What is the incidence and risk for MSA?

Many cases go undetected but MSA is thought to affect approximately 4-5 people per 100,000, primarily 50-60 years old. The incidence is slightly greater in males. The average duration of the illness is 6 years with a range of 4-15 years. The only risk factor is age, as it seldom occurs under 40 years of age. There is no data to support a predisposition due to genetic or environmental factors, though gene research is being explored.3

Diagnosis

A comprehensive physical exam and review of the clinical course of the illness is crucial to accurate diagnosis. A very distinguishing feature between PD and MSA is in PD one exhibits a tremor that is very noticeable at rest. However, in MSA there is little or no tremor and it is more pronounced during voluntary motor activities e.g. lifting an object. Sinemet relieves symptoms of PD, but has minimal if any effect in MSA.1

Diagnostic tests
 
Evaluation of blood pressure (BP) is measured in both arms. Have the patient supine for 3-5 minutes. Using the arm with the higher PB, take the VS every minute for the first 3 minutes while the patient is supine, sitting and standing. If the SBP drops more than 20 mmHg or DBP more than 10 mmHg, it is considered orthostatic hypotension (OH). Document the patient’s subjective symptoms and heart rate. A tilt table may be used for patients who experience imbalance. The patient is safely strapped on a motorized table. The vital signs are measured continuously while the table is tilted upward to vertical position as tolerated.4

MRI and CT scans assist in ruling out neurological diagnoses e.g. tumors, infarcts, NPH(normal-pressure hydrocephalus) etc. and aid in determining the progression of MSA. In MSA-P abnormal signals are in the putamen, a cluster of cells deep in the brain that regulates movement. In MSA-C there is atrophy of the cerebellum and brainstem.1,5. In 63% of MSA cases the pons-T2 weighted MRI reveals the “Hot cross bun sign”, a cruciform hyperintensity.6

PET with fluorodeoxyglucose helps in determining the presence of MSA. It may detect glial intraneuronal cytoplasmic nuclei inclusion bodies, however it is seldom used because it’s very expensive and not readily available.1
 
“The cerebral spinal fluid (CSF) neurofilament light chain and tau tests have been reported to differentiate MSA from PD but remain in an exploratory phase of development.”1

Based on clinical manifestations other tests e..g. urology, sleep and swallow studies may be ordered The only definitive test is autopsy brain cell biopsy showing evidence of alpha-synuclein protein.
 
The role of the nursing is critical in maintaining the patient’s quality of life, potentiating capabilities and preventing complications. “The most common signs in pathologically confirmed cases of MSA are: parkinsonism 87%, autonomic dysfunction 74%, cerebellar ataxia 54% and pyramidal signs 49%:”.2
Potential for injury R/T orthostatic hypotension (OH)

A comprehensive nursing assessment is key to identifying causative factors and instituting specific measures to remedy OH e.g. timing of medications, particularly anti-hypertensives and antidepressants. Symptoms of hypotension can vary from mild fatigue, slowing of thought processes, the inability to participate in ADL’s to falling and sustaining life-threatening injuries. Fatigue and light-headedness may make the patient feel uncertain, fearful, depressed and become socially isolated. Monitoring for supine hypertension is crucial when a patient is receiving meds for hypotension

Vasodilatation, due to prolonged standing, intense physical exertion, rise in environmental and/or body temperature, causes an increased risk for OH.
The autonomic dysfunction inhibits the normal response of vasoconstriction to maintain the blood pressure. Inadequate vascular volume also compounds hypotension. Post-prandial hypotension occurs because the splanchnic-mesenteric vascular bed, is unable to compensate and re-establish equilibrium. The splanchnic-mesenteric bed contains 25-30% of the body’s total blood volume.4

Orthostatic hypotension is managed primarily by patient teaching and medications. Patient compliance is the way to success.
Patient teaching includes the following:

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