Transoral decompression for craniovertebral osseous anomalies: perioperative management dilemmas. (1/92)

The surgical outcome of 74 patients, who underwent transoral decompression (TOD) for ventral irreducible craniovertebral junction anomalies between January 1989 to September 1997, was studied to evaluate the perioperative complications and problems encountered. The indications for TOD included irreducible atlantoaxial dislocation (n=24), basilar invagination (n=16), and a combination of both (n=35). Following TOD, occipitocervical stabilization using Jain's technique was carried out in 50 (67.5%) and atlantoaxial fusion using Brooks' construct in 18 (24.3%) patients. The pre- and postoperative radiology was compared to assess the adequacy of decompression and stability. The major morbidity included pharyngeal wound sepsis leading to dehiscence (20.3%) and haemorrhage (4%), valopharyngeal insufficiency (8.1%), CSF leak (6.7%) and inadequate decompression (6.7%). Neurological deterioration occurred transiently in 17 (22.9%) and was sustained in 7 (9.4%) patients. The mortality in six cases was due to operative trauma, exanguination from pharyngeal wound (one each), postoperative instability and inability to be weaned off from the ventilator (two each). Of the 47 (63.5%) patients available at follow up ranging from 3 months to 2 years, 26 (55.3%) showed improvement from their preoperative status while 14 (29.8%) demonstrated stabilization of their neurological deficits. Seven (14.9%) of them deteriorated. Though TOD is logical and effective in relieving ventral compression due to craniovertebral junction anomalies, it carries the formidable risks of instability, incomplete decompression, neurological deterioration, CSF leak, infection and palatopharyngeal dysfunction.  (+info)

Bow hunter's stroke associated with atlantooccipital assimilation--case report. (2/92)

A 39-year-old male presented with bow hunter's stroke manifesting as repeated vertebrobasilar ischemic attacks induced by head rotation 45 degrees to the left. Three-dimensional computed tomography angiography clearly showed the occluded right vertebral artery (VA) between the axis and atlas. Single photon emission computed tomography study showed diffuse hypoperfusion of the brain stem and bilateral cerebellar hemispheres, suggesting hemodynamic compromise of these regions. He refused surgery and was treated conservatively. The most likely mechanism is that the affected VA was fixed by the ossification of the atlantooccipital membrane, vascular groove, and transverse foramen of the atlas, and therefore became elongated and compressed by head-turning.  (+info)

Surgical treatment of nonunited fractures of the odontoid process, with special reference to occipitocervical fusion for unreducible atlantoaxial subluxation or instability. (3/92)

Fifty-seven consecutive patients treated surgically for nonunited fractures of the odontoid process were reviewed. All patients presented late, exhibiting neurological deficits subsequent to nonunion. Delay in presentation was between 6 and 120 months (mean 32 months) after the original injury, due to missed diagnosis or inappropriate management. Seven patients who were reduced in traction underwent a Gallie atlantoaxial fusion. In the remaining 50 patients who were unreducible, an occipitocervical arthrodesis was performed. They were followed up for a minimum of 2 years, except one who died from postoperative respiratory failure. All patients obtained a solid bony union, including two in whom nonunion occurred following atlantoaxial fusion, and occipitocervical fusion was added as a rescue. Thirty-eight patients achieved excellent neurological recovery, nine still had some disability, five retained their neurological deficits and two reported a deterioration. In two patients, a recurrence in a traumatic episode was experienced long after a resolution. Our findings demonstrate that occipitocervical arthrodesis is preferable for unreducible subluxation or instability of atlantoaxial articulation in nonunion of odontoid fractures.  (+info)

Bilateral type 1 proatlantal arteries with absence of vertebral arteries. (4/92)

The persistent proatlantal artery is a well-described communication between the carotid and vertebrobasilar system. However, persistence of bilateral proatlantal arteries is exceptionally rare. Although usually noted as an incidental finding, the presence of a proatlantal artery, particularly when bilateral, may result in unusual symptoms or may have implications for therapy. We report a case of bilateral proatlantal arteries, describe their embryology, and consider potential clinical implications of this finding.  (+info)

Hindbrain stroke in children caused by extracranial vertebral artery trauma. (5/92)

Hindbrain transient ischemic attacks (TIAs) culminating in posterior circulation stroke are described in five children. Atlanto-axial subluxation and angiographical documentation of C1 to C2 level arterial pathology are documented in one patient. Four additional patients with nearly identical clinical presentations, posterior fossa TIAs, stroke and basilar angiographical pathology are reviewed. A mechanical traumatic etiology is suggested. Unexplained transient repeated brain stem and/or cerebellar sympotomatology may be due to extracranial vetebral artery stenosis or occlusion by atlanto-axial instability. After appropriate documentation, stabilization may prevent further TIAs or strokes.  (+info)

Recognition and management of atlanto-occipital dislocation: improving survival from an often fatal condition. (6/92)

OBJECTIVE: To provide an overview of atlanto-occipital dislocation and associated occipital condyle fracturcs so as to alert physicians to this rare injury and potentially improve patient outcome. The pertinent anatomy, mechanism of injury, clinical and radiologic evaluation and the management of these rare injuries are discussed in an attempt to alert physicians to this type of injury and to improve outcome. DATA SOURCES: The data were obtained from a MEDLINE search of the English literature from 1966 to 1999 and the experience of 4 spine surgeons at a quaternary care acute spinal cord injury unit. STUDY SELECTION: Detailed anatomic and epidemiologically sound radiology studies were identified and analyzed. Only small retrospective studies or case series were available in the literature. DATA EXTRACTION: Valid anatomic, biomechanical and radiologic evaluation was extracted from studies. Clinical data came from limited studies and expert opinion. DATA SYNTHESIS: Early diagnosis is essential and is facilitated by a detailed clinical examination and strict adherence to an imaging algorithm that includes CT and MRI scanning. When the dislocation is identified, timely gentle reduction and prompt stabilization throuigh nonoperative or operative means is found to optimize patient outcome. CONCLUSIONS: Atlanto-occipital dislocation should be suspected in any patient involved in a high speed motor vehicle or pedestrian collision. Once suspected, proper imaging and appropriate management of these once fatal injuries can improve survival and neurologic outcome.  (+info)

Skeletal aspects of the atlanto-occipital fusion in a Japanese brown calf. (7/92)

Atlanto-occipital fusion in a Japanese Brown calf was examined morphologically, paying special attention to skeletal changes. At the craniovertebral junction, the basal occipital bone fused to the cranial extremity of the ventral arch of the atlas with the rudiment of the atlantal centrum. The dens was not formed at the axis. These changes suggest that a hypocentrum and a centrum of the atlas derived from the first cervical sclerotome had failed to separate the occipital base from the proatlantal sclerotome including the apical element of the dens. Although a developmental disturbance at the cervical and thoracic vertebrae was also associated, critical neurological signs such as ataxia and paralysis were absent.  (+info)

Traumatic posterior atlantooccipital dislocation with Jefferson fracture and fracture-dislocation of C6-C7: a case report with survival. (8/92)

Atlantooccipital dislocation (AOD) is a rare and usually fatal injury. In the current study, the authors reported an extremely rare case of posterior AOD with Jefferson fracture and fracture-dislocation of C6-C7. The patient survived the injury and had only incomplete quadriplegia below the C7 segment with anterior cord syndrome. He was successfully managed with in situ occipitocervical fusion using the Cotrel-Dubousset rod system, corpectomy of C6, and anterior interbody fusion of C5-C7 with plating. To our knowledge, this is the first report of posterior AOD with two other non-contiguous cervical spine injuries. A high index of suspicion and careful examination of the upper cervical spine should be considered as the key to the diagnosis of AOD in cases that involve multiple or lower cervical spine injuries.  (+info)