Focal brain syndromes Flashcards
What symptoms can be seen in dorsolateral prefrontal cortex damage (frontal lobe) & what are typical causes?
classic dysexecutive syndrome
Typical causes: tumours, CVA, frontal neurodegeneration
What signs show damage of the orbital prefrontal cortex and typical causes?
disinhibition, restlessness, impulsiveness, impaired empathy
Typical causes: frontal tumours, MS, frontal neurodegeneration, anterior cerebral artery CVA
What are signs of damage to the medial prefrontal cortex and what are typical causes?
apathy and loss of initiative
Typical causes: trauma, hydrocephalus, bilateral anterior cerebral artery occlusion and tumours of the thalamus, 3rd ventricle, hypothalamus and pituitary
Signs of impairment to non-dominant parietal lobe?
disturbed body image and impaired sense of position in external space, left sided neglect
What are signs for a lesion in the dominant parietal lobe?
dysphasia, agnosia
How to devide the temporal lobe?
lateral and ventromedial
What includes the lateral temporal lobe?
neocortex (cognitive functions)
What is included in the ventromedial temporal lobe?
components of limbic system (emotional regulation)
Signs of damage to dominant temporal lobe:
language problems (Wernickes aphasia)
What can a lesion of the acuate fasciculus lead to?
Connecting Wernickes and Brocas area it leads to conduction aphasia (difficulty with repetition)
What are non-dominant temporal lesions associated with?
visuospatial problems
What emotions can be present with TLE seizures
fear,
anxiety,
pleasure,
depersonalisation,
depression,
déjà vu (familiarity) and jamais vu (unfamiliarity).
What can a bilateral hippocampal lesions lead to?
severe amnestic syndromes
What can a bilateral distruction of the amygdala cause?
loss of fear
Are lesions of the occipital lobe common?
Yes due to strokes
What can lesions of the primary visual cortex lead to?
- blind spots (scotomas)
- partial blind spots (amblyopias)
What can bilateral lesions of the occipital lobe lead to?
object agnosia or prosopagnosia (autoprosopagnosia)
What are key features of the Balint syndrom?
- inability to perceive the visual field as a whole (simultanagnosia),
-difficulty in fixating the eyes (oculomotor apraxia)
-inability to move the hand to a specific object by using vision (optic ataxia).
What can excessive bilateral occipital cortex lesions lead to?
Cortical blindness
What is Anton’s syndrome
Denial of visual loss
What do lesions of the dominant occipital lobe lead to?
pure alexia for written material, colour agnosia, simultagnosia
What can bilateral occipitoparietal lesions cause?
Charcot-Wilbrand syndrome (loss of ability to create mental visual images)
Complete callosal damage may lead to…
… left ideomotor apraxia, right or bilateral constructional apraxia, left agraphia, alexia in the left visual field and astereognosis in the left hand. Mutism may also occur.
What has been often observed after a callosectomy and why?
left sided neglect due to underactivation of non-dominant hemisphere