One of seven dogs with clinical signs of hyperadrenocorticism had clinical evidence of neuromuscular disorder. Clinical diagnosis of hyperadrenocorticism was confirmed by plasma cortisol concentrations before and after adrenocorticotrophin hormone and dexamethasone administration. Electromyographic studies showed bizarre, high frequency discharges in all dogs. Examination of muscle biopsies taken from the biceps femoris muscle from each dog revealed mild degenerative changes of fiber size variation, focal necrosis and fiber splitting. Ragged red fibers were prominent and appeared to be related to mitochondrial aggregates. Significant (P < 0.05) type 1 and 2 fiber atrophy was found in all dogs. Fiber grouping was present in four dogs. Studies of fascicular biopsies of the peroneal nerve showed thinly myelinated fibers, onion-bulb formation, segmental demyelination and short intercalated internodes. These findings suggested a glucocorticoid-related myopathy in hyperadrenocorticism that also may have a neurogenic component.
References
1.
AdamsR.D.: Pathological reactions of the skeletal muscle fiber in man. In: Disorders of Voluntary Muscle, ed. Walton, pp. 168–223, 3rd ed.Churchill Livingstone, Edinburgh, 1974
2.
AfifiA.K.; BergmanR.A.; HarveyJ.C.: Steroid myopathy—clinical histologic and cytologic observations.Johns Hopkins Med J123: 158–174, 1968
3.
AfifiA.K.; BergmanR.A.: Steroid myopathy—a study of the evolution of the muscle lesion in rabbits.Johns Hopkins Med J124: 66–86, 1969
4.
ArnoldN.; HarrimanD.G.F.: The incidence of abnormality in control human peripheral nerves studied by single axon dissection.J Neurol Neurosurg Psychiatry33: 55–61, 1970
5.
BabelJ.; BischoffA.; SpoendlinH.: Ultrastructure of the Peripheral Nervous System and Sense Organs, pp. 80–81. Georg Thieme, Stuttgart, 1970
6.
BrookeM.H.; EngelW.K.: The histographic analysis of human muscle biopsies with regard to fiber types.Neurology (Minneapolis)19: 378–393, 1969
7.
BraundK.G.; HoffE.J.; RichardsonK.E.Y.: Histochemical identification of fiber types in canine skeletal muscle.Am J Vet Res39: 561–565, 1978
8.
BraundK.G.; WalkerT.L.; VandeveldeM.: Fascicular nerve biopsy in the dog.Am J Vet Res40: 1025–1030, 1979
9.
BraundK.G., DillonA.R.; MikealR.L.: Experimental investigation of glucocorticoid induced myopathy in the dog.Exp Neurol (in press)
10.
BullockG.R.; ChristianR.A.; PetersR.F.; WhiteA.M.: Rapid mitochondrial enlargement in muscle as a response to triamcinalone acetonide and its relationship to the ribosomal defect.Biochem Pharmacol20: 943–953, 1971
ChenC.L.; KumarM.S.A.; WilliardM.D.; LiaoT.F.: Serum hydrocortisone (cortisol) values in normal and adrenopathic dogs as determined by radioimmunoassay.Am J Vet Res39: 179–181, 1978
13.
D'AgostinoA.N.; ChigaM.: Cortisone myopathy in rabbits.Neurology (Minneapolis)16: 257–263, 1966
14.
DubowitzV.; BrookeM.H.: Muscle Biopsy: A Modern Approach, pp. 74–102. W.B. Saunders, London, 1973
15.
DuncanI.D.; GriffithsI.R.: A myopathy associated with myotonia in the dog.Acta Neuropathol (Berl)31: 297–303, 1975
DyckP.J.: Pathologic alterations of the peripheral nervous system of man. In: Peripheral Neuropathy, ed. Dyck, Thomas and Lambert; pp. 296–336, 1st ed.W.B. Saunders, Philadelphia, 1975
18.
EngelA.G.: Electron microscopic observations in thyrotoxic and corticosteroid-induced myopathies.Mayo Clin Proc41: 785–796, 1966
19.
EngelW.K.; CunninghamG.C.: Rapid examination of muscle tissue. An improved trichrome method for fresh frozen biopsy sections.Neurology (Minneapolis)13: 919–923, 1963
20.
Estable-PuigJ.F.; BauerW.C.; BlumbergJ.M.: Paraphenylene diamine staining of osmium-fixed plastic embedded tissue for light and phase microscopy.J Neuropathol Exp Neurol24: 531–535, 1965
21.
GardinerP.F.; BottermanB.R.; EldredE.; SimpsonD.R.; EdgertonV.R.: Metabolic and contractile changes in fast and slow muscles of the cat after glucocorticoid-induced atrophy.Exp Neurol62: 241–255, 1978
22.
GoldbergA.; GoodmanH.: Relationship between cortisone and muscle work in determining muscle size.J Physiol (Lond)200: 667–675, 1969
23.
GriffithsI.R.; DuncanI.D.: Myotonia in the dog: A report of four cases.Vet Rec93: 184–188, 1973
24.
GriffithsI.R.; DuncanI.D.; QuirkC.; McQueenA.: The central areas of denervated canine muscle.J Comp Pathol83: 493–498, 1973
25.
GriffithsI.R.; DuncanI.D.: Age changes in the dorsal and ventral lumbar nerve roots of dogs.Acta Neuropathol (Berl)32: 75–85, 1975
26.
HoffmanD.L.; MattoxV.R.: Treatment of adrenocortical carcinoma with o,p′-DDD.Med Clin North Am56: 999–1012, 1972
27.
LascellesR.G.; ThomasP.K.: Changes due to age in internodal length in the sural nerve in man.J Neurol Neurosurg Psychiatry29: 40–44, 1966
28.
LiJ.; GoldbergA.: Effects of food deprivation on protein synthesis and degradation in rat skeletal muscles.Am J Physiol231: 441–448, 1976
29.
LubinskaL.: “Intercalated” internodes in nerve fibers.Nature181: 957–958, 1958
30.
MendellJ.R.; EngelW.K.: The fine structure of Type II muscle fiber atrophy.Neurology (Minneapolis)21: 358–365, 1971
NachreinerR.F.; GintherD.V.: Porcine agalactia: hematologic, serum chemical, and clinical changes during the preceding gestation.Am J Vet Res33: 799–809, 1972
33.
OwensJ.M.; DruckerW.D.: Hyperadrenocorticism in the dog.Vet Clin North Am7: 583–602, 1977
34.
PerkoffG.T.; SilberR.; TylerF.H.; CartwrightG.E.; WintrobeM.M.: Studies in disorders of muscle. XII. Myopathy due to the administration of therapeutic amounts of 17-hydroxy corticosteroids.Am J Med26: 891–898, 1959
35.
PleasureD.E.; WalshG.O.; EngelW.K.: Atrophy of skeletal muscle in patients with Cushing's syndrome.Arch Neurol22: 118–125, 1970
36.
PrineasJ.; HallR.; BarwickD.D.; WatsonA.J.: Myopathy associated with pigmentation following adrenalectomy for Cushing's syndrome.Q J Med37: 63–77, 1968
37.
ReddingR.W.; BraundK.G.: Neurologic examination. In: Canine Neurology—Diagnosis and Treatment, ed. Hoerlein; pp. 53–70, 3rd ed.W.B. Saunders, Philadelphia, 1978
38.
RijnberkA.; der KinderenP.J.; ThijssenJ.H.H.: Spontaneous hyperadrenocorticism in the dog.J Endocrinol41: 397–406, 1968
39.
RitterR.A.: Effect of cortisone on the structure and strength of skeletal muscle.Arch Neurol17: 403–413, 1967
40.
SchechterR.D.: Hyperadrenocorticism. In: Current Veterinary Therapy, ed. Kirk; pp. 1027–1032, 6th ed.W.B. Saunders, Philadelphia, 1977
41.
SmithB.: Histological and histochemical changes in the muscles of rabbits given the corticosteroid triamcinalone.Neurology (Minneapolis)14: 857–863, 1964
42.
SternL.Z.; GruenerR.; KirkpatrickJ.B.; NemethP.: The fine structure of cortisone induced myopathy.Exp Neurol36: 530–538, 1972
43.
SwashM.; SchwartzM.S.; SargeantM.K.: The significance of ragged-red fibers in neuromuscular disease.J Neurol Sci38: 347–355, 1978
44.
VignosP.J.; GreeneR.: Oxidative respiration of skeletal muscle in experimental corticosteroid myopathy.J Lab Clin Med81: 365–378, 1973
45.
VizosoA.D.: The relationship between internode length and growth in human nerves.J Anat84: 342–353, 1950
46.
WalshG.; DevivoD.; OlsonW.: Histochemical and ultrastructural changes in rat muscle. Occurrence following adrenal corticotrophic hormone, glucocorticoids, and starvation.Arch Neurol24: 83–93, 1971
47.
WaltonJ.N.; Gardner-MedwinD.: Progressive muscular dystrophy and the myotonic disorders. In: Disorders of Voluntary Muscle, ed. Walton; pp. 561–613, 3rd ed.Churchill Livingstone, Edinburgh, 1974
48.
WentickG.H.; HartmanW.; KoemanJ.P.: Three cases of myotonia in a family of chows.Tijdschr Diergeneeskd99: 729–731, 1974
