Chiari I malformation with syringomyelia. Evaluation of surgical therapy by magnetic resonance imaging

Five patients with a Chiari I-syringomyelia complex of adult onset were evaluated by magnetic resonance (MR) imaging. All patients underwent suboccipital craniotomy with upper cervical (C-1 and part of C-2) laminectomy, arachnoid retraction, and duraplasty. Postoperative MR studies of four patients disclosed collapse of the syringomyelic cavity, even when the cavity extended into the thoracic region. This appeared to be a progressive process taking place over several weeks. Operative complications are noted and physiological implications are discussed.     

Neurologic complications of gas myelography by the lumbar route.

Gas myelography is not a new technique, but its acceptance in neuroradiologic diagnosis has been relatively recent. Previously reported series have emphasized the benign nature of this technique and the lack of significant accompanying complications. From a series of 174 gas myelograms performed during a four-year period, two reports are presented wherein transient exacerbation of neurologic deficit followed exchange of cerebrospinal fluid and gas under pressure by the lumbar route. One patient with cervical spondylotic myelopathy experienced an increase in paresis, while another was found to have marked fasciculations. Speculation regarding possible mechanisms involved with these complications is presented. It is suggested that exchange of cerebrospinal fluid and gas under pressure via the lumbar route be used with caution in those patients with compromised cervical spinal cords.     

Surgical exposure of the high cervical carotid artery: experimental study and review

Difficulty in gaining access to the high cervical internal carotid artery (ICA) has thus far prevented effective operation for intimal repair and treatment of aneurysms at this level. Mobilization of the angle of the mandible by means of mandibular osteotomies considerably improves exposure to the high cervical ICA. This procedure has been performed in rhesus monkeys and in human cadavers. In monkeys, retromandibular external carotid artery-ICA anastomoses were carried out with no problems (neurological, wound healing, or other). This new technique should be considered for the management of some high cervical ICA lesions, particularly those occurring after closed cervical trauma.     

Metastatic carcinoid presenting as a spinal tumor.

A case of carcinoid tumor metastatic to the thoracic spine with associated myelopathy is described. Multiple posterior explorations were singularly unsuccessful in locating and indentifying the metastasis, but an anterior transthoracic exposure allowed identification of the tumor, removal of the osteoblastic epidural mass, and fusion of the spine with a rib graft. The patient's myelopathy improved steadily following surgery without evidence of tumor recurrence or regression of neurologic status. The reasons for the relative absence of central nervous system carcinoid metastases are not known.     

Analysis of cervical spine curvature in patients with cervical spondylosis

Computer-aided design techniques were used to analyze the degree of spinal curvature shown on cervical spine radiograms of 28 patients. On films standardized as to size, a geometrical chord was constructed from the 2nd to the 7th cervical vertebrae (C2 to C7), and an arc was drawn along the posterior margin of the vertebrae. The resulting area was used as an index of curvature, and the spinal canal diameter was measured. Severity of myelopathy as well as clinical improvement was related to the geometrical data. There was no clear correlation between severity of the preoperative myelopathy and degree of curvature. Severe myelopathy was seen in association with straight, lordotic, and hyperlordotic spines. Neck pain was most severe in patients with reversed cervical curvature. The degree of curvature, however, seems to relate to the postoperative clinical outcome. Patients with relatively normal curvature showed the greatest improvement in symptoms and signs. Postoperative magnetic resonance scanning confirms that posterior migration of the spinal cord after laminectomy may be inadequate to clear osteophytes in patients with straightened or reversed curvature of the cervical spine. Spinal geometry should be considered in the selection of the best surgical procedure and the extent of laminectomy for patients with spondylotic myelopathy. Significant abnormalities of spinal curvature may account for some instances of poor outcome after laminectomy.     

Surgical decompressive procedures for cervical spondylotic myelopathy. A study using magnetic resonance imaging

Twenty-two patients who underwent a surgical decompressive procedure for cervical spondylotic myelopathy were studied with magnetic resonance imaging to evaluate the effectiveness of their decompressive procedures. Twelve patients were judged as adequately decompressed by magnetic resonance imaging criteria. Ten patients exhibited evidence of residual cord indentation. This along with cord atrophy, gliosis, and abnormal spine curvature presumably contributed to residual deficit in several patients. One patient underwent a second decompressive procedure for residual cord indentation, which subsequently improved, as seen on his second postoperative magnetic resonance image. Magnetic resonance imaging was useful in distinguishing mechanical problems from intrinsic cord damage or atrophy. Magnetic resonance imaging should be used after operation in patients with residual deficit to detect patients who may be considered for a second decompressive procedure.