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Based on tests:
Brain imaging studies may be required for encephalitis, and multiple sclerosis.
Imaging tests of the spine may be required in transverse myelitis, neuropathic pain, brachial plexitis, and CIDP.
Nerve function tests for neuropathic pain, and brachial plexitis.
Electromyography for GBS and CIDP.
Lumbar puncture (spinal tap) for encephalitis, transverse myelitis, multiple sclerosis, chronic inflammatory demyelinating polyradiculoneuropathy, and Guillain-Barre syndrome.
Other specific tests for each of these conditions may be done by your doctor.
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