Ultrasonography of Leprosy Neuropathy: A Longitudinal Prospective Study

Abstract

BackgroundPrevious studies have shown that leprosy multi-drug therapy (MDT) does not stop the progression of nerve function impairment. There are no prospective studies investigating the evolution of nerve anatomic abnormalities after treatment. We examined leprosy patients aiming to investigate the evolution of nerve ultrasonography (US) abnormalities and the risk factors for poor outcomes after MDT.Methodology/Principal findingsWe performed bilateral US of the ulnar (U), median (M) and common fibular (CF) nerves in 9 paucibacillary (PB) and 64 multibacillary (MB) patients before and after MDT. Forty-two patients had leprosy reactions (type 1, type 2, acute neuritis) during the study. We analyzed nerve maximum cross-sectional areas (CSA), echogenicity and Doppler signal. Poor outcomes included a post-treatment CSA above normal limits with a reduction of less than 30% (U, M) or 40% (CF) from the baseline, echogenicity abnormalities or intraneural Doppler in the post-treatment study. We found that PB and patients without reactions showed significant increases in CSA at CF, whereas MB and patients with reactions had CSA reduction in some nerves after treatment (p<0.05). Despite this reduction, we observed a greater frequency of poor CSA outcomes in the MB compared to the PB (77.8% and 40.6%; p>0.05) and in the patients with reactions compared to those without (66.7% and 38.7%; p<0.05). There was significantly higher odds ratio (7.75; 95%CI: 1.56–38.45) for poor CSA outcomes only for M nerve in patients with reactions. Poor echogenicity outcomes were more frequent in MB (59.4%) compared to PB (22.2%) (p<0.05). There was significant association between poor Doppler outcomes and neuritis. Gender, disease duration, and leprosy classification were not significant risk factors for poor outcomes in CSA, echogenicity or Doppler.Conclusions/SignificanceUS nerve abnormalities can worsen after treatment despite the leprosy classification or the presence of reactions.

Coexistence of Nerve Enlargement and Neuratrophy Detected by Ultrasonography in Leprosy Patients

“…For the MB, PB and control groups, CSA values exhibited the following trends: PB > MB > controls in the upper limbs (M/U nerves), and the PB group exhibited a significantly greater CSA than the MB group at the U nerve (Ut, right). Our results differed from another study, which reported that CSA values of the MB group were greater than those of the PB group regardless of pretreatment or post-treatment status and measurement in the upper or lower limbs 16 . In our study, the PB group also exhibited significantly increased CSA values compared to the controls at the M (forearm1/3, left) and U nerves (Ut, right and Upt, bilateral).…”

“…Significantly higher values were found in the R vs NR, R vs control, and NR vs control groups at the following positions: the M nerve (forearm1/3, left) and U nerve (Ut, right and Upt, bilateral). This result was similar to another study, which reported that the CSA values of the R group were higher than those of the NR group 16 . The CSA was significantly increased in both the R and NR groups compared to the controls at the M (forearm1/3, left) and U nerve (Ut, right and Upt, bilateral).…”

“…Regarding patients with NR, the CF nerve (left) exhibited significant enlargement after MDT compared to before MDT (p = 0.02). In contrast, for patients in the R group, the U nerve (Upt (left)) was significantly thinner (p = 0.03) 16 . Another study compared the CSAs of the nerves in PB and MB patients with or without a reaction before MDT and found that nerve enlargement occurred in the MB and R group.…”

“…For PB patients, the CF nerve (left) exhibited significant enlargement after MDT compared to that before MDT (p < 0.01). In contrast, for MB patients, the U (Ut (left and right) and Upt (left)) and M (left) nerves were significantly thinner (p = 0.02, 0.04, p = 0.03 and p = 0.04, respectively) 16 . The CSAs of the nerves in patients with a reaction (R) were thicker than those in patients with no reaction (NR) before and after MDT.…”

Neurological Complications of Leprosy

“…As such, there may not be meaningful reversal of neuropathy with MDT. 88 For treatment of neuropathic pain, amitriptyline and gabapentin have been demonstrated to have some efficacy, although no formal trials to compare specific neuropathic agents are available. 61 In terms of leprosy reactions, steroids are widely used despite the lack of randomized control trials demonstrating definitive efficacy compared with placebo.…”