Perhaps you should try some spelling variations:
"motor neurone disease" » "motor neutrone disease", "motor neuroe disease"
"motor neuron disease" » "motor neutron disease", "motor neuro disease"
"motor neurons disease" » "motor neutrons disease", "motor neuros disease"
"motor neuronal disease" » "motor neutronal disease", "motor neuroal 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 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 neurons disease\") OR (\"motor neuronal disease\"))))".
• Removing quotes may allow a broader search: (((( motor neurone disease ) OR ( motor neuron 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 neurons disease") OR ("motor neuronal disease"))))*.