Inclusion body myositis
[3] IBM is often confused with an entirely different class of diseases, called hereditary inclusion body myopathies (hIBM).Degeneration is characterized by the appearance of holes, deposits of abnormal proteins, and filamentous inclusions in the muscle fibers.[10] Patients may become unable to perform activities of daily living and most require assistive devices within 5 to 10 years of symptom onset.[11] sIBM does not significantly affect life expectancy,[1] although death related to malnutrition and respiratory failure can occur.[6] The term "sporadic inclusion body myositis" (sIBM) was introduced as a way to refer to IBM to avoid confusion with hIBM.[6] However, one author discourages use of sIBM, as it implies that IBM and hIBM differ only in inheritance; they actually have unrelated mechanisms and manifestations of disease.[1] How sIBM affects individuals is variable, including the age of onset (which generally varies from the forties upwards) and rate of progression.Another common early symptom is trouble manipulating the fingers, such as difficulty with tasks such as turning doorknobs or gripping keys.[citation needed] Progressive difficulty swallowing (dysphagia) is present in 40 to 85% of IBM cases and often leads to death from aspiration pneumonia.Finger functions can become very impaired, such as manipulating pens, keys, buttons, and zippers, pulling handles, and firmly grasping handshakes.Sudden falls, sometimes resulting in major injury to the skull or other bones, can occur, even from walking on minimally irregular ground or from other minor imbalances outside or in the home, due to weakness of quadriceps and gluteus muscles depriving the patient of automatic posture maintenance.Dysphagia can occur, usually caused by upper esophageal constriction that often can be symptomatically improved, for several months to years, by bougie dilation per a GI or ENT physician."[21] Dalakas (2006) suggested that a chain of events causes IBM – some sort of virus, likely a retrovirus, triggers the cloning of T cells.Some 67% of IBM patients have a particular combination of human leukocyte antigen genes in a section of the 8.1 ancestral haplotype in the center of the MHC class II region.Because they do not display inflammation as a primary symptom, they may in fact be similar, but different diseases to sporadic inclusion body myositis.A small percentage of those initially diagnosed with sIBM are later found to have pathogenic mutations in the genes VCP and SQSTM1, which are known to cause hIBM.They are dermatomyositis (DM) and polymyositis (PM) and all three illnesses were called idiopathic (of unknown origin) myositis or inflammatory myopathies.[36] Mutations in valosin-containing protein (VCP) cause multisystem proteinopathy (MSP), which can present (among others) as a rare form of inclusion body myopathy.
SpecialtyRheumatologyNeurologyNeuromuscular medicineSymptomsDifferential diagnosisdeconditioninginflammatory muscle diseasefingerflexorsextensorshereditary inclusion body myopathiesimmune cellsabnormal proteinsactivities of daily livinglife expectancymalnutritionrespiratoryFoot dropquadricepstibialis anterior musclebicepstricepsdysphagiaaspiration pneumoniamuscle atrophyproteosomeendoplasmic reticulumretrovirusT cellsantigensmajor histocompatibility complexHTLV-1leukemiaamyloidbeta amyloidhuman leukocyte antigenhereditary inclusion body myopathycreatine kinaseElectromyographyinclusion bodiesNT5C1ApolymyositisprednisoneMuscular dystrophylimb girdle muscular dystrophySQSTM1anti-inflammatoryimmunosuppressant immunomodulatory medicationssupportive careexercise guidelinesdermatomyositisidiopathicvalosin-containing proteinmultisystem proteinopathymeta-analysisFather StuPeter FramptonInflammatory myopathieseMedicineDiseasesDBGeneReviewsOrphanetconnective tissue disordersSystemic lupus erythematosusDrug-induced SLELibman–Sacks endocarditisLupus nephritisInflammatory myopathyMyositisDermatopolymyositisJuvenile dermatomyositisSclerodermaSystemic sclerodermaProgressive systemic sclerosisCREST syndromeOverlap syndromeMixed connective tissue diseasehypersensitivityautoimmuneSjögren syndromeIgG4-related diseaseBehçet's diseasePolymyalgia rheumaticaEosinophilic fasciitisEosinophilia–myalgia syndromeEhlers–Danlos syndromefibrillinMarfan syndromeCongenital contractural arachnodactylyconditionsmuscleMyalgiaFibromyalgiaDelayed onsetInflammationPyomyositisMyoedemaHypothyroid myopathyMuscle weaknessRhabdomyolysisAmyotrophyMuscle fatigueExercise intoleranceExaggerated cardiorespiratory response to exercise (tachycardia with tachypnea and/or hyperpnea (exercise hyperventilation))Hitting the wallSecond windMetabolic myopathiesDiabetesHyperthyroid myopathyHypoparathyroidismHypokalemiaHypoxic musclePseudohypoxiaIntermittent claudicationScurvyFastingStarvationAlcoholismMuscle crampMyokymiaMuscle spasmFasciculationsMuscle contractureFibrosis