Disorders Flashcards
What does damage to the Cortico-Spinal Tract produce?
-HEMIPLEGIA aka limb paralysis on contralateral side of body.
What is Hemiplegia?
- limb paralysis on contralateral side of body.
- Increased muscle tone.
- hyperreflexia (babinski reflex)
What is the Babiniski Reflex?
If seen in adults what can it implicate?
- Fanning of toes
- Usually seen in babies
Seen in adults when there is damage to the cortico-spinal tract
What are the functions of Cortico-Spinal Tract?
Precise movements of fingers, toes, arms, and legs
What are the functions of the Cortico-Bulbar Tract?
Precise movement of face, eyes, and mouth
What does damage to Cortico-Bulbar Tract produce?
How does damage affect smiling?
-Loss of voluntary facial movements
Person can’t smile on command (volitional) but can smile spontaneously.
What is the General Function of the the Basal Ganglia Motor System?
Functions in very early initiation of movement
“Turning thought into action”
What are disorders are associated with the Basal Ganglia?
- Huntington’s Disorder
- Parkinson’s Disorder
- Tourette’s Syndrome
- Tardive Dyskinesia
What are Huntington’s Disorder Causes?
EXCESS Dopamine due to defective receptors
- Genetic (chromosome #4) , rare, and progressive disorder
- Atrophy of Caudate & Putamen (seen in CAT Scan)
Fatal, No cure. Treatment: Tranquilizer (reduce concentration of dopamine).
What are Motor, Cognitive, and Emotional Symptoms of Huntington’s Disease?
MOTOR:
- Motor slowing
- CHOREIFORM movements (uncontrolled aimless jerky limb movements)
- Normal voluntary movements become impossible
COGNITIVE:
- Subcortical Dementia
- Apathy
EMOTIONAL:
- Depression
- Mania or Paranoid Psychosis
Parkinson’s Disorder Cause
Too Little Dopamine due to degeneration of substantia nigra
-Loss of dopamine producing neurons.
Caused by exposure to CO2, toxins, metal, drugs, head traumas, viruses, “idiopathic”, genetic
No cure and can be treated with L-DOPA (dosage dependent)
PET Scan: Decrease of dopamine activation in caudate and putamen.
-If ask the person to smile they can (volitional) but they can’t spontaneously smile.
Parkinson’s Motor Symptoms
- Resting Tremor
- COGWHEEL RIGIDITY
- Impaired posture and gait
- Shuffle walk
- Akinesia (diminished movement)
- Bradykinesia (slowed movement)
- MASKLIKE FACE
Parkinson’s Cognitive and Emotional Symptoms
- Subcortical Dementia
- Impoverished feelings and emotions (flat voice tone)
-Depression
Tourette’s Syndrome
- Hypersensitivity to dopamine receptors in caudate
- spectrum disorder
- Uncontrollable Tics and vocalizations
- Echolalia
- Involuntary Swearing
- OCD and ADHD symptoms
Childhood onset, peaks at age of 10 and diminishes towards adulthood
Treated with TMS
Tardive Dyskinesia
Side effect of antipsychotic drugs
Symptoms: Involuntary movement of face, mouth, head, and tongue. Dystonia
Incurable symptoms, can lead to permanent damage
General Cerebellar Damage Symptoms
- Intention tremor
- Decomposition of movement (Mr.Roboto)
- Ballistic movements miss target
- Impaired new motor learning
- Cognitive Impairments in procedural learning, coordination of attention and arousal, cognitive “timing”
Vestibulo-cerebellum
Input: Vestibular Nuclei
Damage: Impairment of balance and posture
Spino-cerebellum
Input: Spinal Cord
Damage: Uncoordination of skilled movements
Cerebro-cerebellum
Input: Motor and Association Cortex
Damage: Impaired Motor Learning and Procedural Learning.
Association Cortex
Damages lead to “motor plan” impairments.
Apraxia
Apraxia (in general)
UNILATERAL LESION usually but BILATERAL IMPAIRMENT
-Impairment carrying out voluntary skilled movements.
- Motor strength and coordination intact
- cannot link gestures to coherent act.
- performing whole body movements to command intact.
- Imitation of movements impaired, but better than to verbal command.
- Manipulates actual objects appropriately
Oral Apraxia
INFERIOR FRONTAL LESION
-causes difficulty manipulating objects using facial muscles.
Limb Apraxia
LEFT PARIETAL TEMPORAL LESION
- apraxia manifests in limb movements on both the right and left even if lesion is only on the right.
Blind Sight
These people deny sight but in “blind” field they can:
- Localize position of stimulus
- Judge if stimulus is moving
- Make appropriate hand gestures when reaching for object.
This may be due to connections from the superior colliculus (SC).
-DTI shows that the pathway from the SC to the visual cortex (association areas) is still intact.
Agnosia
This is a modality-specific recognition disorder.
Apperceptive Agnosia
Perceptual Dysfunction
Normal Acuity but appear functionally blind
They can’t:
- match, recognize, copy, or discriminate simple visual stimuli.
-Impaired object recognition.
-difficulty perceiving overall form
-may try to recognize objects by individual features but are thrown off by stray marks. (A heart and a slash through it.)
Motion or manual tracing can aid recognition.
Apperceptive Agnosia Lesion
Perceptual Dysfunction
- Diffuse BILATERAL OCCIPITAL
- RIGHT hemisphere LATERAL OCCIPITAL TEMPORAL
Smiultagnosia
Perceptual Dysfunction
Normal visual fields but act blind
- Can only perceive one object at a time.
- Counting objects is difficult.
- Can’t read text (only see one word at a time).
Dorsal Simultagnosia Lesion
Perceptual Dysfunction
ACT BLIND ALL THE TIME
- can’t see more than 1 object (abnormal limit on visual attention).
- BILATERAL PARIETAL-OCCIPITAL DAMAGE
Visual Object Agnosia
Memory Access Dysfunction
Vision is intact but…
- impaired at naming objects, pictures, and demonstrating their use.
- can’t sort objects by category
- They can recognize faces, and describe shapes/parts of objects. They can also recognize objects via smell, touch or sound and they can correctly copy objects.
They can perceive the objects but can’t access memory of what they do.
-Characteristic motions of objects, seeing object in a familiar context can help them recognize the objects.
Visual Object Agnosia Lesion
Memory Access Dysfunction
BILATERAL injury in LATERAL OCCIPETAL-TEMPORAL AREAS
fMRI data showed that Visual Object Agnosia patient had no activity that could be observed for the real objects over and above what was seen for the scrambled objects.
Prosopagnosia
Memory Access Dysfunction
They are unable to:
-recognize a person by looking at their face (but know that a face is a face).
They can:
- discriminate whether 2 faces are the same or different
- recognize individual based on their voice
- recognize objects
- describe features of a face
- can interpret facial expressions
- “implicit face recognition may be spared (“guilty knowledge test” uses electro-dermal electrodes to measure responses to faces. Get increase response to faces they know.)
Prosopagnosia Lesion
Memory Access Dysfunction
BILATERAL but can be UNILATERAL RIGHT hemisphere lesion
- Ventral & medial temporal-occipetal
- R hemisphere FUSIFORM & PARAHIPPOCAMPAL GYRI
will also have difficulty recognizing their car from another car of the same model.
Auditory Agnosias
Affecting the recognition of sounds…
Lesions in LEFT & RIGHT auditory cortex.
Word Deafness
- Normal pure tone hearing
- Normal recognition of nonverbal sounds
- Can’t recognize or discriminate speech
- Speaking, reading, writing intact
Word Deafness Lesion
- BILATERAL ANTERIOR PART OF SUPERIOR TEMPORAL GYRUS
- UNILATERAL L SUBCORTICAL TEMPORAL (destroying axonsentering Wernicke’s Area
Ventral Simultagnosia Lesion
Perceptual Dysfunction
DON’T ACT BLIND ALL THE TIME
- can’t recognize more than 1 object but can see other objects. (Abnormal limits on object recognition).
- lEFT VENTRAL TEMPORAL- OCCIPETAL DAMAGE
Auditory Agnosias- Specific:
- Agnosia for nonverbal (environmental) sounds
- Amusia (agnosia fro musical sounds only)
Amusia
Lesion in INSULA, inferior frontal gyrus, temporal lobe
- can be congenital
- specific aspects of music impaired after different injuries.
Amusia Case Studies
-Classical composer
LEFT hemisphere injury
- Wernicke’s Aphasia
- could recognize melodies
- good pitch and musical judgement
- COULD NO LONGER COMPOSE OR READ MUSIC.
Amusia Case Studies
-Music Professor
RIGHT hemisphere injury
- retained musical knowledge
- “lost interest” in composing
- did not enjoy listening to music
Topographic Disorders
Spatial Disorders and Attention
- route-finding problems
- loss of familiarity for typical routes and places
- map reading problems
- problems learning new environments/ routes
- can describe some familiar routes from memory
- can recognize building types but can’t be used as spatial cues.
-Often associated with prosopagnosia
Topographic Disorders Lesions
Spatial Disorders and Attention
- Right paraphippocampal gyrus, hippocampus
- LEFT OR RIGHT LINGUAL GYRUS
Constructional Disorders
Saptial Processing and Attention
- Deficits reproducing detailed spatial figures, relations among component parts.
- Deficits in drawing. assembling, building