant to AAN interests or activities.
Varun Kannan, MD (Emory/CHOA)	Dr. Kannan has nothing to disclose.
Shayan Monabbati, PhD	Dr. Monabbati has received intellectual property interests from a discovery or technology relating to health care.
Eswar Damaraju, MS	Mr. Damaraju has nothing to disclose.
Adam Goldman-Yassen	Adam Goldman-Yassen has nothing to disclose.
Kartik Reddy, MD, MSCR	Dr. Reddy has nothing to disclose.

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