Neurology 2 Flashcards
angular acceleration perceived by
Perceived by the hair cells (crista) forming the cupula, located in the ampulla of the semicircular canals
linear acceleration perceived by
Perceived by the hair cells found in the horizontally oriented utriculus
and
the vertically oriented sacculus.
Otolith crystals cover the surface of these hair cells
where are the vestibular nucleus?
pons
name the vestibular nuclei
○ Vestibular nucleus (Bechterew)
○ Lateral vestibular nucleus (Deiters)
○ Medial vestibular nucleus (Schwalbe)
○ Inferior vestibular nucleus (Roller)
degree of nystagmus
● 1st degree: Nystagmus appearing only when looking in the direction of the quick component
● 2nd degree: Appears when looking straight ahead
● 3rd degree: Nystagmus present in any direction of the gaze
where is the peripheral nystagmus lesion located
Caused by
* dysfunction of the labyrinth
* traumatic, toxic, or inflammatory damage of the vestibular nerve
* damage to the Scarpae ggl
* Meniéres syndrom
where is the central nystagmus lesion located
Causes include dysfunction of
* vestibular nuclei
* gaze centers in the brainstem and the
cerebellum.
what is meniers
Caused by increased pressure of the endolymph within the membranous labyrinth, due to a
disorder of endolymph resorption
- intens vertigo, vomiting, tinnitus
what are the lower cranial nerves
CN 9, 10, 11, 12
CN X lesion signs
○ Aphony and respiratory difficulty (paralysis of vocal chords - recurrent laryngeal n.)
○ Dysphagia, regurgitation of fluids through the nose, pharyngeal and laryngeal spasm
○ The paralyzed soft palate is drooping on one side, speech has a nasal character
○ The uvula is pulled to the intact side
○ Loss of sensation in the larynx, the pharynx and the external auditory cana
typical cause of CN XI lesion
The most common cause of accessory n. lesion is surgical procedure in the lateral region of the
neck (LN biopsy or tumor removal)
differentiate between upper and lower CN XII lesion
Supranuclear damage:
○ Causes weakness of contralateral half of the tongue (w/o fibrillation or atrophy)
○ deviates to contralateral side of lesion
Lower motor neuron lesion:
○ Results in atrophy of the tongue on the side of the lesion
○ Tongue deviates to the side of the lesion when asked to protrude.
○ Fibrillation, fasciculation and atrophy
define bulbar palsy
● Lesion of the brainstem nuclei, intramedullary axons and the cranial nerves exiting the brainstem
(CN IX, X, XI or XII)
● Symptoms identical to those of lower motor neuron lesion; weakness, muscle wasting,
fasciculation, loss of reflexes
brainstem blood supply
Midbrain - Posterior cerebral artery
Pons - Basilar artery, superior cerebellar artery
Medulla - Vertebral artery, posterior inferior cerebellar artery
nerve involved in diplopia
Abducent and Occulomotor
