Dementia Causes Corticobasal Degeneration

Corticobasal degeneration (CBD) is a rare progressive neurological disorder resulting in the loss of nerve cells and brain atrophy in one or more regions of the brain.

CBD occurs most commonly in the frontal and parietal lobes of the cerebral cortex region and in the large clusters of nerve cells called the basal ganglia, located in the striatum and sustantia nigra regions of the mid-brain.

Diagnosing Corticobasal Degeneration

Corticobasal degeneration, also called corticobasal ganglionic degeneration is initially characterized by a combination of Parkinson-like symptoms and a range of symptoms associated with the dysfunction of the corticobasal nerve cells.

Because of its similarity to a number of other neural disorders, CBD is often diagnosed incorrectly.

The Causes of CBD

Although corticobasal degeneration has no known cause, research has identified a link between the disease and the abnormal accumulation and malfunction of tau protein in the nerve cells of the brain. Researchers are attempting to establish whether the cause of CBD may be related to a mutation of the tau gene.

In normal, healthy nerve cells, tau protein helps to maintain and stabilize the cells’ internal structure. Tau protein, however, functions abnormally in the degenerating nerve cells of patients suffering from neurological disorders such as CBD, Parkinson’s, Alzheimer’s and Pick’s disease.

Symptoms of Corticobasal Degeneration

The initial symptoms of corticobasal degeneration tend to manifest between the ages of sixty and seventy. Some of the symptoms of CBD are similar to those of Parkinson’s disease.

Early symptoms such as rigidity, stiffness and reduced spatial awareness often affect only one side of the body. Other major symptoms include:

  • akinesia: lack of muscle control and movement
  • alien limb syndrome : the feeling that one’s arms and legs are not connected to the body
  • bradykinesia: slow movements
  • cognitive impairment : reduction in mental capacity and memory loss
  • disequilibrium: poor balance
  • dysphagia: problems swallowing
  • dysarthria: impaired ability to enunciate speech clearly
  • limb apraxia: inability to perform simple co-ordination or physical manipulation tasks
  • limb dystonia : repetitive muscle contractions
  • myoclonus: involuntary, jerking movements.

What is the Treatment for CBD?

No known treatment exists for corticobasal degeneration. Therapies are limited to controlling the symptoms of this debilitating disorder. Speech, physiotherapy or occupational therapy may be prescribed, along with the drug clonazepam for controlling muscle twitching.

The Prognosis for Corticobasal Degeneration

No known cure exists for corticobasal degeneration; the prognosis is generally poor. Death normally occurs within six to eight years of the initial diagnosis and is more likely to result from complications such as sepsis, pneumonia or pulmonary embolism.

Further research and clinical trials are required to establish the precise nature of the brain atrophy associated with corticobasal degeneration.


Hain, T.C. (2001). Corticobasal ganglionic degeneration (CBD).

Beers, M.H.