Chapters 7 - Neurological Disorders 04. Parkinson's Disease

04. Parkinson's Disease

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Parkinson's disease [ 54 , 79 , 187 ] was first described in 1817 by an English physician James Parkinson [ 74 ] which she kept the name. It is a degenerative disorder of the central nervous system disorders primarily responsible for progressive evolution engines. Its causes are poorly understood.

The clinical picture of this disease is the consequence of the loss of neurons in the locus Niger [ 38 ] and impairment of nigro-striated [beams 31 ]. The disease usually begins between 45 and 70 years [ 74 ]. This is the second neurodegenerative disease [ 79 , 91 ], after Alzheimer's disease.

Parkinson's disease is characterized parkinsonian syndromes [ 191 ] which are generally of various origins, generally more severe and more or less respond to treatment.

1. Pathophysiology:

It is a neurodegenerative disorder characterized by the premature death of neurons, mainly those of the black substance (substantia nigra - locus Niger) [ 187 ]. This part of the brain, housed in the midbrain-diencephalon junction is involved in the control of movement in part due to the secretion of a neurotransmitter called dopamine [ 41 ].

Loss of dopaminergic neurons is that there is more than enough dopamine in the striatum amount, and the gradual evolution explains how the disease goes undetected for many years.

The first clinical signs appear only after the destruction of at least about 70% of the neurons [ 192 ] locus Niger.

Over time, other neural structures may be affected, involving other neurotransmitters responsible for the other faculties such as memory control, emotions, balance, blood pressure, sphincters and sexuality [ 191 ] .

2. Diagnosis:

Symptoms of Parkinson's disease are multiple. They are not always very specific, and the disease may begin with waves disorders such as peri-articular pain, depression or fatigue.

At the beginning of the disease, the symptoms are characterized by unilateral aspect [ 79 , 91 ]. These symptoms include:

  • Tremors [ 69 ] They are most evident at rest persist even during sleep and worsen with emotion. They mainly affect the upper limbs, particularly the hands, the head does not shake. They are often a social embarrassment but rarely cause a major handicap.
  • Akinesia [ 185 ]: This is the difficulty to initiate or continue movement, loss of automatic movements.
  • Body rigidity [ 187 ]: excess tension in the muscles leads to a permanent rigidity, increased resistance movements, approach slowly, falls, loss of balance and curvature to the front of the spine.
  • Disappearance of facial expressions: The face becomes expressionless.

3. Treatment:

The treatment of Parkinson's disease has progressed significantly in recent years.

3.1. Drugs:

No drug has demonstrated efficacy on the progression of Parkinson's disease [ 193 , 194 ], there is no cure for the disease. Drug treatments are therefore still purely symptomatic [ 96 ].

Levodopa or L-dopa [ 187 ] is a dopamine precursor used in therapy as dopamine does not cross the blood-brain barrier [ 1 , 41 ]. The L-dopa provides symptomatic relief in many patients. It is converted to dopamine in the brain and covers the needs level lack regions thereof. However, after several years of treatment, levodopa gradually reveals effective [ 31 ].

Other drugs may be administered alone or in conjunction with L-dopa: dopamine agonists [ 79 ], the enzyme inhibiting dopamine degradation [ 178 ] or enzyme inhibiting degradation of levodopa in the blood.

Other treatments may be administered to alleviate tremors, this anticholinergic drugs [ 185 ] which are prescribed alone or in combination with the foregoing.

Some symptoms such as loss of balance, falls of tension, mood or memory impairment respond poorly to antiparkinsonian drugs because they are caused by damage to other brain circuits not being involving dopamine, and therefore require other types of drugs.

3.2. Deep brain stimulation [ 69 ]:

When medications no longer provide the expected benefits, it is possible in some patients to implant in certain brain regions connected to a stimulator (pacemaker) to improve the functioning of damaged areas electrodes.

3.3. Physical rehabilitation:

Parallel to drug treatment, physical rehabilitation (physical therapy [ 193 ], occupational therapy [ 191 ] and speech therapy [ 195 ]) is an essential complement. It will keep the necessary flexibility in the pursuit of motor activities.