histology of frontotemporal dementiafrontotemporal lobe degeneration
Inclusions of hyperphosphorylated tau (round Pick bodies G ) or ubiquitinated TDP-43.
what dirupt the BBB (blood-brain barrier) and increase permeability
of medicationshyperosmolar agents (eg mannitol) neurologypharmacology Jul 6, 2020, 3:57 AM HirotoShishido
origins of meningesDura mater— Derived from mesoderm.
Arachnoid mater— Derived from neural
crest.
mechanism of capsaicinCapsaicin causes release and subsequent ☆depletion of substance P, a polypeptide neurotransmitter involved in transmission of pain signals.
On initial application, topical capsaicin causes burning, stinging, and erythema, but persistent exposure leads to a moderate reduction in pain overtime. neurologyUWorld Jun 29, 2020, 6:24 AM HirotoShishido
Charcot-Marie-Tooth diseasehereditary motor and sensory neuropathy
Group of progressive hereditary nerve disorders related to the ☆defective production of proteins involved in the structure and function of peripheral nerves or the myelin sheath.
autosomal dominant and associated with foot deformities (eg, ☆pes cavus, hammer toe), lower extremity weakness (eg, foot drop), and sensory deficits
Degeneration associated with chronic alcohol use☆Cerebellar vermis
→ Truncal ataxia neurologyUWorld SIM2 Jun 20, 2020, 1:43 AM HirotoShishido
cutaneous receptorsadapt quickly
Meisnner corpuscles (two point discrimination, low frequency vibration, position)
Pacinican corpuscles (high frequency vibration)
adapt slowly (on the finger tips)
Merkel discs (light touch, position)
Ruffini corpuscles (joint angle change, slippage) dermatologyneurology Jun 19, 2020, 12:36 AM HirotoShishido
pathophysiology/microscopic findings of prion disease(Prion proteins are found in both neuronal and non-neuronal brain cells and normally existin an alpha-helical structure (PrPC))
Prion disease occurs after a domain in this protein undergoes a conformation change ☆from an alpha helix into beta-pleated sheet isoform (PrPSc [scrapie]), which ☆confers the ability to induce similar conformational changes in other proteins.
medical condition that mimics hydrocephalus☆hydrocephalus ex-vacuo
Appearance ofCSF on imaging C , but is actually due tobrain tissue and neuronal atrophy (eg, Alzheimer disease, ☆advanced HIV, Pick disease, ☆Huntington disease→ caudate atrophy with ☆enlargement of frontal horn of the lateral ventricles). ICP is normal; NPH triad is not seen. neurologyUWorld Jun 15, 2020, 4:31 AM HirotoShishido
cerebral autoregulationless sensitive to the arterial partial pressure of oxygen(hypoxic vasodilation) than than to carbon dioxide(hypercapnic vasodilation)
a rapid increase in CBF is not triggered until the PaO2 level drops below 50 mmHg
decreased cerebral rerfusion→ neurologic sequelae, including ☆generalized weakness, blurred vision, presyncope neurologyrespiratoryUWorld Jun 15, 2020, 4:12 AM HirotoShishido
decorticate and decerebrate posturingDecorticate (flexor) posturing—lesion above red nucleus, presents with flexion of upper extremities and extension of lower extremities
Decerebrate (extensor) posturing—lesion at or below red nucleus(eg. midbrain tegmentum, pons), presents with extension of upper and lower extremities neurologyneurosurgeryUWorld Jun 13, 2020, 5:33 AM HirotoShishido
onset of complications of subarachnoid hemorrhage(SAH)・vasospasm occurs in approx. 30% of patients with SAH 3–10 days(especially 7,8 days) after SAH
・recurrent bleeding occurs in 4–14% of patients with SAH in the first 24 hours (especially in the first 2–12 hours after SAH)
・Hydrocephalus
Occurs in 20–30% of patients with SAH
①Acute obstructive hydrocephalus
Usually occurs within minutes to hours after SAH
② Chronic communicating hydrocephalus
Usually occurs weeks or months after SAH neurologyneurosurgeryUWorld Jun 12, 2020, 3:17 AM HirotoShishido
axonal reactionReaction of neuronal cell body to axonal injury.
Changes reflect protein synthesis in effort to repair the damaged axon.
・☆Round cellular swelling
・☆Displacement of the nucleus to the periphery
・☆Dispersion of Nissl substance throughout cytoplasm neurologyUWorld Jun 4, 2020, 10:44 AM HirotoShishido
changes in postsynaptic muscle cells in myasthenia gravis(MG)decreased numbers of functional acetylcholine receptors at the neuromuscular junction
→ The decrease in the number of available cation channels ☆reduces the end plate potential following acetylcholine release.
→ Because the threshold potential is not reached, the muscle cells do not depolarize.
(Synaptic concentrations of acetylcholine are unaffected, unlike in botulism or Lambert-Eaton syndrome.) neurology Jun 1, 2020, 4:17 AM HirotoShishido
which structure is targeted at by high-frequency deep brain stimulation(DBS) for medically intractable symptoms of Parkinson disease?globus pallidus internus or subthalamic nucleus
(stimulation of ventral intermediate nucleus of the thalamus may lessen excessive movements of essential tremor) neurologyneurosurgeryUWorld May 31, 2020, 8:51 AM HirotoShishido