With thanks to the authors and contributors to the NeuroLogic Exam website (http://medstat.med.utah.edu/neurologicexam) and Pediatric NeuroLogic Exam website (http://medstat.med.utah.edu/pedineurologicexam) retain
Ptosis is the lagging of an eyelid. It has 2 distinct etiologies. Sympathetics going to the eye innervate Muller's muscle, a small muscle that elevates the eyelid. The III cranial nerve also innervates a much larger muscle that elevates the eye lid: the levator palpebrae. Thus, disruption of either will cause ptosis. The ptosis from a III nerve palsy is of greater severity than the ptosis due to a lesion of the sympathetic pathway, due to the size of the muscles innervated. As an aside, the parasympathetics run with the III cranial nerve and are usually affected with an abnormal III cranial nerve.
This is an acute inflammatory demyelinating polyneuropathy (AIDP). It typically comes on several weeks after viral infection, usually, GI or URTI (also sometimes flu vaccine [controversial]). HIV is also known to be a cause. In up to 40% of cases, no precipitating factor can be found. Epidemiology 1-2 per 100 000 In 40% of cases, no cause is found