<prompt> All are true regarding brachial plexus injury,except -Preganglionic lesions have a better prognosis than postganglionic lesionsErb s palsy causes paralysis of the abductors and external rotators of the shoulder.In Klumpkes palsy, Homers syndrome may be present on the ipsilateral sideHistamine test is useful to differentiate between the preganglionic and postganglionic lesions  <response>: Preganglionic lesions have a poor prognosis as these do not recover and are surgically irreparable. Post ganglionic lesions have better prognosis than preganglionic lesions and histamine test is useful in making the distinction - Apley 