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.