Sixth Cranial Nerve Palsy
Cranial Nerve Palsy
With an Emphasis on
Sixth Cranial Nerve Palsy
I. What are Cranial Nerves? * Cranial nerves are nerves that come directly from the brain stem in contrast to spinal nerves which come from segments of the spinal cord. * There are twelve Cranial nerves in humans that fit this description. * They mainly serve the motor and sensory systems of the head and neck region; except for the tenth and the eleventh nerve. * These nerves are divided to provide one or a few specific functions, and all of them can develop problems.
II. Cranial Nerves and Functions * Olfactory Nerve: Smell * Optic Nerve: Vision * Oculomotor Nerve: Eye Movement; Pupil Dilation * Trochlear Nerve: Eye Movement * Trigeminal Nerve: Somatosensory information (touch, pain) from the face and head; muscles for chewing * Abducens Nerve: Eye Movement * Facial Nerve: Taste * Vestibulocochlear Nerve: Taste * Glossopharyngeal Nerve: Taste * Vagus Nerve: Sensory, Motor and Autonomic Functions of Viscera (glands, digestion, heart rate, etc.) * Spinal Accessory Nerve: Controls muscles used in head movement * Hypoglossal Nerve: Controls muscles of the tongue
III. Cranial Nerve Malfunctions * Nerve 1 (Olfactory Nerve: Anosmia (loss of smell) * Nerve 2 (Optic nerve): Anopsia (loss of vision) * Nerve 3 (Oculomotor): Strabismus, diplopia or double vision, ptosis, pupil enlargement and loss of focus * Nerve 4 (Trochlear): Double vision and strabismus (head leans to injured side) * Nerve 5 (Trigeminal): Trigeminal neuralgia * Nerve 6 (Abducens): Cannot turn eye laterally (abduct) * Nerve 7 (Facial): Bell's palsy, loss of taste, inability to close eyelid * Cranial Nerve Malfunctions (con.) * Nerve 8 (Vestibulocochlear): Vertigo, nystagmus, tinnitus, hearing, balance * Nerve 9
Cited: Beers, Mark H., and Robert Berkow, eds. The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 1999. "Sixth Nerve Palsy." Sixth Nerve Palsy. Wikipedia, 16 Nov. 2008. Web. 05 October 2009. <www.en.wikipedia.org/Sixth_nerve_palsy>.