What causes paralysis of upward gaze?
The most common cause of vertical gaze palsy is damage to the top part of the brain stem (midbrain), usually by a stroke or tumor. In upward vertical gaze palsies, the pupils may be dilated. When people with this palsy look up, they have nystagmus. That is, their eye rapidly moves upward, then slowly drifts downward.
What nerve palsy causes vertical diplopia?
Trochlear nerve palsy is the most common cause for vertical extraocular muscle weakness and vertical diplopia.
What causes parinaud’s syndrome?
Etiology. Parinaud syndrome (PS) results from lesions affecting structures in the dorsal midbrain (e.g., infarction, hemorrhage, tumors, demyelination, inflammation, infection, trauma, hydrocephalus, and arteriovenous malformations).
What is Comitant diplopia?
Diplopia/ocular misalignment that does not change with the direction of gaze is classified as comitant; diplopia that varies depending on the direction of gaze is termed incomitant and most often indicates extraocular muscle dysfunction.
What causes vertical gaze palsy in PSP?
The vertical gaze palsy of PSP has been attributed to the midbrain pathology affecting the tectum and the superior colliculi.
What is sixth nerve palsy of the eye?
Sixth nerve palsy occurs when the sixth cranial nerve is damaged or doesn’t work right. This causes problems with eye movement. The affected eye may not be able to move away from the midline normally. Sometimes, only the sixth cranial nerve has problems.
What happens when cranial nerve 5 is damaged?
Trigeminal neuralgia is severe facial pain due to malfunction of the 5th cranial nerve (trigeminal nerve). This nerve carries sensory information from the face to the brain and controls the muscles involved in chewing. The cause is usually an abnormally positioned artery that compresses the trigeminal nerve.
What is supranuclear gaze palsy?
Definition. A supranuclear gaze palsy is an inability to look in a particular direction as a result of cerebral impairment. There is a loss of the voluntary aspect of eye movements, but, as the brainstem is still intact, all the reflex conjugate eye movements are normal. [ from HPO]
What is a Disconjugate gaze?
Dysconjugate gaze is a failure of the eyes to turn together in the same direction.
What is crossed and uncrossed diplopia?
So in convergent squint, instead of seeing a single image, 2 images will be seen in the temporal fields of each eye. The left eye sees the image on the left and the right eye sees the image on the right – This is UNCROSSED diplopia. Now we can experience crossed diplopia. Keep your eyes fixated on the computer monitor.
What is Disconjugate gaze?