Can diaphragm be paralyzed without phrenic nerve damage?

I had an unsuccessful PVI ablation performed last year. During the procedure, I developed a cardiac tamponade. I went into arrest before the cardiothoracic surgeon could do a pericardiocentesis. It was necessary to crack my chest open. The pericardium was drained successfully. The only thing that the surgeon saw was bruising around the area of the right superior pulmonary vein as it went into the transversesinus area in the roof of the left atrium. After months of recovery, I kept telling the doctors that I was having breathing problems. I was told that this was the normal healing process. Finally, I went to a pulmonary specialist. I was given a "sniff" test which determined that I had a paralyzed right diaphragm. My PFt's were in the low 60% range, down from low 90% prior to the procedure. It was suggested that I have an EMG of the phrenic nerve. A needle was inserted in my right side, below the rib cage. The test results were negative. The neurologist had no explanation for my paralysis. Could there have been an error in the test? Could the phrenic nerve have been damaged in the left atrium area and need to be tested there? Can there be other reasons that the diaphragm is paralyzed?

[CCF-Neuro-M.D.-CS]

When studying the diaphragm with EMG there are two things which can be done. You can stimulate the phrenic nerve in the neck and record the motor response in the diaphragm, and compare the responses from side to side. However, these tests are difficult to perform technically, and one can only comment on a problem if the recording is normal on one side and abnormal on the other. You can also perform a needle examination looking for abnormalities.

If your neurologic examination is otherwise normal, the most likely cause for your diaphragm weakness is an abnormality of your phrenic nerve. Since your right side is paralyzed testing the nerve on the other side does not help. The only other test I could think of performing is a CT scan of MRI of the chest to make sure that nothing is pressing on the phrenic nerve. Good luck.

[douglas500]

A related discussion, Repair of partially paralyzed diaphram was started.