Possible Clues:

• Somehow treat germy stuff in the head
• The trouble with this is it's a shade brainy
• Intelligence; the brain
• Intelligence? Dull subject!
• Common sense, something of concern to elderly people?
• Brains ... or this puzzle's four circled names?
• Aristocratic woman with count shows common sense
• Colourful type from hospital verbalised with intelligence
• Colourful type from major hospital spoke out with intelligence
• Dull affair that shows intelligence