| Objective: The purpose of this study was to summarize and analyse the clinical, laboratory and myopathological features of neuromuscular diseases with thyroid dysfunction, and to classify and explore the influences of thyroid function on the skeletal muscle, neuromuscular junction and peripheral neuropathy. Our study aimed to improve the knowledge how to distinguish neuromuscular diseases with thyroid dysfunction with other diseases.Methods: The study comprised 20 patients with neuromuscular diseases along with thyroid dysfunction who had been admitted to the third hospital of Hebei medical university. All subjucts were received clinical examination, laboratory test, electromyogram in 17 patiens and open biceps brachii biopsy in 19 patiens after anesthesia and signing the consents. The frozen tissues(7um) were stained with haematoxylin-eosin(HE), modified gomori's trichrome (MGT), cytochtome C oxidase(CCO), nicotinanide adenine dinucleotide (NADH-TR), succinate dehydrogenase(SDH), adenosine monophosphate deaminase(AMP), periodic acid schiff(PAS), oil red O(Oil), sudan black B(SBB) and adenosine triphosphatase(ATPase) and were received pathological analysis under optical microscope.Results:1 The clinical manifestations and classifications of neuromuscular diseases with thyroid dysfunction1.1 All symptoms could be divided three classifications: the symptoms involved in skeletal muscle included weakness, muscle strophy, fatigue, myalgia, myotonia and periodic paralysis. the symptoms involved in peripheral nerve such as numbness and weakness. and the symptoms involved in neuromuscular junction function included myokymia and fluctuating weakness. 1.2 Laboratory tests1.2.1 The tests of thyroid functionThere can be divided three classifications by the thyroid function: hyperthyroidism, hyperthyroidism and positive peroxidase antibody(TPOAb).1.2.2 Serum creatine kinase(CK)The level of serum creatine kinase was increased or normal.1.2.3 Serum potassiumThe level of serum potassium was decreased or normal.1.3 The result of electromyogram(EMG)Normal potential, myopathic potential, myotonic potential, myopathic potential combined myotonic potential, myokymia potential, peripheral nerve damage, spinal cord ventral horn damaged.2 The diagnosis combined with symptoms, signs and tests2.1 Weakness, muscle strophy, thyroid dyfunction, combined with the result of serum creatine kinase and electromyogram and excluding others then to think about hyperthyroid or hypothyroidmyopathy.2.2 Young men, repeated muscle weakness attacks without sensory disorder , proximal is heavier than distal and lower limbs is worse than upper, while the period is normal, the test of throid function is hyperthyroidism, the serum potassium is normal or decreased, then the clinical diagnosis: hyperthyroidism with periodic paralysis.2.3 From onset, Interruption or continuous muscular rigidity, sports can improved while rest and cold will aggravate, serum CK is increased, the result of electromyogram is myotonic potential and then the clinical diagnosis is to think about congenital muscular rigidity.2.4 Muscular rigidity with atrophy, serum CK is increasedelevatory, the result of electromyogram is myotonic potential with myopathic potential then the clinical diagnosis is to think about myotonic dystrophy.2.5 Mokymia, the result of electromyogram is myokymia potential and then the clinical diagnosis is to think about neuromyotonia. 2.6 Weakness especially after work while rest can improve the symptoms, fatigue and neostigmine test is positive, then the clinical diagnosis is to think about myasthenia gravis.2.7 Weakness and muscle strophy, proximal is heavier than distal, the result of electromyogram is peripheral nerve damage with conduction block and exclude other neurogenic myopathy, then the clinical diagnosis is to think about multifocal motor neuropathy.2.8 The symptoms and signs of upper and lower motor neuron damaged, the result of electromyogram is spinal cord ventral horn damaged with four parts of cranial,neck,chest,lumbosacral nerve,then the clinical diagnosis is to think about amyotrophic lateral sclerosis.3 Combined with biopsy of skeletal muscle to clear diagnosis and differential diagnosis3.1 Hyperthyroid myopathyMild difference in muscle fiber diameter, there was no typical necrosis, regeneration of fibers, two types of fibers were atrophy and especially for typeâ…¡fibers, intermyofibrillar network was disorder, moth eaten fibers were observed.3.2 Thyrotoxicosis periodic paralysisDifference was in muscle fiber diameter, a few necrosis and regeneration, typeâ…¡fibers atrophy were observed. the characteristic for diagnosis is tubular aggregation.3.3 Hypothyroid myopathyMild difference in muscle fiber diameter were observed, there was no typical necrosis, regeneration of fibers, intermyofibrillar network was disorder, focal activity of enzyme was decreased or absent, even the typeâ… the fiber atrophy or advantages could be observed. with inflammatory changes showed the infiltration of inflammatory cells around blood vessels, the connetive tissue is increased.3.4 Channelopathies with thyroid dysfunction myotonic syndrome(congenital myotonia and myotonic dystrophy )The muscle fibers were not significant of degeneration, necrosis and regeneration. The fiber diameter of typeâ… is smaller than typâ…¡fibers, small angular fibers, centrally nuclei, nuclear clump sarcoplasmic mass were observed. intermyofibrillar network was disorder, moth eaten fibers and ragged red fibers(RRF) were observed3.5 Neuromuscular junction with thyroid dysfunctionThe pathology was lack of specificity and mitochondrial activity was founded decreased.3.6 Neurogenic myopathy with thyroid dysfunction3.6.1 Multifocal motor neuropathyMitochondrial activity was decreased and the big grouping atrophy of typeâ… and typeâ…¡fiber were deserved.3.6.2 Amyotrophic lateral sclerosisMyofibrillar network was disordered, a large number of angular fibers, small grouping atrophy of typeâ… and typeâ…¡and nuclear clump were deserved, the activity of enzyme showed central core.Conclusion:1 Thyroid dysfunction could result in various skeletal muscle diseases and peripheral neuropathy, which included thyroid-related myopathy, periodic paralysis, channelopathies, neuromuscular junction disease, autoimmune diseases and neurogenic myopathy.2 Those patients suffered from skeletal muscle diseases and peripheral neuropathy oughted to receive thyroid function tests, in order to avoid missing diagnosis and wronging diagnosis. And skeletal muscle diseases and peripheral symptoms could be well with the rectification of thyroid dysfunction.3 Electrophysiologic test is important for the diagnosis and differential diagnosis of neuromuscular diseases with thyroid dysfunction. These electrophysiological changes have many types, including myopathic, neurogenic, peripheral neuropathic changes, the meaning for diagnosis was very important especially for channelopathies(myotonic syndrome and neuromyotonia). 4 The analysis of thyroid-related myopathy in the muscle biopsy pathyolog showed intermyofibrillar network disorder, which suggested the metabolism turbulence of myofibrillar protein. This changes of pathyology were not specific, but it have significant function on diagnosis and different diagnosis from others.5 Based on the above findings, the thyrotoxicosis periodic paralysis with ion channelopathies with thyroid dysfunction should to test the genes and to make the further diagnoses.
|
PDF Full Text Request