Chapter 8 Flashcards
olfactory dysfunctions
destruction of the olfactory bulb, tract, and primary cortex results in ipsilateral anosmia
- damage to the olfactory system can occur from traumatic brain injury, cancer, infection, inhalation of toxic fumes, or neurodegenerative diseases such as Parkinson’s disease and Alzheimer’s disease
clinical tests to detect damage to the olfactory system
- presenting the patient with odors via scratch-and-sniff cards
- by having the patient close their eyes and try to identify common available odors like coffee or peppermint candy
- other diseases that inhibit or eliminate the sense of smell, such as chronic colds or sinusitis, must be excluded before making the diagnosis that there is permanent damage to the olfactory damage
hyposmia
a reduced ability to detect odors
anosmia
the complete loss of the sense of smell
dysosmia
a distorted or altered sense of smell
- includes parosmia and phantosmia
parosmia
a distorted perception of a real odor
phantosmia
the perception of a smell that isn’t actually there (olfactory hallucination)
hyperosmia
rare condition typified by an abnormally heightened sense of smell
olfactory hallucinations
caused by lesions of the uncus or seizures in the uncus
uncus
anterior extremity of the parahippocampal gyrus
clinical tests to detect optic deficits
- Snellen chart tests visual acuity
- Rosenbaum card is a miniature scale version of Snellen chart for testing visual acuity at near
retinal detachment
separates the retinal cells from the layer of blood vessels that provides oxygen and nourishment to the eye
- can lead to blindness
- warning signs may include one or all of the following: reduced vision and the sudden appearance of floaters and flashes of light
testing visual fields and defects
- confrontation method: done with fingers; less precise
- perimetry: done with a computer; more precise
evator palpebrae superioris
upper eyelid muscle
lesions of oculomotor nucleus or nerve results in oculomotor nerve palsy
- ipsilateral lateral (external) strabismus (squint): the eye is down and out (medial rectus and inferior oblique) resulting in diplopia
- ipsilateral mydriasis (dilated pupil): due to involvement of the pupillary muscles (via Edinger-Westphal nerve)
- loss of direct and consensual pupillary light reflexes in the ipsilateral eye
trochlear nerve palsy
when walking downstairs, complaining of diplopia
superior oblique (cranial nerve 4) palsy
- complain of diplopia especially when walking downstairs or reading (requiring eye intorsion)
- tilt head away from the side of lesion (to compensate for the alignment of both eyes and help relive the diplopia)
lesion of abducens cranial nerve (6)
- medial strabismus
- medial rectus muscle is unopposed and pulling the eyeball medially
tests of trigeminal nerve (5)
- sensory functions: pin pricks, vibration, light touch on various areas of the face; moving jaws and asking for direction of movement
- motor functions: biting, looking for position of jaw (is it deviated to one side?)
lesion in facial nerve (cranial nerve 7)
Bell’s palsy
- make quadrant of face and look at where the deficit lies
- ask patient to wrinkle forehead and smile
upper motor neuron deficit
forehead spared
lower motor neuron deficit
forehead weak
lesions of cranial nerve 8 (audition)
- test with sounds
- can look for balance issues
lesions of cranial nerves 9, 10, 11, and 12
- say “ahhh” and watch the uvula (should remain in midline)
- put both hands on shoulder and ask patient to resist
- put one hand on cheek and ask patient to try to turn against the hand
- stick out tongue and see if tongue deviates to the side (of the lesion)
grading muscle strength to test corticospinal tract
- 0 = no movement
- 1 = muscle twitch, no movement of limb
- 2 = muscle contracts but no movement against gravity
- 3 = able to provide minimal resistance
- 4 = able to provide moderate resistance
- 5 = normal strength
grading muscle tone to test corticospinal tract
- normal
- decreased - flaccid
- increased - rigid, spastic, cogwheeling
corticospinal tract (motor system) tests
- grading muscle strength
- grading muscle tone
- look for tendon reflexes
- look for abnormal reflexes (e.g., Babinski sign)
spinal reflex arc (test of corticospinal tract)
- stimulate patellar ligament
- sensory neuron signals
- motor neuron causes tendon reflex
- observe if reflex does not occur, happens too weakly, or happens too strongly
Babinski sign
- normal in babies before 8-9 months
- stimulate sole of foot through stroking
- if toes fan out, this is an indication of a cortex issue
tests of spinothalamic tract
- check for pain and temperature
- pin prick
tests of medial lemniscus and dorsal columns
- check for vibration, discrimination touch, proprioception
- Romberg sign (with eyes closed)
Romberg sign
- tests balance
- The patient removes their shoes and stands with their feet together.
- The patient holds their arms at their sides or crosses them in front of them.
- The patient keeps their eyes open while the examiner assesses their balance.
- The patient closes their eyes and stands erect for one minute while the examiner notes any balance issues. (only keep eyes closed for testing medial lemniscus and dorsal columns)
issue with balance when eyes are open in Romberg sign
indicates cerebellum and vestinbulocochlear issues with balance
symptoms of cerebellum lesions
- ataxia
- hypotonia
- asynergia
- nystagmus
- dysmetria
- tremor
ataxia
lack of muscle coordination, causing clumsy movements
hypotonia
decreased muscle tone, causing weakness and floppiness
asynergia
loss of coordination between different muscle groups, making complex movements difficult
nystagmus
involuntary, rapid eye movements
dysmetria
inability to accurately judge distance or scale of movement
tremor
- intention tremor with cerebellar disease
- resting tremor with basal ganglia disease
test of coordination for cerebellum
- finger to nose
- heel to shin test
test of gait for cerebellum
- normal walking
- heel to toe walking
- Romberg test
gait and balance disorders
associated with midline structures of the cerebellum: vermis (legs and midline)
cerebellar atrophy
cerebellum shrinks due to irreversible tissue loss
cerebellar hemorrhage
bleeding occurs in the cerebellum
dentate hemorrhage
a type of cerebellar hemorrhage that occurs when a branch of the superior cerebellar artery ruptures in the dentate nucleus
Parkinson’s disease
- degeneration of substantia nigra and dopamine less than 25%
- basal ganglia (putamen and globus pallidus)
- bradykinesia (slowness of movement or pregressive reduction in speed and amplitude of movement)
- retropulsion (lose balance and lean backward)
- masked facies (blank or expressionless face)
- stooped posture
- resting tremor vs intention tremor
- lead pipe rigidity (constant stiffness of a limb when it moves, as if it’s stuck in place)
Huntington’s disease
- genetic
- basal ganglia (caudate nucleus)
- no caudate
- over dopamine
- quick jerks; rapid movements
- increased muscle tone
- towards the end the patient has trouble swallowing due to twitching
Glasgow Coma Scale (GCS)
system to “score” or measure how conscious a patient is
- eye response
- motor response
- verbal response
- GCS-P only: pupil response
- scores range from (3-15)
- score of 15 indicates a fully alert and oriented person
three criteria of consciousness (as opposed to coma)
awake, alert, oriented
awake
includes whether or not you have the ability to wake up because of voice or touch
- differentiates between sleep and coma
alert
how responsive you are to people talking to you and if you’re able to understand what’s happening in your immediate surroundings
oriented
means you know who you are, where you’re at, what day it is, and other details related to the here and now
eye response in Glasgow Coma Scale
relates to how awake and alert you are (1-4)
motor response in Glasgow Coma Scale
how well does your brain control muscle movement
- can also show if there are any issues with the connections between your brain and the rest of your body
(1-6)
verbal response in Glasgow Coma Scale
tests how well certain brain abilities work, including thinking, memory, attention span, and awareness of surroundings
(1-5)
coma requires
- damage to Reticular Activating System
- both hemispheres impaired
evaluation of coma
- cranial nerves: are any abnormal; then consider brainstem
- pupil reflexes - midbrain
- breathing patterns - all brainstem
- posturing: de-corticate - midbrain (hold hands clenched on chest), de-cerebrate - pons (hold hands clenched at their sides)
criteria for brain dead
no neurological activity above the level of the medulla
- pupils fixed and dilated
- all facial muscles not responding
- no breathing
- no brainstem evoked potential
Reticular Activating System (RAS)
filter of the sensory information (except smell)
- runs with other sensory tracts
- in dorsal pons
- important for arousal
GCS-P only - pupil response
- P in GCS-P stands for “pupil”
- 2 = neither pupil reacts to light
- 1 = one pupil doesn’t react to light
- 0 = both pupils react to light
mental status exam
- can only be performed on conscious patients
1) attention
2) language
3) memory
4) visuospatial
5) executive function
attention in mental status exam
- parietal lobe: spatial
- frontal lobe: planning
- anterior cingulate cortex (ACC): conflict
- brainstem: arousal
exam:
- observe patient
- orientation to person, place, time
- digit span (repeating a sequence of numbers)
- trail making (connecting numbers and letters in a specific order)
attention
a complex cognitive process that allows us to focus on specific stimuli while filtering out distractions
types of attention
- focused attention
- sustained attention
- selective attention
- alternating attention
- divided attention
focused attention
concentrating on one specific thing
sustained attention
maintaining focus over tiime
selective attention
choosing to focus on one thing while ignoring others
alternating attention
switching focus between different tasks
divided attention
trying to focus on multiple things simultaneously
ADHD
individuals often drift from one thought to another
because the information in our surroundings is complex, we often manage our attention by focusing on some information and ignoring others (selective attention)
factors that influence selective attention
1) goals we are pursuing
2) prior knowledge and interest
language in mental status exam
- left hemisphere
exam:
- fluency (phonemic vs. semantic)
- naming
- repetition
- comprehension
- reading
- writing
tests of Alzheimer’s Disease
this disease hits temporal lobes first –> more semantic issues and good with phonemes
- angular gyrus: ask them to read a prompt and they cannot (alexia)
- arcuate fasiculis: cannot do repetition
memory in mental status exam
- medial temporal lobes (hippocampus)
- thalamus
- basal forebrain
exam:
- remember 3 words for 5 minutes
- remember 3 shapes for 5 minutes
- past public and personal events
- factual knowledge
visuospatial/perceptual in mental status exam
- right hemisphere
exam:
- copy of geometric designs
- judgment of line orientation
- object/face/color recognition
Hemineglect Syndrome
- most often with infarcts or other acute lesions of the right parietal or right frontal lobes (rarely left)
- superimposed lesions in right hemisphere
- often exhibit profound neglect for the contralateral half of the external word, as well as for the contralateral half of their own bodies
- despite their deficits, these patients are often unaware that anything is wrong, and they sometimes even fail to recognize that the left sides of their bodies belong to them
tests of hemineglect syndrome
space and objects test: show patient images and ask them to draw it
- often only draw the one half (right) of the image
Albert’s line cancellation test: lines are drawn in random positions on a sheet of paper and presented to patients who are asked to cancel or cross out all the targets
- often only cross out the lines on one half (right) of the page
