Perhaps you should try some spelling variations:
"motor neurone disease" » "motor neurons disease", "motor neuronal disease", "motor neutrone disease", "motor neuronse disease", "motor neuroe disease"
"motor neuron disease" » "motor neutron disease", "motor neurons disease", "motor neuro disease"
"motor neutrons disease" » "motor neutron disease", "motor neurons disease", "motor neutrino disease"
"motor neutrinos disease" » "motor neutrino disease", "motor neutrinoless disease"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("motor neurone disease") or ((("motor neuron disease") or ((("motor neutrons disease") OR ("motor neutrinos disease"))))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("motor neurone disease") OR ((("motor neuron disease") OR ((("motor neutrons disease") OR ("motor neutrinos disease")))))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"motor neurone disease\") or (((\"motor neuron disease\") or (((\"motor neutrons disease\") OR (\"motor neutrinos disease\"))))))".
• Removing quotes may allow a broader search: (( motor neurone disease ) or ((( motor neuron disease ) or ((( motor neutrons disease ) OR ( motor neutrinos disease )))))).
• Adding a wildcard symbol may retrieve word variants: (("motor neurone disease") or ((("motor neuron disease") or ((("motor neutrons disease") OR ("motor neutrinos disease"))))))*.