This is a case of cubital tunnel syndrome, which is caused by compression or irritation of the ulnar nerve as it passes under the medial epicondyle before it branches to deep and superficial branches. Symptoms are usually tingling and numbness in the cutaneous distribution of the ulnar nerve. In severe cases, muscle weakness may be apparent, with atrophy of the hypothenar eminence.Also know: Deep branch of ulnar nerve supplies:Hypothenar compamentAdductor pollicisDorsal interosseiPalmar interosseiMedial lumbricalsSuperficial branch of ulnar nerve supplies:Palmaris brevis Surrounding skin of the digit 5 and the medial side of digit 4