|  | Conditions Treatments | Neurological Disorders

Involuntary Cycle of Movements in Parkinson's Disease

Parkinson's disease results from a malfunction in specific parts of the central nervous system (CNS). The CNS is responsible for the regulation of both voluntary and involuntary movement of your body. Here, we focus on involuntary movements as visible signs of Parkinson's disease.

  1. The Visible Signs

    • Parkinson's disease is characterized by a symptom complex of rigidity, tremor and akinesia. Other noticeable characteristics include mimetic facial expressions, intermittent blinking, limited steps when walking and delayed/slow movements.

    Tremor

    • Tremor is responsible for the involuntary cycle of movements in Parkinson's disease. It is best defined by its relation to activity. In Parkinson's, tremor occurs when the body is at rest; this is also called "pill rolling." It pertains to the involuntary alternate movement of thumb and forefinger while at rest. It occurs in all patients with Parkinson's, although the rate and body parts involved may vary.

    Rigidity

    • Rigidity is caused by a disturbance in equilibrium due to muscle weakness. Patients can't resist simple involuntary movements; then it slowly progresses to more complex movements involving more body parts. Rigidity also accounts for the slow and limited range of hands, legs and feet.

    Bradykinesia

    • Bradykinesia hinders the ability to perform fast and easy voluntary movements. Delayed, stiff, interrupted and very slow movements are some of its characteristics. Depending on the degree of impairment, the conditions bradykinesia, hypokinesia and akinesia refer to this abnormal muscle coordination.

    Rationale

    • The two reasons currently accepted for Parkinson's involuntary movements are as follows:
      1. Low dopamine reaching the basal ganglia of the brain.
      2. Low pigmented nerve fibers in substantia nigra of the basal ganglia.
      Substantia nigra is the part of the basal ganglia responsible for instructing organs to act in a coordinated way. Dopamine is involved in neurotransmission of stimuli to the basal ganglia of the brain. Since the dopamine in the basal ganglia of patients with Parkinson's disease is low, a consequential deficit in nerve fiber stimulus for the substantia nigra to trigger coordinated actions occurs. Therefore, the low dopamine and low pigmented nerve fibers in basal ganglia result in an involuntary cycle of movements in Parkinson's disease (see Image 1).
      These and other factors are still being studied to find a treatment that will normalize the activities in the basal ganglia region of the brain.

Neurological Disorders - Related Articles