In Parkinson’s disease (PD) there is slow and progressive loss and deterioration of nerve cells of the brain especially those involved with regulation and control of movements.

In a healthy person, an adequate amount of dopamine (a chemical messenger present in the body) is present in substantia nigra (an area of cluster of nerve cells in the brain). Normally, dopamine is carried by the nerve cells from this area to another cluster of nerve cells known as the corpus striatum where these nerves terminate. Here, along with dopamine, acetylcholine, another chemical messenger, regulates the bodily movements.

In a patient with Parkinson’s disease there is an imbalance between these two chemical messengers. In most of the cases, there is loss of dopamine in the substantia nigra and degeneration of dopamine nerve terminals in the corpus striatum.

Approximately 60-80% of dopaminergic neurons are lost before the motor signs of Parkinson disease emerge. Rarely, the hyperactivity of acetylcholine nerve cells may be the underlying cause of Parkinson’s disease. Another change observed in some cases is the presence of protein clusters known as “Lewy bodies” in the brain, which are characteristic, but not specific of PD.

At present, it is believed that PD is mainly caused by environmental factors and hereditary factors. A genetic predisposition (i.e. higher risk of disease if any close relative is suffering from PD) has been seen in the patients. There are very rare families where PD is inherited.

Oxidative Stress in Parkinson’s Disease

The possible role of environmental risk factors associated with the development of disease include use of pesticides, consumption of contaminated well water, exposure to herbicides, and proximity to industrial plants or quarries. The most accepted theory establishing the link between these factors and degeneration in the brain is that of “oxidative stress”.

The role of oxidative stress (increased levels of free radicals) in PD has been extensively studied. The utilization of energy in the brain can lead to increase in the concentration of free radicals (unstable highly reactive chemical compounds) e.g. hydrogen peroxide. In healthy individuals a balance is maintained between antioxidants and oxidative ions and thus oxidative stress does not occur. But in patients of PD, increased concentrations of free radicals and decreased levels of antioxidants have been observed which lead to nerve damage by lipid per-oxidation and pore formation in the cell membranes.

Drugs that Affect the Brain Chemistry in PD

The presently available treatments are symptomatic i.e. they treat the disease but do not alter the underlying degenerative process. These are helpful in restoring and maintaining function and quality of life for many years. Most of the drugs help in restoring dopamine levels in the brain. They either :

• increase the synthesis of dopamine (e.g. levodopa and carbidopa combination)
• enhance the action of dopamine (e.g. ropinirole, pramipexole)
• decrease the degradation of dopamine (e.g. selegiline – selective inhibitor of MAO-B / Mono amine Oxidase B, an enzyme degrading dopamine)
• inhibitors (tolcapone and entacapone) of another degrading enzyme, COMT / catechol-O-methyl transferase

The symptoms of PD in patients taking certain drugs especially antipsychotics like chlorpromazine can be treated by giving anticholinergic drugs like benztropine. The drugs which increase the dopamine levels are not helpful in these patients. The preventive role of antioxidants is still under study.

Cognitive Abilities in Parkinson’s Disease

Cognitive disturbances, as well as mood and behavior alterations, can be as traumatic and frustrating as any physical problem, both for the patient as well as the caregiver. Cognitive deficits can be present even in the early stages of Parkinson’s disease, gradually worsening as the disease progresses, and may ultimately lead to dementia. A person with PD is at a greater risk of developing dementia and this risk gradually increases in proportion to the duration of the disease.

Cognition relates to higher level functions of the brain and may be defined as the mental process involved in gaining knowledge and understanding, which includes the process of thinking, knowing, learning, remembering, decision making, judging and problem solving. Language, imagination, perception and planning are the necessary components.
People with PD often have trouble processing two cognitive acts simultaneously. Mild cognitive impairment may be present in most people with PD. Stress, depression, sleep disturbances, or medication can lead to such changes.

The cognitive deficits seen in PD patients (subcortical dementia) are similar to those caused by frontal lobe damage. Due to the degeneration of the cells of the part of the brain known as substantia nigra in the basal ganglia, there is deficiency of the chemical transmitter dopamine. As a result, there is dysfunction of the circuits connecting the frontal lobe of the brain and the basal ganglia, causing problems with memory, language, concentration, attention, visuo-spatial functions, and executive function of the brain.

Memory Loss in Parkinson’s Disease

Anything that affects cognition can affect memory too. However, sometimes it becomes difficult to differentiate memory loss or impairment due to PD from that due to normal aging process.

Subcortical cognitive deficits, as seen typically in PD patients, are characterized more by problems with memory recall (especially of recent events) than by memory formation, decrease in mental speed or slowed thinking (bradyphrenia), and apathy. It is not that PD patients suffering from bradyphrenia are unable to think. It is only that their thinking process is slow, so they need time to answer questions or make decisions.

Executive impairment may be more pronounced than language deficit. Executive functions involve higher level thinking skills such as logical thinking, prioritizing, organizing, planning, and executing. Dementia may be accompanied by psychosis, agitation, and sleep disturbances.

Personality Changes in Parkinson’s Disease

Personality changes occur frequently in people with PD. Frontal cortical damage could account for some of the behavioral and personality changes that are seen in PD patients, such as depression, mental lethargy, mood swings, and irritability. On the other hand, obsessive compulsive behavior such as binge-eating, hypersexuality, and pathological gambling may be related to some drugs used to treat PD.

A Parkinson’s personality is often mentioned in relation to PD patients. Certain personality traits have been noted in people with PD which includes being hard-working, ambitious, serious-minded, dogmatic and honest. They are less likely to have any addictions to alcohol, tobacco or drugs. These traits may be present even before the development of PD. One theory that may explain this is that loss of dopamine (which is thought to be responsible for these personality traits) starts long before the manifestation of motor symptoms.

]]> http://pdring.com/brain-functioning-and-personality-changes-in-parkinson%e2%80%99s-disease.htm/feed 7 http://pdring.com/concussion-in-parkinsons-disease-patients.htm http://pdring.com/concussion-in-parkinsons-disease-patients.htm#comments Wed, 30 Sep 2009 23:49:51 +0000 Dr. P.D. http://pdring.com/?p=170 A concussion usually occurs after severe head trauma and this may be a possibility in the end stages of Parkinson’s disease when patients are more prone to falls. Depending on the extent of the head trauma, a concussion may vary in its presentation and is often ignored after an injury, although the full effect may only be realized a day or two after the trauma. In terms of Parkinson’s disease, there is greater difficulty in identifying a possible concussion since some of the Parkinson’s disease symptoms may blur or mask the signs of a concussion.

Concussion Symptoms

The main symptoms of a concussion include memory loss, confusion, changes in balance and coordination, headaches, dizziness, changes in the senses like blurred vision and ringing in the ears and fatigue. Long terms symptoms of a concussion include difficulties in concentrating, problems with sleep, mood changes and depression. As is evident, most of these symptoms are present in Parkinson’s disease, especially at the latter stages of Parkinson’s disease or a result of long term use of Parkinson’s drugs. Since the disease and a concussion may appear so similar, it is important to take note of other aspects like Parkinson’s symptoms that are suddenly aggravated or the appearance of new symptoms which should not just be attributed to progression of Parkinson’s disease. Post concussion syndrome is a condition whereby the symptoms of a concussion may exist for a long period of time, weeks or months, and could also be mistaken for symptoms of Parkinson’s disease long after sustaining a severe head injury.

Concussion Tests & Complications

In the event of a severe fall or head injury, it is important to consider further tests to rule out any possible complications that may arise from a concussion. A CT scan is the main diagnostic investigation conducted after a concussion and it is important to note that even if a patient does not lose consciousness (faint) as a result of the head trauma, they could still sustain a concussion. In the event that immediate medical attention is not sought and the symptoms of a concussion are noted or the patient experiences seizures, a CT scan should still be considered. Complications of a concussion usually involves serious neurological symptoms which may mistaken for Parkinson’s disease and proper emergency care is necessary in instances of a fall or injury.

Since Parkinson’s disease occurs more in the elderly, who are prone to falls and injuries, extra caution should be paid when in the bath tub, walking around unassisted or lying in a bed. Parkinson’s patients, specifically those in institutions, may be victims of abuse which is on the increase among caregivers of the elderly and debilitated. Friends and relatives of a Parkinson’s patient who is an institution should be cautious of any reports of falls, injuries or assault as many institutions may ignore these incidents and not consider further diagnostic investigation after sustaining an injury. If caring for a Parkinson’s patient, it is advisable to take the necessary measures to prevent injuries which may lead to a concussion as a Parkinson’s patient already has to contend with a degenerative disease and complications should be avoided as far as possible.

Early disease

The biggest question once a correct diagnosis of Parkinson’s disease has been made is when to start treatment and the medication used for that treatment. Treatments can vary greatly depending on the age, condition of the patient and understanding of the disease and its treatment that the patient has. In the early stages of the disease depression and anxiety may also play a part in the debilitating symptoms and therefore will become one of the main objects of concern when deciding on initial treatment.

Neuroprotective agents If Neuroprotective agents are identified then they will obviously be the first treatment which is offered to the patient and treatment will commence as soon as possible. However no agent has been known to offer 100% neuroprotection, one medication that has a mild symptomatic effect is Selegiline and this is very often used in the early stages of Parkinson’s disease.

Starting symptomatic therapy

The decision of when to actually begin treatment is one that is made between the patient and their Doctor and several factors are taken into account, these are the degree of impairment, the effects the symptoms are having on the patient’s employment and the patient’s attitude towards taking medication. If the patient fully understands the limitations and benefits they can reap from the medication then their preference will count for a lot in the decision making process.

The patients understanding makes a huge difference because many times over the treatment period they will have to be re-evaluated and have their medication adjusted with the progression of the disease or the patients response to the therapy. It is therefore in the best interests of both parties that they develop a partnership from the very beginning.

The initial treatment options

The patient’s age and condition will make a huge difference to the choice of initial treatment; the drug Levodopa is usually the first choice of medication for those sufferers who are elderly. A dopamine agonist will usually be chosen for the younger patient as younger people are more tolerant of the side effects the drug can produce.

In the younger patients delaying of the onset of motor skills problems is also a huge concern with Selegiline, amantadine or anticholinergic medication being excellent initial treatments for mild symptoms of the disease, providing of course that the side effects most of these medications produce can be tolerated.

If depression and anxiety are one of the concerns then this will usually be treated with medications such as anti-depressants, it is thought that over 50% of all those suffering with Parkinson’s disease will also suffer from depression and anxiety.

Parkinson’s disease is a terrible progressive illness which not only affects the person who has developed it but also puts a strain on those around them who care for them day in and day out. Not only do they have to see their loved ones going from healthy well balanced individuals to invalids, they also have to go about their own daily life and cope with day to day living. Some of the most common feelings the care giver will have are:

Tension and fatigue

More often than not those caring for someone with Parkinson’s will be putting their needs before those of their own, stress and lack of sleep will bring about tension and tiredness in the care giver.

Irritability

Caring for someone in the later stages of Parkinson’s disease will be a 24 hr 7 day a week duty, tension from this will quickly mount if no respite is given. The lack of sleep and worries not only about your loved one but also about coping with life in general can bring irritability to even the calmest person.

Resentment

Resentment is a normal feeling which the care giver will have and they shouldn’t feel ashamed to feel this way, there will also be many other feelings such as guilt, sadness or disappointment again these are all natural feelings given the circumstances.

Anger

Tension will normally bring about feelings of anger we have all felt it at some time in our lives, we will often lash out with hurtful words aimed at those we love only to be horrified and distressed by what we did.

Be able to recognise your limitations

With all the best will in the world we cannot do everything we want to or what we think we should. The care giver will have tremendous responsibilities but they should also know that they can and should ask for help when the stress and strain becomes too much for them to bear.

Talk with someone

Don’t let the pressure get too much before reaching out to someone; this could be a dear friend offering a shoulder to cry on, a counsellor, therapist, doctor or social worker. While your loved one needs help there are times when the care giver does too and everyone understands this but the caregiver themselves.

Learn to spot the signs of stress and deal with them

Common signs of stress are:

• Feelings of tightness in the chest or the inability to take a deep breath.
• Frequent headaches.
• Stomach aches.
• Weight problems either loss or gain.
• Feeling very tearful.
• Withdrawal from social life.
• No interest in sex.
• Turning to alcohol or tranquilizers.
• Grinding of the teeth or pain around the jaws.

Parkinson’s disease is a debilitating, progressive illness which affects a person’s movement; various parts of the body can be affected and symptoms are stiffness in the muscles, difficulty when starting to move and slowness and tremor in the hands when they are at rest. The disease was named after Dr James Parkinson who first diagnosed the disease around the 1800`s.

Why does Parkinson’s disease happen?

The basal ganglia, a part of the brain is affected by the disease, it is a part which plays a vital role in how we control our movement. Cells in the substantia nigra, which is a part of the ganglia produce what is know as dopamine, when someone is affected by Parkinson’s the dopamine producing cells are lost and this then causes a shortage of dopamine in the brain. As for the reason these cells are lost not much is known on exactly why this happens.

The basal ganglia in our brain stores and helps to adjust voluntary movement, it works alongside another chemical messenger which is called acetylcholine, with dopamine playing a crucial role in the steering mechanism which helps the ganglia to put programs of movement together.

The level of dopamine in someone who has Parkinson’s will fall to about 80% and when this happens this steering mechanism in the brain will fail. The body’s internal communication system will then go awry and messages delivered from the brain to parts of the body are interrupted or slowed down and symptoms of Parkinson’s disease then begin to show.

Exactly which parts of the body and how greatly they are affected will differ from person to person although the symptoms of the disease will always get progressively worse as the disease develops over a period of time; this however will usually happen very slowly. Great strides have been made in the treatment of the disease and there is a lot that can be done to alleviate and ward off the symptoms.

How common is Parkinson’s disease?

Parkinson’s disease occurs anywhere in the world though as the disease chiefly affects older people it is more prevalent in developed countries. It is thought that over 700,000 people worldwide do suffer from the disease with over 50,000 new cases being reported every year. Statistics show that roughly 1 in every 100 people who are over the age of 65 will go on to develop Parkinson’s disease.

What are the common signs of the disease?

There are four major diagnostic symptoms of the disease, these are:

• Tremor or shaking particularly when the limbs are at rest.
• Rigidity or stiffness of the joints which can sometimes be very painful.
• Bradykinesia or slowness of movement.
• Postural instability.