Ulnar Neuritis
The term ulnar neuritis characterizes the disease manifested by sensory or sensory-motor disorders due to the ulnar nerve pressure in the elbow. In 50% of the cases, the cause is undetermined. In the rest of the cases, the condition may be due to space occupying lesions in groove, pressure outside the groove, to congenital abnormalities, trauma, metabolic or other disorders. The differential diagnosis must be made between thoracic outlet syndrome, cervical radiculitis, polyneuropathy, double crush syndrome, Pancoast tumor, or amyotrophic lateral sclerosis. The main symptom is the transient paresthesia of the little finger and ulnar half of the ring finger, aggravated by bending the elbow. The motor disorders appear later on in the muscles that are innervated by the ulnar nerve. During physical examination, Tinel sign is positive, while the symptoms are reproduced during flexion of the elbow with the wrist extended. Weakness and atrophy of the muscles controlled by the ulnar nerve can coexist (see picture). The electromyographic and electroneurographic monitoring helps identify the lesion.