Upper motor neuron, UMN
Clinic
- Upper Motor Neuron Pathways are first-order neurons, responsible for carrying signals that Initiate, Modulate and Coordinate movement.
- The major UMN tract that initiates voluntary movement is the pyramidal tract s
- UMN disease is a wide and varied collection of disease which have UMN involvement in common
Entities
Upper motor neuron is series of entities
- Muscle Weakness / Paralysis
- Incoordination: Decreased motor control including Speed, Accuracy and Dexterity
- Hypotonia or Hypertonia / Spasm
- Decreased endurance
- Hyper reflexia: Exaggerated deep tendon reflexes
- Spasticity
- Clonus
- Reappearance of primitive reflexes, such as the extensor plantar response (Babinski sign)
Causes
| Dynamic | Static |
|---|---|
|
Entity / Miasms
| GSS | CJD | NVCJD | HTLV-1 | JE | EEE/
WEE | |
|---|---|---|---|---|---|---|
| Hyper Reflexia | +++ | +++ | +++ | +++ | +++ | +++ |
| Primitive reflexes | +++ | +++ | ||||
| Incoordination | +++ | +++ | +++ | |||
| Spacticity | +++ | +++ | +++ | +++ | +++ |
Note
- So I suggest The rubric "Spastic paralysis" for problem in initiating muscular movement
- And also the rubric "Incoordination" for problem in coordination
UMNS is the motor control changes that can occur in skeletal muscle after an upper motor neuron lesion.
Following upper motor neuron lesions, affected muscles potentially have many features of altered performance including:
- Muscle weakness
- Decreased motor control including decreased speed, accuracy and dexterity
- Altered muscle tone (hypotonia or hypertonia)
- Decreased endurance
- Exaggerated deep tendon reflexes including spasticity, and clonus
Such signs are collectively termed the "upper motor neuron syndrome". Affected muscles typically show multiple signs, with severity depending on the degree of damage and other factors that influence motor control. In neuroanatomical circles, it is often joked, for example, that hemisection of the cervical spinal cord leads to an "upper lower motor neuron syndrome and a lower upper motor neuron syndrome". The saying refers to lower motor neuron symptoms in the upper extremity (arm) and upper motor neurons symptoms in the lower extremity (leg).