Delayed paralysis of the deltoids due to selective anterior horn necrosis in a patient with traumatic tetraplegia

Abstract

In spinal cord studies of patients with traumatic paraplegia, one sometimes observes a second lesion apparently not related to fracture-dislocation of the spine. We report a case that is particularly interesting in terms of clinicopathological correlations.A 49-year-old man sustained multiple injuries in an automobile accident and was immediately unconscious. At the emergency room he had 3 cardiac arrest but was successfully resuscitated. On the second and fourth days after injury he had two short episodes of cardiac asystole which responded to atropine. Four days after the accident the patient was lethargic but arousable. Pain and touch were absent below C6 bilaterally. Muscle strength in the upper extremities was preserved but the hands were paralyzed; Necrosi.c of the central part of the anterior horns at C5 (arrows). Note the symmetry of the lesion. (Luxol-fast blue.)the paralyzed lower extremities were flaccid. Roentgenograms of the cervical spine showed fractures of the C7 laminae and of the C4, C5, and C6 spinous processes. O n the tenth day after injury the patient showed decreased strength in both deltoid muscles. Two days later, both deltoid muscles had absent function whereas biceps and triceps functions were present. The neurological state remained otherwise unchanged. The patient died of pneumonia on the twentieth day following injury.Autopsy of the spinal cord showed massive necrosis at C8-TI. In view of the bilateral loss of the deltoids with preservation of the biceps, attention was paid to C5. The spinal cord between the C4 and C6 roots was cut into four slices which were embedded separately. Macroscopically, the C5 level appeared normal except for a slight depression in the anterior horns in the second and third slices. Histologically, the three upper slices showed neuronal depopulation and chromatolysis of the surviving motor neurons, progressing to frank central necrosis of the anterior horns with accumulation of lipid macrophages (Figure). The lower slice was normal except for early wallerian degeneration in the posterior columns. The anterior spinal artery and its sulcal branches were normal. Above C5, at C6 and C7, and below T I , the cord was normal except for early wallerian degeneration. The brain was normal.The selective necrosis of the anterior horns at C5 with sparing of two segments above the site of the major traumatic injury at C8-T1 accounts for a clinical finding difficult to explain during life, i.e., sparing of the biceps with complete loss of the deltoids occurring ten days after injury. The innervation of the deltoid is located at a somewhat higher level in the cord compared with the biceps, and sparing of the lower part of C5 and of C6 thus accounts for relative preservation of the biceps in this patient. Selective necrosis of the anterior horns is a pathological entity distinct from central spinal cord necrosis. Central cord necrosis is a common occurrence in spinal cord injury, probably due to stretching of the horizontally oriented blood vessels in anteroposterior compre...