<b>Spinal cord lesion </b>

Abstract

Paraplegia and sensory disturbance are the symptoms often recognized in case of spinal cord lesion including trauma, tumor, demyelinating diseases and spinal cord infarction. In pain clinic area, neurological symptom of paraplegia may occur as an unexpected complication of the nerve block with neurolytics and it is important that we should understand pathological and anatomical basis of the spinal cord lesion. We experienced a case presenting a symptom of the paraplegia which was unexplainable for anterior spinal artery syndrome after the intercostal nerve block with neurolytics. The patient was 72 years old male with post herpetic neuralgia at the second thoracic nerve. The second intercostal nerve was blocked using 2.5 ml of 7% phenol water. Paraplegia and partial sensory disturbance below the 10th thoracic nerve were recognized after the block. We speculated the following mechanism of this complication. Phenol water partially entered into intercostal artery accompanying an intercostal nerve and drug solution spread against arterial blood flow because of the injection pressure was higher than arterial blood pressure. The drug solution entered into the intercostal artery spread to the spinal branch and the spinal cord supplied with this artery was partially damaged. There is a clear somatotopic organization of the fibers and an overlap of collaterals of ascending and descending branches of the dorsal root in the spinothalamic tract. There is also a segmental organization of the fibers in the spinothalamic tract and corticospinal tract. These tracts contain both transverse crossing fibers and uncrossing fibers. Nathan reported that the fibers subserving different sensory modalities did not 1 form the same angle with the long axis of the cord as they cross the cord. The difference in the angle of slope would lead to a different level of sensory loss for different modalities. It is considered that the sensory disturbance observed after the second intercostal nerve block appeared at the level of the 10th thoracic spinal cord level.It is important to be familiar with the anatomy of the spinal cord when performing neurolytic nerve blocks.