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Cerebellar Cortical Degeneration 149.e3

Cerebellar Cortical Degeneration Client Education
Sheet
VetBooks.ir Diseases and Disorders

• In humans, cerebellar cortical degeneration
BASIC INFORMATION
definitive diagnosis can be established only with
can occur as a paraneoplastic condition, but confirming with genetic testing if available. A
Definition this has not been described in companion histopathology; this is especially important if
• Progressive loss of neurons of the cerebel- animals. the patient is not of a breed reported to have
lar cortex primarily due to an underlying • The disease in coton de Tuléar has an inflam- cerebellar cortical degeneration.
genetic disorder; most prominent in the matory component and is hypothesized to
Purkinje or granular cell layers (granuloprival be due to a genetic disorder of the immune Differential Diagnosis
degeneration) system. • Inflammatory and neoplastic diseases
• The animal’s cerebellum develops normally affecting the cerebellum can manifest with
but then degenerates sometime after birth. GEOGRAPHY AND SEASONALITY similar signs, although they tend to have
• It can be a component of multifocal neu- There is no overt relationship to geography or multifocal (encephalitis), asymmetrical signs
rodegenerative conditions such as spinocer- seasonality, although these genetic disorders can and progress rapidly.
ebellar degeneration and canine multisystem cluster regionally due to breeding practices. • Cerebellar hypoplasia is an important dif-
degeneration. ferential for animals younger than 1 month
ASSOCIATED DISORDERS of age, but signs of cerebellar disease are
Synonyms Frequent falls as a result of ataxia can cause evident as soon as the animal begins to walk
Cerebellar abiotrophy, cerebellar degeneration, traumatic and orthopedic injuries. and are not progressive.
hereditary ataxia, cerebellar ataxia • Other neurodegenerative conditions can
Clinical Presentation
produce cerebellar signs.
Epidemiology DISEASE FORMS/SUBTYPES • Encephalitis and lysosomal storage disease
SPECIES, AGE, SEX • The common clinical characteristic of this are important differentials for young to
• Dogs > cats group of diseases is progressive dysfunction middle-aged animals.
• Onset of signs occur at any age; can be of the cerebellar cortex. • Infectious encephalitis can be due to Neospora
subdivided into early (first 2 months), • Each breed exhibits a different age of onset, caninum (dogs) or Toxoplasma gondii (cats);
juvenile (2-12 months), or adult (>1 year) prevalence of each cerebellar sign, and fungal infections such as Cryptococcus,
onset progression rate. Blastomyces, and Histoplasma; algae such as
• Phenotypic variability between individuals Prototheca; and rickettsial diseases such as
dictates that although the majority of animals HISTORY, CHIEF COMPLAINT Erhlichia canis.
manifest signs within one age bracket, there • Insidious onset of progressive gait • Immune-mediated causes of encephalitis
are always outliers. For example, 76% of abnormalities. include idiopathic cerebellitis and menin-
Scottish terriers with cerebellar cortical • Owners report an abnormal gait, with goencephalitis of unknown origin.
degeneration develop signs in the first year, difficulty going up or down stairs, misjudg- • In older animals, neoplasia should be consid-
but onset can be as late as 6 years. ments, and falls, especially when running ered. Slow-growing cerebellar tumors could
• The majority of genetic causes of cerebellar and cornering. produce comparable clinical signs.
cortical degeneration is autosomal recessive • Metronidazole toxicity can cause progressive
with equal representation of both sexes. PHYSICAL EXAM FINDINGS cerebellar signs in dogs at any age and should
However, there are also X-linked causes, • General examination findings are normal, be considered in any animal with an onset
with males overrepresented. although concurrent orthopedic injuries can of signs after starting metronidazole therapy.
be present.
GENETICS, BREED PREDISPOSITION • Neurologic signs include cerebellar ataxia Initial Database
• Reports of cerebellar cortical degeneration (characterized by a high-stepping, hypermet- • Complete blood cell count, serum chemistry
can be sporadic (suspected to be genetic) or ric gait), a broad-based stance, truncal sway, panel, and urinalysis should yield normal
familial. and intention tremor. results.
• Mutations associated with cerebellar cortical • There can be nystagmus (vertical, horizontal, • Thoracic radiographs: in animals older than
degeneration have been described in beagles, or rotary) or opsoclonus (random, rapid eye 6 years, as a screen for metastatic neoplasia
Finnish hounds, Old English sheepdogs, movements), most reliably elicited by placing
Gordon setters, and Italian spinones, and the animal on its back. Advanced or Confirmatory Testing
the disease has been mapped to specific • The menace response can be absent, although • Genetic testing should be performed if
chromosomal regions in Australian kelpies vision is normal. available. For autosomal recessive disorders,
and Scottish terriers. affected animals have two copies of the
• There have been sporadic and unmapped Etiology and Pathophysiology mutation.
familial reports for Rhodesian ridgeback, Genetic causes span genes important in • Brain magnetic resonance imaging (MRI)
Portuguese podengo, miniature poodle, papil- autophagy and protein clearance (SEL1L, (p. 1132) and cerebrospinal fluid (CSF) analy-
lon, miniature schnauzer, English bulldog, RAB24), neuronal infrastructure (SPTBN2), sis (pp. 1080 and 1323): to rule out encepha-
Labrador retriever, boxer, Lagotto Romagnolo, and calcium channels (ITPR1). litis and neoplasia. MRI may demonstrate
border collie, Bavarian mountain dog, Italian cerebellar cortical atrophy with no evidence
hound, and coton de Tuléar and for Persian, DIAGNOSIS of inflammation, and CSF analysis should be
domestic short-haired, and Siamese cats. normal.
Diagnostic Overview
RISK FACTORS Cases exhibit symmetrical, progressive cerebellar TREATMENT
• The primary risk factor is familial due to signs with no evidence of systemic illness and
the genetic nature of the disease. a family history of the condition. Establishing Treatment Overview
• Modifiers of phenotype have not been an antemortem diagnosis involves ruling out There is no known therapy for cerebellar cortical
identified. other central nervous system diseases and degeneration in dogs or cats. Treatment revolves
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