Which sentence is unnecessary and could be eliminated without disturbing the flow and information of the paragraph?
concussions are very serious injuries.
although there is no cure for parkinson's disease, it can be managed
through surgery and/or medications.
repeated concussions may increase a person's risk in later life for
dementia, parkinson's disease, and/or depression.
rest includes both physical and cognitive rest (including going easy on
such activities as school work, television watching and text messaging).

The sentence that can be eliminated is: Rest includes both physical and cognitive rest (including going easy on

such activities as school work, television watching and text messaging).

Explanation:

The paragraph is on Parkinson's disease and concussions. It includes information on how concussions may increase chances of Parkinson's disease or other brain diseases in a person. It explains how through surgery or medications, these diseases can be managed, though cannot be cured.

But the sentence which talks about rest including physical and cognitive rest is out of context and can be eliminated. It talks about school work which is not related to either concession or Parkinson's disease.

the author motivation is to show the power of animal-human relationships.