Changes in muscle performance can be broadly described as the upper<unk><unk>  syndrome. These changes vary depending on the site and the extent of the lesion, and may include: * Muscle weakness. known as 'pyramidal weakness' * Decreased control of active movement, particularly slowness * Spasticity, a velocity-dependent change in muscle tone * Clasp-knife response where initial higher resistance to movement is followed by a lesser resistance * Babinski sign is present, where the big toe is raised (extended) rather than curled downwards (flexed) upon appropriate stimulation of the sole of the foot. The presence of the Babinski sign is an abnormal response in adulthood. Normally, during the plantar reflex, it causes plantar flexion and the adduction of the toes. In Babinski's sign, there is dorsiflexion of the big toe and abduction of the other toes. Physiologically, it is normally present in infants from birth to 12 months. The presence of the Babinski sign after 12 months is the sign of a non-specific<unk> . * Increased deep tendon reflex (DTR) * Pronator drift
Upper motor neuron lesion
Lower motor neuron lesion
Accessory nerve disorder
Motor neuron disease
Upper motor neuron syndrome
Hereditary motor and sensory neuropathy
Neurocristopathy
Neuromuscular junction disease