Rosai‐Dorfman disease (RDD) is a proliferative disorder of histiocytes typically found in nodal sites and commonly observed in females. Patients often present with systemic symptoms such as fever, lymphadenopathy, and weight loss. However, extra‐nodal disease has been identified in locations including the skin and subcutaneous tissue. We present a case of a 59‐year‐old female presenting with abnormal bilateral findings on screening mammography, who was found to have a rare presentation of Rosai‐Dorfman disease.

Introduction Parkinson’s Disease (PD) is a neurodegenerative disease marked by tremor, body tone changes, and cognitive decline with deficits in motor task learning. Characteristic neural patterns during non-Rapid Eye Movement (NREM) sleep have been correlated with learning procedural motor memory tasks. We seek to understand how the neural dynamics of NREM sleep (e.g., sleep spindles and slow waves) interact with motor learning ability in a neurodegenerative disease process. This information might be used to identify electrical biomarkers that could be therapeutically targeted. Methods PD subjects and healthy age-matched controls were identified by physician interview, flyering, and medical chart review. Eligibility requirements for subjects precluded severe cognitive decline and untreated sleep disorders. Baseline sleep characteristics were ascertained via survey data collected prior to and on the day of the sleep study. Subjects were fitted with EEG electrodes prior to an all night polysomnogram. Subjects were also fitted with EMG and EOG electrodes for sleep scoring purposes. Motor tasks were performed prior to and following overnight sleep. Results Surveys indicated worse sleep quality among PD subjects compared to age-matched controls prior to their sleep session. Sleep macro-architecture of PD subjects showed a smaller percentage of sleep time in N2/N3 stages, and at the spectral level, there were indications of reduced power for slow waves and spindling. Furthermore, we observed aberrant patterns of coupling between slow waves and spindling in PD subjects. Conclusion Our study has implications for sleep as a component of motor skill learning and as a marker for a neurodegenerative movement disorder. NREM sleep rhythms such as sleep spindles and slow waves, and their relationships to one another, are thought to be important in motor learning and memory. Aberrations in these rhythms and their coupling may inform potential therapies to enhance motor learning and mitigate the progression of PD. Support (If Any) NCATS of the NIH, Award Number UL1TR003015.