Neuropathy is usually short for peripheral neuropathy. Peripheral neuropathy is defined as deranged function and structure of peripheral motor, sensory, and autonomic neurons, involving either the entire neuron or selected levels.
Lumbosacral would be an indication of where it's located.
So from what I can tell, it's a problem with the nerves in the lower spine.
And why am I not surprised that the word "deranged" appears in a description of something going on with Moo?