Supporting postive and negative findings for each DDX
I have been having trouble understanding the concept of supporting positive and negative findings for each differential diagnosis. Examinees are required to support each diagnosis with pertinent findings based on history and/or physical examination. However, while reading the FA I have come across several DDX where there are absolutely no positive findings on history of PE.
For example Case 22 on the new FA for CS is about a 66 year old man complaining about a tremor. One of the DDX is "Essential tremor." From what we know pts usually alleviate this tremor with alcohol intake and this is a tremor that gets worse with movement. However, the pt is exhibiting a tremor worsened with rest as well as shuffling gait (Classic Parkinson). How you would support the DDX of Essential tremor when there are no findings to support it?
Also can someone please explain the concept of "negative findings"? Does it refer to any signs or symptoms that are missing as opposed to positive findings?
Thank you so much!!