Ultrasonography as a diagnostic tool for Neural Pain in Leprosy.
Leprosy remains a public health problem, despite being an ancient disease. In most cases, it is associated with neuropathy that can be acute or chronic and this neural involvement can occur before, during, or after multidrug therapy (MDT). Acute neuropathy usually occurs during reaction episodes and is called neuritis. It causes compromised nerve function associated with nociceptive pain. The inflammatory process can also develop neuroplasticity of the peripheral and central nervous systems, which perpetuates this sensation; this phenomenon is known as neuropathic pain, a chronic sensation in leprosy. Differential diagnosis between nociceptive and neuropathic pain is not always easy and in some patients there may be an overlap between nociceptive and neuropathic pain. Currently, clinical and electrophysiological criteria are used for the differential diagnosis of neural pain, but especially in the case of recurrent neuritis, these criteria are insufficient. Recent knowledge about pain mechanisms does not define the limit as to where nociceptive ends and neuropathic begins, suggesting that this process is continuous, in addition to being associated. Ultrasonography (US) has been used as an auxiliary tool in the early diagnosis of peripheral nervous system diseases. The method can be implemented in addition to clinical and neurophysiological studies for the diagnosis of neuritis, which allows for the early identification and treatment of the disease.