Upper Motor Neuron Syndrome Flashcards
What is the following a defintion of?
Clinical condition of signs and symptoms arising from upper motor neuron lesions
Upper motor neuron syndrome
What are some causes of UMN lesions?
- Stroke
- Spinal Cord injury
- abnormal development
- neurogenerative disorders
- anoxic brain injury
- traumatic brain injury
- tumor
- infections
- infalmmatory disorders
- metabolic disoders
What is the following a definition of?
Sudden onset of neurologic deficits due to disruption of the blood supply in the brain which damages neural tissue disrupting connections between cortex, subcortical structures, brainstem, cerebellum and spinal cord
Stroke
What is the following a defintion of?
Complete sever of all ascending and descending axons, prevent spinal cord below the level of injury from converying signals to or from the brain
Spinal cord injuries
What is the following a defintion of?
Motor deficits arise from damage to the corticospinal, corticoreticular, and corticobrainstem tracts during perinatal period
Spastic cerebral palsy
What is the following a defintion of?
Demyelination of the CNS UMN which can occur anywhere in the brain and spinal cord
Multiple Sclerosis
Where can UMN be damaged?
anywhere along its route
Damage to UMN can be catagorized as what?
loss of function or gain of function
is the following loss or gain of function?
Absence of a feature that is normally present
Loss of function
is the following loss or gain of function?
Presence of a feature that is not normally present
Gain of function
What is an upper motor neuron sign that can be both loss or gain of function?
Abnormal muscle tone
What are the signs of loss of function in UMN syndromes? (4)
- paresis
- paralysis
- impairted selective motor control
- absent or decreased muscle tone
What are the signs of gain of function in UMN syndomes? (8)
- spasticity
- myoplasticity
- hyperreflexia
- excess reticulospinal drive
- abnormal synergies
- rigidity
- abnormal reflexes
- compensatory and pathologic cocontraction
What are the structures involved in UMN syndromes?
- cerebral hemisphere
- brainstem
- spinal cord
What are the pathologies of UMN syndromes?
- cerebral palsy
- spinal cord injury
- traumatic brain injury
- MS
- medial cerebral artery stroke
What are the voluntary movements of UMN syndromes?
- impaired or absent
- Obligatory abnormal muscle syergies in traumatic brain injury, MS, spastic cerebral palsy or medial cerebral artery stroke
If there is a lateral corticospinal tract lesion above decussation what happens?
Contralateral loss
If there is a lateral cortiocspinal tract lesion below decussation what happens?
Ipsilateral loss
If there is medial UMN damaged in the brainstem what happens?
Ipsilateral loss expect for bilateral loss of reticulospinal influence
If there is medial UMN damaged in the spinal cord what happens?
Ipsilateral loss
What happens to muscle tone in UMN syndromes?
Increased: velocity-dependent hypertonia (spasticity)
What is the following a definition of?
not as severe as neurogenic atrophy
type of muscle bulk sign in UMN syndromes
Disuse atrophy
In spastic cerebral palsy what does abnormal motor development cause?
Reduced muscle volume
What is the following a defintion of?
resistance to stretch in resting muscle
Muscle tone
What type of muscle tone is this?
- type of hypertonia
- velocity-independent increase in resistance to stretch
- excess resistance that does not change with speed of stretch
- occurs in basal ganglia disorders and severe lesions affecting midbrain or structures above it
- diect UMN facilitation of alpha LMN
Rigidity
What type of muscle tone is this?
- type of hypertonia
- velocity-dependent increase in resistance to stretch
- excess resistance that increases with increasing speed of movement
- chronic UMN lesions
- neuromuscular overactivity and/or myoplasticity
Normal muscle tone
What type of muscle tone is this?
- abnormally low musuclar resistance to passive stretch
- less than normal resistance during passive stretch
- developmental disorders: decreased descedning facilitation resulting in fewer weak actin-myosin bonds; excessive muscle length; decrease tone due to abnormal brain development
- LMN disorders: decreasd LMN input to skeletal muscles
- acute UMN lesions that cause CNS shock: spinal or cerebral shock, disrupts descending motor commands that affect LMN and temporarily inactive due to edema
Hypotonia
What type of muscle tone is this?
- compelte loss of muscle tone
- no resistance during passive stretch
- LMN disorders: severe spina bifida, floppy infant syndrome, loss of LMN input to skeletal muscle
Flaccidity
UMN lesions cause paresis whe some descending UMN remain intact which does what to LMN?
provides inadquate facilitation to LMN
What is the following a defintion of?
weakness affecting one side of the body
Hemiplegia
How it hemiplegia caused?
Interruption of the corticobrainstem and medial and lateral corticospinal tracts in one cerebral hemisphere
What does paraplegia affect?
affects body below the arms
What does tetraplegia affect?
Affects all four limbs