The 49-year-old had been drinking in Grimsby's Lifeboat Bar in December last year when his brother entered. The court heard the pair have an ongoing dispute.
John Laine was said to be "well in drink" when he approached his brother, and accused him of having once spiked his drink with drugs.
Laine punched his brother twice in the face and Stephen Laine suffered a dislocated fracture of the cheekbone and jaw, and damaged teeth.
In defence of Laine, Cheryl Mottram said he is a habitual drug user.
She said: "John Laine tells me that he only drinks in two public houses and goes there regularly.
"His brother knows this and his brother had been following him around somewhat prior to this incident.
"He accepts what he has done is wrong and while he doesn't get on with his brother, he should not have assaulted his brother.
"He is emotionally unstable, and has had quite a lot of problems in the past. He is taking anti-depressants."
The court heard Laine suffers from Tinnitus, a condition causing ringing or other unwanted sounds in the ears.
"He can't sleep properly because of the ringing when he lies down," said Miss Mottram.
"Alcohol dulls the noise."
Laine was sentenced to a two-year community rehabilitation order.
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