Ylämotorinen

Ylämotorinen is a neurology term used in Finnish to describe motor pathways and neurons located above the anterior horn cells of the spinal cord, including neurons of the motor cortex and brainstem and their descending tracts, such as the corticospinal and corticobulbar tracts. These upper motor neurons influence lower motor neurons, and thereby control voluntary movement, muscle tone, and reflex activity.

The concept is contrasted with alemm motorinen or lower motor neurons, which include the motor neurons in the anterior horn of the spinal cord and brainstem that directly innervate muscles. Damage to the ylämotorinen pathways can produce an upper motor neuron syndrome, reflecting disruption of central motor control rather than direct muscle or peripheral nerve injury.

Upper motor neuron syndrome is characterized by weakness with increased muscle tone (spasticity), brisk or hyperactive reflexes, and a Babinski sign. Clonus and changes in coordination may occur. Muscle atrophy tends to be less prominent than in lower motor neuron lesions and is often related to disuse.

Common causes of ylämotorinen pathway injury include stroke affecting the motor cortex or internal capsule, traumatic brain injury, spinal cord lesions above the level of the anterior horn, multiple sclerosis, and cerebral palsy. Diagnosis relies on clinical examination and neuroimaging, with electrophysiological testing as needed.

Management focuses on rehabilitation and symptom control, including physical therapy, and pharmacologic strategies to reduce spasticity (for example, baclofen or tizanidine) or focal treatments such as botulinum toxin, as well as addressing the underlying condition.