Parkinson disease: Nursing pathophysiology

Parkinson disease or PD is a progressive neurodegenerative disorder that primarily impacts movement and results from loss of dopamine producing neurons in the brain.

Now, motor activity is regulated by complex neural circuits within the brain. One of the main structures responsible for motor activity is the basal ganglia also called the basal nuclei located deep within the cerebral hemispheres of the brain.

The basal ganglia are a group of interconnected structures that are mainly involved in the planning execution and termination of motor activity through their connection with other parts of the brain.

These include the thalamus which serves as a major relay station in the brain and cerebral cortex which is responsible for many of the brain's higher functions like reasoning and problem solving and which also contains the motor cortex.

One important part of the basal ganglia is called the substantia nigra. This structure contains dopaminergic neurons that produce dopamine, a neurotransmitter involved in motor function and the fine tuning of movements.

Dopamine also inhibits the excitatory effects of neurotransmitters produced in other parts of the basal ganglia like acetylcholine.

In addition to its key role in motor activity, the basal ganglia are also involved in coordinating cognitive behavioral and emotional functions through connections to the limbic system which like the basal ganglia is a group of interconnected structures.

The limbic system is sometimes called the emotional brain due to its role in regulating emotions and behavior. Ok.

So PD is classified as primary or idiopathic and secondary or acquired. Although there's no known cause for most cases of primary PD, the incidence increases with age.

Other cases are related to familial or genetic factors, including those associated with the formation of Lewy bodies which are aggregations of dysfunctional proteins in the brain called alpha synuclein.

That play a role in neurotransmission including regulating dopamine release. Lastly, those who are biologically male have an increased risk of PD.

On the other hand, secondary PD is caused by conditions like head trauma, infection or brain tumors or through exposure to environmental toxins such as pesticides, herbicides and heavy metals.

Additionally, certain medications like antiemetics or neuroleptics can cause PD, which is typically reversible. Now, regardless of the cause of PD.

Pathophysiology includes mitochondrial dysfunction from oxidative stress along with the loss of nerve growth factors. This results in degeneration of dopaminergic neurons in the substantia nigra and a deficiency of dopamine with less dopamine present.

There's a relative excess of acetylcholine and its excitatory effects are unrestrained. Ultimately, this results in unregulated muscle movement as well as other neurologic symptoms.

Ok. So, clinical manifestations of PD develop slowly and worsen over time signs and symptoms of PD can be broadly categorized as motor and nonmotor.

One of the earliest motor symptoms of PD is a resting tremor or involuntary shakiness at rest. Most notable in the hands.

This is characteristically called a pill rolling tremor because it appears as though someone is rolling a pill between their thumb and index finger, eventually resting tremors can involve the jaw, tongue and feet.

Other motor symptoms include muscular rigidity and stiffness. For example, rigidity in the jaw can result in a mask like facial expression as well as difficulty swallowing or dysphasia and difficulty speaking, known as dysarthria.

Another example is cogwheel rigidity or stiffness causes a series of catches or stalls as an individual's arms or legs are passively moved by.

Another individual. Those with PD often have bradykinesia or slow voluntary movement or akinesia, which is an absence of movement initiation altogether.

As a result, patients may report that their legs freeze when trying to walk and some develop a shuffling gait, meaning they take short shallow steps.

Additionally, over time, postural instability results in a stooped posture causing difficulty with balance and increasing fall risk.

Now, nonmotor symptoms are thought to result from dysfunction and dopaminergic signaling in other parts of the brain. These include sleep impairment, decreased sense of smell, difficulty concentrating depression, and later on dementia.

Autonomic nervous system changes may also occur such as excessive sweating, hypertension, urinary retention and constipation.

All right. As a quick recap.

Parkinson disease is a progressive neurodegenerative disorder that results from a loss of dopamine producing neurons in the brain.

Most cases of PD are of unknown origin. Although genetics are thought to play a role.

Other cases are acquired through disorders or exposure to environmental toxins or certain medications. Risk factors include advanced age and being biologically.

Male. Clinical manifestations develop slowly over time and include motor symptoms such as tremors, rigidity and bradykinesia and nonmotor symptoms like sleep disturbances and