BACKGROUND: Nivolumab is an immune checkpoint inhibitor that targets the programmed cell death-1 protein and is effective in treating advanced cancer. However, it is also associated with various immune-related neurological complications, including myasthenia gravis, Guillain-Barré syndrome, and demyelinating polyneuropathy. These complications can easily mimic other neurological diseases and have greatly varying therapeutic approaches depending on the underlying pathophysiology. CASE PRESENTATION: Here, we report a case of nivolumab-induced demyelinating peripheral polyneuropathy involving the brachial plexus in a patient with Hodgkin lymphoma. Approximately 7 months after nivolumab treatment, the patient experienced muscle weakness with a tightness and tingling sensation in the right forearm. Electrodiagnostic studies showed features of demyelinating peripheral neuropathy with right brachial plexopathy. Magnetic resonance imaging revealed thickening with a diffuse enhancement of both brachial plexuses. The patient was eventually diagnosed with nivolumab-induced demyelinating polyneuropathy involving the brachial plexus. Oral steroid therapy improved motor weakness and sensory abnormalities without aggravation. CONCLUSION: Our study indicates the possibility of nivolumab-induced neuropathies in cases involving muscle weakness with sensory abnormalities of the upper extremity following nivolumab administration in patients with advanced cancer. Comprehensive electrodiagnostic studies and magnetic resonance imaging are helpful in the differential diagnosis of other neurological diseases. Appropriate diagnostic and therapeutic approaches may prevent further neurological deterioration.

Objective To evaluate the feasibility and usability of cost-effective complex upper and lower limb robot-assisted gait training in patients with stroke using the GTR-A, a foot-plate based end-effector type robotic device. Methods Patients with subacute stroke (n=9) were included in this study. The enrolled patients received 30-minute robot-assisted gait training thrice a week for 2 weeks (6 sessions). The hand grip strength, functional ambulation categories, modified Barthel index, muscle strength test sum score, Berg Balance Scale, Timed Up and Go Test, and Short Physical Performance Battery were used as functional assessments. The heart rate was measured to evaluate cardiorespiratory fitness. A structured questionnaire was used to evaluate the usability of robot-assisted gait training. All the parameters were evaluated before and after the robot-assisted gait training program. Results Eight patients completed robot-assisted gait training, and all parameters of functional assessment significantly improved between baseline and posttraining, except for hand grip strength and muscle strength test score. The mean scores for each domain of the questionnaire were as follows: safety, 4.40±0.35; effects, 4.23±0.31; efficiency, 4.22±0.77; and satisfaction, 4.41±0.25. Conclusion Thus, the GTR-A is a feasible and safe robotic device for patients with gait impairment after stroke, resulting in improvement of ambulatory function and performance of activities of daily living with endurance training. Further research including various diseases and larger sample groups is necessary to verify the utility of this device.