What is Parkinson’s disease?
Parkinson’s disease is a common, slowly progressive, neurodegenerative disease. It results from the degeneration of neurons in the substantia nigra, a region of the brain that controls movement. This degeneration results in a shortage of a neurotransmitter called dopamine, therefore, causing impaired movement. The first symptoms of the disease are usually seen later in life, 40 years or older. Parkinson’s disease is often called primary Parkinsonism or idiopathic Parkinson’s disease to distinguish it from other forms of Parkinsonism.
We can expect the number of new cases to grow as the average age of the population increases. The disease is most frequently seen in people in their 70s and 80s with a slightly higher incidence in Caucasians, than in African-Americans and Asians. In recent years, more “early” onset (in people under 40) cases have been seen.
What are the Symptoms of Parkinson's Disease?
The symptoms of Parkinson's disease vary in both kind and severity amongst individuals and can progress at different rates throughout the disease. In most cases, the first symptom seen is a tremor, trembling or shaking, in a limb on one side of the body while the body is at rest. Early symptoms are typically mild and progress gradually.
Common Early Symptoms of Parkinson's disease
Ø Difficulty standing from a sitting position
Ø Shakiness of hands initially at resting state (asymmetric to start)
Ø Changes in speech
Ø Handwriting that looks cramped or "spidery"
Ø Losing track of words or thoughts
Ø Irritability and depression
Ø Lack of facial expression and animation
Ø Slow movements of limbs and slowness of gait
Ø Inability to move
Ø Rigid limbs
Ø Shuffling gait
Ø Stooped posture
There are four symptoms that the majority of Parkinson’s disease patients experience.
Ø Rigidity: stiffness when an arm, leg, or the neck is moved. The muscles remain constantly tensed and contracted, so the person feels stiff and/or weak.
Ø Resting tremor: a tremor which occurs when the person is at rest. This often begins with an occasional trembling of one hand, most obvious when the person is at rest or under stress. In about 75% of cases, this tremor affects only one body part or side of the body initially, and then becomes more generalized over time.
Ø Bradykinesia: slowness in initiating movement. This may also contribute to decreased facial movement, change in speech, shuffling gait and trouble with fine-fingered movements. Many patients find this to be the most frustrating aspect of their disease. It results in a loss of independence as it progresses, due to difficulties performing everyday functions, such as getting dressed, using utensils, and rising from chairs or bed.
Ø Loss of postural reflexes or postural instability: resulting in poor balance and coordination. Patients sometimes develop a forward or backward lean and fall easily. This can also cause stooped posture, bowed head and drooped shoulders.
Secondary Symptoms of Parkinson's disease
Ø Personality or emotional changes
Ø Sleep Disturbance
Ø Memory Disturbances
Ø Speech impairments
Ø Difficulty chewing or swallowing (dysphagia)
What Causes of Parkinson's disease?
Parkinson’s disease is associated with a gradual loss of cells in the substantia nigra, which produces dopamine. Dopamine is a chemical messenger that transmits a signal between two regions of the brain, the substantia nigra and the corpus striatum to regulate muscle activity. Insufficient dopamine in the striatum causes the nerve cells in this region to “fire” out of control leaving the individual unable to direct or control movements in a normal manner. This is thought to lead to the initial symptoms of Parkinson’s disease. Later in the disease, other areas of the brain and nervous system degenerate.
The exact cause for the loss of cells is unknown. Possible causes currently being researched are:
Ø Genetic predisposition: The inheritance of a gene passed down from a previous generation.
Ø Free radicals are unstable molecules produced during normal chemical reactions in the body. When these molecules interact with other molecules they have the ability to damage a variety of tissue types, including neurons.
Ø Environmental toxins: This has been seen in people who took an illegal drug contaminated with a chemical called, MPTP. These individuals developed severe Parkinson-like symptoms. This also occurred in the early 1900’s in individuals who had suffered from a severe form of influenza.
Ø Accelerated aging: As a person ages, there is a normal wearing away of dopamine producing neurons, which leads to the premature loss of dopamine.
Ø Genetics-15-20% of Parkinson’s disease patients have a close relative who has also experienced parkinsonian symptoms. This leads us to believe that there may be a genetic component involved in Parkinson's disease. Studies with Parkinson’s disease twins and families have shown a multifactorial pattern of inheritance. This means that there may be a genetic component that makes a person more susceptible to developing Parkinson's disease, but is not enough to cause the disease. Development of the disease is dependent up on the influence of environmental factors.
How is Parkinson's Disease Diagnosed?
A neurologist usually diagnoses Parkinson’s disease. Anti-Parkinson’s drugs are prescribed to confirm the diagnosis. If the patient responds to these drugs, a diagnosis of Parkinson’s can be made. If the patient does not respond to these drugs, other diagnoses will be researched. Brain scans can help doctors determine if a person has true Parkinson’s disease or if it may be another disorder that resembles it. Lewy bodies are the trademark characteristic of the disease, but can only be seen by autopsy. An interesting finding is that a large number of older people without a diagnosis of Parkinson’s disease are shown to have Lewy bodies upon autopsy (8% of people over 50; 13% of people over 70; and 16% of people over 80). This leads us to believe that there may be many undiagnosed cases of Parkinson’s disease in the general public.
How is Parkinson's Disease Treated?
There is no cure for Parkinson’s disease, therefore treatment is symptom specific. A comprehensive approach, including early diagnosis, exercise, good nutrition and medications, is thought to work best in relieving symptoms. Also, some may opt for surgical intervention.
Medications are used to relieve the symptoms of Parkinson’s disease. The type and dosage of each medication is tailored to each person’s individual needs.
Levodopa (L-dopa). Nerve cells use l-dopa to make and replenish the brain’s supply of dopamine. L-dopa is often given along with carbidopa. Carbidopa delays the conversion of levdopa into dopamine until it reaches the brain. This prevents, or diminishes some of the side effects of L-dopa and reduces the amount of L-dopa needed. L-dopa delays the onset of debilitating symptoms and allows many patients to extend the period of time they are able to live “normal” lives. Bradykinesia and rigidity respond best and tremor may be only slightly reduced.
Bromocriptine, pergolide, pramipexole, and ropinirole. These drugs all mimic the role of dopamine in the brain.
Selegiline (deprenyl). This drug may delay the need of l-dopa therapy. When given with l-dopa, it seems to enhance and prolong the response of l-dopa.
Anticholinergic. These may help control tremor and rigidity. They appear to act by blocking the action of acetylcholine.
Amantadine. This is an antiviral drug. It is effective at reducing many symptoms, but its efficacy wears off after several months. Effectiveness may return after a brief withdrawal.
Diet and Exercise
If a person is taking L-dopa, their doctor may recommend adjusting the amount of protein in their diet, since protein may interfere with the absorption of the drug. Swimming, walking, physical therapy, and muscle strength exercises help to maintain muscle tone and strength and improve mobility. Full range of motion exercises improve balance, walking, and strength.
Surgery is not performed as often since the discovery of L-dopa.
Pallidotomy: a portion of the brain, the globuspallidus, is lesioned. This may improve tremor, rigidity, and bradykinesia, possibly by interrupting the neural pathway between the globuspallidus and the corpus striatum or thalamus.
Deep brain stimulation (DBS): implantation of an electrical stimulator, similar to a cardiac pacemaker, to counteract the loss of dopamine producing cells in the substantia nigra. In contrast to the other two forms of surgery, DBS does not form permanent brain lesions. The electrode are placed in STN ad attached with the battery placed over chest wall which can be operated with remote.
Transplantation of healthy dopamine-producing tissue into the brain is currently being tested.
What is DBS?
DBS uses advanced computer technology to pinpoint areas of thepatient’s brain where faulty electrical signals are triggering symptoms.Guided by this information, a neurosurgeon makes a small opening in the skull and implants electrodes in targeted areas of the brain. Depending on the patient’s needs, this procedure is done on one or both sides of the body. In order to ensure that the implants are properly placed, the patient may be awake during part of the surgery so that he/she may communicate with the surgical team. Local anesthesia relieves any pain during this wakeful period. The patient usually goes home two to three days following surgery and returns to the hospital one week later for a second step. At this time, general anesthesia is used as the surgeon implants a battery-powered pulse generator under the patient’s collarbone.
Other movement disorders
Any patient experiencing lack of movement or too much movement most likely has some form of a movement disorder. Other disorders include:
• Restless legs syndrome is perhaps the most common movement disorder, experienced by up to 10 percent of the general population. Symptoms include cramping or other sensory discomfort in the legs at night. The condition is relieved by walking, but returns when the patient goes back to bed.
• Huntington’s disease is a progressive, hereditary neurological disorder characterized by various degrees of chorea (involuntary twitches, clumsiness, jerking, twisting or dance-like movements) and other involuntary movements. Patients also can experience behavioral and mental problems.
• Tourette syndrome is an involuntary disorder often seen in younger patients, with symptoms that include an increasing urge to yell, twitch or move repeatedly, commonly accompanied by obsessive-compulsive behaviors. Our multidisciplinary team works together to provide world-class care during a DBS surgery. clevelandclinic.org/neurorestoration 5 Thin wires placed beneath the skin connect this “brain pacemaker” to the electrodes implanted earlier in the brain. The pulse generator delivers stimulation to these targeted brain areas, blocking the abnormal signals that produce symptoms such as tremor, stiffness and slowed movement. The patient goes home in less than 24 hours, and returns as an outpatient two to four weeks later to turn on and program the pulse generator. Several visits might be necessary to fine-tune the device to control a patient’s particular symptoms. This process is painless. At home, the patient has the ability to switch the stimulation on or off. The device’s batteries generally last three to five years.
Who is a candidate for DBS?
DBS is successful in treating patients as young as 13 years of age; however, it is not for everybody. Generally, DBS candidates are patients under age 75 who:
• Have a Parkinson disease responsive to L-Dopa and a declining quality of life
• Are experiencing worsening of coordination and control of movement with abnormal movements known as dyskinesias which used to become worse with L-Dopa therapy
• Have had an adequate trial of medications A successful outcome depends as much on selecting the right patient as on having a skilled surgical team. That’s why every DBS candidate should first undergo an evaluation conducted by a neurologist, neurosurgeon, psychiatrist and neuropsychologist with special training in DBS.
New advances in DBS For those patients who cannot tolerate or are not considered candidates for traditional DBS surgery, Cleveland Clinic has developed, installed and established training for an interventional MRI suite attached to a conventional operating room, called IMRIS Neuro. The MRI machine is suspended from the ceiling and moved into the operating room only when needed. Guided by feedback from the system, the neurosurgeon can plan and precisely place the leads while the patient is under general anesthesia. Previously, almost all DBS required awake surgery while this advancement now offers patients the option of being asleep.
Are there risks involved with DBS?
As with any surgery, the DBS procedure is not risk free but incidence of adverse events are very less in the hands of experienced neurologist and neurosurgeon. The benefits are far better and outweigh the small risks. There is a risk of brain hemorrhage or stroke that may result in neurological impairments such as paralysis, speech impairment, mental impairment or other neurological problems. Other risks include infection, need for additional surgery, pain and anesthesia-related complications. While there is always a risk of death in brain surgery, this is not common. Most patients will complete the surgery without major complications. A Center for Neurological Restoration patient undergoes DBS surgery for Parkinson’s disease.
Life After DBS
For an appropriate candidate in the hands of an expert team, DBS can mean the difference between unbearable suffering and the ability to reclaim a productive, meaningful life. More than 70 percent of Parkinson’s patients see substantial improvement in all their symptoms, and most people find they can cut back significantly on their medications. The effects of the brain stimulation are reversible and the stimulation can be adjusted without more surgery if a patient’s condition changes.
DR. PUNEET AGARWAL
M.D, D.M(Neurology), FCCN(UCLA,USA)
Ex Asst. Prof Neurology, AIIMS, N.Delhi
HEAD OF NEUROLOGY
Max Superspeciality Hospital
Ph: 011-66116666(O), 9971545666(m),