Olivopontocerebellar atrophy

Olivopontocerebellar atrophy
Sagittal section through right cerebellar hemisphere. The right olive has also been cut sagittally.
Classification and external resources
Specialty
ICD-10	G23.8
ICD-9-CM	333.0
DiseasesDB	2012 9208
MedlinePlus	000758
eMedicine	neuro/282
Patient UK	Olivopontocerebellar atrophy
MeSH	D009849

Olivopontocerebellar atrophy (OPCA) is the degeneration of neurons in specific areas of the brain – the cerebellum, pons, and inferior olives. OPCA is present in several neurodegenerative syndromes, including inherited and non-inherited forms of ataxia (such as the hereditary spinocerebellar ataxia known as Machado–Joseph disease) and multiple system atrophy (MSA), with which it is primarily associated.

OPCA may also be found in the brains of individuals with prion disorders and inherited metabolic diseases. The characteristic areas of brain damage that indicate OPCA can be seen by imaging the brain using CT scans or MRI studies.

The term was originally coined by Joseph Jules Dejerine and André Thomas.

Signs and symptoms

OPCA is characterized by progressive cerebellar ataxia, leading to clumsiness in body movements, veering from midline when walking, wide-based stance, and falls without signs of paralysis or weakness. Clinical presentation can vary greatly between patients, but mostly affects speech, balance and walking. Other possible neurological problems include spasmodic dysphonia, hypertonia, hyperreflexia, rigidity, dysarthria, dysphagia and neck dystonic posture.

Cause

Olivopontocerebellar atrophy is hereditary, but has an unknown genetic basis. There are two forms:

Number	OMIM	Alt. name	Inheritance
OPCA type 2	258300	Fickler-Winkler type OPCA	autosomal recessive
OPCA type 5	164700	OPCA with dementia and extrapyramidal signs	autosomal dominant

A few non-hereditary diseases formerly categorized as olivopontocerebellar atrophy have been reclassified as forms of multiple system atrophy as well as to four hereditary types, that have been currently reclassified as four different forms of spinocerebellar ataxia:

Hereditary OPCA type	OPCA name	SCA #	Gene	OMIM
OPCA type 1	"Menzel type OPCA"	SCA1	ATXN1	164400
OPCA type 2, autosomal dominant	"Holguin type OPCA"	SCA2	ATXN2	183090
OPCA type 3	"OPCA with retinal degeneration"	SCA7	ATXN7	164500
OPCA type 4	"Schut-Haymaker type OPCA"	SCA1	ATXN1	164400

Physiotherapy intervention

Physiotherapy intervention aims to improve balance and gait of OPCA patients, by stimulating neuroplastic changes in the atrophied neural structure. A challenge-oriented treatment program has previously been shown to be beneficial for individuals with ataxia from OPCA. The treatment program was composed of repetitive training with task challenges (e.g. obstacle course) and/or novel motor skills acquisition over a 12-week period under the supervision of a physiotherapist. Task challenges were progressed only when the patient showed mastery of a task.

Overground harness systems may be used to allow OPCA patients to challenge their balance without chance of falling. Furthermore, home exercise programs and/or aquatic exercises are used to allow more repetitions to facilitate balance learning. Treatment programs should be frequently monitored and adjusted based on a patient's progress. Outcome measures such as the Berg Balance Scale, Dynamic Gait Index and activities-specific balance confidence scales are useful to assess patient’s progress over time.

External links

• -113967058 at GPnotebook - "olivopontocerebellar atrophy"
• -429195218 at GPnotebook - "lethal olivopontocerebellar atrophy"
• opca at NINDS
• OPCA Awareness