Olivopontocerebellar atrophy
Encyclopedia
Olivopontocerebellar atrophy (OPCA) is a term used to define neuronal degeneration in the cerebellum
Cerebellum
The cerebellum is a region of the brain that plays an important role in motor control. It may also be involved in some cognitive functions such as attention and language, and in regulating fear and pleasure responses, but its movement-related functions are the most solidly established...

, pontine nuclei
Pontine nuclei
The pontine nuclei are a part of the pons involved in motor activity. Corticopontine fibres carry information from the primary motor cortex to the ipsilateral pontine nucleus in the ventral pons, and the pontocerebellar projection then carries that information to the contralateral cerebellum via...

, and inferior olivary nucleus
Inferior olivary nucleus
The inferior olivary nucleus is the largest nucleus situated in the olivary body, part of the medulla oblongata.-Function:It is closely associated with the cerebellum, meaning that it is involved in control and coordination of movements, sensory processing and cognitive tasks likely by encoding the...

. The use of the term has changed considerably in recent years due to the progressing knowledge of the genetic basis of the disease.

The term was originally coined by Joseph Jules Dejerine
Joseph Jules Dejerine
Joseph Jules Dejerine , was a French neurologist.Joseph Jules Dejerine was born to French parents in Geneva, Switzerland, where his father was a carriage proprietor. During the Franco-Prussian War Dejerine worked as a volunteer in a Geneva Hospital and in the spring of 1871 decided to pursue his...

 and André Thomas.

Current uses of the term

The term "olivopontocerebellar atrophy" currently applies only to two hereditary disorders whose genetic basis remains unknown:
Number OMIM Alt. name Inheritance
OPCA type 2 Fickler-Winkler type OPCA autosomal recessive
OPCA type 5 OPCA with dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...

 and extrapyramidal signs
autosomal dominant

Obsolete uses of the term

In the past, the term "olivopontocerebellar atrophy" extended to both the sporadic (non-hereditary) cases of the disease, which have been currently reclassified as a form of multiple system atrophy
Multiple system atrophy
Multiple system atrophy is a degenerative neurological disorder. MSA is associated with the degeneration of nerve cells in specific areas of the brain. This cell degeneration causes problems with movement, balance and other autonomic functions of the body such as bladder control or blood pressure...

, as well as to four hereditary types, which have been currently reclassified as four different forms of spinocerebellar ataxia
Spinocerebellar ataxia
Spinocerebellar ataxia is a progressive, degenerative, genetic disease with multiple types, each of which could be considered a disease in its own right.-Classification:...

:
Hereditary OPCA type OPCA name SCA
Spinocerebellar ataxia
Spinocerebellar ataxia is a progressive, degenerative, genetic disease with multiple types, each of which could be considered a disease in its own right.-Classification:...

 #
Gene OMIM
>-
| OPCA type 1
"Menzel type OPCA" SCA1 ATXN1  >-
| OPCA type 2, autosomal dominant 
"Holguin type OPCA" SCA2 ATXN2
ATXN2
Ataxin-2 is a protein that in humans is encoded by the ATXN2 gene.-Further reading:-External Links:*...

 
>-
| OPCA type 3
"OPCA with retinal degeneration" SCA7 ATXN7  >-
| OPCA type 4
"Schut-Haymaker type OPCA" SCA1 ATXN1

External links

- "olivopontocerebellar atrophy" - "lethal olivopontocerebellar atrophy"
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