Step 1 Q Bank review Flashcards
(24 cards)
What layers does a needle pass through in a spinal tap?
skin –> superficial fascia –> deep fascia –> supraspinus ligament –> interspinous ligament –> ligamentum flavum –> epidural space –> dura –> arachnoid –> subarachnoid space
Where does the spinal cord end?
usually L1-2
where are lumbar punctures done?
L4-5 interspace; subarachnoid space
where is spinal anesthesia given?
into the subarachnoid space (local anesthesia given into CSF in subarachnoid space)
Effects of benzodiazepines v. barbiturates on GABAa receptor
benzodiazepines increase frequency of GABAa channel opening
whereas
barbiturates increase duration of GABAa channel opening
How do benzodiazepines work?
potentiate the effects of GABA at GABA receptor
- -> antianxiety effect
- increase frequency of GABAa channel opening
How do barbiturates work?
increase duration of GABAa channel opening
What are some names of benzodiazepines?
lorazepam, alprazolam, diazepam
What are some things associated with generalized anxiety disorder (GAD)?
- excessive worry about life events
- may be associated with:
- muscle tension
- impaired concentration
- autonomic arousal
- restlessness
- insomnia
How might you begin treatment of GAD (generalized anxiety disorder)?
may begin with benzodiazepines such as lorazepam
Naegleria fowleri What is it? sx? How is it acquired? dx? treatment? prognosis?
- primary amebic meningoencephalitis (PAM): severe prefrontal headache, nausea, high fever, often altered sense of smell
- acquired from diving into warm, freshwater lakes
- amoebae enter brain through cribriform plate during forceful diving
- dx: motile trophozoites in CSF, culture on plates seeded with gram neg bacteria; amebae will leave trails
- treatment: amphotericin B (rarely successful)
- often fatal
Acanthamoeba
- disease/locale
- onset and prognosis
- form/transmission
- dx
- treatment
- disease/locale: keratitis; GAE - granulomatous amaebic encephalitis in immunocompromised patients
- insidious onset but progressive to death
- form/transmission: free-living amebae in contaminated contact lens solution (airborne cysts); not certain for GAE - inhalation or contact with contaminated soil or water
- diagnosis: star-shaped cysts on biopsy; rarely seen in CSF; culture on plates seeded with gram neg bacteria - amebae leave trails
- treatment:
- for keratitis - topical miconazole and propamidine isethionate
- GAE: sulfadiazine (rarely successful)
CNI name type function results of lesion
olfactory
sensory
smells
results of lesions: anosmia (inability to perceive odor)
CNII name type function results of lesion
optic
sensory
sees
results of lesions: visual field deficits (anopsia), loss of light reflex with III
** only nerve to be affected by MS (multiple sclerosis)
CNIII name type function results of lesion
oculomotor motor fxn: - innervates medial rectus, superior rectus, inferior rectus, inferior oblique (extraocular muscles); adduction (MR) most important - raises eyelid (levator palpebrae superioris) - constricts pupil (sphincter pupillae) - accommodates (ciliary muscle) results of lesion: - diplopia, external strabismus (eyes are not properly aligned with each other) - loss of parallel gaze - ptosis (eyelid droop) - dilated pupil - loss of light reflex with 2 - loss of near response (accomodation)
CNIV name type function results of lesion
trochlear motor function - superior oblique depresses and aBducts eyeball (makes eyeball look down and out) - intorts result of lesions: - weakness looking down w/ adducted eye - trouble going down stairs - head tilts away from lesioned side
CNV name type function results of lesion
trigeminal mixed *ophthalmic (V1) fxn: general sensation (touch, pain, temp) of forehead/scalp/cornea lesion: loss of those sensations loss of blink reflex w/ VII *maxillary (V2) fxn: general sensation of palate, nasal cavity, maxillary face, maxillary teeth lesion: loss of those sensations *mandibular (V3) fxn: general sensation of anterior 2/3 of tongue, mandibular face, mandibular teeth & motor to muscles of mastication (temporalis, masseter, medial and lateral pterygoids) and anterior belly of digastric, mylohyoid, tensor tympani, tensor palati lesion: - loss of those sensations - weakness in chewing - jaw deviation toward weak side
trigeminal neuralgia - intractable pain in V2 or V3 territory
CNVI name type function results of lesion
abducens motor lateral rectus - aBducts eyeball result of lesion: - diplopia - internal strabismus - loss of parallel gaze - "pseudoptosis"
CNVII name type function results of lesion
facial mixed fxn: - muscles of facial expression - motor to posterior belly of digastric, stylohyoid, stapedius - salivation (submandibular, sublingual glands) - taste (anterior 2/3 of tongue/palate) - tears (lacrimal gland) result of lesions: - corner of mouth droops - cannot close eye - cannot wrinkle forehead - loss of blink reflex - hyperacusis - Bell's palsy - lesion of nerve in facial canal - alteration or loss of taste (ageusia) - eye dry andred
CNVIII name type function results of lesion
vestibulocochlear sensory fxn: hearing, angular acceleration (head turning), linear acceleration (gravity) result of lesion: - sensorineural hearing loss - loss of balance - nystagmus
CNIX name type function results of lesion
glossopharyngeal mixed fxn: - sense of pharynx, carotid sinus/body - salivation (parotid gland) - taste and somatosensation of posterior 1/3 of tongue - motor to one muscle - stylopharyngeus results of lesions: - loss of gag reflex with X
CNX name type function results of lesion
vagus mixed fxn: - muscles of palate and pharynx for swallowing except tensor palati (V) and stylopharyngeus (IX) - all muscles of larynx (phonates) - sensory of larynx and laryngopharynx - sensory of GI tract - to GI tract smooth muscle and glands in foregut and midgut results of lesion: - nasal speech - nasal regurgitation - dysphagia - palate droop - uvula pointing away from affected side - hoarseness/fixed vocal cord - loss of gag reflex with IX - loss of cough reflex
CN XI name type function results of lesion
spinal accessory motor head rotation to opposite side (SCM) elevates and rotates scapula (trapezius) weakness turning head to opposite side shoulder droop
CN XII name type function results of lesion
hypoglossal
motor
fxn:
- tongue movement (styloglossus, hypoglossus, genioglossus, intrinsic tongue muscles - palatoglossus is by X)
results of lesion:
- tongue pointing toward same (affected) side on protrusion
