Search results
Results from the WOW.Com Content Network
Videonystagmography (VNG) is a type of testing used to assess vestibular and central nervous system function through the use of eye movement tracking, specifically evaluating nystagmus. [1] The older version of technology used to perform these tests, known as electronystagmography (ENG), leverages electrophysiological signals.
It can also be used to diagnose the cause of vertigo, dizziness or balance dysfunction by testing the vestibular system. [1] Electronystagmography is used to assess voluntary and involuntary eye movements. [2] It evaluates the cochlear nerve and the oculomotor nerve (CN III). [2] The ENG can be used to determine the origin of various eye and ...
Diagram illustrating the locations of extraocular muscles and ocular cranial nerves. Paresis of the oculomotor nerve (CNIII) reduces the strength of medial rectus, superior rectus, inferior rectus, and inferior oblique muscles, while trochlear nerve (CNIV) and abducens nerve (CNVI) paralysis affect superior oblique muscle and lateral rectus muscle respectively.
Unilateral loss indicates a possible nerve lesion or deviated septum. This test is usually skipped on a cranial nerve exam. [1] The short axons of the first cranial nerve regenerate on a regular basis. The neurons in the olfactory epithelium have a limited life span, and new cells grow to replace the ones that die off.
When the optic nerve is damaged, the sensory (afferent) stimulus sent to the midbrain is reduced. The pupil, responding less vigorously, dilates from its prior constricted state when the light is moved away from the unaffected eye and towards the affected eye. This response is a relative afferent pupillary defect (or Marcus Gunn pupil). [1]
Another nerve tract projects from the abducens nucleus by the medial longitudinal fasciculus to the oculomotor nucleus of the opposite side, which contains motor neurons that drive eye muscle activity, specifically activating the medial rectus muscle of the eye through the oculomotor nerve.
The oculomotor nerve (III), trochlear nerve (IV) and abducens nerve (VI) coordinate eye movement. The oculomotor nerve controls all muscles of the eye except for the superior oblique muscle controlled by the trochlear nerve (IV), and the lateral rectus muscle controlled by the abducens nerve (VI). This means the ability of the eye to look down ...
The nucleus of the oculomotor nerve does not consist of a continuous column of cells, but is broken up into a number of smaller nuclei, which are arranged in two groups, anterior and posterior. Those of the posterior group are six in number, five of which are symmetrical on the two sides of the middle line, while the sixth is centrally placed ...