Ganglioradiculitis

From Dog
Ganglioradiculitis in a dog with characteristic Wallerian degeneration in the dorsal funiculi throughout the length of the cord (well-demarcated zones of pallor)[1]

Ganglioradiculitis is an idiopathic progressive, acute-onset neurological disease of dogs.

This condition is similar to acral mutilation syndrome in that peripheral sensory (afferent) loss occurs in the distal extremities (stocking-glove sensory loss) but is more global in sensory loss, involving widespread sensorial deficits including dysphagia, ataxia, hearing loss and visual deficits. Self-trauma may also occur and secondary bacterial infections may lead to skin disease.

Although the cause is suspected to be immune-mediated[1], similar sensory neuropathies have been observed with pyroxidine toxicosis[2].

Clinical symptoms are usually progressive over several months or years and include facial hypalgesia, dysphagia, ataxia, depression of tendon reflexes, masticatory muscle wasting, megaesophagus, aphonia, deafness, visual deficits and occasionally self-mutilation[3].

Blood tests, CSF analysis and radiographic studies are usually unrewarding, although a mild increase in CSF cellularity and total protein may be observed. Sensory nerve conduction velocites (NCVs) are slowed or absent, while motor NCVs are normal.

Pathology is primarily confined to the spinal dorsal roots, ganglions, and dorsal columns and a definitive diagnosis requires nerve and spinal biopsies, where characteristic histopathology is observed; myelin loss, axonal degeneration, infiltration of mononuclear cells and proliferation of small supportive spindle cells (Wallerian degeneration)[4].

A differential diagnosis would include gangliosidosis, masticatory muscle myositis, polyradiculoneuritis and idiopathic acute canine polyradiculoneuropathy.

There is no effective treatment for this disease and drugs such as prednisolone or procarbazine have been effective at ameliorating clinical signs or halting progression of disease.

References

  1. 1.0 1.1 Porter B et al (2002) Ganglioradiculitis (sensory neuronopathy) in a dog: clinical, morphologic, and immunohistochemical findings. Vet Pathol 39(5):598-602
  2. Chung JY et al (2008) In vitro and in vivo gene therapy with CMV vector-mediated presumed dog beta-nerve growth factor in pyridoxine-induced neuropathy dogs. J Vet Sci 9(4):367-373
  3. Cummings JF et al (1983) Ganglioradiculitis in the dog. A clinical, light- and electronmicroscopic study. Acta Neuropathol 60:29-39
  4. Funamoto M et al (2007) Pathological features of ganglioradiculitis (sensory neuropathy) in two dogs. J Vet Med Sci 69(12):1247-1253