What is NA?
What is NA? Neuroacanthocytosis is a group of rare disorders marked by progressive muscle weakness and atrophy, progressive cognitive loss, chorea (involuntary twisting movements of the body) and acanthocytes (spikey red blood cells). Other symptoms include facial tics, uncontrolled muscle movement, instability when walking, seizures, biting of the tongue, cheeks and lips, and changes in personality, comprehension and judgement. The slow movement and, in some cases, tremours of parkinsonism my affect some patients.
NA is due to degeneration of the basal ganglia (the part of the brain that helps to control movement) and loss of neurons in the brain and spinal cord. Neuroacanthocytosis has adult and childhood varieties. It is typically an inherited autosomal recessive disorder and is more common in males than in females. Neuroacanthocytosis diseases have been found to be caused by specific gene defects.
A microscopic inspection of fresh blood samples may find red cells with spur-like or thorny projections (i.e., acanthocytosis), but more accurate diagnosis is through Western blot testing for the absence of specific proteins associated with each sub-type of NA. For example, the Western blot test allows doctors to detect the presence of the protein "chorein"; if it does not appear, ChAc (Chorea-acanthocytosis) is the likely diagnosis.
Treatment is symptomatic and supportive. Antipsychotic drugs that block dopamine, such as halpoperidol, can provide temporary relief from tics and chorea. Drugs used to decrease anxiety, such as diazepam and benzodiazepine, can also decrease movements disorders which are often made worse by associated stress. Injections of botulinum toxin can relax muscles and reduce unintentional movement. Other drug therapies may include anticonvulsants and antidepressants. Proper nutrition and hydration are important as well as maintainance of all skills available for as long as possible. A feeding tube may be needed for some patients as the disorder progresses. Speech, occupational and physical therapies may provide some relief and encourage confidence for some patients.