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Background: Leprosy (or Hansen’s disease) continues to present considerable challenges regarding containment and early diagnosis. Leprosy is considered to be primarily a neural disease that first affects the sensory function of small fibres. Although the condition is well described in terms of clinical manifestations and histology, few studies have been undertaken to detect damage done to small-fibre sensory nerves. In vivo confocal microscopy is a useful tool for conducting a detailed evaluation of these structures, although its use in individuals affected by leprosy has still not been explored. Objective: To evaluate in vivo confocal microscopy findings in Hansen’s disease patients and their association with clinical variables relating to this disease. Method: A cross-sectional case-series type study was carried out between October 2019 and May 2021, in Recife, Pernambuco, Brazil. Socio-demographic and clinical data were gathered from 21 patients with leprosy. The douleur neuropathique 4 neuropathic pain questionnaire was used to evaluate pain. In vivo confocal microscopy of the cornea was employed to evaluate the small-calibre fibres. Findings were compared with those for a control group of 23 healthy individuals. Results: In relation to clinical parameters, 90.5% of the patients were classified as “multibacillary” according to the World Health Organization criteria, and 70% as dimorphic or borderline, in accordance with the Madrid classification. Around 52.4% had received a diagnosis after one year or less of living with the disease, while 95.2% presented alterations in small-fibre sensory function and 35% presented such alterations in the large fibre. Neuropathic pain was present in 81% of the patients. In vivo confocal microscopy found no statistically significant difference in mean age and distribution according to sex between the Hansen disease patients and the control group of healthy individuals. The median-of-means for dendritic cells and volume of sub-basal nerve fibres in the control group were used to test for normality. Both eyes of all leprosy patients examined contained higher number of dendritic cells than the median value and a volume of sub-basal nerve fibres lower than the mean. These differences were statistically significant (P < 0.001 and P < 0.001, respectively). Multibacillary individuals had a median number of dendritic cells two times that of paucibacillary individuals (P = 0.035). Limitations: No association was found between the variables examined using in vivo confocal microscopy and clinical variables relating to small-fibre damage, the neuropathic pain questionnaire or alterations detected by the neurological examination. We believe, however, that Cochet-Bonnet esthesiometry of the cornea may have revealed such an association. Conclusion: In vivo confocal microscopy is a useful diagnostic tool for detecting small fibre loss in individuals affected by leprosy and may constitute a useful addition to the range of tools available to help curb the effects of neuropathy in these patients.
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Objectives: As neuropathy predominates vasculopathy, predicting functional deterioration of autonomic neurovascular dysfunction is essential to reduce diabetic foot ulcers. The present study has evaluated the possibility of stimulating the TRPV1 receptors of the small fibres using topical capsaicin to assess diabetic neuropathy in the dorsum of the foot functionally. Materials and Methods: A prospective cross-sectional study was carried out on ten healthy volunteers and 20 diabetic patients after receiving ethical approval. The subjects underwent vascular Doppler analysis after giving written agreement followed by monofilament testing. Then, topical capsaicin was applied to measure the local autonomic neurovascular reaction. With the use of an infrared-based digital instrument that was specially created, the vasodilation and proportional increase in temperature brought on by the application of capsaicin were quantified. Results: The percentage change in the local temperature in the control group varied from 0.478 to 3.315 compared to the diabetic group, which varied from 1.862 to ?3.932. There is a statistically significant difference in the mean of the two groups (P = 0.006) at a 95% confidence interval. Conclusion: This study suggests that TRPV1 receptor stimulation using capsaicin and resultant vasodilation monitored by the increase in local temperature can be used as a quantitative predictor of the early small fibre neuropathy in Distal Symmetric Polyneuropathy before the patient ends up with diabetic foot ulcer.
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Objective To explore the diagnostic value of corneal confocal microscopy in the early small fibre neuropathy (SFN).Methods A total of 45 patients with small fibre neuropathy and 50 age-matched healthy subjects undertook a neurological evaluation,neurological deficits score (NDS),sural nerve conduction velocity,contact heat evoked potential (CHEP) and corneal confocal microscopy (CCM) to quantify small nerve fibre pathology.Four parameters including nerve fiber length (NFL),nerve branch density (NBD),nerve fiber density (NFD) and nerve fibre tortuosity (NFT) were calculated from the observation of corneal confocal microscopy.Results Compared with the control group,significantly decreased NFD and NBD were found in the SFN group [(42.00 ±25.26)/mm2 vs (72.38 ± 14.09) /mm2 ;(31.93 ± 13.21)/mm2 vs (46.24 ± 11.48)/mm2 ; with all P ＜ 0.05],while NFT were significantly increased in the SFN group [(2.48 ±0.87) levels vs (0.88 ±0.56) levels,P ＜0.001].The neurological deficits score was correlated with NFT,NFD and NBD (r =0.782,-0.376,-0.504 ; with all P ＜ 0.001).Conclusion CCM is a new and sensitive noninvasive clinical technique that may be used to detect early small fibre nerve damage in patients with SFN.