spasticita

Spasticity is a motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes and exaggerated tendon jerks. It is one of the common symptoms of upper motor neuron syndrome, which results from damage to the neural pathways controlling voluntary movement. This damage can occur due to various conditions affecting the brain or spinal cord, such as stroke, cerebral palsy, multiple sclerosis, traumatic brain injury, and spinal cord injury.

The primary feature of spasticity is increased muscle tone, leading to stiffness and resistance to passive movement. This resistance can vary depending on the speed of the stretch; a faster stretch elicits a stronger, more resistant response. This phenomenon is often described as a "clasp-knife" effect, where initial resistance suddenly gives way. Spasticity can affect individual muscles or groups of muscles, leading to abnormal postures and involuntary muscle spasms. These spasms can be painful and interfere with daily activities like walking, eating, and dressing.

The impact of spasticity varies greatly among individuals. While some may experience mild stiffness, others can have severe, debilitating muscle spasms. The exact mechanisms underlying spasticity are complex and involve alterations in spinal reflexes and descending motor control. Diagnosis typically involves a neurological examination assessing muscle tone, reflexes, and functional limitations. Treatment aims to reduce muscle stiffness and improve function, and may include physical therapy, occupational therapy, medications (such as baclofen or tizanidine), and in some cases, surgical interventions.