Weakness

Question 1

LMN

Answer 1

-can occur anywhere along the length of the sc or BS LMN

Question 2

peripheral neuropathy/polyneuropathy

Answer 2

-multiple nerve involvement manifests as distal limb LMN signs and sensory loss (stocking and glove); typically beginning in lower limbs

Question 3

general rule about pain

Answer 3

may accompany lesions or roots, plexus or nerves but not lesions of anterior horn cells

Question 4

hemiplegia from an ipsi cervical spinal cord lesion

Answer 4

-may be accompanied by neck and radicular pain if a cervical root is also involved at the level of the lesion (which may also create LMN signs at that root level)

Question 5

hemiplegia form a brainstem lesion

Answer 5

-may be accompanied by facial weakness, dysarthria, or dysphagia

Question 6

hemiplegia from a subcortical lesion in the internal capsule or corona radiata

Answer 6

-cause relatively equal weakness in contra lower face and upper and lower limbs

Question 7

hemiplegia from a cortical lesion

Answer 7

-unequal weakness between the affected upper and lower limbs

Question 8

hemiplegia with the leg weaker than the face and arm

Answer 8

is caused by a lesion in the more medial (parasagittal) portion of the contra motor cortex
-ischemic infarction of this area is produced by an occlusion of the ACA

Question 9

hemiplegia with the face and arm weaker than the leg

Answer 9

2/2 a lesion in more lateral portion of the contra motor cortex
-ischemic infarction of the area is produced by an occlusion of the middle cerebral artery (MCA) or one of its branches

Question 10

sudden vs gradual onset of hemiplegia

Answer 10

• sudden: d/t cerebrovascular lesion, such as ischemic infarct or hemorrhage, or the result of trauma
• gradual: tumor, or degenerative dz (ALS)

Question 11

motor vs sensory

Answer 11

motor: precentral gyrus; sensory: postcentral gyrus

Question 12

bulbar/bulb/lower brain stem

Answer 12

-lesions of CN 5,7,9,10,12 can cause weakness of chewing, speaking, or swallowing (bulbar functions)

Question 13

bulbar weakness (bulbar palsy)

Answer 13

LMN signs are manifest as atrophy and fasciculations of muscles of the face, jaw, palate or tongue

Question 14

pseudobulbar weakness (pseudobulbar palsy)

Answer 14

-causes weakness of chewing speaking or swallowing, but causative lesions involve UMN (corticobulbar tract)

Question 15

weak pts lacking LMN or UMN signs

Answer 15

• d/o of muscle or NMJ; sensation is preserved
• muscle dz: weakness typically affects proximal limbs, MSR initially preserved, disappear after significant muscle atrophy occurs
• NMJ d/o (MG): variable weakness and fatigue of limbs, often accompanied by ptosis, diplopia, dysarthria, dysphagia, or dyspnea

Question 16

basal ganglia

Answer 16

influence postural control, muscle tone, and “automatic” types of movement

Question 17

cerebellum

Answer 17

important for balance, smoothness, and coordination of movement