Progress in peripheral nerve disease research in the last two years

Peripheral neuropathy in persons with tuberculosis

Peripheral neuropathy (PN) is a serious condition affecting the nerves that is commonly seen in patients with tuberculosis (TB). Causes of PN in patients with TB are multiple, and can include TB itself, other co-morbid conditions, such as Human Immune-deficiency virus (HIV) disease, malnutrition, or diabetes mellitus (DM), and several anti-tuberculous medications. The condition can manifest with a variety of symptoms, and a diagnosis can usually be made on a clinical basis. Treatment and prognosis of PN vary depending on the underlying cause, but often the condition can lead to permanent disability in individuals with TB. For this reason, primary prevention is key as is early identification and management of symptoms. Treatment can include withdrawal of possible offending agents, vitamin supplementation, physical therapy, analgesics, and targeted agents, including tricyclic antidepressants, selective serotonin reuptake inhibitors, and gabapentin. Additional research is needed to better describe the morbidity and disability associated with PN in persons with TB and to improve management strategies for persons at risk for and affected by this condition. Case review: RM is a 47 year-old man who is in his third month of treatment for drug-resistant TB (DR-TB). His treatment regimen consists of kanamycin (1 gm intramuscular daily), levofloxacin (1000 mg by mouth daily), cycloserine (750 mg by mouth daily), ethionamide (750 mg by mouth daily), pyrazinamide (1500 mg by mouth daily), and Para-Amino Salicylate (12 gm by mouth daily). He is HIV-infected with a CD4 count of 470 cell/µl and on a stable antiretroviral therapy regimen of tenofovir, lamivudine, and efavirenz, which he started 8 weeks ago. He works in a platinum mine, denies smoking, reports drinking beer "on the weekend" and denies other drugs. He presents for his 3 month clinical visit for his DR-TB follow-up and states he is doing well, but he does report some "burning" in the bottom of his feet.

Noninvasive imaging of peripheral nerves

Recent developments in the field of peripheral nerve imaging extend the capabilities of imaging modalities to assist in the diagnosis and treatment of patients with peripheral nerve maladies. Methods such as magnetic resonance imaging (MRI) and its derivative diffusion tensor imaging (DTI), ultrasound (US) and positron emission tomography (PET) are capable of assessing nerve structure and function following injury and relating the state of the nerve to electrophysiological and histological analysis. Of the imaging methods surveyed here, each offered unique and interesting advantages related to the field. MRI offered the opportunity to visualize immune activity on the injured nerve throughout the course of the regeneration process, and DTI offered numerical characterization of the injury and the ability to develop statistical bases for diagnosing injury. US extends imaging to the treatment phase by enabling more precise analgesic applications following surgery, and PET represents a novel method of assessing nerve injury through analysis of relative metabolism rates in injured and healthy tissue. Exciting new possibilities to enhance and extend the abilities of imaging methods are also discussed, including innovative contrast agents, some of which enable multimodal imaging approaches and present opportunities for treatment application.