Developmental and Acquired Disorders of The Spine
Milosh Perovitch in 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.
The neck
Ashley W. Blom, David Warwick, Michael R. Whitehouse in Apley and Solomon’s System of Orthopaedics and Trauma, 2017
Basilar invagination can be congenital or acquired. More commonly, primary invagination occurs in association with occipitoatlantal fusion, hypoplasia of the atlas, a bifid posterior arch of the atlas, odontoid anomalies, Morquio syndrome, Klippel–Feil syndrome and achondroplasia. Secondary basilar impression is seen in association with conditions such as osteomalacia, rickets, osteogenesis imperfecta, Paget’s disease, neurofibromatosis, skeletal dysplasia and degenerative destructive osteoarthropathies affecting the craniovertebral junction (for example, rheumatoid arthritis). Basilar impression is frequently associated with other congenital neurological anomalies, such as Arnold- Chiari malformation and syringomyelia.
Individual conditions grouped according to the international nosology and classification of genetic skeletal disorders*
Christine M Hall, Amaka C Offiah, Francesca Forzano, Mario Lituania, Michelle Fink, Deborah Krakow in Fetal and Perinatal Skeletal Dysplasias, 2012
Prognosis: the most severe forms, which can be seen prenatally, are usually lethal in the perinatal period due to pulmonary insufficiency (small thorax, rib fractures, flail chest). Survival beyond one year is very rare and usually requires intensive support. Infants who survive this period generally have normal intelligence, unless there have been intracerebral haemorrhages, but do not walk without assistance because of severe bone fragility and deformity. Growth is minimal, adult stature may be less than one metre. Hearing loss is common. Basilar invagination can cause brainstem compression, obstructive hydrocephalus, syringomyelia, sleep apnoea and death.
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.
Posterior fossa morphometry in 170 South Asian children and adults with Chiari malformation and its correlation with tonsillar descent
Published in British Journal of Neurosurgery, 2022
Bijesh Ravindran Nair, Vedantam Rajshekhar
Chiari malformation type 1(CM1) is characterized by various morphometric abnormalities resulting from a smaller posterior cranial fossa (PCF) and overcrowding of the neural structures. Neurological dysfunction occurs due to inferior displacement of the cerebellar tonsils causing hindbrain compression and hydrosyringomyelia. It is hypothesised that CM1 is primarily a mesodermal developmental anomaly, based on experimental observations of vitamin A-induced occipital bone undergrowth and cerebellar displacement in rodents.1 Various morphometric studies have confirmed the occurrence of hypoplastic PCF and normally developed hindbrain structures in CM1.2–11 Basilar invagination (BI) is often associated with CM1, and is seen in 5–13.6% of CM1 patients.5,6,10 However, most morphometric studies do not compare the posterior fossa morphology in patients with and without BI.
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].
Related Knowledge Centers
- Brainstem
- Dysphagia
- Foramen Magnum
- Invagination
- Spinal Cord
- Brain
- Dysarthria
- Base of Skull
- Axis
- Chiari Malformation