A 40-year-old woman began taking risperidone (Risperdal) for symptoms of schizoaffective disorder 3 days ago, and today she feels restless. She is pacing around and is unable to remain still. Which action should the PMHNP perform first?

Choice A reason: The amygdala is primarily involved in emotional processing, particularly fear and aggression. While it may influence sleep indirectly through emotional arousal, it is not the central regulator of the sleep-wake cycle.

Choice B reason: The hypothalamus plays a critical role in regulating the sleep-wake cycle. It contains the suprachiasmatic nucleus (SCN), which serves as the body’s master circadian pacemaker. The SCN receives light input from the retina and synchronizes physiological processes, including melatonin release and sleep timing.

Choice C reason: The cerebellum is responsible for coordination of voluntary movements, balance, and motor learning. It does not have a direct role in sleep regulation.

Choice D reason: The frontal lobe is involved in executive functions, decision-making, and personality. Although sleep deprivation affects frontal lobe performance, it is not the primary center for sleep-wake regulation.

Choice A reason: While pain and pallor are features of compartment syndrome, the inability to perform passive movements is not a hallmark sign. In fact, pain with passive movement is more indicative of increased intracompartmental pressure. This choice omits critical signs such as paresthesia and pulselessness, which are essential for diagnosis.

Choice B reason: This option includes pain and weakness, which may be present, but again lacks the specificity of pain with passive movement and the full spectrum of neurovascular compromise. Weakness alone is not sufficient to confirm compartment syndrome, and the absence of paresthesia and pulselessness makes this choice incomplete.

Choice C reason: This choice correctly lists the classic “5 P’s” of acute compartment syndrome: pain, pulselessness, paresthesia, paralysis, and pallor. These signs reflect severe neurovascular compromise due to increased pressure within the compartment. Pain is typically out of proportion to the injury and worsens with passive stretch. Pulselessness and paralysis are late findings, indicating advanced ischemia.

Choice D reason: Pain with passive movement is a key early sign of compartment syndrome, but the inability to perform active movement and weakness alone do not encompass the full clinical picture. This option lacks paresthesia and pulselessness, which are critical for diagnosis.