Purkinje Cell Degeneration

Cerebellar Purkinje cell degeneration is a progressive genetic (autosomal recessive) disease of the central nervous system marked by degeneration of virtually all cerebellar Purkinje cells. This process results in a condition called cerebellar cortical atrophy.

The central nervous system (CNS) is composed of both white and gray matter. These can be divided into spinal cord and brain white or gray matter. Gray brain matter is positioned at the periphery, or cortex of the cerebrum and cerebellum, and it is made up of three layers. The neurons, or nerve cells of the outer (molecular) and inner (granular) layers are small. The major function of the cerebellum is to coordinate voluntary, postural and reflex movements. It coordinates motor activity that is initiated elsewhere, (coordination NOT initiation). The cerebellum also assists with the maintenance of equilibrium. Purkinje cells are the only cortical neurons whose axons extend through the white matter.

The term abiotrophy refers to spontaneous, premature neuronal death. In most types of abiotrophy, an inherited inborn error of metabolism (usually unidentified) is considered to be responsible. Most abiotrophies involve the cerebellar Purkinje cells, which appear to be exquisitely susceptible to derangement of their metabolism. Abiotrophies may affect the cerebellum alone or may affect the cerebellum and other areas of the brain.

Signs

Common signs of this condition include growth retardation, and progressive ataxia (lack of muscle coordination. Animals may stand with a broad-based stance and swaying of the body may be present. Tremors, spastic, high stepping "over-measurement" gait in all four limbs may also be seen. Nystagmus, progressive gait abnormalities, and diluted coat color in some breeds also occur. Littermates with non-diluted coat color are neurologically normal. The signs of incoordination in affected Scottish Terriers have been recognized by owners or breeders as early as 10 weeks of age, and as late as 4 years of age. Recognition of clinical signs has more to do with the severity of the disorder than the actual onset of cerebellar degeneration. Many affected dogs remain with mild incoordination their entire lives, and live out a normal life span. Other animals progress to the point where they can not walk without assistance.

Breeds at Risk

Cerebellar abiotrophies have been identified in cats and in many dog breeds including Kerry Blue terrier, Gordon setter, rough coated Collie, and Brittany spaniel.

A syndrome of cerebellar Purkinje cell degeneration and coat color dilution was diagnosed in a family of Rhodesian Ridgeback dogs, and Staffordshire terrier. A slowly progressing late-onset form of cerebellar degeneration develops in Old English Sheepdogs. Epilepsy was reported in several litters of Lagotto Romagnolo dogs which was associated with loss of Purkinje cells.

References

1. Chieffo C, Stalis IH, Van Winkle TJ, Haskins ME, Patterson DF. Cerebellar Purkinje's cell degeneration and coat color dilution in a family of Rhodesian Ridgeback dogs.
2. H. Steven Steinberg, VMD, DACVIM Thomas Van Winkle, VMD, DACVP Jerold S. Bell, DVM Alexander de Lahunta, DVM, PhD, DACVIM. Cerebellar degeneration in Old English Sheepdogs.
3. T.S. Jokinen, L. Metsa¨honkala, L. Bergamasco, R. Viitmaa, P. Syrja¨ , H. Lohi, M. Snellman, J. Jeserevics, and S. Cizinauskas. Benign Familial Juvenile Epilepsy in Lagotto Romagnolo Dogs
4. Open Letter from Dr. Bell, DVM. Scottish Terrier Club of America.
5. Richard A. LeCouteur, BVSc, PhD, Diplomate ACVIM (Neurology), DECVN. Cerebellar Diseases of Dogs and Cats.

ADD POST TO THIS PAGE