E3: everything else Flashcards
What is the most common motor disorder and how do you treat it?
Essential tremor
Treat w/ Propanolol or Primidone
What is the MOA of botulinum toxin?
Interferes with SNARE proteins in presynaptic cell –> inhibition of Ach release
What are the limbs of the corneal reflex?
Afferent: V1
Efferent: VII
Where is the lesion in right hemianopia of the left eye?
Right optic tract
Where is the lesion in right superior homonymous quadrantopia of the left eye?
Meyer’s loop (temporal lobe infarct) –> post-chiasmal
What is papilledema?
Optic disc swelling due to increased intracranial pressure
CN XI lesion results in loss of function on which side?
Ipsilateral
What are the abnormal results of a Weber’s test?
Conductive –> Affected Ear
Sensorineural –> Unaffected ear
What are the limbs of the gag reflex?
Afferent: IX
Efferent: X
Patient presents with dysphagia, dysarthria, and difficulty gagging. Where is the lesion?
Efferent limb –> CN X
Which nerve is tested in Hoffmann’s reflex?
Median nerve - C5-7
Which muscles are involved in Hoffmann’s reflex?
Stretched: lumbricals 1 and 2, flexor pollicis brevis
Contracted: abductor pollicis or opponens pollicis
What is the abnormal result in testing Hoffmann’s reflex?
Thumb flexion
Abnormal Hoffmann’s reflex indicates what kind of lesion?
UMN lesion (corticospinal tract)
Which nerve is tested in the jaw jerk reflex?
CN V3
What are the limbs of the biceps reflex?
Musculocutaneous nerve - C5,6
What are the limbs of the Achilles reflex?
Tibial nerve - S1-2
Absent direct response, present consensual response. Where is the lesion?
Ipsilateral damage to CN III or Edinger-Westphal nucleus
Present direct response, absent consensual response. Where is the lesion?
Contralateral damage to CN III or Edinger-Westphal nucleus
What are the limbs of the pupillary light reflex?
Afferent: CN II
Efferent: CN III
What is the chemical formula for extraocular muscles?
LR6SO4R3
Nystagmus on abduction. Where is the lesion?
Contralateral MLF
Inability of the eye to abduct. Where is the lesion?
CN VI
What nerves are tested in the Glabellar reflex?
Afferent: CN V
Efferent: CN VII
Parkinson’s patients often present with what abnormal reflex response?
Glabellar –> persistent blinking
What are the limbs of the anal sphinchter reflex?
Afferent: Pudendal
Efferent: S2-4
What are the limbs of the plantar reflex?
Tibial nerve - L5-S1
Muscles involved in plantar reflex
Normal: flexor hallucis longus, flexor digitorum longus
Abnormal: extensor hallucis longus, extensor digitorum longus
What are the limbs of the triceps reflex?
Radial nerve - C7-8
What are the limbs of the patellar reflex?
Femoral nerve - L2-4
UMN or LMN lesion will present with positive Babinski?
UMN
How does fat appear on MRIs?
T1: bright
T2: dark
How does water appear on MRIs?
T1: dark
T2: bright
What is dark on T1 and T2?
Air
Calcium – bone also tendons & ligaments
Rapidly flowing blood
Hyper acute hemorrhage
What kind of imaging can detect active MS lesions?
Gadolinium-enhanced T1-weighted MRIs
Why is MR preferred for Alzheimer’s imaging?
It allows for accurate measurement of the 3-dimensional (3D) volume of brain structures, especially the size of the hippocampus and related regions.
What is the hallmark of MS on MR?
HYPERINTENSE OVOID PERPENDICULAR LESIONS TO
VENTRICLES—IF MS ACTIVE, then will ENHANCE WITH GADOLINIUM
What are the pathologic hallmarks of Alzheimer’s?
Betaamyloid (Aß) plaques, neurofibrillary tangles
(NFTs), and reactive gliosis
What has been used to detect persons at risk for Alzheimer disease even before the onset of symptoms?
FDG-PET
_______ _______ _______ has been noted in Alzheimer’s and the degree is associated with the severity of the disease.
Temporoparietal glucose hypometabolism
Most common sites of lesions in MS patients
Periventricular spaces
Blood supply for optic nerve?
Central retinal artery
Pituitary adenoma would cause what visual deficits?
Bitemporal hemianopia (chiasmal)
What is glaucoma?
Increased fluid pressure in the eye leading to optic nerve damage
Papilledema is always ______.
bilateral
Possible cause of papilledema
Intracranial hypertension
Where is the vascular occlusion for an right eye that is down and out?
Right PCA
Dilated pupil indicates what sort of vascular occlusion?
PCA aneurysm
Ptosis and diplopia indicates palsy of which nerve?
CN III
Diplopia
Eye down and out
Dilated pupil
3rd nerve palsy
What type of strabismus is equal in all directions of gaze?
Concomitant
Damage to rostral pontomesencephalic RF causes…
Coma
Damage to caudal pontomedullary RF causes….
Respiratory failure
T/F: The Medial Forebrain bundle caries NE, DA, and Serotinergic projections from the RF nuclei.
True
Where are motor neurons located in the motor cortex?
Layer V
Where are motor nuclei in the thalamus?
VA, VL
What two areas are important in planning movement?
Lateral premotor area
Supplementary motor area
What are the symptoms of a posterior parietal cortex lesion?
Apraxia, sensory neglect, or hemispatial neglect on the side contralateral to the lesion. Patient denies the condition or is unaware of it. If this patient is asked to draw something, they will draw only half of it.
What is apraxia?
Loss of the ability to execute or carry out learned purposeful movements. A person may not be able to pick up a phone when asked to do so, but can perform the action without thinking when the phone rings.
Where do UMNs arise?
May arise from the cerebral cortex or the brainstem
Where are the cell bodies of LMNs?
Gray matter of spinal cord and brainstem
MCA stroke often leads to what key symptom?
Apraxia
What plays a role in the inhibition of muscles during active movement, and in the execution of subconscious “motor programs” (e.g. swinging the arms while walking)?
Basal ganglia
What plays a role in the execution of learned, skilled motor movement?
Cerebellum. Critical for the proper timing of movement and correction of movement errors during active voluntary movement.
What are the symptoms of a UMN lesion?
1) Weakness or paralysis of specific movements
- extension of the upper limbs and flexion of the lower limbs, termed pyramidal weakness
2) No wasting of muscle
3) Spasticity: increased resistance to passive stretching of muscles
4) Clasp knife response: initial response to muscular stretching followed by relaxation
5) Hyperreflexia: Hyperactivity of deep tendons reflexes
6) Positive Babinski Reflex: Emergence of the extensor plantar response leading to dorsiflexion of the great toe after stimulation of the sole of the foot
What are the symptoms of a LMN lesion?
1) Weakness (paresis) or Paralysis (plegia) of individual muscles
2) Wasting of muscles
3) Fasciculation: visible spontaneous contractions of motor units
4) Hypotonia: Reduced resistance to passive stretching
5) Hyporeflexia or Areflexia: Diminution or loss of deep tendon reflexes
Lesions in the cerebral hemispheres and upper brainstem produce what symptoms?
Paralysis of the limb opposite (contralateral) to the side of the lesion - this is because of the decussation of the principal motor pathways in the lower brain stem
Even though it is often difficult to attribute clinical deficits to involvement of particular pathways damage to the pyramidal tract causes what sxs? and what sxs are due to the involvement of other pathways?
1) Damage to the pyramidal tract itself probably accounts for the loss of discrete movements and the appearance of the Babinski reflex
2) Hyperreflexia and spasticity are due to the involvement of other pathways
What is decorticate posturing? What lesions would cause this?
Flexor posturing –> arms flex and point upward
Lesion is rostral to red nucleus, so rubrospinal tract is SPARED. Corticospinal, corticorubral, and corticoreticular tracts are interrupted.
What is decerebrate posturing? What lesions would cause this?
Extensor posturing –> arms extend and point down, rotated inward
Corticospinal, corticorubral, corticoreticular, AND rubrospinal tracts are interrupted.
What is pyramidal weakness?
Spasticity (increased tone)