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103 Cards in this Set
- Front
- Back
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what is paresis?
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mild to moderate weakness
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what is plegia?
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severe weakness
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what is hemiparesis, and what causes it?
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paresis of lower face arm and leg one side
damage to contralateral cerebrum or corticospinal (pyramidal) tract above decussation of pyramids |
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what are the ocular motility nerves?
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CN III, IV and VI
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what are the cerebellopontine angle nerves?
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CN V, VII and VIII
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what are frontal release signs, and what do they indicate?
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face (snout, suck and rooting reflexes)
jaw (jaw jerk reflex) palm (palmomental and grasp reflexes): frontal lobe damage: congenital cerebral injury neurodegenerative condition (frontotemporal dementia) |
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what is anosgnosia?
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failure to recognize one's own deficit or disease?
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what is aphasia?
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disorder of verbal or written language rather than simply speech production, resulting from lesions in dominant cerebral hemisphere's perisylvan language arc or neurodegenerative conditions (e.g. Alzheimer's disease or frontotemporal dementia).
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what is astereognosis?
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inability to identify items by touch, found with lesions of contralateral parietal lobe.
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what is athetosis?
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involuntary slow writhing, sinous movements of arms/legs most prominent in distal part of limbs, usually causes by congenital basal ganglia damage from perinatal jaundice (kernicterus), anoxia or prematurity.
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what is bradykinesia?
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slowness of movement, seen in many basal ganglia diseases, such as parkinsonism.
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what is chorea?
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Involuntary movement characterized by intermittent random jerking of limbs, face or trunk, caused by basal ganglia diseases (e.g. Huntington disease where caudate nucleus atrophies) or medications such as L-dopa or typical neuroleptics.
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what is dementia?
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impairment of memory, judgment, abstract thinking and other cognitive functions to degree sufficient to impair social activities or interpersonal relationships.
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what is dysdiadochokinesia?
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impairment of rapid alternating movements, caused by cerebellar injury or red nucleus (in midbrain) damage.
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what is Gerstmann syndrome?
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combination of:
agraphia (inability to express thoughts in writing) finger agnosia (inability to identify fingers) acalculia (impaired arithmetic skills) left/right confusion due to lesion in angular gyrus of dominant parietal lobe. |
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what is dysarthria?
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impairment of speech due to lesions in cerebrum, brainstem, cranial nerves or vocal cords.
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what is ataxia?
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incoordination of voluntary movements, associated with dysmetria, intention tremor, hypotonia and impaired rapid alternating movements, which are signs of cerebellar injury.
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what is dysmetria?
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irregularity in limb or eye trajectory while performing rapid alternating or other active movement, resulting in under-/over-shooting target, which is sign of cerebellar injury.
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what is the corticospinal tract?
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AKA pyramidal (crossing at pyramids of medulla) tract major descending, entirely motor, pathway
from cerebral cortex to anterior horn cells of spinal cord upper motor neuron (UMN) |
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what are the signs of corticospinal tract lesions?
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UMN lesion signs:
palsy weakness spasticity hypereflexive DTRs clonus Babinski signs |
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UMN injury: where does it occur? what are signs?
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cerebral cortex to anterior horn cells of spinal cord:
paresis with muscle spasticity hyperactive DTRs Babinski signs |
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LMN injury: where does it occur? what are signs?
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corticospinal (pyramidal) tract
anterior horn cells of spinal cord to peripheral nerve: paresis with muscle flaccidity and atrophy hypoactive DTRs no Babinski signs |
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what are signs of cerebral hemisphere lesions?
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contralateral UMN injury (paresis with muscle spasticity, hyperactive DTRs, Babinski signs)
contralateral hemisensory loss (position, two-point discrimination, stereognosis) contralateral homonymous hemianopsia without visual field deficit partial seizures (90% originating in temporal lobe) |
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what are signs of dominant cerebral hemisphere lesions?
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aphasia
right hemiparesis Gerstmann syndrome alexia without agraphia |
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what are signs of non-dominant cerebral hemisphere lesions?
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hemi-attention
anosognosia constructional apraxia (inability to copy simple forms or create simple patterns) |
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what are signs of bilateral cerebral hemisphere lesions?
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pseudobulbar palsy: emotional liability from bilateral corticobulbar tract damage.
dementia |
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what is the corticobulbar tract?
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tract going from motor cortex in posterior frontal lobe to brainstem motor nuclei innervating head/neck muscles.
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what are the basal ganglia?
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foundation of extrapyramidal (above pyramids of medulla) motor system:
Striatum (composed of caudate, globus pallidus and putamen) substania nigra subthalamic nucleus |
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what is the extrapyramidal tract?
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modulates corticospinal or pyramidal tract
originates from basal ganglia acts on CNS structures such as cerebral cortex and thalamus controls muscle tone, regulates motor activity, generates postural reflexes |
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what are signs of basal ganglia lesions?
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involuntary movement disorders:
parkinsonism athetosis chorea hemiballismus usually bilateral (contralateral if not) without corticospinal damage signs (paresis, Babinskis, abnormal DTRs) without cognitive impairment (though advanced disease can) |
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what is parkinsonism?
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bradykinesia or akinesia (absence of movement)
rigidity resting tremor postural abnormalities micrographia festinating gait due to substantia nigra (midbrain) degeneration or toxins or dopamine antagonist antipsychotic meds |
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what is hemiballismus?
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intermittent flinging of arm and leg on one side of body, often associated with contralateral subthalamic nucleus infarcts.
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what are the major divisions of the brainstem?
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Midbrain
Pons Medulla |
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What are important components of the midbrain?
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CN III and IV nuclei
medial longitudinal fasciculus (MLF) red nucleus (cerebellar outflow to contra limbs) substantia nigra cerebral penduncles (corticospinal tracts) |
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What are important components of the pons?
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motor division of CN V, CN VI, VII nuclei
locus ceruleus / dorsal raphe nucleus medial longitudinal fasciculus (MLF) corticospinal tracts |
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What are important components of the medulla?
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CN IX, X and XI nuclei and CN V sensory nucleus
cerebellar penduncles sympathetic fiber tracts corticospinal tracts (pyramids) olivary nuclei |
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What are signs of brainstem lesion?
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combination of CN and contra hemiparesis
nystagmus internuclear opthalmopegia (MLF syndrome) bulbar palsy without cerebral injury signs (e.g. visual field cuts, aphasia, dementia) |
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What is Wallenburg syndrome?
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lateral medullary infarction from PICA or vertebral artery occlusion:
ipsi Horner's syndrome (miosis/pitosis) from sympathetic fiber damage ipsi diminished facial pain with contra diminished trunk/limb pain from CN V sensory nuclei/spinothalamic tract damage ipsi dysarthria from nucleus ambiguus (CN IX-XI motor nuclei) damage (palate deviates to contra side) ipsi ataxia from cerebellar tract damage |
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what is the most common sign of brainstem dysfunction?
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nystagmus (repetitive jerk-like eye movements, usually simutaneous, of both eyes)
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what are signs of cerebellar lesions?
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ipsilateral intention tremor
impaired raid alternating movements (dysdiadochokinesia) ataxic gait scanning speech without cognitive/language impairment, dementia |
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what is a unique characteristic of the cerebellum?
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controls coordination of limbs on same side of body
"everything in the brain, except the cerebellum, is contralateral." |
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what is gait ataxia (ataxic gait)?
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feet placed widely apart when standing
lurching, unsteady wide-based walking such as staggering & reeling of drunk people prevents tandem gait (walking heel-to-toe) test due to cerebellar lesions |
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what is scanning speech?
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incoordination of speech production:
poor modulation irregular cadence inability to separate adjacent sounds |
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what are spinocerebellar ataxias (SCAs)?
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genetic illnesses causing excess trinucleotide repeats
AKA polyglutamine diseases progressively severe gait ataxia scanning speech hand/finger incoordination (limb ataxia) posterior column (sensory) loss Babinski sign possible cognitive impairment/spasticity/ocular motility problems |
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what is Friedreich ataxia?
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most common hereditary ataxia in US and Europe
SCA involving excess trinucleotide repeats cerebellar signs kyphosis pes cavus (high arch, elevated dorsum, retracted 1st metatarsal) cardiomyopathy |
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what is the composition of the spinal cord?
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gray matter on the inside with white matter outside
(opposite of the cerebrum) gray matter: H-shaped structure consisting of neurons transmitting nerve impulses in a horizontal direction. white matter: myelinated tracts transmitting nerve impulses in a vertical direction. |
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what are the major pathways of the spinal cord?
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major descending pathway (motor): lateral corticospinal tract
major ascending pathways (sensory): posterior (dorsal) columns (fasciculi cuneatus [upper liimbs]/gracilis [lower limbs]) - position(proprioception)/vibration sense to thalamus lateral spinothalamic tracts - temp/pain to thalamus anterior spinothalamic tracts - light touch to thalamus spinocerebellar tracts - joint/movement to cerebellum |
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what are the clinical landmarks of spinal cord injury?
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C4: hyperalgesia below neck
T4: hyperalgesia below nipples T10: hyperalgesia below umbilicus S2: bladder control and sexual function |
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what is the Brown-Sequard syndrome?
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ipsi limb paralysis from corticospinal tract damage
contra loss of vibration/proprioception from dorsal column damage contra loss of tempature/pain from lateral spinothalamic tract damage "one leg is weak and the other is numb" |
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what is syringomelia?
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AKA syrinx or hematomyelia if blood-filled
lesion of cervical spinal cord elongated cavity adjacent to central canal pressure rips crossing lateral spinothalamic tract fibers & compresses anterior horn cells of anterior gray matter loss of pain/temp, muscle bulk, DTRs in shoulders/arms spares position/vibration sense because posterior columns undamaged |
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what illnesses target the posterior columns? what signs are seen?
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tabes dorsalis (syphilis)
combined systems disease (vit B12 def): also damages corticospinal tracts Friedreich ataxia and other SCAs: can also damage other tracts heavy metal intoxication steppage gait (knees excessively raised due to loss of positon sense) Romberg sign (inability to maintain balance with eyes closed) also often accompanied by dementia |
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what is the face-hand test?
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patient momentarily exerts sufficient strength to prevent dropped hand from striking face indicating psychogenic paresis
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what is the Hoover sign?
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normally, patient presses down with opposite leg when lifting leg.
patient does not press down with opposite leg when attempting to raise paretic leg patient presses down with "paretic" leg when lifting "unaffected" leg |
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what is the abductor sign?
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normally, when asked to abduct one leg, patient reflexively forcefully abducts both.
hemiparetic patient will be unable to abduct paretic leg hoover sign: patient reflexively abducts "paretic" leg when abducting normal leg, or does not abduct uneffected leg when unable to abduct "paretic" leg |
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what is splitting the midline?
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loss of sensation to pinprick/vibration at middle of face/body indicates psychogenic deficit
sensory fibers and vibration normally spread across midline |
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what is a nonanatomic deficit?
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deficit violating laws of neuroanatomy and therefore most likely psychogenic
e.g.: loss of pain sensation without loss of tempature sensation, or tunnel vision (excepting migraine aura in some cases) |
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what are possible indications of psychogenic nonepileptic seizures?
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verbalizing throughout episode (vs.only at onset)
maintaining body tone alternating flailing limb movements (vs.bilateral clonic jerks) pelvic thrusts |
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"On old Olympus' towering top, a Finn and German viewed some hops."
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I - Olfactory --- VII - Facial
II - Optic --- VIII - Acoustic III - Oculomotor --- IX - Glossopharyngeal IV - Trochlear --- X - Vagus V - Trigeminal --- XI - Spinal Accessory VI - Abducens --- XII - Hypoglossal |
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what is psychogenic anosmia?
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normally, volatile/irritative substances can bypass damaged olfactory nerves
patient who denies smelling ammonia or alcohol demonstrates psychogenic anosmia. (this would occur only if both trigeminal and both olfactory nerves were completely obliterated) |
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what is the Foster-Kennedy syndrome?
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meningioma compresses olfactory and optic nerve
unilateral optic atrophy/blindness and anosmia contra papilledema from increased intracranial pressure |
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what is the light reflex?
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optic nerve (afferent limb) to midbrain nuclei
oculomotor nerve (efferent limb) contain parasympathetic fibers to pupils' constrictor fibers (miosis) in both pupils if light only cause other pupil to react, efferent limb damaged if neither pupil react in only one eye, afferent limb damaged light reflex is brainstem function: dysfunction sign of brain death |
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how does optic nerve makeup explain their involvement in certain illnesses and not others?
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myelin on optic nerves derived from oligodendrocytes (extension of CNS)
other CNs have myelin from Schwann cells (extension of PNS) optic nerves vulnerable to diseases attacking CNS, e.g.: MS, metabolic storage diseases optic nerves immune to PNS-targeting diseases, e.g.: Guillian-Barre syndrome |
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what is the accomodation reflex?
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optic nerve (afferent limb) to midbrain nuclei
oculomotor nerve (efferent limb) contain parasympathetic fibers to pupils' accommodation fibers on lens in both eyes. |
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what does a normal optic disc look like?
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yellow, flat, well demarcated from surrounding red retina
pulsating retinal veins, larger than corresponding arteries |
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where do the oculomotor and trochlear nerves originate from?
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Midbrain
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what does the oculomotor nerve supply? what does its impairment look like?
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pupil constrictor, eyelid, adductor/elevator muscles
dilated pupil (miosis), ptosis, outward deviated (abducted) eye |
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what does the trochlear nerve supply?
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superior oblique muscle
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what does the oculomotor nerve supply? what does its impairment look like?
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ipsi lateral rectus muscle
inwardly deviated (adducted eye) |
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Is conjugate gaze damaged from infarctions, tumors or Alzheimer's dementia?
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No, because ocular CNs are not damaged by lesions in cerebral hemispheres.
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what would characterize a midbrain lesion?
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ipsi miosis, ptosis and diplopia from oculomotor nerve palsy
contra hemiparesis from corticospinal tract damage crossing in medulla contra arm ataxia from red nucleus damage affecting cerebellar outflow |
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what would characterize a pons lesion?
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ipsi eye adduction from abducens nerve palsy
ipsi upper & lower facial weakness from facial nerve palsy contra hemiparesis from corticospinal tract damage crossing in medulla |
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what is the MLF syndrome?
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AKA intranuclear opthalmoplegia
damage to medial longitudinal fasciculus (links oculomotor and abducens nuclei in midbrain & pons) ipsi eye fails to adduct & contra eye develops nystagmus (if bilateral, as in MS, neither eye adducts & abducting eyes show nystagmus) |
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what is a diabetic infarction?
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most frequent lesion of oculomotor nerve
sharp headache, ptosis, abduction but spares pupil |
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what is strabismus?
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congenital dysconjugate gaze
"crossed" eyes does not cause double vision because brain suppresses one of the images. |
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what is amblyopia?
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blindness in deviated eye
occurs if strabismus not corrected in childhood |
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what is the corneal reflex?
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trigeminal nerve (afferent limb) to pons nuclei
facial nerve (efferent limb) to both sets of orbicularis oculi muscles causing both eyes to blink. if touch only cause other eye to blink, efferent limb damaged if neither eye blinks if one eye touched, afferent limb damaged |
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where are the nuclei of the trigeminal nerve?
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motor nucleus in pons (with CN VI and VII nuclei)
sensory nucleus extends from mibrain to medulla |
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which nerves pass through the cerebellopontine angle?
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trigeminal (V), facial (VII) and acoustic (VIII) nerves
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what is the jaw jerk reflex?
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tapping open relaxed jaw causes soft rebound closing
hypoactive (little/no closing) in bulbar palsy hyperactive (quick/forceful closing) in pseudobulbar palsy |
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what are the differences between facial paresis types?
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facial nerve injury causes ipsi paresis of upper & lower face muscles (LMN/peripheral weakness)
cerebral cortex or brainstem injury causes contra paresis of lower face muscles (UMN/central weakness) |
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what conveys taste sensation?
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facial nerve (VII) conveys taste from anterior 2/3 of tongue to brainstem
glossopharyngeal nerve (IX) conveys taste from posterior 1/3 of tongue to brainstem |
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where do the glossopharyngeal, vagus and spinal accessory nerves come from?
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Medulla
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what is pseudobulbar palsy?
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UMN damage to corticobulbar tract in frontal lobe
explosive dysarthria (speech impairment) dysphagia (swallowing impairment) hyperactive jaw jerk/gag reflexes slack jaw, sagging face, vacant stare emotional liability not connected to mood (pseudobulbar affect) |
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where does the vagus nerve's afferent fibers run?
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originate in thoracic/abdominal viscera
travel through neck terminate in solitary nucleus of medulla |
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where does the hypoglossal nerve originate from?
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Medulla
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what does hypoglossal palsy look like?
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tongue deviates towards side of lesion
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what are signs of autonomic neuropathy?
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impotence/erectile dysfunction
urinary bladder hypotonicity gastroenteropathy anihidrosis retrograde ejaculation can be accompanied by orthostatic hypotension |
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what is the cauda equina?
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structure composed of lumbosacral nerve roots
which are LMNs and part of PNS |
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what is meralgia paraesthetica?
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lateral femoral cutaneous nerve compression in inguinal area
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what is the Romberg sign? What does it indicate?
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inability to maintain balance with eyes closed
damage to either posterior columns (loss of joint position sense) occurs in combined system disease, MS and tabes dorsalis or damage to LE peripheral nerves (loss of touch/position/vibration sense) occurs in diabetic or other peripheral neuropathy (more common), alcoholism and uremia |
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what are signs of intoxication? what are likely causes?
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ataxic gait
slurred/scanning speech bilateral/horizontal/vertical nystagmus alcohol, barbituates, phencyclidine, antihistamines or other drugs |
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what is the most caudal level of the CNS? where is it?
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spinal cord, which ends at T12-L1
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what is gait apraxia?
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AKA apraxic gait
inability to alternate leg movements with inappropriately attempting to lift weight-bearing foot feet seem magnetized to floor turning/walking take excessive number of steps seen in normal-pressure hydrocephalus (with dementia and urinary incontinence) |
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what is astasia-abasia?
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psychogenic pattern of walking
alternates between broad base and tightrope like stance with contortions of trunk/limbs giving appearance of imminent fall patients seem to prevent fall by last minute acrobatics/grasping items/examiners |
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what is hemiparetic gait?
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patient forced to swing (circumduct) paretic leg from hip
weak ankle drags front surface of foot due to cerebral lesions |
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what is HTLV-1 myelopathy?
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infection endemic to Caribbean islands
spasticity greater than paresis |
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what are signs of HIV spinal cord infection?
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myelopathy with sensory loss with little spasticity
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which maneuver reveals the most about a patient's motor system?
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observation of gait:
walking normally requires: normal corticospinal tracts normal LMNs normal coordination, proprioception and balance |
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what separates cerebrum and cerebellum?
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tentorium
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what separates the two cerebral hemispheres?
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falx cerebri
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what is Wallerian degeneration?
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loss of black stain on cross-section due to loss of myelin from axonal injury distal (downstream) from lesion
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what is Horner syndrome?
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unilateral sympathetic fiber lesion
caused by lateral medullary infarct or upper lobe lung CA ipsi miosis, ptosis and anhidrosis |
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what is the Adie pupil?
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ciliary ganglion damage interrupts parasympathetic innervation of pupil's sphincter muscle
unopposed sympathetic innervation dilates pupil denervation sensitivity cause constriction with pilocarpine drops too dilute to constrict normal pupil |
