Neuro - Stuff Missed Flashcards
Tabes dorsalis
degeneration of dorsal spinal columns and nerve roots in patients with tertiary syphillis
JC virus
can cause chronic CNS demyelonation through infection of oligodendrocytes (e.g. progressive multifocal leukoencephalopathy)
Histo changes in brain 12-48 hours after infarct
“Red neurons” (Eosinophilic cytoplasm, pyknotic nuclei, loss of Nissl substance)
Histo changes in brain 24-72 hours after infarct
Necrosis and neutrophilic infiltration
Histo changes in brain 3-5 days after infarct
Macrophage infiltration and phagocytosis
Histo changes in brain 1-2 weeks after infarct
Microscopic: reactive gliosis and vascular proliferation around necrotic area
Macroscopic: Liquefactive necrosis: well-demarcated soft area (1 week - 1 month)
Histo changes in brain > 2 weeks after infarct
Microscropic changes: Glial scar
Macroscopic changes: Cystic area surrounded by gliosis (> 1 month)
Pupillary light reflex
assessed by shining light in eye and observing the response in that eye (direct) and opposite eye (consensual)
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Nerves responsible for pupillary light reflect
Afferent limb: CN II (optic nerve)
Efferent limb: CN III (occulomotor nerve)
CN III
Somatic: innvervates and inferior, superior, medial rectus, inferior oblique, and levator palpebrae
Parasympathetic fibers: contract iris sphincter and ciliary muscle
Signs of CN III palsy
- Ptosis (due to paralysis of levator palpebrae)
- “Down and out” gaze - due to unopposed actions of LR and SO
- Fixed dilated pupil and loss of accomodation - loss of PS fibers
Absence of corneal reflex can result from lesions involving which CN?
CN V1 (afferent limb) CV VII (efferent limb)
Inward deviation of left eye is caused by a lesion to what?
CN VI - result of unopposed action of CN III
Meningiomas
located to cerebral surface
- parasaggital meningomas can cause contralateral spastic paresis of leg due to compression of leg-foot motor area
Tinnitus and unilateral hearing loss are associated with which tumors?
Cerebellopontine angle tumor (e.g. acoustic neuroma)
Headache and anosmia associated with which tumors
Meningioma located in olfactory groove
Bitemporal heminopia associated with which tumors?
Pituitary adenomas and craniopharyngiomas
due to compression of central part of optic chiasm
Meningiococcal pilli
responsible for epithelial attachment to nasopharynx
- responsible for preventing invasion and disease
Common causes of Down’s Syndrome
- Trisomy 21 (95% of cases)
- Unbalanced Robertsonian translocations (usually 14 and 21)
- Mociaism: patients have two cell lines: one normal and one with trisomy 21
Uniparental disomy
when patient inherits two copies of a chromosome from one parent and no copies of a chromosome from the other.
Symptoms associated with pineal tumors
- Precocious puberty - caused by B-hcG production
- Parinaud syndrome
- Obstructive hydrocephalus
Precocious puberty
in males: enlarged genitalia with pubic and facial hair younger than 9
in females: appearance of breasts, pubic hair before age 7
– if associate with paralysis of upward gaze then that suggests hormone secreting tumor
Parinaud syndrome
paralysis of upward gaze and of convergence - these symptoms due to compression of tectal area of midbrain
Lateral medullary syndrome (Wallenberg(
- due to lesions of lateral side of medulla
leads to contralateral loss of pain and temperature sensation along ipsilateral paralysis of CN V, IX, X, XI