Flashcards in DISORDERS OF HIGHER CEREBRAL FUNCTION Deck (31)
What is the blood supply to the frontal lobe?
Anterior cerebral artery and the middle cerebral artery. The anterior cerebral artery supplies the medial surface of the primary motor cortex and hence the leg. The middle cerebral artery supplies the lateral surface and hence the face and arms.
A lesion in what part of the frontal lobe would cause contralateral weakness?
Pre-central gyrus - causes an upper motor neurone pattern of weakness.
A lesion in what part(s) of the frontal lobe would cause gait apraxia? Give a brief definition of gait apraxia.
Pre-motor and supplementary motor area.
It is the inability to walk properly in spite of preservation of normal power, coordination and sensory function, and extrapyramidal dysfunction. The gait is slow and shuffling but upright and wide based, distinct from the flexed posture of Parkinsonian gait.
What are the features of focal seizures in the frontal lobe?
Clonic movements of the contralateral lower face, arm and leg
Conjugate deviation of the head and eye towards the convulsing side (i.e. away from the lesion)
A lesion in what part of the frontal lobe would cause anosmia? Give a brief definition of anosmia.
Lesions of the inferior or orbital frontal lobes can be accompanied by disturbances of the olfactory pathway and optic nerves as a result of close proximity of these pathways. Anosmia is an inability to smell.
A lesion in which lobe of the brain would cause urinary incontinence?
What is the blood to the parietal lobe?
Middle cerebral artery
What is astereognosis?
The inability to identify an object by active touch of the hands without other sensory input.
A lesion is which lobe causes a contralateral homonymous inferior quadrantanopia?
What is Wernicke's dysphasia?
Impaired comprehension of speech and written language. Speech is fluent but does not make sense. Patient has poor insight into the problem.
A lesion in one of which two lobes of the brain can cause Wernicke's dysphasia?
Inferior parietal (dominant)
Superior temporal (dominant)
What is Gerstmann's syndrome?
Consists of the inability to differentiate the right and left sides of the body, inability to distinguish fingers of the hand (finger agnosia) and impairment of calculation (dyscalculia) and writing (dysgraphia). Lesions in the dominant parietal lobe will lead to the develop of one or more of these symptoms.
What is bilateral ideomotor and ideational apraxia?
Inability to carry out a sequence of tasks when there is normal comprehension and intact motor and sensory function. Results from a lesion in the dominant parietal lobe.
What is contralateral sensory inattention?
An inability to perceive a contralateral stimulus when two simultaneous sensory stimuli are applied with equal intensity to corresponding sites on opposite sides of the body. Unilateral application of the stimulus is perceived. This inattention can be motor, sensory or visual. Results from a lesion of the non-dominant parietal lobe.
What is constructional apraxia?
Difficulty drawing simple objects or difficulty construction simple objects. Results from a lesion of the non-dominant parietal lobe.
What is dressing apraxia?
Inability to put on clothes. Results from a lesion of the non-dominant parietal lobe.
What is topographical disorientation (topographagnosia)?
Patients cannot find his or her way around normally familiar spaces.
What are the visual disturbances associated with lesions of the temporal lobe?
Superior homonymous quadrantanopia
A lesion in which lobe in the brain is associated with memory impairment?
Medial temporal lobe involving the hippocampus and parahippocampal gyrus.
With regard to memory impairment as a result of lesions in the parietal lobes, which lobe will be associated with the learning of verbal information?
The dominant lobe (most often the left)
A lesion in which lobe in the brain is associated with emotional disturbances?
The limbic system is part of the parietal lobe. There are parts of the limbic system that are subcortical.
What is auditory agnosia?
The inability to recognise sounds. Results from lesions of the non-dominant temporal lobe.
A lesion in which lobe(s) in the brain is associated with cortical deafness?
This occurs only with bilateral lesions of the primary auditory cortices in the temporal lobes and as such is very rare.
What is global dysphasia?
Lesions to both Broca's and Wernicke's area leads to loss of fluent speech and impaired comprehension of language. This is the most common type of dysphasia and is usually caused by a stroke affecting the left middle cerebral artery.
What is the blood supply to the occipital lobe of the brain?
Posterior cerebral artery
Occipital poles, subserving macular vision, have additional supply from a branch of the middle cerebral artery.
A lesion of which lobe and artery causes contralateral homonymous hemianopic field defects?
Lesion of the posterior cerebral artery and hence occipital lobe
A lesion in which lobe(s) in the brain is associated with cortical blindness?
Bilateral occipital lesions render the patient blind, with retention of the pupillary reflexes.
What is Anton's syndrome?
Patient deny's being blind despite cortical blindness.
What is visual agnosia?
Lesions of the visual association cortices cause impairment of perception or identification of faces and objects even though visual acuity and fields are normal.