Neuro Flashcards
Hypothalamic nuclei
- Lateral vs. Ventral
- Anterior vs. Posterior
- SCN
Lateral (hunger) vs. Ventral (satiety)
Anterior (cooling “A/C” - parasymp) vs Posterior (heating- sympathetic)
SCN = circadian rhythm
Thalamic nuclei:
VPL, VPM
LGN, MGN
VL
VPL - STT (pain & temp) & dorsal column/medial lemniscus (touch, etc)
VPM - Facial sensation & taste (trigeminal, gustatory tracts)
LGN = "Light"/vision; MGN = "Music"/hearing VL = motor (from basal ganglia to motor cortex)
Limbic systems structures
= hippocampus, amygdala, fornix, mammillary bodies, cingulate gyrus
for the “5 Fs” (Feeding, Fleeing, Fighting, Feeling, & Fornication/Sex)
Direct pathway in basal ganglia
disinhibits thalamus => STIMULATES mvmt
striatum (D1 from SNc) –l Globus Pallidus interna
=> thalamus free to transmit signal
INdirect pathway in basal ganglia
INhibits motion by inhibiting thalamus, using GABA.
striatum (D2 from SN) –l GPe => STN not inhibited -> GPi –l thalamus
Function of therapeutic hypOventilation
decrease ICP (brain pressure/edema) by decreasing cerebral perfusion
- bc blood flow = controlled by PCO2 level
(ie: in case of stroke or trauma) - Hypoxemia only influences cerebral perfusion when PO2 > 50 mmHg!
Brown-Sequard Syndrome
= hemisection of spinal cord, so mixed sensory, motor & pain Sxs
- IPsilateral: AT level of lesion - LMN & all sensation lost; below - UMN & touch/vibration/proprioception lost
- Contralateral: below lesion - pain & temp sensation lost
AND Horner’s S. if lesion above T1!
Horner’s syndrome
Sxs, scenario
Sxs: Ptosis, Miosis, Anhydrosis (all controlled by descending sympathetics from superior cervical ganglion, via IML in spinal cord)
When: lesion to spinal cord above T1
CNs that innervate the eye muscles
CN III (occulomotor) = SR, IR, MR, IO --> "down & out" if damaged CN IV (trochlear) = SO CN VI (abducens) = LR
Uvula, tongue & jaw deviations w/ CN damage…
- Uvula deviates AWAY from lesion (CN X)
- Tongue deviates TOWARD lesion (CN XII)
- Jaw deviates TOWARD lesion (CN V)
muscles that move the jaw
Open: Lateral Pterygoid (only, “Lateral Lowers”)
Close: Medial pterygoid, Masseter, teMporalis
Glaucoma:
Acute angle closure vs. chronic/open
= optic neuropathy w/ increased IOP
Acute angle closure: painful! sudden vision loss, HARD eyeball, headache do NOT give epinephrine!!
Chronic/open: gradual, not painful
Case:
Infant born w/ port wine stains in V1 distribution, hemiparesis, and mental retardation…
What other risks should be checked for?
= Sturge Weber syndrome (sporadic)
Risks: ipsilateral leptomeningeal angiomas, pheochromocytomas, Glaucoma, and seizures.
Case:
Child with mental retardation, ash leaf spots, and cutaneous angiofibromas (“adenoma sebaceum”).
What other risks should be expected?
= Tuberous Sclerosis (AD) Other risks: - Hamartomas in CNS & skin, seizures - mitral regurgitation & cardiac rhabdomyoma - renal angiomyolipomas.
Case:
Infant born with cafe-au-lait spots. Look for what other problems?
= NF1, NeuroFibromatosis/”vonRecklinghausen’s disease” (AD)
Mut: NF1 gene on chrom. 17
Other risks: Lisch nodules (iris hamartomas), neurofibromas in skin (from neural crest tissue), optic gliomas, pheochromocytomas
Case:
Infant born w/ cavernous hemagiomas on skin. Has family Hx of neuro disorder(s).
= von Hippel-Lindau disease (AD), VHL mut on chrom. 3
Other problems:
- hemangioblastomas in retina, brainstem, or cerebellum
- pheochromocytomas
- bilat. renal cell carcinoma
Case:
Young boy can’t keep up with classmates when playing. To stand up from the ground he “climbs” himself up with his arms. Muscle hypertrophy apparent in both legs.
Duchenne Muscular Dystrophy, X-linked recessive
= deleted dystrophin gene (muscle structural protein)
=> proximal muscle weakness (“Gower’s sign” to stand)
Histo: necrotic muscle tissue
Case:
Young child with kyphoscoliosis, dysarthria, and ataxia.
What neural pathways are affected? What other risks?
= Freidrich’s ataxia (AR) trinucl. repeat in Frataxin gene
(mitochondrial impairment –> excess free radicals)
=> degeneration of spinocerebral tract, dorsal column & DRG.
Risks: hypertrophic cardiomyopathy, DM, foot deformities.
Neural crest derivatives
- PNS
- Ganglion cells (of ANS & CNs)
- Pia mater & arachnoid (“leptomeninges”)
- Melanocytes
- Chromaffin cells (adrenal medulla)
- Parafollicular cells (make calcitonin)
- Bone & CT of pharyngeal arches
Alar plate vs. basal plate
(Embryological components of spinal cord)
Alar => sensory neurons
Basal => motor neurons
Spinal cord level for ankle jerk reflex
S1 (gastrocnemius m.)
Spinal cord level for knee jerk reflex
L2 - L4 (quadriceps m.)
Spinal cord level for biceps jerk reflex AND forearm jerk reflex
C5, C6
Spinal cord level for triceps jerk reflex
C7, C8
