Perhaps you should try some spelling variations:
"motor neurone disease" » "motor neutrone disease"
"motor neuron disease" » "motor neutron disease"
"motor neurons disease" » "motor neutrons disease"
"motor neuronal disease" » "motor neutronal disease", "motor neural 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 neuro disease"))))) or ((("motor neurons disease") or ("motor neuronal disease"))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("motor neurone disease") OR ((("motor neuron disease") OR ("motor neuro disease"))))) OR ((("motor neurons disease") OR ("motor neuronal disease")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"motor neurone disease\") or (((\"motor neuron disease\") OR (\"motor neuro disease\"))))) or (((\"motor neurons disease\") or (\"motor neuronal disease\"))))".
• Removing quotes may allow a broader search: (((( motor neurone disease ) or ((( motor neuron disease ) OR ( motor neuro disease ))))) or ((( motor neurons disease ) or ( motor neuronal disease )))).
• Adding a wildcard symbol may retrieve word variants: (((("motor neurone disease") or ((("motor neuron disease") OR ("motor neuro disease"))))) or ((("motor neurons disease") or ("motor neuronal disease"))))*.