Web-Vet TM Neurology Specialists
Polyneuropathies
Immune-mediated polyneuropathy in cats: Clinical description, electrodiagnostic assessment, and treatment
The aim of this study of 55 cats was to describe the clinical presentations and review the classification of this condition based on electrodiagnostic investigation and evaluate the benefit of corticosteroid treatment and L‐carnitine supplementation.
The male‐to‐female ratio was 2.2. The median age of onset was 10 months, with 91% of affected cats being <3 years of age.
The electrodiagnostic findings supported purely motor axonal polyneuropathy.
Histological findings from nerve biopsies were consistent with immune‐mediated neuropathy in 87% of the tested cats. The overall prognosis for recovery was good to excellent, as all but 1 cat achieved clinical recovery, with 12% having mild sequelae and 28% having multiple episodes during their lifetime. The outcome was similar in cats with no treatment when compared with cats receiving corticosteroids or L‐carnitine supplementation.
Clinical Course and Diagnostic Findings of Biopsy Controlled Presumed Immune-Mediated Polyneuropathy in 70 European Cats
The aim of the study was to describe the clinical features, diagnostic investigations, and outcome of a large cohort of cats with inflammatory polyneuropathy.
Median age at onset in 70 cats was 10 months (range: 4–120 months). The most common breed was British short hair (25.7%), followed by Domestic short hair (24.3%), Bengal cat (11.4%), Maine Coon (8.6%) and Persian cat (5.7%). Male cats were predominantly affected (64.3%). Clinical signs were weakness (98.6%) and tetraparesis (75.7%) in association with decreased withdrawal reflexes (83.6%) and, less commonly, cranial nerve signs (17.1%), spinal pain/hyperesthesia (12.9%), and micturition/defecation problems (14.3%). Onset was sudden (30.1%) or insidious (69.1%), and an initial progressive phase was reported in 74.3%. The clinical course was mainly described as remittent (49.2%) or remittent-relapsing (34.9%), while stagnation, progression or waxing and waning were less frequently reported. Relapses were common and occurred in 35.7% of the cats' population. An overall favorable outcome was reported in 79.4% of patients
Serum anti-GM2 and anti-GalNAc-GD1a ganglioside IgG antibodies are biomarkers for immune-mediated polyneuropathies in cats
This study investigated the serum prevalence of serum antibodies in cats clinically diagnosed with immune-mediated polyneuropathies. The sera from 41 cats clinically diagnosed with immune-mediated polyneuropathies (IPN) were examined for the presence of IgG antibodies against glycolipids GM1, GM2, GD1a, GD1b, GalNAc-GD1a, GA1, SGPG, LM1, galactocerebroside and sulphatide.
A total of 29/41 IPN-cats had either anti-GM2 or anti-GalNAc-GD1a IgG antibodies, with 24/29 cats having both.
Direct comparison of anti-GM2 (sensitivity: 70.7%; specificity: 78.2%) and anti-GalNAc-GD1a (sensitivity: 70.7%; specificity: 70.9%) antibodies narrowly showed anti-GM2 IgG antibodies to be the better marker for identifying IPN-cats when compared to controls.
These antibodies may serve as serum biomarkers for immune-mediated polyneuropathies in cats based on this study.
Biopsy Characteristics, Subtypes, and Prognostic Features in 107 Cases of Feline Presumed Immune-Mediated Polyneuropathy (IMPN)
This study investigated the prognostic biopsy findings in a large cohort of histologically confirmed IMPN cases with clinical follow-up. In total, nerve and muscle specimens of 107 cats with biopsy diagnosis of presumed autoreactive inflammatory polyneuropathy were reviewed.
Cases were divided into three groups - purely inflammatory IMPN vs. inflammatory with demyelinating features vs. Wallerian degeneration.
Cats with a purely inflammatory histopathology had a higher probablility to recover.
Juvenile-onset motor polyneuropathy in Siberian cats
Thirteen closely related Siberian cats, 4 clinically affected and 9 clinically unaffected individuals were evaluated to charaterize a novel polyneuropathy in this breed.
Onset of signs was 4 to 10 months in affected cats. Clinical signs in all affected were progressive or waxing/waning neuromuscular weakness, normal sensory function, and variably decreased withdrawal reflexes in 3/4.
All cats returned to normal neurologic function within 1 to 4 weeks. All cats had a recurrence of weakness (3/4 had 1 recurrent episode, 1/4 had 3 relapses) from which they recovered fully.
Pedigree analysis suggests an autosomal recessive mode of inheritance, although neither a genetically complex/polygenic condition nor an acquired inflammatory polyneuropathy could be ruled‐out.
Electrophysiologic Confirmation of Heterogenous Motor Polyneuropathy in Young Cats
One of the first papers describing motor polyneuropathies in young cats of various breeds. Five cats with heterogeneous chronic or relapsing episodes of weakness were evaluated.
Disease onset was at 3 months to 1 year of age and in 5 breeds. The most common clinical sign was weakness. Additional neurologic deficits consisted of palmigrade and plantigrade posture, low carriage of the head and tail, and variable segmental reflex deficits . Motor nerve conduction studies were abnormal for the ulnar, peroneal, and tibial nerves (increased latencies, reduced amplitudes, slow velocities). A marked decrement was observed on repetitive nerve stimulation of the peroneal nerve in 3 cats for which autoimmune myasthenia gravis was ruled out. All sensory nerve conduction studies were normal. Histologic evaluation of muscle and nerve biopsies supported heterogenous alterations consistent with motor polyneuropathy with distal nerve fiber loss
Canine Neuropathies
Sera from 175 dogs clinically diagnosed with acute canine polyradiculoneuritis, 112 dogs with other peripheral nerve, cranial nerve or neuromuscular disorders and 226 neurologically normal dogs were screened for anti-glycolipid antibodies against 11 common glycolipid targets to determine the immunoglobulin G anti-glycolipid antibodies with the highest combined sensitivity and specificity for acute canine polyradiculoneuritis.
Based on this study, Anti-GM2 and anti-GalNAc-GD1a immunoglobulin G anti-glycolipid antibodies represent serum biomarkers for acute canine polyradiculoneuritis.
Anti-GM2 ganglioside antibodies are a biomarker for acute canine polyradiculoneuritis (ACP)
In this study, the sera of 25 ACP dogs, 19 non-neurological, and 15 epileptic control dogs were screened for IgG Abs to 10 glycolipids and their 1 : 1 heteromeric complexes using combinatorial glycoarrays.
Anti-GM2 ganglioside Abs were detected in 14/25 ACP dogs, and anti-GA1 Abs in one further dog without ACP.
BP avulsion is the most common traumatic peripheral neuropathy in the dog. It results from forced abduction of the forelimb and subsequent stretching or tearing of nerve roots. Damage most often occurs at the level of the spinal nerve roots where resistance to stretch is less than in peripheral nerves owing to the lack of perinerium. Three types of lesion can be distinguished depending on the degree of nerve damage: neurapraxia, axonotmesis and neurotmesis. The latter involves complete rupture of a nerve (axon, myelin, and surrounding structures). However, this classification of nerve damage only applies to traumatic nerve lesions and do not cover nerve root lesions which have different susceptibility and different responses to traumatic injuries than those of nerves. Additionally, nerve root avulsion occurs at the junction between the spinal cord and both ventral and dorsal nerve roots and is irreversible. Establishing a prognosis and deciding the best options for the dog (spontaneous improvement, reconstructive surgery or amputation) can be extremely challenging. Clinically, poor prognostic indicators include evidence of a caudal (absent radial nerve function and therefore elbow extension) or complete avulsion, loss of nociception, and no evidence of a return of function within 1 to 2 months.
This retrospective study evaluates the electrodiagnostic characteristics of traumatic bracial plexus injury and their association with clinical outcomes in dogs and cats. In this study, radial compound muscle action potential amplitude offers a valuable diagnostic test to refine the prognosis of these animals and predict the evolution of nerve lesions.
Tongue atrophy as a neurological finding in hereditary polyneuropathy in Alaskan malamutes
An uncommon but serious sign of several neurologic and neuromuscular diseases can be tongue atrophy and paresis. Although we may think of diseases affecting the specific muscles of the tongue or the innervation of these muscle (CN XII - hypoglossal), a recent publication describes tongue atrophy in Alaskan malamutes with a polyneuropathy.Dogs with this sign may initially present with dysphagia, before the disease progresses to an evident atrophy as seen in the picture. This paper makes us aware of a new consideration for these clinical signs.
An Inversion Disrupting FAM134B Is Associated with Sensory Neuropathy in the Border Collie Dog Breed
Sensory neuropathy in the Border Collie is a severe neurological disorder caused by the degeneration of sensory and, to a lesser extent, motor nerve cells with clinical signs starting between 2 and 7 months of age. Using a genome-wide association study approach with three cases and 170 breed matched controls, a suggestive locus for sensory neuropathy was identified that was followed up using a genome sequencing approach. This investigation demonstrates the identification of a novel sensory neuropathy associated mutation, by mapping using a minimal set of cases and subsequent genome sequencing.
This study evaluated 38 dogs and 10 cats with confirmed SNI referred for neurologic and electrodiagnostic evaluation.
Surgery (42%) and trauma (33%) were the most common causes of SNI. Ability to flex and extend the tarsus was significantly associated with positive outcome in dogs. Mean time from onset of clinical signs until electrodiagnostic evaluation was 67 ± 65 (range, 7-300) days and 65 ± 108 (range, 7-365) days for dogs and cats, respectively. A cut-off amplitude of 1.45 mV for compound motor action potentials (CMAP) was predictive of positive outcome in dogs (P = .01), with sensitivity of 58% and specificity of 100%.
In conclusion, clinical motor function predicts recovery better than sensory function. Electrodiagnostic findings also may play a role in predicting the outcome of SNI.
Acute canine polyradiculoneuritis (ACP) is one of the most common polyneuropathies occurring in dogs. The disease is very similar to the Guillain–Barré syndrome in humans.
This case report describes the clinical and neurological presentation, electrodiagnostic findings and manual therapeutic plasma exchange treatment in a small breed dog with suspected ACP.