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Metabolic Bone Disease
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
Involvement of the skull leads to an increase in head size. Hearing loss may also occur (conductive and/or sensorineural). When the skull base is involved, this can lead to basilar invagination. Increased vascularization of skull lesions may result in vascular steal syndrome, which causes blood to be diverted away from the cerebrum, leading to somnolence.
Atlantoaxial Subluxation in Rheumatoid Arthritis
Published in Kelechi Eseonu, Nicolas Beresford-Cleary, Spine Surgery Vivas for the FRCS (Tr & Orth), 2022
Kelechi Eseonu, Nicolas Beresford-Cleary
There are two other major patterns of cervical instability. Basilar invagination, or cranial settling, describes the migration of the dens through the foramen magnum secondary to C1 lateral mass erosion. Subaxial subluxation is due to synovitis of the uncovertebral joint and facet instability due to bone and soft tissue erosion. This is concerning if subluxation is present >3mm or if there are multiple subluxations present.
Developmental and Acquired Disorders of The Spine
Published in Milosh Perovitch, Radiological Evaluation of the Spinal Cord, 2019
Developmental abnormalities of the spinal canal represent various disorders of the bony structures of the spine which may cause damage to the spinal cord by exerting a pressure on its substance. The atlas fusion, for example, since it was extensively studied by McRae in 1953, has been known to produce neurologic signs when the anteroposterior diameter of the bony canal is narrowed to 19 mm or less. The atlas fusion can be further complicated by the merging of other cervical vertebrae.4 Standard radiographs and tomograms, usually preceding other radiologic examinations, will indicate the presence of this abnormality. Myelographic studies in such cases (Myodil,® Oxygen®) showed a flattening of the upper cervical cord at the level of narrowing. Platybasia and basilar invagination (basilar impression) affect the spinal cord by compression. Basilar invagination can cause a narrowing of the spinal cord by an angulation of the spine, mostly behind the odontoid process. In this way, the spinal cord is compressed and flattened to a considerable degree.5 Thus occurring compression is often associated with a vascular impairment and obstruction to the flow of the CSF. Basilar invagination is usually documented on radiographs and tomograms of the base of the skull and the upper cervical spine, combined with various linear measurements. These radiologic examinations most of the time precede consideration for a myelography or vertebral angiography.
Rotational vertebral artery occlusion in a patient with basilar invagination
Published in British Journal of Neurosurgery, 2023
Hui Yang, Shuisheng Zhong, Yunxin Hu, Zeyan Bao
Rotational vertebral artery occlusion, or Bow hunter’s stroke (BHS), is a cerebrovascular disease caused by compression of the dominant VA by contra-lateral rotation of the head.1 Osteophytes was the most common etiology for BHS.2 As VA have close anatomical relationship with cervical vertebrae, blood flow of VA may be compromised in CVJ anomaly, especially with head rotation.3 However the hemodynamics of VA has been rarely evaluated in CVJ anomalies. Only CTA were performed to prevent potential injury during surgery treatment.4 In scaterred cases of BI digital subtraction angiography (DSA) revealed that dissection of VA was the primary mechanism of ischemic stroke.5 In this case intermittent compression of right dominant VA led to thrombus formation, therefore causing recurrent posterior circulation thromboembolic strokes. As far as we know, this is the first case of Bow Hunter's stroke due to dynamic right VA occlusion from BI. This case highlighted the necessary of hemodynamic evaluation in asymptomatic basilar invagination.
Experience with revision craniovertebral decompression in adult patients with Chiari malformation type 1, with or without syringomyelia
Published in British Journal of Neurosurgery, 2022
Adikarige Silva, Gopiga Thanabalasundaram, Ben Wilkinson, Georgios Tsermoulas, Graham Flint
Fifteen patients had Chiari type 1 with syringomyelia and 20 did not (Figure 2). Of the 20 patients without syringomyelia, 3 had additional pathologies. Two had idiopathic intracranial hypertension (IIH) and both had undergone CSF diversion prior to their revision surgery. The third patient had basilar invagination and had undergone occipito-cervical stabilisation at the same time as the primary decompression. Of the 15 patients with syringomyelia, 10 were known to have a syrinx prior to primary surgery. The remaining 5 had originally undergone surgery for Chiari type 1 alone but then went on to develop symptomatic syringomyelia following their primary surgery. One of these 5 patients had syndromic craniosynostosis – Crouzon’s syndrome - and this patient had undergone, as a child, fronto-orbital advancement and remodeling.
Long-term outcomes of surgical management in subtypes of Chiari malformation
Published in Neurological Research, 2021
Recep Basaran, Caglar Bozdogan, Mehmet Senol, Dogan Gundogan, Nejat Isik
In the literature, studies concerning symptom relief typically consider only about CM-1 [39,40]. More than three-quarters of the patients still considered their situation to be improved at long-term follow-up after surgery. These results support surgical intervention in symptomatic CM-1 patients [39–43]. The duration of symptoms, respiratory distress, and basilar invagination are significant predictors of outcome in CM patients. The effect of SM in predicting the clinical outcomes could not be determined, due to differences in the numbers of patients in the groups with and without SM [44]. Peripheral neuropathy, valsalva headache and paresis can be predictors for poor outcome and on the other hand surgery in the early age can be a predictor for a better outcome [45].