The Application of Integrated Ocular Tracking and Balance Therapy System in Rehabilitation of a Patient with Anti-IgLON5 Disease: A Case Report

Case Diagnosis: A 75 year old Female with Anti-IgLON5 Disease

Case Description or Program Description: Patient admitted to acute hospital for cognitive decline, sleep disturbances, difficulty swallowing, unwitnessed fall and acute respiratory failure requiring intubation. EEG showed moderately diffuse encephalopathy and no seizure activity. Patient remained encephalopathic. She underwent tracheostomy on the 12th day of hospitalization after failed extubation. MRI Brain showed mild generalized parenchymal volume loss; cerebellar atrophy was greater than cerebral atrophy.

Setting: Inpatient rehabilitation

Assessment/Results: Lumbar puncture and CSF neuroimmunological testing showed elevated IgG and positive IgLON5 antibodies. IV methylprednisolone and IVIG were used for medical treatment. She was transferred to inpatient rehabilitation on 38th hospital day. Neurological exam revealed 2 beat vertical nystagmus, 4-6 beat horizontal nystagmus, and BLE ataxia. Integrated Ocular Tracking and Balance Therapy System (Bioness BITS) was used. Patient spontaneously used head turning to decreased nystagmus when using Bioness BITS. Berg Balance improved from 4/56 to 24/56 after 16 days IRF stay. Admission GG Score was 44 and improved to discharge GG Score of 78.

Discussion (relevance): Anti-IgLON5 disease is a rare antibody-mediated disorder that presents with variable symptoms of sleep disorder, bulbar symptoms, oculomotor symptoms, gait abnormalities, and cognitive decline. Diagnosis is with detection of serum or CSF antibodies to IgLON5, a protein found mainly in the cerebellum and thought to maintain blood-brain barrier integrity and has a role in neuroplasticity and neurogenesis. Additionally, the disease is characterized by hyperphosphorylated tau deposits in the brainstem and hypothalamus. Pathogenesis of the disease is unclear whether there is an antibody-mediated inflammatory response resulting in neurodegeneration or continual tau deposition worsening immunological response to IgLON5 antibodies.

Conclusions: Anti-IgLON5 disease, a rare and underdiagnosed disease that affects function and quality of life. While prognosis remains guarded, this case demonstrates use of Integrated Ocular Tracking and Balance Therapy System and the role of inpatient rehabilitation in improving function.