Paradoxical Kinesia Induced by Nightmare: Unique Case Report and Insights regarding the Neural Mechanism Based on Human and Rat Studies.

Introduction: Bradykinesia, characterized by slowed movement, stands out as a primary symptom observed in individuals with Parkinson's disease (PD). Nonetheless, there are instances where PD patients exhibit sudden and effective movements despite the presence of bradykinesia. This phenomenon, referred to as paradoxical kinesia, has remained a subject of interest for neuroscientists, who have struggled to unravel its underlying neural mechanisms for decades. Case Presentation: We describe a patient who is suffering from advanced PD. The patient has severe motor limitations, including difficulty rising from bed and walking, as well as cognitive decline and visual impairment. However, an interesting occurrence took place during a nightmare episode. Surprisingly, the patient was able to get out of bed and quickly run away from the perceived threat within the nightmare, without any assistance. Conclusion: This report presents the first documented case of paradoxical kinesia induced by nightmares in a patient with PD. This phenomenon raises questions about the neurological mechanisms involved, which are still not fully understood. Based on existing research conducted on both animal and human subjects, we propose that after processing the emotion of fear, the brain aversive system activates motor outputs to generate appropriate behavior. Thus, the brain aversive system converts the emotion of fear into action through projections from the inferior colliculus to motor-related areas such as the mesencephalic locomotor region, pontine nuclei, and substantia nigra.