A particular case of the bilateral C5 palsy resulting after operation for cervical spondylotic amyotrophy is reported here. An 89-year-old female suffered from muscle weakness in the left shoulder girdle. In primary physical examination, manual muscle testing (MMT) of the ipsilateral trapezius muscle and biceps muscle were both 0(zero). Aslightly long tract sign was also pointed out, but there was no sensory disorder. X-ray findings demonstrated a narrow spinal canal from the C3 to C7 level. Magnetic resonance imaging (MRI) revealed that the left anterolateral element compressed the spinal cord severely at C4/5 and moderately at C3/4. Anterior interbody fusion at C3/4 and en-block laminoplasty from C4-7 were therefore performed. Although muscle weakness more or less recovered once postoperatively, subsequent bilateral C5 palsy (MMT 1) was indentified. After ten months of follw-up without any additional treatment, the palsy recovered spontaneously to MMT 4.
It has been suggested that postoperative C5 palsy tends to occur after posterior decompression of severe anterior C4/5 compression. In the treatment of cervical spondylotic amyotrophy, especially when severe C4/5 compression is suspected, simultaneous foraminotomy should be necessary for preventing anxious postoperative C5 palsy.
