Exam II Random Mix Flashcards
Acoustic Reflex
- VIII in and VII out
* stapedial contraction to decrease low frequency noises
Otoacoustic Emission
- VIII in and VIII out
- decrease in contractility of outer hair cells in the presence of high frequency noise
- bilateral distribution, the inner hair cells can affect the outer hair cells of both ears
Vestibuloocular Reflex
- 3 neuron Reflex arc
- vestibular afferents project ipsilaterally to the vestibular nuclei which then project (mostly, not entirely) through the MLF to the oculomotor, trochlear and abducens nuclei
Meniere’s Disease
- vertigo, hearing loss, tinnitus, fullness of affected ear
- 20 min-4 hours
- idiopathic endolymphatic hydrops
- men and women affected the same
- 20-50 yo
Benign paroxysmal positional vertigo
- detachment of otoconia in the utricle, allowing them to enter the semicircular canal
- posterior canal
- vertigo and nystagmus
Vertigo
- change in density of cupola and endolymph
* positionally dependent vertigo
Conductive hearing loss
•obstruction, processes that prevent sound from reaching the lymph
Sensoneuronal hearing loss
- damage to hair cells, cochlear nerve fibers, cochlear nuclei
- bone and air conduction loss
Ansomia
•loss of sense of smell •conductive or sensoneuronal Others: •hyposomia •hypersomia •dysomia •olfactory agnosia
Nystagmus
- An involuntary eye movement which may cause the eye to rapidly move from side to side, up and down, or in a circle, and may slightly blur vision
- refers to the fast movement
Presbycusis
• age related hearing loss that is progressive and bilateral due to loss of the stereociliated cells of the Organs of Corti most often at the base (loss of high frequency)
Meibomian glands
Sebaceous gland that prevent the desiccation of tears
Inflammation causes painful styes
Aniscoria
Aniscoria - unequal pupils
Difference in pupil sizes greater in darkness = sympathetic pathway problem
Difference in pupil size greater in bright light = parasympathetic pathway problem
Third Nerve Palsy
•pupil involving
- accompanied by some degree of motility dysfunction and/or ptosis
•pupil sparing
-diabetes or hypertension (microvascular injury to nerve fibers)
-physical compression of the nerve itself as it leaves the brainstem and heads to the orbit —>brainstem herniation and compression by tumors, intracranial aneurysm (junction of PCOM and ICA) angiography for diagnosis
Iris Damage
- damage to iris musculature can cause both parasympathetic-mimicking and sympathetic-mimicking aniscoria - can be ruled out using slit lamp microscopic exam of the iris tissue
- scarring of the pupil to the lens capsule typically freezes the pupil in a smaller state, miming a sympathetic lesion
- injury, such as tearing, of the sphincter muscle mimics a parasympathetic lesion
Horner Syndrome
•interruption of the sympathetic pathway at any point
•miosis (sphincter muscles contracts against a weakened dilator muscle), ptosis (interruption of innervation to Müller’s muscle in the upper eyelid) and anhydrosis (decreased innervation to the sweat glands on the ipsilateral side of the face - disruption of 1st or 2nd order neuron)
•Is t 1st/2nd or 3rd Order neuron??? Pharmacologic testing with eye drops!
-4% cocaine, instilled into both eyes
cocaine blocks the reuptake of NE, causing a build up in the synapse and potentiates pupillary dilation IF NE is present
-hydroxyamphetamine instillation releases NE from an intact neuron 3rd Order - no dilation 1st/2nd Order - dilation
Pharmacologic Aniscoria
•most common is scopolamine patches, post auricular to treat postop nausea or neurology nausea
Light Near Dissociation
- when the near response (pupil constriction to accommodation, or looking at a near target) exceeds the maximal light response (the largest amounts of contstriction with a very bright light)
- unusual finding that can denote some very serious neurological conditions - syphilis (Argyll-Robinson pupil) or tumors/compression of the rectus of the midbrain
Neurofibromatosis
- anterior eye nodules
* glioma
Tuberous sclerosis
•retinal hematomas, hyperpigmented lesions
Thyroid/Graves Disease
•Orbit - bulging due to fibrosis in muscles
Albinism
•Retina - lack of pigment
Osteogenesis Imperfecta
•blue sclera
Rubella
•retina - pigmentary retinopathy
Mucor/Invasive Fungal Disease
•orbit - scrape fungus out of eye
Diabetes
•retina - diabetic retinopathy, proliferative vs. No proliferative
Hypertension
•hypertensive retinopathy
Melanoma
•cancer
Central Retinal Artery Occlusion
- lose vision suddenly and permanently
- cherry red spot secondary to thinned retinal layers in the fovea that allow the color of the pigment epithelium show through
- ”stroke in the eye”
- localizing factors (severely high intracranial pressure), embolus, thrombus
- if caused by emboli phenomenon, insults to the brain commonly follow
Tay Sachs Disease
- deterioration of nerve cells due to accumulation of gangliosides
- cherry red spot secondary to accumulation of sphingolipids within retinal ganglion cells and since the fovea does not contain retinal ganglion cells, the red spot shows through since the fovea receives its blood supply from the choriocapillaris while the surrounding retina is pale due to infarction
Niemann Pick Disease
- accumulation of sphingomyelin
- cherry red spot secondary to accumulation of sphingolipids within retinal ganglion cells and since the fovea does not contain retinal ganglion cells, the red spot shows through since the fovea receives its blood supply from the choriocapillaris while the surrounding retina is pale due to infarction
Diabetic retinopathy
- non-proliferative
- proliferative
- neovascularization
- starts with mild findings: spots of blood in retina, cotton wool spots, edema within macula - diffuse loss of the capillary network within retinal tissue
- as capillaries are lost, nutrition supplied to the area decreases and cellular function declines
- VEGF initiates formation of new blood vessels in an attempt to restore blood flow
- these blood vessels are thin, fragile and do not work well with ocular tissue - they bleed easily and cause damage to the retina and scarring —-> retinal detachment*
Macular Degeneration
•age related
•metabolic by products (drusen) accumulate around the retinal pigment epithelium - non proliferative
•as more accumulation occurs, the boundary between the pigment epithelium and the choriocapillaris breaks down and new blood vessels grow between the layers
these blood vessels are fragile and bleed easily, causing damage to the retinal tissue
•mostly involves macula —> central visual deficits
Amblyopia
•a condition where abnormal vision develops due to the inability of the visual system to receive, develop and process visual signals
Accommodation reflex
•vergence movement, most reflexes involve brainstem or spinal cord, this one involves the cortex!
1) pupils constrict, which improves the optical performance of the eye and increases the depth of field
2) ciliary muscles contract, allowing the lenses to get fatter and so focus the eyes on the nearby object
3) the medial recti of both eyes contract, causing the eyes to converge. This causes the image of the nearby object to fall on both foveae.
Abducens Palsy
- damage to Abducens nerve fiber
* no or limited abduction seen of the involved eye
Gaze Palsy
- abducens nucleus damage
* no or limited abduction in involved eye, no or limited adduction in contralateral eye
Internuclear opthalmoplegia
- damage to MLF
* normal abduction in both eyes, limited or no adduction on the involved side (can be bilateral)
Lower Motor Neuron Damage
- Weakness
- Hyporeflexia
- Fasiculations
- Atrophy
- Hypotonia
Also, fibrillation and giant motor units
Spinal Muscle Atrophies
- genetic diseases where there is a loss of LMN in the anterior horn
- Werdnig-Hoffman: autosomal recessive that affects primarily proximal muscles in people of all ages and is progressive over time
- many SMAs are due to a genetic mutation in the survival motor neuron protein - responsible for transcriptional regulation and cellular trafficking
Myasthenia Gravis
- antibodies attack and degrade nicotinic channels in the NMJ
- eye muscle weakness (diplopia), droopy eyelid, difficult in swallowing, slurred speech, overall tiredness
- edrophonium blocks breakdown of ACh
Apraxia
• a neurological disorder characterized by the inability to perform learned (familiar) movements on command, even though the command is understood and there is a willingness to perform the movement.
UMN Damage
•spinal cord injury, MS (demyelinating disease of the corticospinal and corticobulbar tracts thought to be due to CNS inflammation), amyotrophic lateral sclerosis (degenerationof UMN and/or LMN), cerebral palsy (abnormal development or damage/complications during pregnancy), most common cause? —->vascular events!
- Weakness
- Exaggerated reflexes
- Hypertonia
- Clonus
- Spasticity
Damage to lateral hemisphere of cerebellum
•ipsilateral ataxia, especially pronounced in the limbs
Damage to medial hemisphere of cerebellum
•intention tremors
Damage to vermis
- difficulty coordinating the movements of trunk muscles
* wide based, staggering gait, inability to walk heel to toe
Damage to flocculonodular lobe
- wide based, staggering gait accompanied by vertigo and nystagmus
- deficits in tracking eye movements
Friedrich’s Ataxia
- autosomal recessive
- begins in childhood and leads to impaired muscle coordination that worsens over time
- spinal cord, peripheral nerves and cerebellum degenerate
- awkward, instead movements, impaired memory, loss of tendon reflexes (especially in knees and ankles), scoliosis, dysarthria
- defect in FXN
Lesions of left hippocampus
•trouble with verbal memory
Lesions of right hippocampus
•trouble with spatial orientation
Bilateral damage to medial temporal lobes, including hippocampus and parahippocampal
•amnesia
Retrograde amnesia
•prior to injury
Antergrade
•after the injury
Wernicke Korsakoff Syndrome
•lack of thiamine
•confusion, nystagmus, opthalmoplegia, aniscoria, ataxia, coma
•anterograde and retrograde amnesia, confabulation and hallucinations
•reduction in size and function of mammillary bodies
*alcoholics, gastric surgeries
Damage to higher somatosensory association areas
- unable to coordinate visual and motor functions
* Balint Syndrome
Broca’s Area
- opercular and triangular parts of the left inferior frontal gyrus
- damage causes problems producing language
Wernicke‘ s Area
- posterior part of the left auditory association cortex
* damage causes problems with the comprehension of language
Stroke in ACA
- hemiplegia or hemiparesis of contralateral lower limbs and pelvic muscles; arms and face typically unaffected
- contralateral sensory deficit on lower limbs and pelvic area; hands and face typically unaffected
- no speech impairment
- symptoms of disconnection caused by damage to the corpus callosum and cingulate gyrus
Stroke in MCA
- hemiplegia or hemiparesis of contralateral upper limbs; contralateral lower limbs can also be affected, but to a lesser degree; contralateral lower face,upper ace not affected due to bilateral cortical input
- speech impairment: global aphasia or motor (Broca’s) or sensory (Wernicke) aphasia if stoke is on left side
- spatial hemineglect (if right sided stroke)
- anosognosia
- apraxia and visuo-spatial disorientation (cannot button clothes)
Stroke in PCA
- visual deficits (cortical blindness or homonymous hemianopsia on contralateral side
- prosopagnosia
- visual agnosia (temporal damage to “what” pathway)
- anomia (inabilityto name objects or colours sue to visual association areas)
- amnesia (damage to hippocampus or parahippocampal gyrus)
- spatial deficits (getting lost) due to damage to right hippocampus
- alexia without agraphia (inability to read but able to write) due to damage to visual areas but motor areas in MCA territory are still functional
Damage to fusiform gyrus (occipital-temporal gyrus)
•prosopagnosia
Damage to Right Frontal Inferior Gyrus
•diminished ability to convey emotions through voice and gestures
Damage to Right Superior Temporal Gyrus
•inability to comprehend emotion or emphasis in the voice or gestures of others
Damage to Left Parietal Lobe
- bilateral apraxia
* loss of purposeful movement
Damage to Left Parietal Cortex
•math and reading problems - no math, alexia
Damage to Right Parietal Cortex
•spatial awareness - hemineglect
Damage to Dorsolateral Prefrontal Cortex
•management of cognitive processes - working memory, cognitive flexibility and planning
Damage to Ventromedial Prefrontal Cortex
•moral judgement
Lesions to ventromedial hypothalamus
- overeating, obesity
* overproduction of leptin
Lesions to lateral hypothalamus
•weight loss, decreased appetite, leading to cachexia and death
Disconnection syndromes
•Loss of higher cortical functions
Damage to left CNS
•language aphasias
Meningioma
•A usually noncancerous tumor that arises from the membranes surrounding the brain and spinal cord.
Ageusia
•loss of taste
Pupil reflex
- CN II in, III out
* consensual
Gag reflex
•CN Ix in, CN X out
Gastric Reflex
•CN I, VII, IX in, CN X out
