Cerebellar hypoplasia (non-human)

Cerebellar hypoplasia (CH) is a neurological condition in which the cerebellum is smaller than usual or not completely developed.[1] It has been reported in many animal species.[2]

Function and development of the cerebellum

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The cerebellum is the brain's main control center for planning, adjusting, and executing movements of the body, the limbs and the eyes. It plays a major role in several forms of motor learning, including balance and posture.[3]

In the past, the evidence for a role for the cerebellum in cognitive functions was rather weak.[4] However, investigations into the cognitive neuroscience of the cerebellum are rapidly advancing, extending far beyond the traditional view. For humans, current theories support that what the cerebellum does to sensorimotor and vestibular control, it also does to cognition, emotion, and autonomic function.[5][6]  How it functions in cognition, emotion, or autonomic function in animals is still largely unknown. In 2012, a study in mice provided direct evidence that subtle disruptions in cerebellar architecture can have pronounced effects on behaviors typically associated with autistic-like behavior.[7]

Development of the cerebellum starts in a fetus in utero and, depending on the species, may continue for some period after birth. Postnatal development periods vary by species including: dogs up to 75 days, cats to 84 days, calves up to six months.[8]

Causes

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A hereditary link to CH has been established in some animals, including certain breeds of cows[2] and dogs.[9] 

There are numerous other potential causes for CH. It is suspected that the most common cause is animal parvoviruses.[10]

Feline panleukopenia ("FPLV" a.k.a. Feline Distemper or Feline Parvo) virus has long been known to cause cerebellar hypoplasia in neonatal kittens through in utero or perinatal infection.[11] In utero, the virus can pass from the dam to the developing fetus and may then disrupt the development of its cerebellum by hindering cell division. This can happen when the dam is actively infected with the virus or given a modified-live FPV vaccine when pregnant.[12] Kittens are particularly vulnerable to CH, in particular when the protective antibodies present in their mothers' milk are no longer present at four to twelve weeks of age. Unvaccinated adult cats are also prone to developing the condition.[13]

In most cases the cause is unknown. However, in dogs and cats it is thought to be most likely related to in utero viral infections, toxins or genetic disorders.[14]

Other possible causes, if they occurred during the development period of the cerebellum and inhibit its growth, include:[15]

Symptoms

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  • ataxia
  • altered motor function
  • intention tremors

Diagnosis

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Numerous problems can be mistaken for CH. These include (but are not limited to):

Treatment

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Special considerations

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In 2004, a study was published that linked ketamine to post-anesthetic cerebellar dysfunction in cats.[20] 11 cats that did not have any indication of cerebellar deficits before surgery developed deficits post-surgery. All of these cats were Persian crossbreeds. Ketamine can cause erratic and spastic, jerky movements and muscle tremors and is slow to be metabolized out of the system.[citation needed] The 2018 American Association of Feline Practitioner's Feline Anesthesia Guidelines[21] lists numerous alternatives. Gas anesthesia offers a number of advantages in many circumstances. In CH cats the rapid recovery is its primary advantage.[citation needed]

Prognosis

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If the root cause of the CH impacted other parts of the developing brain and/or body, the overall health and life-span may or may not be impacted. For instance, fetuses infected in utero by FPLV that survive, and kittens less than a few weeks of age that become infected with it, can also have retinal dysplasia, and optic neuropathy.[22]

See also

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References

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  1. ^ "Cerebellar Hypoplasia Information Page".
  2. ^ a b "Congenital and Inherited Cerebellar Disorders - Nervous System". Merck Veterinary Manual. Retrieved 2019-02-20.
  3. ^ "Neural - Cerebellum Development". Archived from the original on 2015-05-18.
  4. ^ Glickstein M (October 2007). "What does the cerebellum really do?". Current Biology. 17 (19): R824-7. Bibcode:2007CBio...17.R824G. doi:10.1016/j.cub.2007.08.009. PMID 17925205. S2CID 14683993.
  5. ^ Schmahmann JD (January 2019). "The cerebellum and cognition". Neuroscience Letters. 688: 62–75. doi:10.1016/j.neulet.2018.07.005. PMID 29997061. S2CID 51623392.
  6. ^ Basson MA, Wingate RJ (September 2013). "Congenital hypoplasia of the cerebellum: developmental causes and behavioral consequences". Frontiers in Neuroanatomy. 7: 29. doi:10.3389/fnana.2013.00029. PMC 3759752. PMID 24027500.
  7. ^ Tsai PT, Hull C, Chu Y, Greene-Colozzi E, Sadowski AR, Leech JM, Steinberg J, Crawley JN, Regehr WG, Sahin M (August 2012). "Autistic-like behaviour and cerebellar dysfunction in Purkinje cell Tsc1 mutant mice". Nature. 488 (7413): 647–51. Bibcode:2012Natur.488..647T. doi:10.1038/nature11310. PMC 3615424. PMID 22763451.
  8. ^ DeLahunta A, Glass E (2009). Veterinary Neuroanatomy and Clinical Neurology. Saunders Elsevier. pp. 348–350. ISBN 9780721667065.
  9. ^ "Brain Tissue Undervelopment in Dogs | petMD". www.petmd.com. Retrieved 2019-03-01.
  10. ^ Pattison, John R.; Patou, Gary (1996), Baron, Samuel (ed.), "Parvoviruses", Medical Microbiology (4th ed.), Galveston (TX): University of Texas Medical Branch at Galveston, ISBN 978-0-9631172-1-2, PMID 21413262, retrieved 2021-05-02
  11. ^ De Lahunta A, Glass E (2009). "Cerebellum". Veterinary Neuroanatomy and Clinical Neurology. pp. 348–388. doi:10.1016/B978-0-7216-6706-5.00013-5. ISBN 9780721667065.
  12. ^ "Feline panleukopenia". Archived from the original on 2019-03-02. Retrieved 2019-03-01.
  13. ^ "Feline Parvovirus (FPV)" (PDF). Archived (PDF) from the original on 2020-10-28.
  14. ^ LeCouteur RA (2002). "Cerebellar Diseases of Dogs and Cats". Vin.com. WSAVA 2002 Congress.
  15. ^ Delauche A, Franklin R, Marsella R, Garosi L (February 2019). "Brain: cerebellar disease". Vet Stream. ISSN 2398-2950.
  16. ^ Hartmann, Katrin (January 2005). "Feline infectious peritonitis". The Veterinary Clinics of North America. Small Animal Practice. 35 (1): 39–79. doi:10.1016/j.cvsm.2004.10.011. ISSN 0195-5616. PMC 7114919. PMID 15627627.
  17. ^ Wilson J (7 March 2017). "Ataxia (Wobbly Gait) in Cats - Causes, Symptoms & Treatment - Cat World – Cat Health, Cat Care & Cat Advice". Retrieved 2019-03-02.
  18. ^ "Feline infectious peritonitis". 16 October 2017.
  19. ^ Skelly, Barbara J.; Franklin, Robin J. M. (2002). "Recognition and Diagnosis of Lysosomal Storage Diseases in the Cat and Dog". Journal of Veterinary Internal Medicine. 16 (2): 133–141. doi:10.1111/j.1939-1676.2002.tb02344.x. ISSN 1939-1676. PMID 11899921.
  20. ^ Shamir M, Goelman G, Chai O (May–Jun 2004). "Postanesthetic cerebellar dysfunction in cats". Journal of Veterinary Internal Medicine. 18 (3): 368–9. doi:10.1111/j.1939-1676.2004.tb02562.x. PMID 15188828.
  21. ^ "Anesthesia Guidelines". catvets.com. American Association of Feline Practitioners. Retrieved 2019-03-03.
  22. ^ Infectious Diseases of the Dog and Cat (4th ed.). Elsevier. 15 November 2011. ISBN 978-1-4160-6130-4. Retrieved 2019-03-14.

Further reading

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