Hereditary neuropathies: Genetics and utility of nerve biopsy

Peripheral neuropathy is one of the most common neurological conditions of the nervous system. Hereditary neuropathies (HNs) form an important group with varying degrees of severity, causing a significant disease burden. Accurate diagnosis is essential for management, counseling, and preventing unnecessary extended workups for acquired etiologies and inappropriate treatment. Several hereditary neuropathies have characteristic or diagnostic histologic findings; however, in the era of molecular diagnostics, the role of nerve biopsy in the diagnosis of hereditary neuropathy has reduced significantly. Nevertheless, in sporadic cases, cases without a clear family history, clinical mimics, cases with rare mutations, and genetic variants of unknown significance, a nerve biopsy can confirm the diagnosis, provide an unexpected diagnosis, or direct a targeted molecular testing. HN may be non-syndromic, affecting predominantly the peripheral nervous system or syndromic where it is a part of more widespread neurological or multisystem involvement. This review summarizes the microscopic pathological features in a nerve biopsy in some of the more commonly encountered inherited peripheral neuropathies highlighting their utility in selected cases.

Role of 5% Imiquimod Cream in the Prevention of Recurrence of Keloids Post Shave Excision

Introduction: Keloids represent an excessive connective tissueresponse to injury, which may be trivial. Despite numeroussmall case series advocating a wide range of therapies, there isno level one evidence for any single treatment. This study wasdone to know the role of 5% imiquimod cream in preventingrecurrence of excised keloids.Material and methods: Study was done on 30 Cases ofkeloids attending the Department of DVL, Osmania generalhospital for a duration of 6 months from December 2017 toMay 2018.Results: It was observed that after 6 months, 7 of 8 keloidson the trunk and 4 of the 6 keloids on the extremities hadevidence of recurrence while of 14 auricular keloids, only2 had evidence of recurrence and none of the keloids in thesuprapubic region had evidence of recurrence.Conclusion: According to the present study the use ofpostoperative, topically applied imiquimod following shaveexcision is a more effective intervention compared to thestandard, complete excision of keloids.

Analysis of calpain-3 protein in muscle biopsies of different muscular dystrophies from India.

Background & objectives: Calpain-3, a Ca2+-dependent protease has been implicated in the pathology of neuromuscular disorders (NMDs). The current study aimed to analyze calpain-3 expression in cases diagnosed as muscular dystrophy from the Indian population. Methods: Calpain-3 Western blot analysis in muscle biopsies of immunohistochemically confirmed cases of Duchenne muscular dystrophy (DMD) (n=10), dysferlinopathy (n=30) and sarcoglycanopathy (n=8) was carried out. Calpain-3 Western blotting was also used in a blinded study to identify cases of calpain-3 deficiency in 28 NMD patients with potential muscular dystrophy. Results: Calpain-3 appeared as a full length 94 kDa band with an autolytic product (~60 kDa) on Western blots with antibody NCL-CALP-12A2 (Ab-2). Eight of the 10 DMD samples showed absence of 94 kDa band but presence of 60 kDa band while one case of sarcoglycanopathy showed absence of both. Twenty one of the 30 dysferlinopathy samples showed both bands while six showed only the 60 kDa band and three showed absence of both. In the blinded study, five NMD cases with potential muscular dystrophy that showed complete absence of both bands in retrospect exhibited clinical features of limb girdle muscular dystrophy 2A (LGMD2A). Interpretation & conclusions: While the study revealed a consistent pattern of calpain-3 in DMD, one sarcoglycanopathy and three dysferlinopathy samples exhibited secondary reduction in calpain-3. It was recognized that both calpain-3 bands should be considered to confirm calpain deficiency. Further, western blot offers an economical and fast preliminary screening method for LGMD2A especially in cases of complete absence of calpain-3 prior to conclusive diagnosis by genetic testing.

Dysferlinopathy: Spectrum of pathological changes in skeletal muscle tissue.

Background: Dysferlinopathy is an autosomal recessive-limb girdle muscular dystrophy (AR-LGMD) caused due to the defect in gene encoding dysferlin, a sarcolemmal protein. Awareness of the variants and their relative frequency is essential for accurate diagnosis. Aim: To study the spectrum of morphologic changes in immunohistochemically proven cases of dysferlinopathies, to correlate the findings with clinical phenotype and durations of illness and determine the frequency. Materials and Methods: Dysferlinopathies seen over a period of 2 years at a tertiary neurological center were analyzed. Results: Clinically, majority had Miyoshi phenotype (46.6%) with distal involvement and LGMD phenotype (40%) with proximal muscle involvement. In addition, a proximo-distal and tibial muscle phenotype was encountered. Morphologically, rimmed vacuoles were noted in the Miyoshi phenotype. The presence of ragged red fibers, lobulated fibers and inflammation had no preference to a particular phenotype. Significant atrophy and lobulated fibers were noted in patients with longer duration of illness. Conclusions: Dysferlinopathy was the second most common identifiable cause (21%) of LGMD next to sarcoglycanopathies (27%).

Ullrich congenital muscular dystrophy: report of nine cases from India.

BACKGROUND: Ullrich congenital muscular dystrophy (UCMD) is a unique congenital disorder characterized clinically by generalized muscle weakness, contractures of the proximal joints and hyperextensibility of the distal joints and begins from birth or early infancy. MATERIALS AND METHODS: We prospectively evaluated nine cases of classical UCMD and recorded the clinical phenotypic characteristics and the histopathological findings. RESULTS: There were eight boys and one girl child with classical features of severe muscle weakness, prominent proximal contractures, distal hyperlaxity and prominent calcanei. Immunohistochemistry for Collagen VI A1 done on seven cases showed total absence of labeling in six while sarcolemmal-specific deficiency was noted in one case confirming the diagnosis of UCMD. Interestingly, all our patients were noted to have near total absence of major palmar and plantar creases, and instead there were fine mesh-like lines in addition to the soft velvety skin on the palms and soles suggestive of altered collagen arrangements in the skin. Hitherto, this clinical finding has not been described in UCMD in the English literature.

Dysferlinopathy: A clinical and histopathological study of 28 patients from India.

Background: Miyoshi myopathy (MM) and limb girdle muscular dystrophy (LGMD2B) are distinct clinical entities because different muscle groups are involved at the onset. We describe the clinical features in 28 patients with dysferlin deficiency confirmed by muscle immunohistochemistry (IHC). Settings and Design: A case series from a tertiary national referral center for neurological disorders. Materials and Methods: Patients with classical phenotype of MM and LGMD2B underwent a thorough phenotypic characterization followed by muscle histopathological study including IHC for dysferlin deficiency. Results: There were 28 patients (20 men and eight women) presenting with manifestations of distal myopathy or LGMD2B and had absence of dysferlin staining on IHC. Patients presented predominantly with distal myopathy of Miyoshi type (MM) or proximal LGMD type and were diagnosed to have dysferlinopathy on IHC. Two patients had the proximodistal form and two had onset as tibial muscular dystrophy. The main clinical features in these patients were onset in late adolescence or early adulthood (mean age of onset for MM was 22.0 +/- 6.7 years and for LGMD2B 19.4 +/- 5.1 years). There was early and predominant involvement of the posterior compartment muscles of the leg or proximal pelvic girdle muscles, dystrophic features with necrotic regeneration pattern without vacuoles on muscle biopsy and markedly elevated serum creatine kinase values with mean of 10033.8 +/- 9283 IU/l (range 402-27460). Consanguinity was reported in 46.4%. The mean duration of illness was 6.4 +/- 4.2 years. Dysferlinopathies formed nearly one-fourth of our patients with LGMD. Conclusion: In our experience dysferlinopathies was not an uncommon form of LGMD.

Emery dreifuss muscular dystrophy: a clinico-pathological study.

Emery-Dreifuss muscular dystrophy (EDMD) is a rare and genetically heterogeneous disorder. We report two patients with emerin deficient X-linked EDMD and two probable patients with EDMD with typical early contractures, progressive muscle weakness and cardiac involvement. Family history was noted in one case. Muscle biopsy revealed features of dystrophy in all.

Vitamin E prevents deleterious effects of di (2-ethyl hexyl) phthalate, a plasticizer used in PVC blood storage bags.

Vitamin E administration prevented DEHP induced deleterious effects like (i) degenerative changes in the brain and thyroid, (ii) decrease in the activity of neuronal membrane Na+ - K+ ATPase, (iii) decrease in the concentration of insulin, cortisol and TSH, and (iv) the increase in T3 and T4 in female Albino rats. The results suggest use of vitamin E to prevent harmful effects of repeated transfusion of DEHP containing blood as in thalassemia patient. The possibility of using vitamin E to prevent the harmful effects of repeated transfusion of DEHP containing blood, as in thalassemia patients, is discussed.

Changes in some hormones by low doses of di (2-ethyl hexyl) phthalate (DEHP), a commonly used plasticizer in PVC blood storage bags & medical tubing.

BACKGROUND & OBJECTIVES: Di (2-ethyl hexyl) phthalate (DEHP), a plasticizer commonly used in PVC blood storage bags leaches out in significant amounts into blood during storage. In view of many reports on the toxicity of this compound, it was considered necessary to investigate the effect of DEHP at the low level solubilized in blood on some important hormones in rats and in human blood stored in DEHP plasticized blood bags. METHODS: Rats were administered DEHP at a low level of 750 microg/100 g body weight on alternate days for 14 days. Changes in the serum insulin, blood glucose, liver glycogen level and T3, T4 and thyroid stimulating hormone (TSH) as well as cortisol in the serum were studied. Changes in the hormones were also studied in blood stored in DEHP plasticized PVC bags. RESULTS: The results indicated decrease in serum insulin, cortisol and liver glycogen, and increase in blood glucose, serum T3 and T4 in rats receiving DEHP. These changes were reversed when administration of DEHP was stopped. Similar changes in hormones were also observed in the blood stored in DEHP plasticized blood bags. INTERPRETATION & CONCLUSION: The results indicated that administration of DEHP at low levels to rats caused symptoms of diabetes, thyroid and adrenocortical dysfunction. Though the results obtained in rats cannnot be extrapolated to human, the fact that similar hormonal changes seen in human blood stored in DEHP plasticized blood bags may suggest possibility of DEHP causing similar changes in human. The fact that these changes were reversed in rats when DEHP administration was stopped, indicates that transfusion of a few units of blood to a recipient may not be harmful, but it may pose a problem during repeated transfusions such as in thalassaemia patients.

Vasculitic neuropathy in HIV infection: a clinicopathological study.

Vasculitis causing peripheral neuropathy may be the first sign of HIV infection. We report four such cases in whom the onset of peripheral neuropathy led to the detection of HIV infection. Two patients presented with features of mononeuritis multiplex, while the other two had a lumbosacral polyradiculopathy. A prior history of blood transfusion was forthcoming in one of the patients. Sural nerve biopsies in all the four cases and the muscle biopsy in two, histologically showed evidence of vasculitis. Immunohistochemically, the viral antigen was not demonstrable in any of the biopsies, but on electron microscope, virus-like particles were identifiable in the Schwann cell cytoplasm and the perivascular macrophages in one case. To the best of our knowledge, this is the only report that has documented the virus in the Schwann cells as well as the perivascular macrophages lending credence to the fact that these viruses are neurotropic as well as lymphotropic. Immunoglobulin deposits were not demonstrable in any of the cases, suggesting that direct viral invasion may have a role in the pathogenesis of peripheral nerve vasculitis.

Centronuclear myopathy--morphological relation to developing human skeletal muscle: a clinicopathological evaluation.

Centronuclear myopathy (CNM), an uncommon condition, is one of the congenital myopathies. It is believed to arise as a result of maturational arrest, with persistence of myotubes postnatally. However, denervation being the basic disease process and its possible influence on central nervous system causing defect in nuclear migration has also been postulated. Keeping in view these existing controversies, we have studied 17 cases of CNM (neonatal - 1, childhood - 13, adulthood - 3) during the last twelve and a half years. Diagnosis was based on histological and enzyme histochemical findings of muscle biopsy along with clinical data. Ultrastructural characterstics of muscle have been studied in 10 cases. The affected muscle fibres showed a central nucleus (40-99%) with perinuclear halo. Type I fibre predominance with hypoplasia was consistently seen. Fibre type disproportion was noticed in 7 cases. The neonatal form revealed dense oxidative enzyme reaction product in the centre. The morphological features of CNM were compared with foetal skeletal muscles obtained at gestational ages ranging from 9 weeks - 36 weeks (n = 18). In the severe neonatal form th myofibres resembled the foetal myotubes. In the less severe childhood and adult form of CNM, aberrant organization of cytoskeletal network might have played a pathogenetic role in causing the disease.