or unequal pupil size is an alarming physical sign, leading most of the time to an extensive and expensive neuroradiologic investigation to rule out life-threatening conditions such as cerebral tumor, expanding aneurysm or intracranial bleeding (1, 2).
Within the next eight hours, the anisocoria
resolved and the pupil reduced to 2 mm in size and reacted normally to light.
Afferent pupillary defects do not cause anisocoria
but they do cause abnormal light responses.
and middle cerebral artery saccular (berry) aneurysm in a rhesus macaque (Macaco mulatto).
The ocular examination was also remarkable for anisocoria
(differently sized pupils), as the pupil of the right eye was larger than that of the left eye in both light and dark settings.
He also had anisocoria
(the right pupil was larger than the left), pupillary light reflex was absent in both eyes, and his right eye deviated laterally.
Investigation of third cranial nerve palsies Under 10 years 11 - 50 years >50 years Anisocoria
less MRI, MRA.
This reversal of anisocoria
is easily detected with the naked eye.
Buxton and colleagues reported many possible complications from neuroendoscopy including delay in awakening, pneumocephalus, transient anisocoria
, transient hemiparesis, cerebral infarction, transient fever, meningism, infection, short-term memory loss, diabetes insipidus, inappropriate antidiuretic hormone secretion, transient cerebrospinal fluid leaks, chronic subdural haematomas, traumatic basilar artery aneurysm and hydrocephalus (1).
Such studies have been largely inconclusive, however, because of the inconsistencies in the pupillary measurements and the lack of standard definitions for pupillary dilatation, pathologic anisocoria
Physical examination revealed anisocoria
, ptosis of the left upper eyelid, and strabismus.
This is more accurate than simply observing the pupil with the naked eye and makes it much easier to detect anisocoria
and other pupil abnormalities (particularly in patients with dark irises).
On day 2 (24 hours after initial presentation), anisocoria
any neurological signs such as motor deficit, anisocoria
, meningism and respiratory pattern changes
Physical examination now demonstrated anisocoria
(right pupil 4 mm and left 2 mm) and complete bilateral facial paralysis (House-Brackmann grade VI).