Rodney Tinayeshe Mudzenda
Parkinson disease is a type of movement disorder, which is progressive and of unknown cause. Usually it commences between the ages of 45 and 55 years, but can start earlier. It is associated with neuronal degeneration in the substantia nigra and, to a lesser extent, in the globus pallidus, putamen, and caudate nucleus (gray matter inside cerebral hemisphere of the brain). Degeneration results in the cells of the brain failing to produce a chemical called dopamine. This affects the way the brain coordinates movements of muscles in the body.
It is not contagious nor infectious, neither is it curable but its symptoms can be managed. Parkinson’s disease is globally distributed, affecting all cultures and races, with an estimated prevalence of 6(+) million people.
CAUSES
Currently there is no known cause, however, there are many theories as to the causes and it is generally thought that multiple factors are responsible. Medical experts are not yet certain as to what destroys the dopamine secreting cells in the brain or what predisposes some people to develop Parkinson’s disease and not others.
Genetics: Several changes in one’s genetic make-up (mutations) have been identified as increasing a person’s risk of developing Parkinson’s disease. Parkinson’s disease can therefore run in families as a result of these faulty genes being passed on to off springs by their parents. However chances of inheriting this disease in this way are very slim, although it is possible.
Environmental factors: Our surroundings are also thought to play a pivotal role in increasing a person’s risk of developing Parkinson’s disease. Pesticides and herbicides used in farming, traffic chemicals and industrial pollutants may contribute to one developing the condition. Therefore potential environmental risk factors include farming activities, pesticide exposures and a history of head trauma
Other Causes of Parkinsonism
Having the understanding that Parkinsonism is an umbrella term used to describe symptoms of tremors, muscle rigidity and slowness of movement; Parkinson’s disease is the most common type.
Medication (‘drug induced): Symptoms may develop after taking certain medications such as antipsychotic drugs and usually improve once the medication is stopped. It is to be noted that not all antipsychotic drugs bring these symptoms.
Progressive brain conditions: When one gets a severe stroke, multiple parts of the brain die and may cause symptoms manifest.
Parkinson’s disease (PD) is in the family of motor system disorders, which are a result of the loss of dopamine producing brain cells. This disease is caused by a loss of nerve cells in part of the brain called substantia nigra. This area sends messages to the spinal cord via the cerebral cortex to control the muscles of the body in a well-coordinated manner. The neurotransmitter, dopamine, plays a vital role in movement regulation and lack its lack means that people will have problems in moving freely and controlling their movements.
PARKINSON’S SYMPTOMS
Can be motor and non-motor and their adverse effects can be of different intensity across individuals and race.
There are four non-motor symptoms namely: pain, depression, dementia and sleeping disorders.
The four main symptoms of Parkinson’s disease affect physical movement:
Tremor: The most common symptom of Parkinson’s disease is the unilateral, resting tremor in the body and mainly in the limbs.
It is an early symptom seen in about 70% of people presenting with Parkinson’s disease. It begins when a person is not trying to use the limb, and diminishes when the limb is in use. Begins in the limbs and spread to other parts slowly.
Slowness of movement (bradykinesia): Is the most disabling symptom of the condition and refers to slowness, decreased movement amplitude and dysrhythmia. Walking becomes slow as one moves with small steps as well as a shuffling gait.
Muscle stiffness (rigidity): Stiffness of muscles may not be apparent in an individual with Parkinson’s disease but only a medical person can feel it. Stiffness of muscles makes it difficult to move around and make facial expressions and can result in painful cramps (dystonia).
Postural instability: it is also a disabling symptom which often experienced in the late stages of Parkinson’s disease and is a marker of the disease’s progression. One losses his/her postural reflexes and these postural disturbances contribute to recurrent falls and fall related injuries. In early Parkinson’s the posture may show a slight flexion of the trunk or neck with a slight lean to one side.
Anxiety, anosmia (loss of smell), constipation, depression, fatigue, festination of speech, postural hypotension and micrographia are some the other symptoms.
Parkinson’s disease is a neurological disorder that progresses with time and symptoms are initially affecting one side of the body. Medication can help manage symptoms but unfortunately, are not implicated for slowing the progression of Parkinson’s disease.
DIAGNOSIS
It is not easy to diagnose Parkinson’s disease (there are no blood test or brain scans) and it is of great importance that diagnosis is made by a specialist, preferably a neurologist. Having one of the mentioned symptoms doesn’t call for immediate concern, however if you have one or two of the following symptoms seek medical attention; small crowded handwriting, loss of smell, tremor, frozen shoulder, change in voice and sleeping problems.
CT (computerized tomography) scan, (magnetic resonance imaging) MRI scan and (dopamine transporter) DaT scan can be performed so as to get a better glimpse of the events taking place in the brain.
TREATMENT
Parkinson’s disease has no cure, but symptom treatment is possible.
Physiotherapist can help relieve muscle stiffness through exercises. Occupational therapist can be of great importance when dealing with movement.
Medication: improves the main symptoms of Parkinson’s disease such as shaking and movement. However, not all medications available are useful to everyone. Most pharmaceutical treatment options focus on restoring balance of dopamine. So most drugs used contain levodopa, dopamine agonist and monoamine oxidase-B inhibitors.
Dopamine agonist function my mimicking the effects of dopamine and monoamine oxidase-B inhibitors they function by inhibiting the degradation of dopamine. This all amounts to a positive treatment of symptoms.
So, in conclusion, Parkinson’s disease is a neurological disorder characterized by movement disorders and progresses slowly. It has no known cause and there is no cure at the moment, though research is ongoing on how to develop new ways of treating the condition.
Rodney is a medical student at University of Zimbabwe and a member of ZiMSA.education
