Massive Pyramidal Tract Signs after Endotracheal Intubation : A Case Report of Spondyloepiphyseal Dysplasia Congenita

An 18-yr-old man with spondyloepiphyseal dysplasia congenita was scheduled for surgery to remove retained hardware after surgical correction of a genu valga. His height was 120 cm and his weight was 30 kg. Medical history included diabetes mellitus type I treated with insulin. Former surgery of the genu valga, 3 months previously, occurred uneventfully. Preoperative physical examination revealed thoracic kyphoskoliosis, a short neck, systolic murmur, and respiratory arrhythmia. Laboratory data were within the normal range with the exception of the blood glucose level. Plain radiography of the cervical spine (no flexion/extension series) noticed only “little abnormality caused by spondylosis.” Surgery was planned using a balanced anesthetic technique. After administration of a nondepolarizing muscle relaxant (vecuronium) and controlled ventilation for 3 min by mask, the intubation was performed during direct laryngoscopy with a McIntosh 3 laryngoscope blade (Rusch, Vienna, Austria). The procedure was performed by an experienced staff anesthesiologist without using a cervical collar. During induction and intubation, the head was maintained in moderate flexion. The anesthesiologist could visualize only the posterior commissure, but nevertheless placed the tube, with a guide wire inside, on the first pass. He described the procedure as “not very difficult.” The intraoperative course occurred uneventfully. The patient was extubated, and the early postoperative period in the recovery room and at the ward was uneventful. On the first postoperative day, a spastic tetraparesis, right more than left, was diagnosed. Neurologic examination revealed a paresis of the upper and lower extremities, right more than left, with positive pyramidal tract signs: increased reflex activity with intact sensibility. Computerized tomography was ordered immediately and showed a massive cord compression to a diameter of 6 mm. Inside the foramen magnum an os odontoid of an 8-mm diameter could be recognized. The anterior arch of the atlas came close to the foramen magnum in a distance of 2 mm. The second vertebra was almost totally inside the atlas (Figure 1). For better normal anatomy is provided (Figure 2). The difference in C2 with the dens axis in a healthy patient and the hypoplastic dens axis in a chondrodystrophic patient can be seen. The patient was transferred to the department of neurosurgery. He did not require traction, but a steroid medication was administered. During this therapy the paresis decreased and, after 3 weeks, muscle power returned to 100%. Craniocervical instability and stenosis indicated surgical intervention later in the course. The foramen magnum was enlarged and the vertebrae C0 to C3 were stabilized by Compact Cotrell Dufoiset cervical titanium. Postoperatively, symptoms of tetraplegia developed because of stenosis at the level of C1. Paresis persisted despite revised surgery. Two weeks later, drainage of cerebrospinal fluid accumulation in the cervicooccipital region was performed. Later in the course, bronchopulmonary infection and respiratory insufficiency developed. Despite controlled ventilation and intensive medicine care the patient finally died.

Spondyloepiphyseal dysplasia is characterized by disproportionate dwarfism with shortening, predominantly of the trunk, and primary progressive involvement of the spine and epiphyses of long bones, particularly of the upper femur. There are two types of spondyloepiphyseal dysplasia: congenital, which can be detected at birth, and tarda, which manifests itself later in childhood. The tarda type has a prevalence of three or four children per one million children in the population of western industrialized countries, the prevalence of the congenita type is one or two per million people. In both clinical types of spondyloepiphyseal dysplasia the vertebrae are flattened throughout and “pear shaped” during early infancy. The odontoid process is dysplastic and delayed in ossification with risk of atlantoaxial instability. Skoliosis and kyphosis develop in late childhood or early adolescence, and the thorax is deformed with pectus carinatum. Other epiphyses of the long bones show varying degrees of involvement. [1] 

Atlantoaxial instability is well known in this specific patient population, but rarely leads to neurologic sequelae (in contrast to this case). [2,3]However, most case reports and articles dealing with anesthesia management of children with dwarfism stress the difficult airway more than the neurologic risk for the patient. [4,5]A case report with fatal outcome after anesthesia and laryngoscopy in dwarfism could not be found in the literature before.

As a consequence of this case, our regime in children with dwarfism scheduled for surgery is as follows: The exploration is performed very thoroughly while watching for signs of atlantoaxial instability. The first clinical signs without neurologic deficits are history of cyanosis after crying and feeding, respiratory difficulties, poor head control, fatigue, and decreased exercise tolerance. Muscle weakness of the upper or lower extremities is already a sign of cord compression and myelopathy.

Plain radiography of the cervical region provides limited evidence only of the cervicooccipital anatomy, as aforementioned. In this specific patient population we recommend a neutral and extension lateral view of the cervical spine. In the case of suspicion of atlantoaxial instability computerized tomography is added to exclude cord compression. A consultation with a neurosurgical consultant is advisable. Patients with signs of cord compression should undergo surgical correction. Management of children with unstable but asymptomatic upper cervical spine still is a subject of debate because surgical intervention is not without risk. [6]However, preoperatively, patients with an unstable neck should either be put in traction or otherwise immobilized. The objective is not to flex or extend the head or to move it laterally during the course of intubation. We prefer to approach the airway by controlled, preplanned fiberoptic intubation in deep, general anesthesia and ventilation over a nasopharyngeal tube. The endotracheal tube with the fiberoptic device inside can be positioned via the contralateral nostril. [7]Postoperative close monitoring that includes neurologic evaluation is mandatory.