These are neurological conditions that affect movement in various forms which may be in the form of increased or reduce, voluntary or involuntary movement which is not related to primary muscle weakness or paralysis.
Movement is an important function coordinated by the brain with contribution from the spinal cord. Any problem along this pathway or the chemicals involved would cause a type of movement disorder which are classified into hypokinetic (reduced movement) or hyperkinetic (excessive movement).
- Parkinson's disease
Parkinson's disease (PD) is an age-related progressive deterioration of certain nerve systems in the brain, which affects movement, balance, and muscle control. Parkinson's disease is not a hereditary disease. The average age of onset is about 60 years. Onset before age 40 years is relatively uncommon.
In Parkinson's disease, brain cells deteriorate (or degenerate) in an area of the brain called the substantia nigra. This leads to a reduction in the chemical involved in the transmission of signals (neurotransmitter) in the brain – dopamine.
The cause of this is not really known but it has been associated with genetics, head injuries, pesticides or herbicides, saw dust, toluene (in dyes) etc.
The three key signs of Parkinson's disease are tremor (shaking) at rest, rigidity, and slowness in the initiation of movement (called bradykinesia). Of these features, two are required to make the diagnosis. Postural instability is the fourth key sign, but it happens late in the disease dues to imbalance or loss of reflexes.
There is also associated alteration of mental status later on. Memory and spatial function i0s affected. Depression is also common with constipation, sweating abnormalities, sexual dysfunction and sleep disturbances.
Diagnosis is based on patient's symptoms, medical history and neurologic examination, and response to a treatment schedule with the combination medicine generically termed carbidopa-levodopa.
This is associated with a problem with part of the brain associated with the coordination of movement (cerebellum). This may lead clumsiness and irregularities in speaking or movement.
- Hutchinson’s chorea
This is a disease that affects mood and movement due to death of brain cells. It is an inherited disorder that presents with unsteady gait to uncoordinated and jerky movement. This could worsen till the person is unable to speak or move their limbs.
Symptoms most often appear between the ages of 30 and 50.
This is a movement disorder where there is sustained or frequent contraction of muscles that leads to wriggling movements and abnormal posture. The disorder can be hereditary or caused by trauma at birth, brain infection or toxic substances.
The movement can involve the whole body (generalized) or affect just a part (focal)
Diagnosing a specific movement disorder involves tying up the symptoms with the examination findings and investigations carried out. Some of these disorder present in similar patterns. But with meticulous observation and investigation, a precise diagnosis can be reached.
Metabolic screening, brain imaging, cerebrospinal fluid assay, genetic screening, brain stimulation and testing are helpful in diagnosis.
The management depends on the disorder. However, rehabilitative therapy is often coupled with medical treatment although most of these disorders do not have a cure. As disease progresses, it is usually important to provide a lot of support for the patient.