Question

MK is a 57-year-old woman who recently retired and relocated to a small farm in the country. She decided to take up gardening/farming as a new hobby. About a week ago, she sprayed her plants and garden with pesticides, however she removed her protective gear because it was “hot and obscured my vision”. The past few days she has noticed a loss of sensation in her hands and feet, impaired coordination of both hands (“clumsy”) and feet (“tripping a lot”), and weakness of grip and pinch. She was referred to a neurologist who diagnosed her with a polyneuropathy secondary to exposure to a toxic substance (pesticide). A diagnostic work-up revealed that MK’s polyneuropathy is a result of demyelination of the peripheral nerves.

1.What is the pathophysiology associated with demyelinating disorders, i.e., how does the pathology lead to sensory and motor changes?

2. Is this a CNS or PNS problem and how might that impact her recovery? Discuss the differences that may or may not exist in terms of recovery.

3. What are the implications of this sensorimotor loss on MK’s function?

4. Assuming that MK has learned her lesson and will not expose herself to toxic substances in the future, what is her prognosis in terms of sensorimotor function? Provide a rationale, based on your understanding of neuroscience and your research, to support your answer.

Answer 1

1) myelin sheath is responsible for smooth conduction of nerve impulse and minimize loss of nerve impulse. Secondary Demylenation leads to degradation of myelin sheath along with axon which causes the beaking of conduction pathway of nervous system.

2) it is the PNS problem because the neurons which are responsible for this disease are associated with PNS.

3) the implications of sensorymotor loss include-

Loss of sensation

Numbness

Loss of grip

Inability of sweat properly

4) Prognosis depends on the condition itself. Demylenated neurons cannot be regenerated so the patient has to take care of it. Patient has to remain safe from environmental stimulli that can affect the disease affected area.