As the disorder worsens, the damage appears less multifocal and more symmetric, resembling polyneuropathy. Common causes include a lack of oxygen from decreased blood flow or inflammation of blood vessels. About one-third of cases are without identifiable cause. Connective tissue disease is the most common cause in children. Prevention techniques vary depending on the specific disorder.
Specific symptoms vary with the individual nerve involved.
Examination and neuromuscular testing may show a specific loss of sensation and movement associated with dysfunction of specific nerves. Reflexes may be abnormal. Diagnosis of mononeuritis multiplex usually involves deficits of two or more isolated, unrelated nerve areas. Tests of nerve conduction velocity usually indicate axonal degeneration. A nerve biopsy may be appropriate for some cases.