What is Lioresal Intrathecal (baclofen) used to treat when oral antispastic medicines are ineffective or cause unacceptable side effects?

Lioresal Intrathecal (baclofen) treats severe chronic spasticity of spinal or cerebral origin when oral antispastic medicines are ineffective or cause unacceptable side effects at effective doses; for spasticity due to head injury, a delay of at least one year is recommended to allow symptoms to stabilise.