The spectrum of central nervous system manifestations in leprosy: a systematic review of published case reports and case series.

BACKGROUND: This systematic review aimed to investigate central nervous system (CNS) involvement in leprosy by analysing multiple cohort studies, individual cases and case series. METHODS: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. PubMed, Scopus and Embase databases were searched up to 8 July 2023, using a predefined search strategy. Inclusion criteria included patients diagnosed with leprosy with evidence of CNS involvement. The quality of the included cases was evaluated using the Joanna Briggs Institute checklist. RESULTS: A total of 34 records were identified, including 18 cohort studies and 16 reports describing 27 isolated cases. Autopsies revealed macroscopic changes in the spinal cord, neurofibrillary tangles and senile plaques. Mycobacterium leprae was detected in neurons of the medulla oblongata and spinal cord using PCR and phenolic glycolipid 1 staining. Cerebrospinal fluid (CSF) analysis showed inflammatory changes, increased gamma globulins and detection of Mycobacterium leprae antigens and antibodies. In 21 patients (78%), spinal cord/brachial plexus abnormities were detected. In the majority, MRI revealed T2/fluid-attenuated inversion recovery (FLAIR) hyperintensity in the cervical cord. In patients with brainstem involvement, T2/FLAIR hyperintensity was noted in the cerebellar peduncles, facial nerve nuclei and/or other cranial nerve nuclei. Brain parenchymal involvement was noted in three patients. CONCLUSIONS: This systematic review provides evidence of CNS involvement in leprosy, based on autopsy findings, neuroimaging, CSF analysis and neurophysiological studies.

Nerve biopsies in patients with peripheral neuropathy: A prospective evaluation.

Background: In approximately 25% of peripheral neuropathy cases, diagnosis remains obscure. In India, leprosy continues to remain one of the most frequent causes of peripheral neuropathy. We, in this prospective evaluation, performed nerve biopsies in patients with peripheral neuropathy for early confirmation of the diagnosis. Materials and Methods: A total of 55 consecutive cases of peripheral neuropathy were included in this study. All patients were subjected to clinical and electrophysiological evaluation. Sural nerve biopsies were performed in all the patients. Result: After a nerve biopsy in 29 cases, we were able to identify the underlying cause of peripheral neuropathy. In 26 cases, the diagnosis remained obscure. The most frequent histopathological diagnosis was leprosy, which was seen in 20 cases. Other diagnoses were chronic demyelinating neuropathy (four cases), vasculitis (two cases), and amyloidosis in one case. In two biopsies, the findings were consistent with hereditary neuropathies. The demonstration of lepra bacilli was the most distinctive feature. In addition, foamy macrophages (100%) and granuloma (100%) formation, epineurial (83.3%) and endoneurial infiltration (69%) along with epineurial (87.5%) and perineurial thickening (77.3%) were also noted more frequently in leprosy-associated neuropathy. Conclusion: The nerve biopsies revealed that leprosy was the most common etiology in patients with peripheral neuropathy. In approximately 47% of the cases, even nerve biopsies failed to establish a confirmed diagnosis.

Central nervous system, spinal root ganglion and brachial plexus involvement in leprosy: A prospective study.

Background: Leprosy is primarily a disease of peripheral nerves. Some isolated case reports and case series have communicated imaging changes in the central nervous system (CNS) and brachial plexus in patients with leprosy. Objectives: To study the neuroimaging abnormalities in patients with lepra bacilli-positive neuropathy in the context of CNS, spinal root ganglion, and brachial plexus. Design: Prospective observational study. Methods: We screened newly-diagnosed patients with multibacillary leprosy presenting with neuropathy. Patients with bacilli-positive sural nerve biopsies were included in the study and subjected to magnetic resonance imaging (MRI) of the brain and spinal cord. Results: A total of 54 patients with bacteriologically confirmed multibacillary leprosy were screened; Mycobacterium leprae was demonstrated in the sural nerve biopsies of 29 patients. Five patients (5/29; 17.24%) had MRI abnormalities in CNS, spinal root ganglion, and/or brachial plexus. Three patients had MRI changes suggestive of either myelitis or ganglionitis. One patient had T2/FLAIR hyperintensity in the middle cerebellar peduncle while 1 had T2/FLAIR hyperintensity in the brachial plexus. Conclusion: CNS, spinal root ganglion, and brachial plexus are involved in patients with leprous neuropathy. Immunological reaction against M leprae antigen might be a plausible pathogenetic mechanism for brachial plexus and CNS imaging abnormalities.

Pathological, ultrasonographic, and electrophysiological characterization of clinically diagnosed cases of pure neuritic leprosy.

A subset of neuritic form of leprosy, called pure neuritic leprosy (PNL), seen in a minority of leprosy patients, is characterized by peripheral neuropathy without skin lesions and an absence of acid-fast bacilli on skin smears. Patients with PNL are often started on drug therapy without confirmation of diagnosis. We, therefore, did a prospective study of clinically diagnosed PNL patients with correlation of ultrasonographic and biopsy findings. A total of 100 consecutive patients with PNL, diagnosed according to the consensus case definition, were included in the study. All patients underwent nerve conduction study, peripheral nerve ultrasonography, and sural nerve biopsy. Multiple mononeuropathies were present in 75% of cases, mononeuropathy in 18%, and polyneuropathy in the remaining 7%. Compared to clinical examination, ultrasonographic assessment of the peripheral nerves was not only better at the detection of thickening but also helped in characterization of their fascicular architecture, echogenicity, and vascularity. A total of 32 cases were confirmed on nerve biopsy, out of which 75% had demonstrable lepra bacilli. Cranial nerve involvement, presence of trophic ulcers, and bilateral thickening of the great auricular nerve were significantly associated with the positivity of lepra bacilli. A significant improvement in the disability score happened after multidrug therapy. A comprehensive electrophysiologic, ultrasonographic, and histological evaluation may be helpful in establishing a diagnosis of PNL with greater confidence, while ruling out other non-leprosy diagnoses.

Comprehensive electrophysiology in leprous neuropathy - Is there a clinico-electrophysiological dissociation?

OBJECTIVE: The diagnosis of leprous neuropathy is mostly empirical and electrophysiological studies may not truly represent the clinical findings. This study comprehensively evaluates the neuroelectrophysiology and looks at clinico-electrophysiological dissociation. METHODS: Conventional electrophysiological recording included evaluation of median, ulnar, radial, tibial, and common peroneal nerve; an extended protocol included great auricular, phrenic, and facial nerves, along with sympathetic skin response and blink reflex. Nerve biopsy and slit skin smear were done to aid categorization. RESULTS: Forty-six patients of leprosy were enrolled. Mononeuritis multiplex was the commonest presentation. Sensory loss was commoner than motor deficits. Approximately 60% of all cases were nerve-biopsy proven. Nerve thickening was present in 38.7% (214/552) of nerves examined. Clinico-electrophysiological dissociation between nerve thickening and nerve conduction findings was present in median, ulnar, great auricular, and common peroneal nerves. CONCLUSION: Electrophysiological findings outnumber occurrence of nerve thickening and clinical deficits in leprous neuropathy. From a clinical perspective, enlargement of great auricular, ulnar, and common peroneal nerves may be more sensitive in predicting electrophysiological abnormalities. SIGNIFICANCE: A comprehensive nerve conduction study including great auricular and phrenic nerves, coupled with a sympathetic skin response, may aid in detecting cases with paucity of findings since such a combination is seldom seen in other disorders.

Thalidomide: chemistry, therapeutic potential and oxidative stress induced teratogenicity.

Thalidomide and its one analogue, lenalidomide (CC5103 or revlimid) are recently approved for the treatment of multiple myeloma. Multiple myeloma is characterized by an overproduction of malignant plasma cells in the bone marrow. The journey of thalidomide was started in 1956 when it was marketed as a non-barbiturate sedative agent. It was considered as a "wonder drug" that provided safe and sound sleep and hence, used to cure morning sickness in pregnant women. Later, in 1961, it was withdrawn from the world market due to its serious side effects, i.e., teratogenic activity. However, the recent decade has witnessed a true renaissance in interest in its broad biological activity. In particular, thalidomide was reevaluated and attracted significant attention due to its selective inhibitory activity of tumor necrosis factor-α (TNF-α), which is a clinically important activity against serious diseases such as rheumatoid arthritis, Crohn's disease, leprosy, AIDS, and various cancers. The comeback of thalidomide to the legitimate status of a marketed drug came in 1998 when it received FDA approval for the treatment of erythema nodosum leprosum (ENL). Recently, the drug has got FDA approval for the treatment of multiple myeloma. In the last few years, number of thalidomide analogues have been synthesized and are in clinical development as a class of immunomodulatory drugs. Among these, lenalidomide is more potent than thalidomide, and is also non-neurotoxic. It was shown in vitro studies to induce apoptosis or arrest growth even in resistant multiple myeloma cell lines, decrease binding of the cells to bone marrow stromal cells, and stimulate host natural killer cell immunity. It also inhibits tumour growth and decreases angiogenesis. Earlier reviews have described the pharmacological aspects of thalidomide and a review has focused only on synthetic aspect of thalidomide. However, review focusing on chemistry and metabolism and mechanism of biological activity is still lacking. In this review, we will concisely describe the therapeutic aspects, metabolism and synthesis of thalidomide.