Sporadic late onset nemaline myopathy with concurrent dermatological symptoms responding to immunosuppressive treatment.

BACKGROUND: Sporadic late onset nemaline myopathy is a rare, progressive muscle disease, presenting in adulthood, mainly affecting proximal limb and bulbar muscles. Muscle biopsies show characteristic nemaline rods. The putative mechanism is considered immune-related. Other manifestations aside from neuromuscular symptoms have not been described previously. CASE PRESENTATION: We present a case with atypical sporadic late onset nemaline myopathy (SLONM) of a non-HIV, non-MGUS subtype, where skin manifestations preceded neuromuscular symptoms, and a residual thymus with the histology of thymic follicular hyperplasia was detected during the diagnostic workup. Thorough dermatological investigations could not explain the skin presentations. Muscle biopsy revealed variation in fiber diameter, ragged-red and COX-negative fibers associated with discrete fibrosis. Electron microscopy detected atrophic muscle fibres with disorganization of the myofibrils, nemaline rods and abnormal mitochondria. Single-fiber EMG suggested signs of a neuromuscular transmission defect, EMG showed signs of myopathy. Analyses of antibodies associated with myasthenia gravis were negative. The patient showed improvement after intravenous immunoglobulin treatment regarding both the skin and the muscle symptoms. CONCLUSIONS: Our case highlights the heterogeneity of SLONM with its varied spectrum of presentation. A unique combination of dermatological symptoms and SLONM could be seen with skin lesions as primary presenting symptoms. An association can be considered between the different manifestations, presumably based on immune etiology, where immunosuppressive therapy has been beneficial.

HTLV-1-associated myelopathy/tropical spastic paraplegia with sporadic late-onset nemaline myopathy: a case report.

BACKGROUND: Sporadic late onset nemaline myopathy (SLONM) is a muscle disorder characterized by the presence of nemaline rods in muscle fibers. SLONM has no known genetic cause but has been associated with monoclonal gammopathy of undetermined significance and with human immunodeficiency virus (HIV) infection. Human T-cell leukemia virus-1 (HTLV-1) is a known causative agent of adult T-cell leukemia/lymphoma and HTLV-1 associated myelopathy/tropical spastic paraplegia (HAM/TSP), a chronic inflammatory neurological disease. HTLV-1 has been reported to be implicated in inflammatory myopathies, as well as in HIV infection.; however, there have been no reports of an association between HTLV-1 infection and SLONM to date. CASE PRESENTATION: A 70-year-old Japanese woman presented with gait disturbance, lumbar kyphosis, and respiratory dysfunction. The diagnosis of HAM/TSP with SLONM was made based on characteristic clinical symptoms of HAM/TSP, such as spasticity in the lower extremities, and cerebrospinal fluid test results; and of SLONM, such as generalized head drooping, respiratory failure, and muscle biopsy results. Steroid treatment was initiated and improvement in her stooped posture was observed after 3 days of treatment. CONCLUSION: This is the first case report of SLONM combined with HTLV-1 infection. Further studies are needed to elucidate the relationship between retroviruses and muscle diseases.

68-year old man with progressive weakness and ventilator dependent respiratory failure: a case report of sporadic late onset nemaline myopathy.

BACKGROUND: Neuromuscular pathologies must be considered when caring for patients with persistent or progressive respiratory failure. Pertinent disease states may involve skeletal muscles of respiration or associated neurologic structures including motor neurons, peripheral neurons and the neuromuscular junction. Diagnosis may require pulmonary function testing, neurophysiologic studies, imaging, and/or muscle biopsy. CASE PRESENTATION: A 68-year-old male was transferred to our intensive care unit (ICU) for management of ventilator dependent respiratory failure. Upon further historical review, he described gradually worsening gait instability and muscle weakness, which was previously attributed to vascular Parkinsonism in the setting of known cerebrovascular disease. Upon arrival to our hospital, he was found to have elevated muscle specific enzymes, prompting evaluation for neuromuscular causes of respiratory failure. He was also found to have elevated HMG-CoA Reductase (HMGCR) antibodies. Ultimately, a right quadriceps muscle biopsy was performed and electron microscopy identified nemaline bodies within skeletal myofibers. Given the clinical course and other histopathologic findings, he was diagnosed with Sporadic late-onset nemaline myopathy (SLONM). CONCLUSION: The diagnosis of neuromuscular disease in patients with ventilator dependent respiratory failure is challenging. A detailed history of a patient's clinical course prior to hospitalization is key and may raise suspicion for underlying neuromuscular pathology. Further evaluation in non-critically ill patients may include pulmonary function, electromyography and confirmatory muscle biopsy. Sporadic late onset nemaline myopathy remains a rare disease entity which rarely presents with respiratory failure and lacks effective treatment.

Further delineation of MYO18B-related autosomal recessive Klippel-Feil syndrome with myopathy and facial dysmorphism.

Klippel-Feil syndrome 4 (KFS4; MIM# 616549) is an autosomal recessive disorder caused by biallelic pathogenic variants in MYO18B and comprises, in addition to Klippel-Feil anomaly (KFA), nemaline myopathy, facial dysmorphism, and short stature. We aim to outline the natural history of KFS4 and provide an updated description of its clinical, radiological, laboratory, and molecular findings. We comprehensively analyzed the medical records of 6 Saudi and 1 American patients (including 5 previously unpublished cases) with a molecularly confirmed diagnosis of KFS4. All patients had myopathy of varying severity that followed a slowly progressive or non-progressive course, affecting primarily the proximal musculature of the lower limb although hand involvement with distal arthrogryposis and abnormal interphalangeal creases was also observed. KFA and characteristic dysmorphic features, including ptosis and bulbous nose, were observed in all but two patients. The causal MYO18B variants were a founder NM_032608.5:c.6905C>A; p.(Ser2302*) variant in the Saudi patients (P1-P6) and a novel MYO18B homozygous variant (c.6660_6670del;p.[Arg2220Serfs*74]) in the American Caucasian patient (P7). We report the phenotypic and genetic findings in seven patients with KFS4. We describe the natural history of this disease, confirm myopathy as a universal feature and describe its pattern and progression, and note interesting differences between the phenotypes observed in patients with KFA and those without.

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.

Nemaline myopathy and distal arthrogryposis associated with an autosomal recessive TNNT3 splice variant.

A male neonate presented with severe weakness, hypotonia, contractures and congenital scoliosis. Skeletal muscle specimens showed marked atrophy and degeneration of fast fibers with striking nemaline rods and hypertrophy of slow fibers that were ultrastructurally normal. A neuromuscular gene panel identified a homozygous essential splice variant in TNNT3 (chr11:1956150G > A, NM_006757.3:c.681+1G > A). TNNT3 encodes skeletal troponin-Tfast and is associated with autosomal dominant distal arthrogryposis. TNNT3 has not previously been associated with nemaline myopathy (NM), a rare congenital myopathy linked to defects in proteins associated with thin filament structure and regulation. cDNA studies confirmed pathogenic consequences of the splice variant, eliciting exon-skipping and intron retention events leading to a frameshift. Western blot showed deficiency of troponin-Tfast protein with secondary loss of troponin-Ifast . We establish a homozygous splice variant in TNNT3 as the likely cause of severe congenital NM with distal arthrogryposis, characterized by specific involvement of Type-2 fibers and deficiency of troponin-Tfast .

[Sporadic late-onset nemaline myopathy with monoclonal gammopathy of undetermined significance mimicking POEMS syndrome].

A 40-year-old female presented with a skin rash, hepatosplenomegaly, hypothyroidism, IgG-λ monoclonal gammopathy, slightly elevated serum VEGF levels, and >1-year history of weakness in the posterior cervical muscles. Based on these symptoms and her clinical course, she was suspected of having POEMS syndrome. However, because there was no sign of peripheral neuropathy (PN), the criteria for the diagnosis of POEMS syndrome were not met. Consequently, she continued follow-up and was under close observation as an outpatient. She complained of slowly progressive dyspnea that was identified as type 2 respiratory failure requiring non-invasive positive pressure ventilation. She received systemic chemotherapy, including thalidomide and dexamethasone, as the respiratory failure was predominantly a result of POEMS-associated PN. Although the skin eruptions improved upon treatment, respiratory failure gradually worsened, and she required mechanical ventilation. The patient was suspected of having sporadic late-onset nemaline myopathy with monoclonal gammopathy of undetermined significance (SLONM-MGUS), because of resistant to chemotherapy and second opinion suggestion. A thigh muscle biopsy revealed the presence of nemaline rods and led to the definitive diagnosis of SLONM-MGUS. Unfortunately, she was unable to receive autologous stem cell transplantation, and finally died because of progressive respiratory failure. SLONM-MGUS is an extremely rare disease but should be considered as a critical, monoclonal-protein related condition.

Craniofacial Manifestations in Severe Nemaline Myopathy.

Nemaline myopathy (NM) is a rare congenital muscular disease characterized by the presence of rod (nemaline) bodies visualized on muscle biopsy. The disease is genetically and clinically heterogeneous, and the age of onset can vary from neonate to adult. Patients typically present initially with diffuse muscle weakness and hypotonia. The disease also afflicts facial musculature and can cause anomalous facial growth and development. The authors report a patient of early onset NM with significant craniofacial abnormalities. The untreated facial growth is discussed and illustrated in this article. The authors reviewed the current knowledge in the literature regarding the molecular and genetic pathogenesis of NM. The roles of both surgical and supportive management are discussed in this particular patient.

Sporadic late-onset nemaline myopathy as a rare cause of slowly progressive muscle weakness with young adult onset.

INTRODUCTION: Sporadic late-onset nemaline myopathy (SLONM) is a rare intractable acquired myopathy characterized by progressive muscle weakness and atrophy, usually with middle to late adult onset. Autologous peripheral blood stem cell transplantation (auto-PBSCT) has been reported to be a promising treatment for SLONM. METHODS: In this study we performed clinical characterization, muscle histopathological analysis, and muscle power monitoring after auto-PBSCT in a 27-year-old HIV-negative man with monoclonal gammopathy. RESULTS: He showed improved muscle strength after treatment with high-dose melphalan and auto-PBSCT. CONCLUSIONS: Considering the recent reports of successful treatment of SLONM, early and correct diagnosis of this condition in association with monoclonal gammopathy is important. SLONM should be added to the list of diseases to consider in the differential diagnosis of progressive muscle weakness with young adult onset.

Nemaline myopathy and heart failure: role of ivabradine; a case report.

BACKGROUND: Nemaline myopathy (NM) is a rare congenital myopathy characterized by muscle weakness, hypotonia and the presence in muscle fibers of inclusions known as nemaline bodies and a wide spectrum of clinical phenotypes, ranging from severe forms with neonatal onset to asymptomatic forms. The adult-onset form is heterogeneous in terms of clinical presentation and disease progression. Cardiac involvement occurs in the minority of cases and little is known about medical management in this subgroup of NM patients. We report a rare case of heart failure (HF) in a patient with adult-onset NM in whom ivabradine proved to be able to dramatically improve the clinical picture. CASE PRESENTATION: We report a case of a 37-year-old man with adult-onset NM, presenting with weakness and hypotonia of the proximal limb muscles and shoulder girdle, severely limiting daily activities. He developed progressive HF over a period of 6 months while attending a rehabilitation program, with reduced left ventricular ejection fraction (LVEF = 20%), manifested by dyspnea and signs of systemic congestion. The patient was started HF therapy with enalapril, carvedilol, spironolactone and loop diuretics. Target HF doses of these drugs (including carvedilol) were not reached because of symptomatic hypotension causing a high resting heart rate (HR) ≥70 beats per minute (bpm). Further deterioration of the clinical picture occurred with several life-threatening arrhythmic episodes requiring external defibrillation. An implantable cardioverter defibrillator (ICD) was then implanted. Persistent high resting HR was successfully treated with ivabradine with HR lowering from 90 bpm to 55 bpm at 1 month follow up, LVEF rising to 50% at 3 month follow up and to 54% at 2,5 year follow up. To date no more hospitalizations for heart failure occurred. A single hospitalization due to aspiration pneumonia required insertion of a tracheostomy tube to protect airways from further aspiration. At present, the patient is attending a regular rehabilitation program with net improvement in neuromotor control and less limitations in daily activities. CONCLUSIONS: HF is a rare feature of NM, but it can negatively influence prognosis. Conventional HF therapy and/or heart transplant are the only reasonable strategy in these patients. Ivabradine is a useful, effective and safe drug for therapy in NM patients with HF and should be considered when resting HR remains high despite beta-blockers' full titration or beta-blockers' underdosing due to intolerance or side effects.

HIV-associated nemaline myopathy manifesting as bent spine syndrome.

HIV-associated myopathies include HIV-associated polymyositis, inclusion body myositis, diffuse infiltrative lymphocytosis syndrome and sporadic late-onset nemaline myopathy (HIV-NM). HIV-NM typically manifests as a painless, progressive proximal and axial muscle weakness with characteristic histological findings of intracytoplasmic rods, or nemaline bodies, seen in atrophic muscle fibres. HIV-NM presents prior to or shortly after initiation of antiretroviral therapy (ART) and is treated with intravenous immunoglobulin, glucocorticoids or immunosuppression. We present a case of HIV-NM in a patient with well-controlled HIV on decades-long ART with progressive bent spine syndrome, or camptocormia. This case highlights the importance of considering HIV-associated myopathies such as HIV-NM in patients with HIV who present with musculoskeletal complaints.

Sporadic late onset nemaline myopathy and immunoglobulin deposition disease.

INTRODUCTION: In monoclonal gammopathy, organ dysfunction can occur due to deposition of immunoglobulin fragments. A rare form of acquired myopathy often associated with monoclonal gammopathy is sporadic late onset nemaline myopathy (SLONM), which is characterized by nemaline rods in myofibers. The pathogenetic link between monoclonal gammopathy and SLONM has not yet been elucidated. METHODS: Case report of a patient with monoclonal gammopathy who developed a progressive myopathy, finally diagnosed as SLONM. RESULTS: A muscle biopsy showed mild myopathic changes. A second biopsy 1 year after clinical onset demonstrated deposition of immunoglobulin light and heavy chains and the presence of nemaline rods. The patient experienced marked improvement of muscle strength after autologous stem cell transplantation and treatment with bortezomib, a therapy that is known to be effective in light chain deposition disease. CONCLUSIONS: We speculate that deposition of light and heavy chains, rather than nemaline bodies, has myotoxic effects on skeletal muscle.

Nemaline myopathy in a newborn infant: a rare muscle disorder.

Nemaline myopathy (NM) is a genetically and clinically heterogeneous muscle disorder, defined by the presence of characteristic nemaline bodies on muscle biopsy. The disease has a wide spectrum of phenotypes, ranging from forms with neonatal onset and fatal outcome to asymptomatic forms. The neonatal form is severe and usually fatal. The clinical variability, with differing age of onset and severity of symptoms makes the diagnosis difficult during infancy. There is no curative treatment. L-tyrosine may prevent aspiration by reducing pharyngeal secretions and drooling. Most of the patients die from respiratory and cardiac failure. This article discusses a newborn infant who presented with generalized weakness and respiratory failure. Partial response to L-tyrosine treatment was noted. The case is worth presenting to remind clinicians of congenital myopathies in the differential diagnosis of floppy infant during neonatal period and to emphasize the importance of muscle biopsy in diagnosis.

Anesthetic management for surgery in a nemaline myopathy patient with difficult airway: A CARE-compliant case report.

RATIONALE: Nemaline myopathy (NM) is a congenital disease characterized by nonprogressive or slowly progressing muscle weakness and may increase the risk of anesthesia in case of respiratory muscle or cardiac involvement. Care should be taken to prevent respiratory failure after surgery. PATIENT CONCERNS: A 35-year-old man with NM, who had difficult airway, restrictive ventilatory pattern, and pulmonary hypertension, required general anesthesia for surgery because of limited mouth opening. DIAGNOSES: The patient was diagnosed with NM (ACTA1 mutation) and coronoid hyperplasia. INTERVENTIONS: Awake fiberoptic nasal intubation was performed following preparations for analgesia. General anesthesia was maintained using inhalational anesthetics and opioids without using neuromuscular blocking agents. OUTCOMES: General anesthesia remained well maintained during surgery, with no movement or spontaneous breathing of the patient and he recovered from anesthesia uneventfully without complications. LESSONS: This report highlights the safe performance of anesthesia induction and recovery in a case where anesthesia management is necessary for surgery in a patient of NM at a high risk of anesthesia-related complications.

On a case of respiratory failure due to diaphragmatic paralysis and dilated cardiomyopathy in a patient with nemaline myopathy.

Nemaline myopathy is a rare congenital disease that generally occurs in childhood. We report a case of a 50-year-old man who presented with severe heart failure as the initial manifestation of nemaline myopathy. Soon after he developed acute restrictive respiratory failure due to the diaphragmatic paralysis. The diagnosis of "nemaline myopathy" was obtained on muscle biopsy performed one year later. After starting appropriate cardiological treatment and non-invasive ventilation, his cardiac and pulmonary functions improved substantially, remaining stable for over the 10 years since diagnosis. In the last two years the patient had a progressive deterioration of respiratory function, enabling him to attend daily activities. Few cases of respiratory failure in patients with adult-onset nemaline myopathy are reported, but the insidious onset in this case is even more unusual. This case highlights the wide spectrum of presenting features of adult-onset nemaline myopathy and the temporary efficacy of non invasive ventilation on respiratory function.

Proteomic profiling of sporadic late-onset nemaline myopathy.

OBJECTIVE: To define the proteomic profile of sporadic late-onset nemaline myopathy (SLONM) and explore its pathogenesis. METHODS: We performed mass spectrometry on laser-dissected frozen muscle samples from five patients with SLONM, three of whom with an associated monoclonal protein (MP), and four controls, to determine the proteomic profile of SLONM. Furthermore, we assessed the role of the MP by evaluating the expression of the immunoglobulin light chain variable regions (IGVL). RESULTS: There were 294 differentially expressed proteins: 272 upregulated and 22 downregulated. Among the top 100 upregulated proteins, the most common categories were: nuclear or nucleic acid metabolism (24%), extracellular matrix and basal lamina (17%), immune response (13%), and actin dynamics (8%). Downregulated proteins consisted mostly of contractile proteins. Among upregulated proteins, there were 65 with a role related to the immune system, including eight proteins involved in major histocompatibility complex 1 (MHC1) and antigen processing, 15 in MHCII complex and phagocytosis, and 23 in B and/or T-cell function. Among nine upregulated immunoglobulin proteins, there were two IGVL genes. However, these were also detected in SLONM cases without an MP, with no evidence of clonally dominant immunoglobulin deposition. In muscle sections from SLONM patients, nemaline rods tended to accumulate in atrophic fibers with marked rarefaction of the myofibrils. Increased MHC1 reactivity was present in fibers containing nemaline rods as well as adjacent nonatrophic fibers. CONCLUSION: Our findings suggest that aberrant immune activation is present in SLONM, but do not support a direct causal relationship between the MP and SLONM.

Coexisting sporadic late onset nemaline myopathy and AL amyloid myopathy - incidental or related?

Sporadic late onset nemaline myopathy (SLONM) and amyloid myopathy are frequently unrecognized acquired and treatable myopathies, which classically present with rapidly progressive and severe proximal muscle weakness. We report a case of SLONM and amyloid myopathy associated with IgM lambda monoclonal gammopathy in a 77-year-old Caucasian man. Creatine kinase (CK) was mildly elevated. Myositis panel was negative. Electromyogram showed prominent fibrillation potentials and positive sharp waves with myopathic motor unit action potentials. Muscle biopsy revealed nemaline rods and amyloid deposits with characteristic apple-green birefringence under polarized light, and liquid chromatography tandem mass spectroscopy detected a peptide profile consistent with AL (lambda) type amyloid deposition. Genetic testing for congenital nemaline rod myopathy was negative. The patient was treated with dexamethasone and chemotherapy x3 cycles with very good partial remission. CK and lambda light chain normalized. Our case emphasizes the importance of completing a thorough histochemical and pathological evaluation by muscle biopsy analysis, to provide timely and optimal treatment of these conditions.

Nemaline Myopathy Initially Diagnosed as Right Heart Failure with Type 2 Respiratory Failure.

Nemaline myopathy (NM) is a rare muscle disease with various clinical types. In some cases, NM can lead to type 2 respiratory failure and right heart failure. We herein report a patient with congenital NM with nebulin gene mutation who presented with acute right heart failure and type 2 respiratory failure due to respiratory muscle paralysis after upper respiratory tract infection, needing a permanent ventilator for assistance. However, the limb and trunk muscle strengths were within normal limits. This case showed that NM should be considered as a cause of right heart failure and type 2 respiratory failure.