There are other features in Horner's syndrome like small pupils
, anisokoria ( difference in the size of the pupils in both eyes) in addition to ptosis
which may not be present in myasthenia.
There are various tests to differentiate between the two..
Further evaluation should be done to know the cause of horner's syndrome..
For ptosis of Horner's syndrome surgery can be done..
For myasthenia ptosis medical management is sufficient.
I don't think there is any relation of ptosis to bruise
on the neck...