523 - Upper Extremity Robot-Assisted Therapy for Coordination Training in Paraneoplastic Chorea due to Squamous Cell Lung Cancer: A Case Report

Paraneoplastic chorea linked to Squamous Cell Carcinoma (SCC).

Case Description:

A 68-year-old man, former smoker, with a lung nodule developed progressive choreiform movements and ataxic gait over two years. PET and biopsy confirmed SCC. Declining health led to hospitalization for chorea and severe motor incoordination. Low-titer GAD-65 antibody suggested paraneoplastic etiology. He received IVIG for five days plus clonazepam, with mild improvement, and was discharged to acute rehab (AR) while tumor resection was planned. At AR, he showed UE chorea and LE ataxia (R >L), with intact strength and sensation. Therapy included Armeo Robotics with interactive games, three times weekly, along with box-and-blocks coordination training. The Armeo was intermittently locked to isolate joint movements. Coordination was measured with the Box Blocks Test (BBT) and 9-Hole Peg Test (9HPT). After two weeks, BBT improved bilaterally (L: 33→37; R: 21→28 blocks) and left 9HPT improved (40→33 s). Upon discharge, he achieved independence in UE ADLs; GG score improved from 49 to 82.

Discussions:

Paraneoplastic movement disorders with antibodies like anti-GAD65 are often linked to SCC. Before diagnosis, chorea and ataxia may occur. Current treatment includes tumor control, immunotherapy, and symptom management. In this case, exercises and robot-assisted therapy, utilizing the spring mechanism of the Armeo Robotics, enabled gravity support and coordination during limb movement. This resulted in fine movement control and independence in UE ADLs.

Conclusions:

This rare case illustrates the use of robot-assisted therapy to enhance UE coordination in patients with paraneoplastic chorea from SCC. Further studies are recommended to verify the consistency of results.