Parkinson's disease - Essay Example

Damaging approximately 60% to 80% of the cells producing dopamine would cause its deficiency and consequently lead to the appearance of PD motor symptoms. The National Institute of Neurological Disorders and Stroke, NINDS (2013) refers to this brain cells impairment process as neurodegeneration. Prevalence and Incidence About 1 million people in the US suffer from PD with between 50,000 to 60,000 new cases being diagnosed annually. Worldwide, between 4 million and 6 million people suffer from PD (National Parkinson Foundation, 2013).

It has been particularly noted to set in at age 50 to 65 with a lower incidence in African Americans as compared to the Caucasians and 3:2 for male to female ratio incidence (Talan, 2011). Motor Manifestation Years before the motor manifestation, people with PD experience non-motor symptoms including sleep disorders, loss of smell, hyposmia and constipation. The Braak’s hypothesis cited by the NPF (2013) observes its earliest signs in the medulla, particularly the olfactory bulb which controls the sense of smell.

It would then gradually progress to the cortex and substantia. Notwithstanding, the four motor symptoms cited by NFP (2013) are cardinal in PD: postural instability, slowness of movement, rigidity and tremor. The well-known symptom of tremor has been referred to as rest tremor by NINDS (2013) as it becomes maximal on rested limbs and disappears with sleep or voluntary movement. It begins with a single leg or arm and later becomes bilateral. The tremors have a frequency of between 4 and 6 Hz. Secondly, the slowness of movement referred to as bradykinesia by NFP (2013) relates to difficulties in the whole movement process: planning, initiation and execution.

This early manifestation hinders simultaneous and sequential movement performance indicated by problems related with performance of fine motor controlled tasks like sewing, writing and dressing up. The magnitude would be determined by one’s emotional state or activity. Rigidity would be manifested by stiffness of the limb and resistance to movement due to excessive continuous muscle contraction or muscle tone. This could be uniform or ratchet referred to as lead-pipe and cogwheel rigidity respectively.

It could be accompanied by pain. Whereas in the early stages it affects the shoulder and neck muscles, it later progresses to the whole body. Finally, the late stages of the disease exhibits impaired balance causing frequent falls and bone fractures due to postural instability. It would be experienced by 40% of the patients. Talan (2011) adds posture and gait disturbances like festination to the list of these motor manifestations. Diagnosis and Detection Initial diagnosis requires the identification of at least two of these four motor manifestations (NPF, 2013).

Bedside examination by a neurologist remains the most basic diagnostic tool for suspect patients. To aid this diagnosis, emergent imaging modalities including PET and DAT scans would be performed by a neuroimaging expert with DATscan playing a critical role of differentiating PD from other essential tremors but cannot indicate the PD subtype. Also to aid in accurate diagnosis would be the need for information on physical and medical examination and also medication history to ascertain the absence of medication that causes symptoms similar to those of PD. The