Respiratory dysfunction in patients with chronic-onset cervical myelopathy.

Study Design: A retrospective study. OBJECTIVE To clarify the characteristics of respiratory dysfunction associated with chronic-onset cervical myelopathy.

Summary Of Background Data: In acute cervical cord injury, respiratory dysfunction, especially vital capacity (VC), is impaired, which causes respiratory complications. No comprehensive study has been published about respiratory dysfunction in patients with chronic-onset myelopathy.

Methods: Eighty-four consecutive patients without history of respiratory disease who underwent surgery for cervical myelopathy were studied. The control group consisted of 84 age-matched patients with lumbar degenerative diseases. Parameters of spirometry, arterial blood gas, height of the diaphragm, and the score for neurologic impairment were analyzed before and after surgery.

Results: Percent VC (%VC) was significantly lower in the study group than in the control group. In patients with cranial cord lesions and multilevel cord lesions, %VC was lower than in those with a caudal lesion and a single-level lesion, respectively. Percent VC correlated with the preoperative neurologic score in the study group. In patients having the lesion at or above C4, %VC improved after surgery, whereas in those with a lower lesion, %VC had not decreased before surgery, and no further improvement was obtained.

Conclusions: In patients with chronic-onset cervical myelopathy, %VC significantly decreases when they have more cranial or multilevel lesions. Percent VC also correlates with the preoperative neurologic score and improves with surgical treatment in patients with more cranial cord lesions. Respiratory dysfunction should be taken into consideration as a part of neurologic impairment in chronic-onset cervical myelopathy.