Chronic Refractory Insomnia in a Patient With Undiagnosed Bipolar Disorder and Long-Standing Traumatic Brain Injury

Traumatic brain injury (TBI), a form of acquired brain injury, occurs when a sudden trauma causes damage to the brain. TBI can result when the head suddenly and violently hits an object or when an object pierces the skull and enters brain tissue. TBI can be classified into primary and secondary brain injury. Primary injury refers to the structural damage caused upon impact. Secondary injury refers to the damage from subsequent cellular processes following a prior injury, such as excitotoxicity, free radical generation, calcium-mediated damage, hypoxia, and increased intracranial pressure. Unsurprisingly, these mechanisms can produce structural, biochemical, and genetic changes implicated in sleep disturbance. A coup-contrecoup injury typically occurs at the base of the skull in areas of bony prominences, hence, the anterior temporal and inferior frontal regions, including the basal forebrain, are frequently injured. Because the basal forebrain contributes to sleep initiation, injury to this region can lead to insomnia symptoms. In this report, we present a case study of a 41-year-old Caucasian male who experienced a TBI at the age of seven due to a motor vehicle accident. The left frontotemporal lobe was affected as a result of the incident. He was admitted to the emergency room in March 2023 for safety concerns in the context of extreme anger and irritability, which could endanger others and himself. Additionally, he struggled with chronic insomnia. The chart review showed that the patient's chronic insomnia was poorly controlled and probably contributed to the current presentation. The patient was observed in the days following admission while various medication changes were attempted to treat his chronic insomnia. Unique limitations were encountered in managing this patient's insomnia, as he has multiple drug allergies, including some of the commonly used medications to treat insomnia. A particularly unique observation was that the medications that finally worked for this patient had anticholinergic side effects. They are usually contraindicated in post-TBI patients. However, it was beneficial to use them in this case, which can be explored further.