Patterns of peripheral nerve injury beyond the spinal cord

What it is

Beyond the spinal cord, damage is named by how many nerves it takes and how the loss is laid out:

• Mononeuropathy: damage to a single peripheral nerve.
• Mononeuritis multiplex: damage to more than one peripheral nerve, which results in an asymmetrical distribution.
• Polyneuropathy: damage to the terminal branches of multiple nerves, which results in a symmetrical, distal distribution.
• Plexopathy: damage to a nerve plexus, for example the brachial plexus.
• Radiculopathy: damage to a nerve root, so the distribution follows the corresponding dermatome.

Mononeuritis multiplex and polyneuropathy are told apart by symmetry: asymmetrical for the first, symmetrical and distal for the second.