Cortical Lesions Flashcards
What area of the cortex is phylogenetically older?
The hippocampus
The cerebral cortex comprises how many cells?
20 billion
Each cortical neuron connects to _________ other neurons.
20,000
There are diffuse and focal disorders of cortical dysfunction. Describe some examples.
Diffuse: neurodegenerative disorders (like Alzheimer’s); metabolic disorders
Focal: stroke; contusion; neoplasm
Benign tumors damage the brain by ___________, while malignant tumors damage the brain by ___________.
mass effect; infiltration
What are the functions of the frontal lobes?
Voluntary movement Comportment Prosody Executive function Motivation Language production
What are the functions of the temporal lobes?
Audition Language comprehension Sensory prosody Memory Emotion
What are the functions of the parietal lobes?
Tactile sensation Visuospatial reasoning Attention Reading Writing Calculation
What are the functions of the occipital lobes?
Vision
Prosody is primarily controlled by ____________.
the inferior gyrus of the nondominant frontal lobe
Someone who presents with perseveration may have lesions to ____________.
the frontal lobes (this is a form of executive dysfunction)
Because of the experience of H.M., surgeons now do what for temporal lobe epilepsy?
They remove only one lobe, not both.
Temporal lobe epilepsy results from _____________.
focal cortical lesions in the temporal lobe
Patients with temporal lobe epilepsy often develop what personality changes?
Hyperreligiosity
Deepened emotional states
Hypergraphia
Hemineglect most often presents after lesions to the ________ lobe.
right parietal
What is the pathophysiologic basis of hemineglect?
The right parietal lobe can attend to both sides of the visual field, but the left can only attend to the right. As such, a lesion to the left will not produce hemineglect of the right, but a lesion of the right will produce hemineglect of the left.
Prosopagnosia results from lesions to what brain region?
right occipitotemporal lobe
What is alexia without agraphia?
A syndrome in which the patient is able to write but not read (also called pure alexia)
What area, if lesioned, can produce inability to understand the prosody of speech?
Right Brodmann 22 (the analogue of Wernicke’s area)
Bilateral occipitoparietal lesions can lead to a condition in which multiple inputs are not understood. What is this called?
Simultanagnosia
What brain area is usually damaged in pure alexia?
The splenium of the corpus callosum and the left occipital lobe
Motivation is mediated by the _________________.
medial frontal cortices
Left occipitotemporal lobe lesions produce ______________, while right occipitotemporal lobe lesions produce _______________.
object agnosia; prosopagnosia
Describe the presentation of conduction aphasia.
Normal comprehension, but poor ability to repeat phrases. Speech inflected with paraphasias.
What effects can be seen with disconnection of the corpus callosum?
Left hand apraxia, anomia, and agraphia
