Abstract Introduction For those experiencing neurological symptoms and being evaluated for multiple sclerosis (MS), it is important to assess whether sleep disturbance is primary or secondary to neurological disease. In this case, CBT-I was initiated to rule out a sleep disorder as an underlying cause of neurological symptoms. Report of case(s) The patient is a 61-year-old, White, female with chronic insomnia, excessive daytime sleepiness, and mild OSA comorbid with abnormal brain MRI (significant non-specific lesions). Patient is followed by neuroimmunology for management of neurological symptoms with unclear etiology (fatigue, paresthesia, neuropathic pain, and impaired cognition). She was referred to sleep medicine by her neurologist who suspected severe fatigue and sleepiness may be contributing to complex medical presentation. Patient endorsed a history of sleep-maintenance insomnia associated with drowsy driving (1 MVA and 3 near-misses). Of note, patient discontinued CPAP use for mild OSA in spring 2022 due to device recall. Her sleep physician recommended CBT-I to increase TST prior to OSA re-evaluation. Patient presented as anxious and distressed regarding safety while driving. She initiated CBT-I and engaged in stimulus control, cognitive restructuring, sleep diaries, relaxation, motivational interviewing, and supportive therapy. Baseline sleep diaries showed average WASO=146 minutes, SE=58%, and TST=4.1 hours. At week 7, average WASO=60 minutes, SE=86%, and TST=6.0 hours. Though no baseline measure was obtained, sleep disturbance (PROMIS Sleep T Score) was WNL (T=54) at week 7. Depression, anxiety, and pain-related disability decreased: PHQ-9 (11-moderate to 8-mild), GAD-7 (6-moderate to 4-mild), PDI (41 to 33). Measures of daytime sleepiness remained in the severe range (ESS 20 to 18), suggesting the need for OSA re-evaluation. Although sleep quality improved, patient reported new and worsening neurological symptoms including dysphagia and falls at home. CBT-I treatment is ongoing. Conclusion As individuals diagnosed with MS and other neurological disorders are more likely to experience insomnia than the general population, assessment of sleep disorders and evidenced-based treatments should be part of comprehensive neurological evaluation. In this case, the patient’s sleep parameters improved with CBT-I, but neurological symptoms persisted and worsened, suggesting the need for continued assessment and follow-up with neurology and sleep physicians. Support (if any) None.