Module 1 Disorders Flashcards
(43 cards)
What is visual agnosia
failure to recognize objects from sight
Subtypes of visual agnosia
Apperceptive
Associative
What is apperceptive visual agnosia
Where is the damage
Patient can process elements of what the person is looking at, but is unable to comprehend a fully formed percept of what the object is
Bilateral occipital/occipital parietal type lesions - extensive damage
What is associative visual agnosia
The percept of the object is fully formed, but the person cannot connect the visual representation with semantic meaning - disconnect between the visual representation and semantic meaning
Damage more anterior
What is prosopagnosia
Where is the damage
Deficit in identifying familiar faces
Can usually describe discrete aspects (nose, mouth etc)
Sometimes use other sensory cues to identify the person (voice, posture, key feature)
Damage in the ventral processing stream, in the fusiform face area
What is simultanagnosia
Another type of agnosia where there is impairment in the ability to see more than one object in a scene at a time or appreciate the multiple aspects of a single object
Difficulties reading - have to process each letter individually
What is cortical blindness and what is is caused by
Loss of vision caused bilateral damage in the visual pathway posterior to the LGN (very early in the visual processing pathway) - entire occipital lobe or major components of the pathway
Patient cannot see however, this is not typical blindness due to eyes (their eyes are healthy)
Interestingly, they can avoid obstacles - another visual pathways that bypasses the LGN - used for reflexes information and operates outside consciousness
Most common cause is anoxia
Have normal pupillary reflexes
What is hemispatial neglect
Failure to report, respond or orient to stimuli on one side
Patients may behave like one side of space does not exist
Different from visual field deficit patients, who would think to turn their heads, hemispatial neglect patients don’t think to turn their heads - nothing exists on that side to them
Almost like an attention deficit
Not attributed to sensory or motor impairment
Neglect is perceptual and representational
What form of hemispatial neglect is most common
Left side hemispatial neglect, resulting from a lesion on the right side
Diseases that impact visuospatial abilities
Stroke (right MCA or PCA)
Anoxia
Alz
Lewy Body
Posterior cortical atrophy
Symptoms of corticospinal tact lesions
- Weakness
- Increased muscle tone / hypertonia
- Increased reflexes / hyperreflexia
Stroke - Upper or lower
Upper motor neuron damage
Contralateral lower portion of the face is affected, but NOT the upper part - can raise their eyebrows. This is because there is bilateral innervation of the upper part of the face
Bell’s palsy - upper or lower
Lower motor neurone damage of cranial nerve 7 (not brain injury)
Complete weakness on the contralateral side - cannot raise eyebrow
Term: -paresis (hemi)
Weakness (partial paralysis) - partial weakness
Term: -plegia (hemi)
Complete paralysis
Term: Plasy
Weakness (partial) or complete paralysis due to lower motor neuron lesion
Basal ganglion damage
contralateral movement disorders
weakness +/- involuntary movements
(also cognitive and behavioural changes)
Lesions in the cerebellum
Ipsilateral deficits
Ataxic gait
Intention Tremor
Nystagmus
Scanning speech
3 types of disorders involving muscle tone
- Spasticity
- Rigidity
- Dystonia
Symptoms of hyperkinetic movement disorders
Tremor
Tics
Myoclonus
Chorea
Hemi/ballismus
Three types of tremors
Essential
Resting
Intention/Action
Types of gait disorders
Spastic/hemiplegic
Ataxic
Parkinsonian
What is a spastic/hemiplegic gait disorder
Stiff-legged, decreased arm swing on same side
One leg is tight (hypertonic), doesn’t bend at the knee, stays stiff and swings + upper extremity weakness and spasticity on the same side
MCA stroke, cerebral palsy
Typically CST lesion
What is an ataxic gait disorder
Wide-based, unsteady, staggering
Cerebellar stroke or tumour, alcohol intoxication
