Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation ?
    ### Response:
    Leukoencephalopathy with brain stem and spinal cord involvement and lactate elevation (LBSL) is a rare neurological disease characterized by slowly progressive cerebellar ataxia (lack of control of the movements) and spasticity with dorsal column dysfunction (decreased position and vibration sense) in most patients.
    