Corticobasal Degeneration Health Article

Definition

Corticobasal degeneration (CBD) is a rare, progressive, neurodegenerative disease that causes movement disorders and dementia.

Description

CBD occurs when brain cells in two areas of the brain—the cortex and the basal ganglia—die off. The cause of this neurodegeneration is unknown. CBD is also called cortical basal degeneration and corticobasal ganglionic degeneration.

Demographics

It is not known exactly how many people have CBD. In the United States, the number is probably fewer than 10,000. Men and women are equally affected. Symptoms usually appear when a person is 50 or 60 years old.

Causes and symptoms

The ultimate cause of CBD is unknown. No genes have been found to be responsible, and no environmental or other risk factors have been identified. The brain areas affected are the cerebral cortex and the basal ganglia. The cerebral cortex is the center of mental activities such as planning, memory, language, and reasoning. The basal ganglia help control movements.

The symptoms of CBD may begin with either movement disorders or cognitive disorders. The movement disorders seen in CBD are similar to those in Parkinson's disease (PD), and CBD is often initially misdiagnosed as PD. In CBD, movements become slow and stiff, and may be accompanied by sustained abnormal postures (dystonia) or sudden violent jerks (myoclonus). Cognitive symptoms include memory impairment, loss of judgment, and difficulty planning or executing movements. Additional features may include impaired speech, and the "alien hand" phenomenon, in which the patient feels disconnected from, and not in control of, a hand or limb. Loss of sensation may also occur.

Diagnosis

Corticobasal degeneration is diagnosed with a neurological exam (testing of reflexes, coordination, sensation, etc.) and neuroimaging studies, including computed tomography (CT) scan and magnetic resonance imaging (MRI) to detect characteristic loss of brain tissue. Neuropsychological testing is also usually done to determine the kind and degree of cognitive impairment.

Treatment team

The treatment team includes a neurologist, neuropsychologist, speech/language pathologist, geriatric medicine specialist, and possibly a physical or occupational therapist.