Acanthocytes (from the Greek word acantha, which means thorn), or spur cells, are spiculated red cells with a few projections of varying size and surface distribution. The cells appear contracted, dense, and irregular. The morphology of acanthocytes in these various conditions is similar, but the pathogenesis and clinical context often greatly differ. In general, the formation of acanthocytes depends on alteration of the lipid composition and fluidity of the red cell membrane. Acanthocytosis is a red cell phenotype associated with various underlying conditions. The most frequent and most significant conditions include abetalipoproteinemia
Chorea-acanthocytosis affects movement in many parts of the body.
- Chorea refers to the involuntary jerking movements made by people with this disorder.
- People with this condition also have abnormal star-shaped red blood cells (acanthocytosis).
- Another common feature of chorea-acanthocytosis is involuntary tensing of various muscles (dystonia), such as those in the limbs, face, mouth, tongue, and throat. These muscle twitches can cause vocal tics (such as grunting), involuntary belching, and limb spasms. Eating can also be impaired as tongue and throat twitches can interfere with chewing and swallowing food.
- People with chorea-acanthocytosis may uncontrollably bite their tongue, lips, and inside of the mouth.
- Nearly half of all people with chorea-acanthocytosis have seizures.
- Individuals with chorea-acanthocytosis may develop difficulty processing, learning, and remembering information (cognitive impairment).
- They may also have reduced sensation and weakness in their arms and legs (peripheral neuropathy) and muscle weakness (myopathy).
- Impaired muscle and nerve functioning commonly cause speech difficulties, and can lead to an inability to speak.
- Behavioral changes are also a common feature of chorea-acanthocytosis and may be the first sign of this condition. These behavioral changes may include changes in personality, obsessive-compulsive disorder (OCD), lack of self-restraint, and the inability to take care of oneself.
- Abnormality of erythrocytes
- Muscular hypotonia
- Neurological speech impairment
- Peripheral neuropathy
Chorea-acanthocytosis is caused by mutations in the VPS13A gene and is inherited in an autosomal recessive manner.
Tests that may be done to help diagnose this condition include:
- Genetic Testing Registry (GTR)
- Apolipoprotein B blood test
- Blood tests to look for vitamin deficiencies (fat-soluble vitamins A, D, E, and K)
- Complete blood count (CBC)
- Cholesterol studies
- Eye exam
- Nerve conduction velocity
- Stool sample analysis
How well a patient does depends on the amount of brain and nervous system problems.
There are currently no treatments to prevent or slow the progression of chorea-acanthocytosis; treatment is symptomatic and supportive.
- Botulinum toxin for decreasing the oro-facio-lingual dystonia
- Feeding assistance
- Speech therapy
- Mechanical protective devices
- Splints for foot drop
- Phenytoin, Clobazam and Valproate for seizure management
- Antidepressant or antipsychotic medications
- Dopamine antagonists such as atypical neuroleptics or tetrabenazine
- Standard treatment for cardiomyopathy
- Monitoring of nutritional status
- Adaptation of diet to assure adequate caloric intake
- Cardiac evaluations every five years,
- EEG every third year.