Craniocervical instability in patients with Ehlers-Danlos syndromes: outcomes analysis following occipito-cervical fusion.

Craniocervical instability (CCI) is increasingly recognized in hereditary disorders of connective tissue and in some patients following suboccipital decompression for Chiari malformation (CMI) or low-lying cerebellar tonsils (LLCT). CCI is characterized by severe headache and neck pain, cervical medullary syndrome, lower cranial nerve deficits, myelopathy, and radiological metrics, for which occipital cervical fusion (OCF) has been advocated. We conducted a retrospective analysis of patients with CCI and Ehlers-Danlos syndrome (EDS) to determine whether the surgical outcomes supported the criteria by which patients were selected for OCF. Fifty-three consecutive subjects diagnosed with EDS, who presented with severe head and neck pain, lower cranial nerve deficits, cervical medullary syndrome, myelopathy, and radiologic findings of CCI, underwent open reduction, stabilization, and OCF. Thirty-two of these patients underwent suboccipital decompression for obstruction of cerebral spinal fluid flow. Questionnaire data and clinical findings were abstracted by a research nurse. Follow-up questionnaires were administered at 5-28 months (mean 15.1). The study group demonstrated significant improvement in headache and neck pain (p < 0.001), decreased use of pain medication (p < 0.0001), and improved Karnofsky Performance Status score (p < 0.001). Statistically significant improvement was also demonstrated for nausea, syncope (p < 0.001), speech difficulties, concentration, vertigo, dizziness, numbness, arm weakness, and fatigue (p = 0.001). The mental fatigue score and orthostatic grading score were improved (p < 0.01). There was no difference in pain improvement between patients with CMI/LLCT and those without. This outcomes analysis of patients with disabling CCI in the setting of EDS demonstrated significant benefits of OCF. The results support the reasonableness of the selection criteria for OCF. We advocate for a multi-center, prospective clinical trial of OCF in this population.

Refractory Syncope and Presyncope Associated with Atlantoaxial Instability: Preliminary Evidence of Improvement Following Surgical Stabilization.

BACKGROUND: The proclivity to atlantoaxial instability (AAI) has been widely reported for conditions such as rheumatoid arthritis and Down syndrome. Similarly, we have found a higher than expected incidence of AAI in hereditary connective tissue disorders. We demonstrate a strong association of AAI with manifestations of dysautonomia, in particular syncope and lightheadedness, and make preliminary observations as to the salutary effect of surgical stabilization of the atlantoaxial motion segment. METHODS: In an institutional review board-approved retrospective study, 20 subjects (16 women, 4 men) with hereditary connective tissue disorders had AAI diagnosed by computed tomography. Subjects underwent realignment (reduction), stabilization, and fusion of the C1-C2 motion segment. All subjects completed preoperative and postoperative questionnaires in which they were asked about performance, function, and autonomic symptoms, including lightheadedness, presyncope, and syncope. RESULTS: All patients with AAI reported lightheadedness, and 15 had refractory syncope or presyncope despite maximal medical management and physical therapy. Postoperatively, subjects reported a statistically significant improvement in lightheadedness (P = 0.003), presyncope (P = 0.006), and syncope (P = 0.03), and in the frequency (P < 0.05) of other symptoms related to autonomic function, such as nausea, exercise intolerance, palpitations, tremors, heat intolerance, gastroesophageal reflux, and sleep apnea. CONCLUSIONS: This study draws attention to the potential for AAI to present with syncope or presyncope that is refractory to medical management, and for surgical stabilization of AAI to lead to improvement of these and other autonomic symptoms.

Atlanto-axial rotary instability (Fielding type 1): characteristic clinical and radiological findings, and treatment outcomes following alignment, fusion, and stabilization.

Atlanto-axial instability (AAI) is common in the connective tissue disorders, such as rheumatoid arthritis, and increasingly recognized in the heritable disorders of Stickler, Loeys-Dietz, Marfan, Morquio, and Ehlers-Danlos (EDS) syndromes, where it typically presents as a rotary subluxation due to incompetence of the alar ligament. This retrospective, IRB-approved study examines 20 subjects with Fielding type 1 rotary subluxation, characterized by anterior subluxation of the facet on one side, with a normal atlanto-dental interval. Subjects diagnosed with a heritable connective tissue disorder, and AAI had failed non-operative treatment and presented with severe headache, neck pain, and characteristic neurological findings. Subjects underwent a modified Goel-Harms posterior C1-C2 screw fixation and fusion without complication. At 15 months, two subjects underwent reoperation following a fall (one) and occipito-atlantal instability (one). Patients reported improvement in the frequency or severity of neck pain (P < 0.001), numbness in the hands and lower extremities (P = 0.001), headaches, pre-syncope, and lightheadedness (all P < 0.01), vertigo and arm weakness (both P = 0.01), and syncope, nausea, joint pain, and exercise tolerance (all P < 0.05). The diagnosis of Fielding type 1 AAI requires directed investigation with dynamic imaging. Alignment and stabilization is associated with improvement of pain, syncopal and near-syncopal episodes, sensorimotor function, and exercise tolerance.

Optimizing Alignment Parameters During Craniocervical Stabilization and Fusion: A Technical Note.

Proper craniocervical alignment during craniocervical reduction, stabilization, and fusion optimizes cerebrospinal fluid (CSF) flow through the foramen magnum, establishes the appropriate "gaze angle", avoids dysphagia and dyspnea, and, most importantly, normalizes the clival-axial angle (CXA) to reduce ventral brainstem compression. To illustrate the metrics of reduction that include CXA, posterior occipital cervical angle, orbital-axial or "gaze angle", and mandible-axial angle, we present a video illustration of a patient presenting with signs and symptoms of the cervical medullary syndrome along with concordant radiographic findings of craniocervical instability as identified on dynamic imaging and through assessment of the CXA, Harris, and Grabb-Oakes measurements.

Utility of the clivo-axial angle in assessing brainstem deformity: pilot study and literature review.

There is growing recognition of the kyphotic clivo-axial angle (CXA) as an index of risk of brainstem deformity and craniocervical instability. This review of literature and prospective pilot study is the first to address the potential correlation between correction of the pathological CXA and postoperative clinical outcome. The CXA is a useful sentinel to alert the radiologist and surgeon to the possibility of brainstem deformity or instability. Ten adult subjects with ventral brainstem compression, radiographically manifest as a kyphotic CXA, underwent correction of deformity (normalization of the CXA) prior to fusion and occipito-cervical stabilization. The subjects were assessed preoperatively and at one, three, six, and twelve months after surgery, using established clinical metrics: the visual analog pain scale (VAS), American Spinal InjuryAssociation Impairment Scale (ASIA), Oswestry Neck Disability Index, SF 36, and Karnofsky Index. Parametric and non-parametric statistical tests were performed to correlate clinical outcome with CXA. No major complications were observed. Two patients showed pedicle screws adjacent to but not deforming the vertebral artery on post-operative CT scan. All clinical metrics showed statistically significant improvement. Mean CXA was normalized from 135.8° to 163.7°. Correction of abnormal CXA correlated with statistically significant clinical improvement in this cohort of patients. The study supports the thesis that the CXA maybe an important metric for predicting the risk of brainstem and upper spinal cord deformation. Further study is feasible and warranted.

Neurological and spinal manifestations of the Ehlers-Danlos syndromes.

The Ehlers-Danlos syndromes (EDS) are a heterogeneous group of heritable connective tissue disorders characterized by joint hypermobility, skin extensibility, and tissue fragility. This communication briefly reports upon the neurological manifestations that arise including the weakness of the ligaments of the craniocervical junction and spine, early disc degeneration, and the weakness of the epineurium and perineurium surrounding peripheral nerves. Entrapment, deformation, and biophysical deformative stresses exerted upon the nervous system may alter gene expression, neuronal function and phenotypic expression. This report also discusses increased prevalence of migraine, idiopathic intracranial hypertension, Tarlov cysts, tethered cord syndrome, and dystonia, where associations with EDS have been anecdotally reported, but where epidemiological evidence is not yet available. Chiari Malformation Type I (CMI) has been reported to be a comorbid condition to EDS, and may be complicated by craniocervical instability or basilar invagination. Motor delay, headache, and quadriparesis have been attributed to ligamentous laxity and instability at the atlanto-occipital and atlantoaxial joints, which may complicate all forms of EDS. Discopathy and early degenerative spondylotic disease manifest by spinal segmental instability and kyphosis, rendering EDS patients prone to mechanical pain, and myelopathy. Musculoskeletal pain starts early, is chronic and debilitating, and the neuromuscular disease of EDS manifests symptomatically with weakness, myalgia, easy fatigability, limited walking, reduction of vibration sense, and mild impairment of mobility and daily activities. Consensus criteria and clinical practice guidelines, based upon stronger epidemiological and pathophysiological evidence, are needed to refine diagnosis and treatment of the various neurological and spinal manifestations of EDS. © 2017 Wiley Periodicals, Inc.

Carotid artery compression by the hyoid bone.

An 83-year-old male presented with bilateral carotid stenosis. Stenosis on the left side was reported to be greater than 70%. A left carotid endarterectomy was undertaken to increase the lumen size and remove the atherosclerotic plaque. During surgery, the hyoid bone was observed to have a 2-cm calcified horn capable of compressing the carotid artery. This unusual compression was confirmed by radiographic images. In cases where the carotid artery is compressed by the hyoid bone, a carotid endarterectomy rather than a stent may be the procedure of choice.

Asymmetries in visual-spatial processing following childhood stroke.

The authors compared hemisphere-based and cognitive-domain-based hypotheses for visual-spatial deficits in children with stroke (n = 33) and children without stroke (n = 43). Children with unilateral left (n = 14) or right (n = 7) injury showed less efficient search for the visual field contralateral to their injury. Right-hemisphere injury was associated with deficient global-level processing and coordinate spatial judgments. Left-hemisphere injury resulted in relatively intact local versus global processing and categorical versus coordinate judgments. Bilateral injury (n = 12) resulted in disruption of visual search across visual fields and relative deficits in global-level processing and coordinate spatial judgments. Recovery of visual-spatial processing in children following childhood stroke is task specific. Certain visual-spatial functions typically mediated by the left hemisphere appear less vulnerable to disruption.