Resistance of the Peripheral Nervous System to the Effects of Chronic Canine Hypothyroidism

Rossmeisl, John H.

doi:10.1111/j.1939-1676.2010.0515.x

Cited by 14 publications

(11 citation statements)

References 15 publications

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“…The presumptive diagnosis of idiopathic neuropathy was made in all cases based on the failure on revealing an underlying cause. A putative association between cranial neuropathy and hypothyroidism has been stated in the veterinary literature, however, this is not borne out by other studies . None of the dogs of this study showed clinical signs of hypothyroidism and the thyroidal function was normal in the three dogs tested.…”

Section: Discussionsupporting

confidence: 86%

Clinical and Magnetic Resonance Imaging Features of Idiopathic Oculomotor Neuropathy in 14 Dogs

Pont

Freeman

Dennis

et al. 2017

Vet Radiology Ultrasound

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Ophthalmoplegia/ophthalmoparesis (internal, external, or both) has been reported in dogs secondary to neoplasia affecting the oculomotor nerve and is usually given a poor prognosis. The purpose of this retrospective study was to describe the clinical findings, magnetic resonance imaging (MRI) findings, management, outcome, and follow-up in a group of canine cases with idiopathic oculomotor neuropathy. Inclusion criteria included cases with ophthalmoplegia/ophthalmoparesis (internal, external or both) as sole neuroophthalmologic signs, complete ophthalmic and neurologic examination, head MRI, and a minimum follow-up period of 1 year. Dogs with progressive neurological signs not related to oculomotor neuropathy were excluded. Fourteen cases met the inclusion criteria. All cases were unilaterally affected. Magnetic resonance imaging showed equivocal enlargement of the oculomotor nerve in three cases, mild enlargement in five, and marked enlargement in six. Contrast enhancement was present in 12 cases, being marked in six. When present, the contrast enhancement was focal in eight cases and diffuse in four. The median follow-up time was 25 months. External ophthalmoparesis improved in seven cases, five cases under no treatment and two under systemic corticosteroid therapy. The clinical signs in the other seven cases remained unchanged. Idiopathic oculomotor neuropathy should be included as a differential diagnosis in dogs presenting with unilateral ophthalmoplegia/ophthalmoparesis (internal, external, or both) with the absence of other neurologic and ophthalmic signs, and with the MRI findings restricted to the oculomotor nerve. Idiopathic oculomotor neuropathy has a good prognosis as the clinical signs do not deteriorate and they can improve without treatment.

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Section: Discussionsupporting

confidence: 86%

Clinical and Magnetic Resonance Imaging Features of Idiopathic Oculomotor Neuropathy in 14 Dogs

Pont

Freeman

Dennis

et al. 2017

Vet Radiology Ultrasound

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“…Therefore, genes encoding these proteins do not seem to be responsible for the onset of the disease. MPZ expression in the myelin sheath was observed only in [4,24,25,42,49]. Even though hypothyroidism is a common endocrinopathy of dogs and has been blamed for generalized peripheral neuropathy, there is currently insufficient objective evidence to prove a causal relationship between hypothyroidism and acquired polyneuropathy in dogs [11].…”

Section: Discussionmentioning

confidence: 99%

“…Even though hypothyroidism is a common endocrinopathy of dogs and has been blamed for generalized peripheral neuropathy, there is currently insufficient objective evidence to prove a causal relationship between hypothyroidism and acquired polyneuropathy in dogs [11]. Previously, Rossmeisl [42] experimentally induced chronic hypothyroidism in dogs using radioactive iodine administration, and evaluated clinical and electrophysiologic effects on multiple peripheral nerves. The previous report succeeded in replicating the hypothyroid condition, but failed to detect any adverse clinical or electrophysiologic peripheral neuropathic changes.…”

Section: Discussionmentioning

confidence: 99%

Pathological Features of Polyneuropathy in Three Dogs

Tsuboi

Uchida

et al. 2013

The Journal of Veterinary Medical Science

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ABSTRACT. Canine polyneuropathy is a neurological disorder characterized by a dysfunction of multiple peripheral nerves. The etiology of the disease is diverse; it may occur in cases of infectious, immune-mediated, or hereditary conditions or in association with endocrinopathy, neoplasm, or chemical intoxication. It is often difficult to determine the etiology through clinical symptoms. The aim of this study is to investigate pathological differences among three canine polyneuropathy cases with each presumably having a different etiology. Cases included a 13-month-old female border collie (Dog No.1), a 21-month-old male chihuahua (Dog No.2) and an 11-year-old male beagle (Dog No.3 Polyneuropathy in dogs is a neurological disorder characterized by a dysfunction of multiple peripheral nerves. Initial symptoms of the disease are a lack of coordination and instability, and often progress to decreased reflexes and muscle tone, paralysis, and sensory deficits [45]. Electromyographic evidence of denervation and decreased nerve conduction velocity has been observed in affected nerves [45]. Somatic nerve dysfunctions are most predominant, and autonomic nerves may also be affected. As autonomic dysfunction may lead to laryngeal or pharyngeal paralysis, aspiration pneumonia is frequently diagnosed as a cause of death in canine polyneuropathy cases [6,16,26,32,46].Several etiologies of polyneuropathy in dogs have been previously proposed. In some cases, the disease occurs in association with Neospora caninum infection [10] or some immune-mediated diseases, such as systemic lupus erythematosus [11]. Primary autoimmune diseases against peripheral nerve myelin may also lead to the disease [1,51]. Some seem to occur in specific breeds, indicating that hereditary, familial or breed-associated factors are related to the etiology of the disease [17]. It may also be associated with endocrinopathy including diabetes mellitus [27,34,47] and hypothyroidism [25,49], intoxication of n-hexane [37] or acrylamide [20], administration of cisplatin [36] or vincristine [21], or paraneoplastic syndromes in cases of insulinoma [3,5], multicentric lymphoma [5], or disseminated carcinoma [5]. It is often difficult to distinguish the etiology of this disease through clinical symptoms.The distribution of lesions (i.e. motor or sensory, distal or proximal, anterior or posterior and symmetric or asymmetric) is useful for etiology-based classification of polyneuropathy [7,8,10]. In the human-inherited polyneuropathy, CharcotMarie-Tooth (CMT) disease, classification is established according to lesion distribution, age onset, progression speed and pathological features [18], and a number of genetic mutations have been identified in respective subtypes [7,43]. In contrast, little information on genetic factors has been accumulated in canine-inherited polyneuropathy [8]. So far, canine-inherited polyneuropathy has been reported in 22 breeds, but underlying genetic defects are not yet confirmed in most breeds [8,17].The aim of this study is to investigate ...

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“…In our study, all dogs had normal thyroid function and none showed any clinical signs of hypothyroidism. Furthermore, Rossmeisl () demonstrated resistance of the peripheral nervous system to developing neuropathy in experimentally induced chronic hypothyroidism in beagles. A viral origin ( Herpes simplex , Herpes zoster and Epstein‐Barr viruses) has been proposed for Bell's palsy in humans (Peitersen ), and Furuta et al .…”

Section: Discussionmentioning

confidence: 99%