MBB Vol I: Exam Review
How to remember what basal and alar plate form?
Basal is motor (LMN) and autonomics (preganglionics). Alar is everything else!!
What is the parasympathetic lesion (Hutchinson pupil)?
CN III lesion wherein pupil cannot constrict ever. Anisocoria present.
Right PCA occlusion ...?
Contralateral visual field loss. (Left homonymous hemianopia) Equivalent to optic tract lesion. Also contralateral numbness bc VPL/M of thalamus damage.
Ds vs As (eg dysarthria vs aphasia), how to place them in the brain?
Ds: brain stem dysfunction As: higher cortical regions
In the most basic sense, how do neurotransmitters work in the peripheral nervous system?
Everything is ACh and Nicotinic but SNS inevitably ends up NE and PeNS ends up ACh with Muscarinic.
What's the lateral lemniscus ?
For the auditory pathway. (Cochlear nuclei in pons.)
Infarction of middle cerebral = ?
Internal capsule damage and weak face + limbs. IF PROXIMAL.
What is the afferent pupillary defect (Marcus-Gunn)?
Issue with CN II wherein pupil constricts to consensual but NOT direct light. No anisocoria.
Folate is used to prevent....
Issues in primary neurulation, weeks 3-4 (craniorachischsis, anencephaly, myelomeningeocoele, etc.).
What is the tertiary syphilis response (Argyll-Robertson pupil)?
Lesion to pretectum causing loss of light constriction but not near vision constriction.
Huntington = ...
Psychosis, chorea
What are the nerve root levels for the 5 major reflexes?
Remember the Laverne and Shirley theme song: "12345678 schlamiel, schlamazle!" Because schlamiels and schlamazles have terrible reflexes!!
Relationship between fast fatigable fibers and slow fibers vis a vis recruitment time and composition?
Slow fibers are the first to fire because they have lots of mitochondria and are energy efficient. Weak contractions. Fast fatigable fibers are last to fire because they depend on glycolysis, lacking mitochondria. Strong contractions.
Relationship between fiber size and conduction velocity?
Smaller = slower. Small caterpillar, slow, unmyelinated.
What is the sympathetic lesion (Horner's syndrome)?
Sympathetic deficit wherein dim light does not yield dilation. Anisocoria present.
What's the medial lemniscus?
The somatosensory epicritic lemniscus. Medial is in the middle. It's main, most important, first place, refined.
PICA occlusion?
lateral medullary syndrome Lateral medulla is ipsilateral facial numbness and contralateral spinothalamic tract so opposite side of body. Palatal weakness because of nucleus ambiguus. Vestibular lesion is feelings of vomiting.