Nerve conduction studies are a useful adjunct to clinical examination, but TTS is possible with normal nerve conduction studies.
It should also be noted that in normal elderly patients, sensory responses may be absent.
MRI and ultrasound may be useful in diagnosis if soft tissue masses, or a space occupying lesion, are considered the cause for the nerve compression.
Plain radiography may be useful for diagnosis of fractures, bony masses and osteophytes, which may cause the nerve compression.