Peripheral nerve biopsy: Is it still important for the early diagnosis of neural leprosy?

Background: The early recognition of neural impairment in leprosy represents a challenge in clinical practice and peripheral nerve biopsy may be required for diagnostic. Objective: Characterize the epidemiological, clinical, electroneuromyographic, laboratory and histopathological aspects of patients undergoing peripheral nerve biopsy during investigation of primary neural leprosy. Methods: 104 patients with peripheral neuropathy, referred to a national reference center leprosy, were biopsied. All patients had clinical evidence of peripheral neuropathy associated with the absence of skin lesions and were being investigated. Results: Of 104 biopsied, leprosy was confirmed in 89.4%. 66 were classified as primary neural leprosy and 27 as neural relapse or reinfection. All cases confirmed presented asymmetric neural impairment with predominance of sensory symptoms (88.2%), followed by muscular weakness and/or amyotrophy in 44.1% and pain in 34.4%. Neural thickening of one or more nerves was observed in 78.5% of the patients. The biopsied nerves were: ulnar (67.8%), superficial fibular (21.5%), sural (8.6%), radial (1.1%) and deep fibular (1.1%). 29% presented histopathological abnormalities and 4.4% acid fast bacilli. Nerve and superjacent skin qPCR were positive in 49.5% and 24.8% of cases, respectively. The patients with multiple mononeuropathy presented higher frequency of neural thickening (p<0.0001) and histopathological abnormalities (p=0.0077), but lower rates of positivity of ELISA anti-PGL-I (p=0.0100), qPCR in the peripheral blood (p=0.0157), and in the slit skin smear (p=0.0032). Conclusions: Peripheral nerve biopsy is an important tool in the investigation of primary neural cases, contributing to the early diagnosis and reducing diagnostic errors and the need for empirical treatment.

Early diagnosis of neural involvement in home contacts of leprosy patients: The experience of a national reference center between 2014- 2020

Background: The long incubation period of leprosy, its insidious signs and symptoms produce difficulties in its diagnosis and correct clinical classification. The early recognition of neural impairment in leprosy, especially in household contacts with subclinical infection and in the primary neural form, in which the classic clinical and laboratory findings of the disease are, by definition, absent, represents a major challenge in clinical practice. Objectives: Characterize the clinical, molecular, serological and neurophysiological aspects in the early diagnosis of leprosy neuropathy, in household contacts with subclinical infection (positive ELISA anti-PGL1 serology. Design and setting: Longitudinal study carried out at the Clinics Hospital - Federal Univeristy of Uberlândia, a center specialized in Leprosy/Sanitary Dermatology. Methods: 361 seropositive household contacts (CDSP), defined as subclinical infection, were recruited, followed up at a national referral center for leprosy in Brazil, from 2014 to 2016. All individuals underwent a clinical, laboratory and neurophysiological evaluation. Results: 361 CDSP were evaluated. The qPCR analysis was positive in 35.5% (128/361) in the dermal shaving and in 25.8% (85/361) in the skin biopsy of the CDSP. In the electroneuromyographic evaluation, 23.5% (93/361) of the CDSP showed signs of neural involvement, with an average of 2.1 nerves compromised by CDSP. 62.3% (53/93) presented a pattern of mononeuropathy in ENMG. Conclusions: Annual monitoring of CDSP, a prevalence of peripheral neural impairment assessed by ENMG, favoring early treatment.

Peripheral nerve biopsy: a tool still needed in the early diagnosis of neural leprosy?

Background The early recognition of neural impairment in leprosy, especially in primary neural forms, represents a challenge in clinical practice and a peripheral nerve biopsy may be required for diagnostic confirmation. This study aims to characterize the epidemiological, clinical, electroneuromyographic, laboratory and histopathological aspects of patients undergoing peripheral nerve biopsy during investigation of primary neural cases in leprosy. Methods A total of 104 patients with peripheral neuropathy who were referred to a national reference centre for leprosy were biopsied from 2014 to 2018. All cases underwent clinical, laboratory, histopathological and electroneuromyographic evaluations. Results Of 104 biopsied patients, leprosy was confirmed in 89.4% (93/104). The biopsied nerves were the ulnar (67.8% [63/93]), superficial fibular (21.5% [20/93]), sural (8.6% [8/93]), radial (1.1% [1/93]) and deep fibular (1.1% [1/93]). Twenty-nine percent (27/93) presented histopathological abnormalities and 4.4% (4/93) presented acid-fast bacilli. Nerve and superjacent skin quantitative polymerase chain reaction were positive in 49.5% (46/93) and 24.8% (23/93) of cases, respectively. Patients with multiple mononeuropathy had a higher frequency of histopathological abnormalities (p=0.0077). Conclusions This study reinforces peripheral nerve biopsy's role as an important tool in the investigation of primary neural cases, contributing to the early diagnosis and also reducing diagnostic errors and the need for empirical treatment.

A Mobile Application for Smart Computer-Aided Self-Administered Testing of Cognition, Speech, and Motor Impairment

We present a model for digital neural impairment screening and self-assessment, which can evaluate cognitive and motor deficits for patients with symptoms of central nervous system (CNS) disorders, such as mild cognitive impairment (MCI), Parkinson’s disease (PD), Huntington’s disease (HD), or dementia. The data was collected with an Android mobile application that can track cognitive, hand tremor, energy expenditure, and speech features of subjects. We extracted 238 features as the model inputs using 16 tasks, 12 of them were based on a self-administered cognitive testing (SAGE) methodology and others used finger tapping and voice features acquired from the sensors of a smart mobile device (smartphone or tablet). Fifteen subjects were involved in the investigation: 7 patients with neurological disorders (1 with Parkinson’s disease, 3 with Huntington’s disease, 1 with early dementia, 1 with cerebral palsy, 1 post-stroke) and 8 healthy subjects. The finger tapping, SAGE, energy expenditure, and speech analysis features were used for neural impairment evaluations. The best results were achieved using a fusion of 13 classifiers for combined finger tapping and SAGE features (96.12% accuracy), and using bidirectional long short-term memory (BiLSTM) (94.29% accuracy) for speech analysis features.

Cognitive Disability and Embodied, Extended Minds

Many models of cognitive ability and disability rely on the idea of cognition as abstract reasoning processes implemented in the brain. Research in cognitive science, however, emphasizes the way that our cognitive skills are embodied in our more basic capacities for sensing and moving, and the way that tools in the external environment can extend the cognitive abilities of our brains. It is important to address the implications of research in embodied cognition and extended cognition for how we think about cognitive impairment and rehabilitation, how cognitive reserve mitigates neural impairment, and the distinction between medical and social models of disability.