CNS Anatomy Flashcards
What cranial nerves and other structures run through the cavernous sinus?
Oculomotor, Trochlear, Ophthalmic (V1), Maxillary (V2), Abducens, internal carotid artery
What are the most common pineal-region tumors?
Germinomas
Frontal eye fields are cortical areas that generate saccades in the _____ direction.
Contralateral
What is the medial longitudinal fasciculus?
It links the 3rd cranial nerve on one side with the 6th cranial nerve on the other side, ensuring simultaneous activation of the medial and lateral rectus muscles to preserve conjugate gaze.
What is treatment for optic neuritis (blurry vision and eye pain on movement)?
IV steroids followed by oral taper.
What is the afferent pupillary defect?
In patients with an APD, the direct pupil response is impaired. As such, the affected eye will paradoxically dilate when a flashlight is swung from the unaffected eye to the affected eye. When the flashlight is held in front of the unaffected eye, both pupils will constrict due to preservation of the consensual pupil response. When the eyes are simply observed together in ambient light, each eye perceives the same average amount of light and the pupils will therefore be the same size.
MS symptoms can be temporarily worsened by what?
Heat, hot baths. Called Uhthoff’s phenomena.
Which vitamin deficiency has been linked to an increased risk of developing MS?
Vitamin D - less common near equator
What is L’Hermitte’s sign?
Electrical shock sensations in the limbs and body brought on by movement of the neck, due to pathology of cervical spinal cord.
What is Fingolimod (Gilyena) and how does it work?
First oral MS drug - blocks T-cell egress from lymph nodes. Can cause first dose bradycardia.
Scale to measure MS disability?
Expanded Disability Status Scale (EDSS).
What is Neuromyelitis optica (Devic’s Disease)?
A demyelinating illness characterized by optic neuritis (often bilateral), transverse myelitis, brain MRI non-diagnostic for MS, and NMO-IgG seropositivity (against BBB astrocytes).
Intractable hiccups and nausea/vomiting in NMO patients - where is the lesion?
Area Postrema
Electrical shock pain in the posterior tongue and pharynx.
Glossopharyngeal neuralgia
Best initial treatment for trigeminal neuralgia?
Carbamazepine
Trigeminal neuralgia may be the presenting symptom for what disease?
MS
The trigeminal nerve innervates what?
Muscles of mastication
The trigeminal nerve carries the afferent limb of the _____ reflex, causing what?
Corneal reflex - causes eyes to blink if irritated.
What is the most common form of hearing loss in the elderly?
Presbyacusis - progressive bilateral symmetrical age-related sensorineural hearing loss.
Which muscles act to dampen sounds when talking or chewing?
The Tensory Tympani (Trigeminal nerve) and the Stapedius muscle (seventh nerve).