Is deltoid muscle biopsy useful in isolated camptocormia? A prospective study

Histopathological features of systemic sclerosis-associated myopathy: A scoping review

BACKGROUND

Scleromyositis (SM) is an emerging subset of myositis associated with features of systemic sclerosis (SSc) but it is currently not recognized as a distinct histopathological subset by the European NeuroMuscular Center (ENMC). Our aim was to review studies reporting muscle biopsies from SSc patients with myositis and to identify unique histopathological features of SM.

METHODS

A scoping review was conducted and included all studies reporting histopathological findings in SSc patients with myositis searching the following databases: PubMed, MEDLINE, EMBASE, CINAHL and EBM-Reviews. Clinical, serological, and histopathological data were extracted using a standardized protocol.

RESULTS

Out of 371 citations, 77 studies that included 559 muscle biopsies were extracted. Fifty-seven percent (n = 227/400) had inflammatory infiltrates, predominantly T cells, which were endomysial (49%), perimysial (42%) and perivascular (41%). Few studies (18%, n = 8/44) evaluated the presence of B-cells. Myofiber atrophy was present in 48% (n = 104/218) of biopsies, and was predominantly perifascicular in 19% (n = 6/31), with necrosis reported in 56% (n = 162/290) of cases. Sarcolemmal MHC-I upregulation was found in 72% (n = 64/89) of biopsies. Non-specified C5b-9 deposition was described in 39% of muscle biopsies (n = 28/72). Neurogenic features were present in 23% (n = 44/191); endomysial fibrosis was reported in 35% (n = 120/340); and rimmed vacuoles were observed in 32% (n = 11/34) of biopsies. Capillaropathy, such as capillary dropout and/or ultrastructural endothelial abnormalities, was reported in 33% (n = 43/129) of cases. Reported ENMC categories were mainly polymyositis (21%), non-specific myositis (19%), immune-mediated necrotizing myopathy (16%), and dermatomyositis (8%). Histopathological features were analyzed according to serological subtypes in 28 studies, including anti-PM-Scl (n = 48), -Ku (n = 23) and -U1RNP (n = 90). Most of these biopsies demonstrated inflammatory infiltrates (range 49-85%) as well as MHC-I expression (range 63-81%). Necrosis was associated with anti-Ku (85%) and anti-U1RNP (73%), while anti-Ku was also associated with neurogenic features and rimmed vacuoles in 57% and 25% of cases, respectively.

CONCLUSION

Our review suggests that SM is characterized by heterogeneous pathological features using definitions included in current histopathological criteria. Whether a distinct histopathological signature exists in SM remains to be determined. SSc-specific and SSc-associated autoantibodies may help define more homogeneous histopathological subsets.

Camptocormia and Other Orthopedic Compromise Dominating Mitochondrial Disorder: A Case Report

Objectives: Camptocormia and other orthopedic abnormalities have been only rarely reported as a phenotypic manifestation of a mitochondrial disorder (MID). Here we present an MID patient with multiple orthopedic abnormalities dominating the phenotype.

Case report: The patient is a 55-year-old male in whom MID was diagnosed at age 34 upon clinical presentation, muscle biopsy, and biochemical investigations. Phenotypically, he manifested with multisystem disease including the brain (mental retardation, epilepsy, sleep disorder, cerebellar atrophy), eyes (cataract, myopia), ears (hypoacusis), heart (hypertrophic, cardiomyopathy, QT-prolongation, left anterior hemiblock, noncompaction), intestines (hepatopathy, cholecystolithiasis), muscle (myopathy), peripheral nerves (neuropathy), and the bone marrow (anemia). Additionally, there was facial dysmorphism (upslanting palpebral fissures, hypertelorism, protruding bulbs) and multiple orthopedic abnormalities, including camptocormia in the absence of axial myopathy, barrel thorax, gibbus, genu valga, knee contractures, bilateral gonarthrosis, bilateral ankle arthroses, and outwardly rotated feet. These abnormalities were complicated by wedge vortex, vertebral stenosis, and coxarthrosis requiring right hip endoprosthesis. His mother manifested with a largely different phenotype.

Conclusions: An MID can manifest phenotypically with orthopedic abnormalities, which may dominate the phenotype. According to this case, orthopedic abnormalities in a MID can be unrelated to the severity of myopathy and intrafamilial phenotypic variability can be high in a MID.

Inflammatory Myopathies: Utility of Antibody Testing

Inflammatory myopathies are a group of immune-mediated muscle disorders comprising dermatomyositis; polymyositis; overlap myositis, including antisynthetase syndromes and nonspecific myositis, immune-mediated necrotizing myopathies, and sporadic inclusion body myositis. They are now much more eloquently classified both pathologically and clinically because of the discovery of several myositis-specific and myositis-associated antibodies. These antibodies also aid in choosing the best treatment options in each case. Based on the initial classifications of inflammatory myopathies, inclusion body myositis, overlap myositis, and necrotizing myositis were all included in the polymyositis group. This article discusses cases, diagnostic tools, associated antibodies, and pathology.

Camptocormia as a Novel Phenotype in a Heterozygous POLG2 Mutation

Mitochondrial dysfunction is known to play a key role in the pathophysiological pathway of neurodegenerative disorders. Nuclear-encoded proteins are involved in mtDNA replication, including DNA polymerase gamma, which is the only known replicative mtDNA polymerase, encoded by nuclear genes Polymerase gamma 1 (POLG) and Polymerase gamma 2 (POLG2). POLG mutations are well-known as a frequent cause of mitochondrial myopathies of nuclear origin. However, only rare descriptions of POLG2 mutations leading to mitochondriopathies exist. Here we describe a 68-year-old woman presenting with a 20-year history of camptocormia, mild proximal weakness, and moderate CK increase. Muscle histology showed COX-negative fibres. Genetic analysis by next generation sequencing revealed an already reported heterozygous c.1192-8_1207dup24 mutation in the POLG2 gene. This is the first report on a POLG2 mutation leading to camptocormia as the main clinical phenotype, extending the phenotypic spectrum of POLG2 associated diseases. This underlines the broad phenotypic spectrum found in mitochondrial diseases, especially in mitochondrial disorders of nuclear origin.

Camptocormia as the presenting symptom in sporadic late onset nemaline myopathy: a case report

Background

Camptocormia has been reported in a plethora of diseases comprising disorders of the central nervous system, the peripheral nervous system, and the neuromuscular junction as well as hereditary and acquired myopathies. In sporadic late onset nemaline myopathy concomitant axial myopathy is common, but reports about camptocormia as the only presenting symptom in this condition are very rare. Notably, sporadic late onset nemaline myopathy is a potentially treatable condition in particular when associated with monoclonal gammopathy of unknown significance, HIV or rheumatological disorders.

Case presentation

We report the case of a 62-year-old female patient, who presented with slowly progressive camptocormia. Comprehensive work-up including neurological work-up, laboratory tests, MR-imaging, muscle biopsy and genetic testing led to the diagnosis of sporadic late onset nemaline myopathy.

Conclusions

Our case report highlights that sporadic late onset nemaline myopathy has to be considered in patients presenting with isolated camptocormia and comprehensive work-up of camptocormia is mandatory to ascertain the individual diagnosis, especially in consideration of treatable conditions.

Camptocormia and myalgia as the revealing symptoms of a drug-induced myopathy related to chronic orlistat intake: a case report

The presented case concerns a 77-year old man who had been chronically taking colchicine for treatment of gout. He was admitted because of a transient ischemic cerebrovascular attack with motor aphasia and complained of preexisting paraesthesias in the lower extremities. Neurological examination revealed a global muscular weakness, absent myotatic reflexes and a diminished sensation. Serum creatine kinase (CK) levels were increased and electromyography showed spontaneous fibrillations in deltoid muscles, positive spikewaves in deltoids and anterior tibial muscles. Motor and sensory conduction velocities were mildly reduced. Nerve biopsy findings were compatible with a chronic axonal neuropathy having produced a significant loss of myelinated axons and also denervation features of unmyelinated axons. In muscle, combined neurogenic and myogenic features were found. The former result from the axonal neuropathy. The latter were mainly characterized by focal myofibrillar disorganisation and accumulation of autophagic vacuoles in muscle fibres. The presented neuromuscular symptoms and signs, the increased CK values, the electromyographic and nerve conduction velocity findings as well as nerve and muscle biopsy observations, are consistent with the diagnosis of colchicine-induced myopathy and neuropathy. Furthermore, the disappearance of paraesthesias, normalisation of CK values, and disappearance of fibrillations and positive spike waves in deltoid and anterior tibial muscles on electromyography, after stopping of the colchicine therapy, supported the diagnosis.