upper motor neuron sign (pyramidal tract sign)

Etiology

• spinal cord disease
  • lesions in the corticospinal tract or corticobulbar tract
  • lesions in the spinal cord above L1 where the spinal cord normal ends (adults)

Clinical manifestations

• spasticity
• increased deep tendon reflex* (hyperreflexia)
• upgoing & fanning toes in the Babinski's reflex
• hypertonicity of muscles*
• myoclonus
• pseudobulbar palsy

* tone & deep tendon reflexes are diminished acutely with upper motor neuron lesions, but increased chronically

More general terms

• sign/symptom

Additional terms

• upper motor neuron