Brain lesions

Question 1

Homunculus

Answer 1

Toes, legs at the top
Hand in the middle
Face and teeth at the bottol

Ex: lower extremity deficit in sensation or movement may indicate movement of the ACA.

Question 2

Cerebral cortex function

Answer 2

Primary auditory cortex: in the temporal lobe
Arcuate fasciculus: parietal lobe
Premotor area: part of extra prymaidal circut, anterior to principal motor area.

Question 3

Amygdala (bilateral) lesion

Answer 3

Kluver Bucy sydrome: hyperorality, hypersexuality, disinhibited behavior

Associated with HSV-1

Question 4

Frontal lobe lesion

Answer 4

Disinhibition and deficits in concentration, orientation, and judgment; may have re-emergency of primitive reflexes

Question 5

Right parietal lobe lesion

Answer 5

Spatial neglect syndrome

Agnosia of the contralateral side of the world

Question 6

Reticular activating system (midbrain) lesion

Answer 6

Reduced levels of arousal and wakefulness (e.g. coma)

Question 7

Mammillary bodies (bilateral) lesion

Answer 7

Wernicke-Korsakoff syndrome: confusion, opthalmoplegia, ataxia; memory loss, (antero and retrograde), confabulation, personality change

Associated with B1 deficiency, EtOH use.
Can be precipitated by giving glucose with B1 in B1 deficient patients.

Question 8

Basal ganglia lesion

Answer 8

May result in tremor at rest, chorea, athetosis

Parkinson’s

Question 9

Cerebellar hemisphere lesion

Answer 9

Intention tremor, limb ataxia, and loss of balance
Damage to the cerebellum results in ipsilateral deficits;
fall toward side of lesion

Cerebellar hemisphere are LATERALly located- thus affects LATERAL limbs

Question 10

Cerebellar vermis lesion

Answer 10

Truncal ataxia, dysarthria

Vermis is centrally located–affected central body

Question 11

Subthalamic nucleus lesion

Answer 11

Contralateral hemiballismus

Question 12

Hippocampus lesion

Answer 12

Anterograde amnesia - inability to make new memories

Question 13

Paramedian pontine reticular formation (PPRF) lesion

Answer 13

Eyes look away from side of lesion

vs. toward on frontal eye field lesion

Question 14

Frontal eye field lesion

Answer 14

Eyes look toward lesion

vs. away in PPRF lesion

Question 15

Central pontine myelinolysis

Answer 15

Acute paralysis, dysarthria, dysphagia, diplopia, and loss of conciousness

Can cause locked-in syndrome

Caused by overly rapid correction of hyponatremia

T2-weighted MRI with FLAIR shows abnormal increased signal in central pons.

Question 16

Aphasia vs dysarthria

Answer 16

Aphasia= higher order inability to speak
Dysarthria = motor inability to speak (movement deficit)

Question 17

Broca’s

Answer 17

Nonfluent aphasia with intact comprehension.

Broca’s area- inferior frontal gyrus of frontal lobe

Question 18

Wernicke’s

Answer 18

Fluent aphasia with impaired comprehension.

Wernicke’s- superior temporal gyrus of temporal lobe

Question 19

Global aphasia

Answer 19

Both broca’ and werniche’s involved

Nonfluent aphasia with impaired comprehension

Question 20

Conduction

Answer 20

Poor repetition but fluent speech, intact comprehension.
Can be caused by damage to arcuate fasciculus

Can’t repeat phrases such as “no ifs, ands, or buts.”

Question 21

Watershed zone

Answer 21

Between anterior cerebral/middle cerebral, posterior cerebral/middle cerebral arteries.

Damage in severe hypotension => upper leg/upper arm weakness, defects in higher-order visual processing.