Localization of Cortical Syndromes Flashcards
draw out the optic tract/visual pathway seen from above. Note the cross over points
apraxia
loss of the ability to execute or carry out skilled movements and gestures, despite preserved motor, sensory and visual function
most common apraxia caused by primary motor cortex problems/unimoal motor association cortex
Buccofacial or orofacial apraxia: most common. Cannot carry out commands like licking the lips or winking
Limb-kinetic apraxia:
inability to make fine, precise movements with an arm or lef such as manipulating coins, finger tapping, finger apposition, wave goodbye, but there is preserved primary motor, cerebellar and sensory function.
Ideomotor apraxia
inability to make the proper movement in response to a verbal command,
Occipital-Temporal Lobe Unimodal Association Cortex : the visual unimodal areas include the __-__ dorsal stream AND __-__ ventral stream. The __-__l lobe is responsible for identifying things we see.
Occipital-Temporal Lobe Unimodal Association Cortex : the visual unimodal areas include the occipital-parietal dorsal stream AND occipital-temporal ventral stream. The occipital-temporal lobe is responsible for identifying things we see.
Recall: the visual unimodal areas include the occipital-parietal dorsal stream AND occipital-temporal ventral stream. The occipital-temporal lobe is responsible for identifying things we see.
Damage to theoccipital temporal lobe can cause (2 conditions)
- visual agnosia: total or partial loss of the ability to recognize and identify familiar objects by sight.
* Individual can still see and can still recognize objects through other modalities (by touch, smell taste or hearing) - prosopagnosia: inability to identify the person by name by facial recognition. Individuals can see the person clearly and can describe the person.
- May identify people by touch, smell, speech, or the way they walk.
- In some rare cases, affected individuals cannot recognize their own face.
- Localization: bilateral or occasionally right unilateral fusiform gyrus
Recall: the visual unimodal areas include the occipital-parietal dorsal stream AND occipital-temporal ventral stream.
The occipital-parietal is responsible for: analysis of ___ and ___ relations.
Damage to the occopital parietal lobe can cause (Balints Triad):
The occipital-parietal is responsible for analysis of motion and spatial relations.
- simultagnosia:
inability to read and inability to view one’s surroundings as a whole. The individual can see parts of the surrounding scene, but not the whole.
Inability to comprehend more than one part of a visual scene at a time, or coordinate the parts. If presented with an image of a table containing both food and various utensils, a patient will report seeing only one item, such as a spoon.
- Optix ataxia: impairment in using visual information to guide motor movements
- Ocular apraxia: impared voluntary purposeful vertical or horizontal eye movements.
balints triad of occipital parietal lobe syndrome (unimodal motor association cortex)
Balint’s Triad: simultagnosia, optic ataxia and ocular apraxia. Indicates problems in the dorsal stream (occipital-parietal) and problems in the ventral stream (occipital-temporal)
Causes of Posterior Cortical Syndromes (occipital-parietal or temporal syndromes)
Posterior Cortical Atrophy, Alzheimer’s variant
Creutzfeldt-Jacob Prion Disease
Posterior Cerebral Artery Stroke
Posterior Reversible Encephalopathy Syndrome (PRES) - Hypertensive Encephalopathy, Eclampsia… ..
Opportunistic Infections – JC virus
what are heteromodal association areas
Heteromodal regions in the frontal, temporal, and parietal lobes receive and integrate multiple inputs from unimodal sensory/motor areas and from other heteromodal areas
Various complex clinical syndromes can be localized to specific lobar cortical regions
ex / Gerstman’s: angular gyrus, left parietal lobe; dressing apraxia– right parietal lobe; expressive non-fluent aphasia– inferior frontal gyrus, left frontal lobe; receptive fluent aphasia– posterior third superior temporal gyrus, left temporal lobe.
the glabellar reflex is indicative of:
frontal lobe clinical syndrome (heteromodal PFC)
- repetitive behaviours to an unchanged stimuli
Key test for frontal lobe clinical syndromes
MOCA
Behavioural variant frontotemporal dementia diagnostic criteria: DAPHNE
has a 3/6 criteria of the following traits:
- Disinhibition
- Apathy
- (No empahty) Loss of empathy
- Perseveration
- Hyperorality
- Executive dysfunction
Types of Frontal Lobe Clinical Syndromes
- lateral convexity syndrome
- medial frontal lobe syndrome
- orbital frontal lobe syndrome
descrbe general syndromes
Causes of these frontal lobe clinical syndromes: head injury, stroke, behavioral variant of frontotemporal dementia, frontal variant of Alzheimer’s brain tumours, brain abscess.
Lateral Convexity Syndrome: indifference, psychomotor retardation, aggressive outburst, perseveration, stimulus-bound behaviour, poor abstraction, poor phonetic fluency tests
- Can test using the phonetic fluency test: poor F’A’S word list generation
- Poor expressive language.
Mesial Frontal Lobe Syndrome: mutism, gait apraxia, paucity of spontaneous movement, incontinence, apathy.
Orbital Frontal Lobe Syndrome: disinhibition, impulsive behaviour, distractibility, emotional lability, primitive reflexes.
hemi-neglect usually happens in patients with damage to the __ hemisphere
right
Bedside tests for Non-dominant right parietal lobe syndrome: single line bisection, multiple line bisection, circle letter A, draw a daisy, draw a clockface.
