Clinicopathologic and magnetic resonance imaging characteristics associated with polioencephalomyelopathy in a Shih Tzu

Marc Kent Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Marc Kent in
Current site
Google Scholar
PubMed
Close
 DVM, DACVIM
,
Simon R. Platt Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Simon R. Platt in
Current site
Google Scholar
PubMed
Close
 BVM&S, DACVIM
,
Raquel R. Rech Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Raquel R. Rech in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
Dharshan Neravanda Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Dharshan Neravanda in
Current site
Google Scholar
PubMed
Close
 DVM
,
Elizabeth W. Uhl Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Elizabeth W. Uhl in
Current site
Google Scholar
PubMed
Close
 DVM, DACVP, PhD
, and
Scott J. Schatzberg Department of Small Animal Medicine and Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA 30602.

Search for other papers by Scott J. Schatzberg in
Current site
Google Scholar
PubMed
Close
 DVM, DACVIM, PhD

Abstract

Case Description—A 17-month-old 7-kg (15.4-lb) Shih Tzu was evaluated because of progressive thoracic limb weakness of 3 months' duration.

Clinical Findings—Neuroanatomic diagnosis was consistent with a lesion affecting the cervicothoracic (C6 through T2) spinal cord segments. Electrophysiologic testing revealed abnormal spontaneous activity in the thoracic limbs. Via magnetic resonance (MR) imaging, a lesion in the spinal cord that extended from the C5 through C7 vertebrae was detected, as were symmetric lesions in the cranial portion of the cervical spinal cord, caudal colliculi, and vestibular and cerebellar nuclei. Tests to detect metabolites indicative of inborn errors in metabolism revealed no abnormalities.

Treatment and Outcome—Prior to undergoing MR imaging, the dog received clindamycin (14 mg/kg [6.4 mg/lb], PO, q 12 h), trimethoprim-sulfadiazine (17 mg/kg [7.7 mg/lb], PO, q 12 h), and prednisone (1 mg/kg [0.45 mg/lb], PO, q 24 h). Because of its deteriorating condition, the dog was euthanized. During necropsy, gross lesions were identified in the cervical spinal cord, caudal colliculi, and vestibular and cerebellar nuclei (corresponding to lesions detected via MR imaging). Microscopic evaluation of the brain and spinal cord revealed polioencephalomyelopathy; there was severe spongiosis of the neuropil with reactive astrocytes (many with high numbers of swollen mitochondria) and preservation of large neurons.

Clinical Relevance—The form of polioencephalomyelopathy in the Shih Tzu of this report was similar to that described for Australian Cattle dogs; the similarity of findings in dogs with those in humans with Leigh disease is suggestive of a mitochondrial defect.

Abstract

Case Description—A 17-month-old 7-kg (15.4-lb) Shih Tzu was evaluated because of progressive thoracic limb weakness of 3 months' duration.

Clinical Findings—Neuroanatomic diagnosis was consistent with a lesion affecting the cervicothoracic (C6 through T2) spinal cord segments. Electrophysiologic testing revealed abnormal spontaneous activity in the thoracic limbs. Via magnetic resonance (MR) imaging, a lesion in the spinal cord that extended from the C5 through C7 vertebrae was detected, as were symmetric lesions in the cranial portion of the cervical spinal cord, caudal colliculi, and vestibular and cerebellar nuclei. Tests to detect metabolites indicative of inborn errors in metabolism revealed no abnormalities.

Treatment and Outcome—Prior to undergoing MR imaging, the dog received clindamycin (14 mg/kg [6.4 mg/lb], PO, q 12 h), trimethoprim-sulfadiazine (17 mg/kg [7.7 mg/lb], PO, q 12 h), and prednisone (1 mg/kg [0.45 mg/lb], PO, q 24 h). Because of its deteriorating condition, the dog was euthanized. During necropsy, gross lesions were identified in the cervical spinal cord, caudal colliculi, and vestibular and cerebellar nuclei (corresponding to lesions detected via MR imaging). Microscopic evaluation of the brain and spinal cord revealed polioencephalomyelopathy; there was severe spongiosis of the neuropil with reactive astrocytes (many with high numbers of swollen mitochondria) and preservation of large neurons.

Clinical Relevance—The form of polioencephalomyelopathy in the Shih Tzu of this report was similar to that described for Australian Cattle dogs; the similarity of findings in dogs with those in humans with Leigh disease is suggestive of a mitochondrial defect.

  • 1.

    Summers BA, Cummings JF, DeLahunta A. Degenerative diseases of the central nervous system. In: Veterinary Neuropathology St Louis: Mosby, 1995;208350.

    • Search Google Scholar
    • Export Citation
  • 2.

    Read DH, Harrington DD. Experimentally induced thiamine deficiency in beagle dogs: pathologic changes of the central nervous system. Am J Vet Res 1986;47:22812289.

    • Search Google Scholar
    • Export Citation
  • 3.

    Read DH, Harrington DD. Experimentally induced thiamine deficiency in beagle dogs: clinicopathologic findings. Am J Vet Res 1982;43:12581267.

    • Search Google Scholar
    • Export Citation
  • 4.

    Jubb KV, Saunders LZ, Coates HV. Thiamine deficiency encephalopathy in cats. J Comp Pathol 1956;66:217227.

  • 5.

    Hazlett MJ, Smith-Maxie LL, de Lahunta A. A degenerative encephalomyelopathy in 7 Kuvasz puppies. Can Vet J 2005;46:429432.

  • 6.

    Garosi LS, Dennis R, Platt SR, et al. Thiamine deficiency in a dog: clinical, clinicopathologic, and magnetic resonance imaging findings. J Vet Intern Med 2003;17:719723.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 7.

    Harrison LH, Colvin BM, Stuart BP, et al. Paralysis in swine due to focal symmetrical poliomalacia: possible selenium toxicosis. Vet Pathol 1983;20:265273.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 8.

    O'Brien DP, Kroll RA, Johnson GC, et al. Myelinolysis after correction of hyponatremia in two dogs. J Vet Intern Med 1994;8:4048.

  • 9.

    Zachary JF, O'Brien DP. Spongy degeneration of the central nervous system in two canine littermates. Vet Pathol 1985;22:561571.

  • 10.

    O'Brien DP, Zachary JF. Clinical features of spongy degeneration of the central nervous system in two Labrador retriever littermates. J Am Vet Med Assoc 1985;186:12071210.

    • Search Google Scholar
    • Export Citation
  • 11.

    Neer TM, Kornegay JN. Leucoencephalomalacia and cerebral white matter vacuolar degeneration in two related Labrador retriever puppies. J Vet Intern Med 1995;9:100104.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12.

    Mariani CL, Clemmons RM, Graham JP, et al. Magnetic resonance imaging of spongy degeneration of the central nervous system in a Labrador Retriever. Vet Radiol Ultrasound 2001;42:285290.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 13.

    Gamble DA, Chrisman CL. A leukoencephalomyelopathy of rottweiler dogs. Vet Pathol 1984;21:274280.

  • 14.

    Oevermann A, Bley T, Konar M, et al. A novel leukoencephalomyelopathy of Leonberger dogs. J Vet Intern Med 2008;22:467471.

  • 15.

    Brenner O, Wakshlag JJ, Summers BA, et al. Alaskan Husky encephalopathy—a canine neurodegenerative disorder resembling subacute necrotizing encephalomyelopathy (Leigh syndrome). Acta Neuropathol (Berl) 2000;100:5062.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 16.

    Wakshlag JJ, de Lahunta A, Robinson T, et al. Subacute necrotising encephalopathy in an Alaskan husky. J Small Anim Pract 1999;40:585589.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 17.

    Cachin M, Vandevelde M. Congenital tremor with spongy degeneration of the central nervous system in two puppies. J Vet Intern Med 1991;5:8790.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 18.

    Carmichael S, Griffiths IR, Harvey MJ. Familial cerebellar ataxia with hydrocephalus in bull mastiffs. Vet Rec 1983;112:354358.

  • 19.

    Brenner O, de Lahunta A, Summers BA, et al. Hereditary polioencephalomyelopathy of the Australian cattle dog. Acta Neuropathol (Berl) 1997;94:5466.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 20.

    Harkin KR, Goggin JM, DeBey BM, et al. Magnetic resonance imaging of the brain of a dog with hereditary polioencephalomyelopathy. J Am Vet Med Assoc 1999;214:13421344.

    • Search Google Scholar
    • Export Citation
  • 21.

    Paciello O, Maiolino P, Fatone G, et al. Mitochondrial myopathy in a german shepherd dog. Vet Pathol 2003;40:507511.

  • 22.

    Olby NJ, Chan KK, Targett MP, et al. Suspected mitochondrial myopathy in a Jack Russell terrier. J Small Anim Pract 1997;38:213216.

  • 23.

    Houlton JEF, Herrtage ME. Mitochondrial myopathy in the Sussex spaniel (lett). Vet Rec 1980;106:206.

  • 24.

    Herrtage ME, Houlton JEF. Collapsing Clumber spaniels. Vet Rec 1979;105:334.

  • 25.

    Breitschwerdt EB, Kornegay JN, Wheeler SJ, et al. Episodic weakness associated with exertional lactic acidosis and myopathy in Old English sheepdog littermates. J Am Vet Med Assoc 1992;201:731736.

    • Search Google Scholar
    • Export Citation
  • 26.

    Gruber AD, Wessmann A, Vandevelde M, et al. Mitochondriopathy with regional encephalic mineralization in a Jack Russell Terrier. Vet Pathol 2002;39:732736.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 27.

    Brenner O, de Lahunta A, Cummings JF, et al. A canine encephalomyelopathy with morphological abnormalities in mitochondria. Acta Neuropathol (Berl) 1997;94:390397.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28.

    Rahman S, Blok RB, Dahl HH, et al. Leigh syndrome: clinical features and biochemical and DNA abnormalities. Ann Neurol 1996;39:343351.

  • 29.

    Medina L, Chi TL, DeVivo DC, et al. MR findings in patients with subacute necrotizing encephalomyelopathy (Leigh syndrome): correlation with biochemical defect. AJR Am J Roentgenol 1990;154:12691274.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 30.

    Koch TK, Yee MH, Hutchinson HT, et al. Magnetic resonance imaging in subacute necrotizing encephalomyelopathy (Leigh's disease). Ann Neurol 1986;19:605607.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 31.

    Detre JA, Wang ZY, Bogdan AR, et al. Regional variation in brain lactate in Leigh syndrome by localized 1H magnetic resonance spectroscopy. Ann Neurol 1991;29:218221.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 32.

    Krageloh-Mann I, Grodd W, Schoning M, et al. Proton spectroscopy in five patients with Leigh's disease and mitochondrial enzyme deficiency. Dev Med Child Neurol 1993;35:769776.

    • Search Google Scholar
    • Export Citation
  • 33.

    Abramson CJ, Platt SR, Jakobs C, et al. L-2-Hydroxyglutaric acid-uria in Staffordshire Bull Terriers. J Vet Intern Med 2003;17:551556.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 34.

    Penderis J, Calvin J, Abramson C, et al. L-2-hydroxyglutaric aciduria: characterisation of the molecular defect in a spontaneous canine model. J Med Genet 2007;44:334340.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 35.

    Garosi LS, Penderis J, McConnell JF, et al. L-2-hydroxyglutaric aciduria in a West Highland white terrier. Vet Rec 2005;156:145147.

  • 36.

    Platt S, McGrotty YL, Abramson CJ, et al. Refractory seizures associated with an organic aciduria in a dog. J Am Anim Hosp Assoc 2007;43:163167.

  • 37.

    Podell M, Shelton GD, Nyhan WL, et al. Methylmalonic and malonic aciduria in a dog with progressive encephalomyelopathy. Metab Brain Dis 1996;11:239247.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 38.

    O'Brien DP, Barshop BA, Faunt KK, et al. Malonic aciduria in Maltese dogs: normal methylmalonic acid concentrations and malonyl-CoA decarboxylase activity in fibroblasts. J Inherit Metab Dis 1999;22:883890.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 39.

    Kelmer E, Shelton GD, Williams DA, et al. Organic acidemia in a young cat associated with cobalamin deficiency. J Vet Emerg Crit Care 2007;17:299304.

    • Crossref
    • Search Google Scholar
    • Export Citation

Advertisement