Essay on Parkinson’s Disease

The first layer of the brain is the cortex which covers the top and sides of the brain. This area controls reasoning and language, and this area will be less active when under sedative drugs. The basal ganglia are located underneath the cortex and it is made up of by the striatum. The striatum controls muscle tone and is part of the dopamine pathway which is a potential transport highway for psychoactive drugs. The hypothalamus is at the base of the brain and serves as liaison between the brain and pituitary gland.

The basal ganglia, otherwise known as the basal nuclei, is the structure in the brain responsible for controlling movement. Specifically, the basal ganglia are responsible for the inhibition of muscle tone throughout the body; the selection and maintenance of purposeful motor activity, as well as the suppression of useless or unwanted patterns of

Parkinson’s disease is a “neurodegenerative disorder of the basal nuclei due to insufficient secretion of the neurotransmitter dopamine” (Marieb & Hoehn, 2013, p. G-17). The cause of Parkinson’s disease is unknown, but many factors play a role in the development of Parkinson’s disease. One factor that has been found in an individual who has Parkinson’s disease causes over activity of targeted dopamine-deprived basal nuclei. This over activity is caused by the breakdown of neurons that release dopamine in the substantia nigra (Marieb & Hoehn, 2013). Another factor that is present in a person who has Parkinson’s disease, is the presence of lewy bodies in the brain stem ("What is lbd?," 2014). Lewy bodies are unusual

In Parkinson's Disease and Huntington's disease the nigra-striatum neural communication assemblage is severely hampered. PD results from a depletion in the amount of dopamine produced by the brain. At the onset of the disease, dopamine-secreting cells of the substania nigra, either because of genetic factors or environmental toxins, experience mass cell death. Thus, the nigra cells are unable to form synapses through which they secrete and relay dopamine to the striatum in a neural circuit within the basal ganglia (18).

Some dopaminergic (i.e., dopamine-releasing) neurons run from the substantia nigra to the corpus striatum; their loss gives rise to the clinical manifestations of Parkinson's Disease (Korczyn 1994); others, involved in the rewarding effects of drugs and natural stimuli, run from the mesencephalon to the nucleunucleus accumbens.

Then information from the sensory cortex is sent to the to motor cortex. Her motor cortex processes incoming motor neurons and is responsible for controlling, planning and executing movement. The premotor cortex influences motor movement through connections with the primary motor cortex and with connections of axons in the corticospinal and corticobulbar pathways. This influences lower motor neurons of the brainstem and the spinal chord. Laila’s primary motor cortex is responsible for working with other motor areas to plan and coordinate movement.

Parkinson disease is a neurodegenerative disorder affecting primarily the patient’s motor function. The disease is characterized by rigidity, tremor at rest, bradykinesis, and decreased postural reflexes (Bollinger, Cowan, LaFontaine, Ronai, 2012). Parkinson disease was largely documented and brought to the forefront by James Parkinson, who published an article discussing the condition in 1817 (Lees, 2007). While great strides in understanding and treatment have been made, Parkinson disease is still considered an idiopathic disease (Lau & Breteler, 2006). Many areas of the disease process have been noted, but no one has been marked as the primary causative process, as well as little has been solidified in diagnostic procedures

neurons in the substantia nigra in case of Parkinson’s disease, motor neurons in the motor

Parkinson’s disease is affected by the degeneration of dopaminergic neurons which is responsible to produce dopamine. Dopaminergic neurons have their cell bodies in substantia nigra pars compacta (SNpc) in basal ganglia (O’Sullivan and Schmitz, 2007). Basal ganglia are a collection of interconnected gray matter nuclear masses deep within the brain”. These gray matter masses are caudate, putamen, globus pallidus, subthalamic nucleus and the substantia nigra. Basal ganglia receive its input through striatum (O’Sullivan and Schmitz, 2007).

The basal ganglia are a collection of deep nuclei situated outside the central nervous system, located within the white matter of the cerebral cortex (Grants.hhp.uh.edu, 2018). Gilman and Newman (2003) explain that the basal ganglia are comprised of subcortical nuclei belonging to the telencephalon, midbrain, and sub-thalamus. The basal ganglia control several motor and cognitive functions of the cerebral cortex (Gilman and Newman, 2003). The cerebellum aids the basal ganglia in ensuring smooth and coordinating motor movement (Grants.hhp.uh.edu, 2018).

In terms of motor control, the basal ganglia is composed of interconnected nuclei located in the telencephalon, diencephalon, and midbrain which include the striatum, globus pallidus (GP), entopeduncular nucleus (globus pallidus internal in humans), subthalamic nucleus, and the substantia nigra (figure1) (6,8). Although there are multiple structures that partake in the modulation of movement, the basal ganglia serves to integrate information deriving from the parietal, frontal, and temporal cortex. In particular, electrical stimulation from the cortex to the striatum derive from regions implicated in the planning and execution of motor movement (6). All of this information converges and activates GABAergic medium spiny neurons (9). Of note,

Parkinson’s disease (PD), is a neurodegenerative disease of the brain affect nerve cells that associated with control normal movement and balance. The mechanism of PD start when loss of dopamine neurons that’s produced by nerve cells in substantia nigra . Dopamine is a neurotransmitter or chemical messenger that helps in transmission of signals between neurons in the brain . The etiology of PD is idiopathic, and it is supposed to be due to many risk factors such as, mutation in gene , age and exposure to some pesticides.

Parkinson disease (PD) is a progressive neurodegenerative disorder characterized mainly by physical and psychological disabilities. This disorder was named after James Parkinson, an English physician who first described it as shaking palsy in 1817 (Goetz, Factr, and Weiner, 2002). Jean- Martin Charcot, who was a French neurologist, then progressed and further refined the description of the disease and identified other clinical features of PD (Goetz, Factr, and Weiner, 2002). PD involves the loss of cells that produce the neurotransmitter dopamine in a part of the brain stem called the substansia nigra, which results in several signs and symptoms (Byrd, Marks, and Starr, 2000). It is manifested clinically by tremor,

Rationale: Parkinson’s disease is caused by the degeneration of nerves responsible for the production of the dopamine (inhibitory neurotransmitter) within the basal ganglia inside the substantia nigra. Nerve fibers that connect the corpus striatum and substantia nigra are responsible for complex body movements, such unconscious movement, control of position, and posture by the balancing of acetylcholine (excitatory), and dopamine (inhibitory). The loss of dopamine creates an imbalance and causing the manifestations of Parkinson’s disease (Karch, 2013).

The circuits of the basal ganglia are connected with the corticospinal cerebellar system, with the the motor cortex, with the thalamus and with the premotor and supplemental motor association areas for movement control. In fact, when associated with the corticospinal system, the basal ganglia control complex patterns of motor activity such as writing a letter, cutting paper with scissors, vocalization and controlled movements of the eyes. The relations between this circuits are complex, but it has to be said that the caudate and the putamen send information back to the cortex by passing first at the ventrolateral and ventroanterior nuclei of the thalamus.