Clincial Correltations With Lesions Of The Cerebral Cortex Flashcards
Motor cortex lesions
Causes damage/weakness to specific parts of the body based on where specifically the lesion on the motor cortex is
note: contralaterally influences the sides, so right motor cortex = left side oft he body and vise versa
Supplemental and promotor cortex lesions
Leads to apraxia (motor planning is disabled/weakened, strength is fine/normal though)
Can be oral or extremity apraxia
Can also show alien hand syndrome
- patient cant control arm movements and believe it has its own brain.
Broca’s area lesion
Causes Broca’s aphasia
Patients understand speech perfectly and can form sentences/speak but struggle to respond easily.
“Non-fluent aphasia”
Prefrontal cortex lesions
Results in ability to control decision making and emotions
- apathetic or depression
- mania symptoms
Primary somatosensory cortex lesions
Results in ability to determine temperature, vibrations and positioning/ proprioception
Patient will lose ability of sensation (or hyper sensation) to specific parts of the body depending on the specific area of cortex lesion
(note: just like motor, sides control the contralateral side)
Wernicke area lesions
Loses ability to understand and memorize language traits
Results in word salad speech (wernicke’s aphasia)
- patient can make words physically but staring sentences together properly
“Fluent aphasia”
Posterior parietal cortex lesions
Losses ability for Sensation of visual signals and special arrangement
Patients will try to pick stuff up and miss completely
Shows unconscious non-attention/neglect to the side that the lesion (agonosia) is on (doesnt worry about one side )
- they can make conscious movements on that side though
Can show Gusherman syndrome
- fingers cant distinguish their own fingers and left/right fingers
Two-streams hypothesis
There are two streams (dorsal and ventral streams) used in the occipital visual cortex ECs
Dorsal = interprets motion, spacial relationships between objects “where”
Ventral = interprets colors, numbers, shapes, etc. “what”
Primary visual cortex lesions
Causes left or right homonymous hemianopia based on what side the lesion was (contralateral)
- ex: right lesions = left homonymous hemianopia
Secondary tertiary visual cortex lesions
Results in color or visual agnosia
- cant relate correct colors to objects or cant understand what they are looking at
Superior temporal gyri lesions
Results in patients being able to hear but can recognize the sound (auditory agnosia)
Middle temporal gyri lesions
Movement agnosia develops (motion blindness)
- cant tell if an object is moving and or if its far/close to the person
Inferior temporal gyri lesions
Results in prosopagnosia
- cant recognize faces that they have already seen since all angles and noteworthy facial features blur together
Anterior cerebral artery syndrome
Interruption of blood flow through the anterior cerebral artery in some manner
Results in damages to the precentral gyrus and contralateral paralysis, primarily to the lower extremities as well as sensory loss.
Right = left leg weakness/sensory loss. Also frontal lobe behavior abnormalities
Left = right leg weakness/sensory loss. Also frontal lobe behavior abnormalities.
Middle cerebral artery syndrome
Interruption of blood flow through the middle cerebral artery in some manner
Results in contralateral hemiplegia (paralysis) of the upper extremities and face. May also show sensory disabilities on the same areas.
if the left hemisphere middle cerebral artery is occluded also shows speech issues since the speech center is on the left
Left superior
- right face/arm weakness/sensory issues
- Broca’s aphasia
Left inferior
- right face/arm weakness/sensory issues
- wernickes aphasia
- possible right visual field defects*
Right
- left face/arm weakness
- left hemineglect
