Signs That Distinguish the Origin of Weakness | ||||
| SIGN | UPPER MOTOR NEURON | LOWER MOTOR NEURON | MYOPATHIC | PSYCHOGENIC |
|---|---|---|---|---|
| Atrophy | None | Severe | Mild | None |
| Fasciculations | None | Common | None | None |
| Tone | Spastic | Decreased | Normal/decreased | Variable/paratonia |
| Distribution of weakness | Pyramidal/regional | Distal/segmental | Proximal | Variable/inconsistent with daily activities |
| Muscle stretch reflexes | Hyperactive | Hypoactive/absent | Normal/hypoactive | Normal |
| Babinski sign | Present | Absent | Absent | Absent |