The facet orientation circle. A new parameter for facet joint angulation in the lower lumbar spine.

STUDY DESIGN: A descriptive quantitative evaluation was done of the transverse orientation of the lower lumbar facet joints as measured by computed tomography scanning. OBJECTIVES: To evaluate a new parameter for facet joint angulation in the transverse plane (the "facet orientation circle") and to obtain reference values for this new parameter. SUMMARY OF BACKGROUND DATA: In other studies, both in vitro and in vivo, the angulation of the facet joints has been measured in degrees relative to the frontal or sagittal plane. These methods have some limitations. The parameter used in the present study has not been described in the literature. METHODS: Lower lumbar facet joint orientation was measured in 212 vertebral levels of 123 consecutive patients using the facet orientation circle parameter. Patients with degenerative or developmental abnormalities of the lumbar spine were excluded, as were those with technically inadequate computed tomography studies. RESULTS: Mean facet orientation circle diameters (+/-SD) were: L3-L4, 43.7 +/- 10.5 mm; L4-L5, 63.8 +/- 26.4 mm; and L5-S1, 82.3 +/- 23.5 mm. Differences between right and left sides were: L3-L4, 6.3 +/- 7.1 mm; L4-L5, 13.9 +/- 25.3 mm; and L5-S1, 17.9 +/- 16.2 mm, intra-observer variability was 2.3%. CONCLUSIONS: Measurement of facet joint angulation using the facet orientation circle is possible and reproducible. The morphometric data presented may be useful as a reference for biomechanical and clinical research of facet joint orientation and asymmetry.

Delayed radiation myelopathy: serial MR-imaging and pathology.

Clinical data, MR-scans, time-dose fractionation schemes and neuropathologic findings of two cases of delayed radiation myelopathy (DRM), are presented. Both patients, a 72-year-old diabetic woman with cervical lymphnode metastasis from a squamous cell carcinoma and a 46-year-old woman with tonsillar carcinoma, developed paraparesis followed by quadriplegia, at 7 and at 10 months following radiation. The spinal cord received 46 and 49 Gy. (Fraction dose 2.25 Gy and 2.0 Gy, 4 times/week). Serial MR-scans showed spinal cord enlargement and focally increased signal intensity (T1-gd). The second patient survived and stabilized following therapy with coumarins. The first patient died 13 months after radiotherapy. At autopsy necrosis, local calcium deposits, lipid macrophages and swollen astrocytes were observed in the white matter. There was slight hyalinosis of the intramedullary vessel walls. We conclude that serial MRI may be helpful to distinguish DRM from other causes of spinal cord injury. DRM may occur at a total dose less than 50 Gy. Additional risk factors (diabetes, hypertension), and fraction doses above 2 Gy contribute to the development of DRM.

Dose-effect relationship of dexamethasone on Karnofsky performance in metastatic brain tumors: a randomized study of doses of 4, 8, and 16 mg per day.

The purpose of this study was to determine whether lower doses of dexamethasone for treatment of brain tumor edema are as effective as the conventional dose of 16 mg/d. We consecutively executed two double-blind randomized trials in patients with CT-proven brain metastasis and Karnofsky scores of 80 or less. In the first series, we compared 8 mg dexamethasone per day versus 16 mg/d; in the second series, 4 mg/d versus 16 mg/d. Standardized evaluation of quality of life and side effects took place at days 0, 7, 28, and 56. We randomized a total of 96 patients and evaluated eighty-nine. The Karnofsky score improved in the 8-mg group, which had improvement of 8.0 +/- 10.1 (mean +/- SD) points at day 7 versus 7.3 +/- 14.2 points in the 16-mg group. In the second series, the 4-mg group had improvement of 6.7 +/- 11.3 points at day 7 and 7.1 +/- 18.2 points at day 28 versus 9.1 +/- 12.4 and 5.6 +/- 18.5 points in the 16-mg group. Toxic effects occurred more frequently in the 16-mg group (p < 0.03). We conclude that administration of 4 mg dexamethasone per day for treatment of brain tumor edema results in the same degree of improvement as does administration of 16 mg/d after 1 week of treatment in patients who have no signs of impending herniation. Toxic effects are dose-dependent and, during a 4-week period, occurred more frequently in patients using 16 mg/d.(ABSTRACT TRUNCATED AT 250 WORDS)

Removal of aneurysmal bone cyst in the area of C1, C2 and foramen magnum. Follow-up of surgical osteoplastic repair by means of 3 D CT studies 15 years later.

First, the author relates his memories of his first encounter with the new Editor-in-Chief of the Acta Neurochirurgica in 1957 and the reasons why it made such an unforgettable impression. Next, follows a discussion of the technical difficulties in the treatment of spinal aneurysmal bone cysts, which may produce extensive destruction of its bony elements. The relatively rare occurrence of these lesions and resulting limited experience provide insufficient grounds for developing rigid rules of surgical treatment. Their treatment must rather rely on experience by means of examples (paradigms). The present author's principles of surgical strategy are total removal of these cysts and repair by means of stabilizing bony autotransplants. A description is given of an unusual case of an aneurysmal bone cyst localized in the cervical-occipital transition area in which 3 D CT images give a better view on stabilization reached by osteoplastic repair of the destroyed structures than can be achieved with previous imaging methods.

Medical therapy of malignant nerve pain. A randomised double-blind explanatory trial with naproxen versus slow-release morphine.

It is uncertain whether there exists a nociceptive component in malignant nerve pain responsive to NSAIDs and opioids. 20 patients with malignant nerve pain were randomly assigned to treatment with naproxen 1500 mg versus slow-release morphine 60 mg daily during 1 week, followed by cross-over medication during the second week in a double-blind, double-dummy protocol. In the 16 evaluable patients, a significant (P < 0.05) reduction of 26% (S.E. +/- 7.9) in pain intensity was reached at day 7, compared to baseline pain. At day 7, significant pain relief of 32% (P < 0.05) was observed in the naproxen group, but not in the morphine group (21%, P = 0.14). Patients using morphine needed approximately twice as much paracetamol rescue than patients using naproxen. Additional pain relief could be observed in 4/9 patients with cross-over medication. These data support the concept of a nociceptive component in malignant nerve pain responding to NSAIDs and opioids, and favour the combination of both an anti-inflammatory drug and an opioid for symptomatic pain relief.

Carbamyl phosphate synthetase-1 deficiency discovered after valproic acid-induced coma.

Valproic acid induced coma is presented in an adult patient without a history of metabolic disease. Liver biopsy revealed a reduction in activity of carbamyl phosphate synthetase-I, an enzyme obligated for transformation of ammonia to urea in the urea cycle. After recovery CT scan follow-up showed marked cerebral atrophy which did not exist prior to the state of coma. Risk factors are discussed.

The course of neuropathy after cessation of cisplatin treatment, combined with Org 2766 or placebo.

Peripheral neuropathy is an important and disabling side-effect of cisplatin treatment. A new drug, Org 2766, has been found to prevent this neuropathy up to 1 month after treatment. A group of 18 patients with ovarian cancer, who participated in an earlier randomized study with placebo or Org 2766, together with cisplatin and cyclophophamide, were thereafter prospectively followed up to 2 years after discontinuation of treatment to monitor the development of neurological signs and symptoms and vibration perception threshold (VPT). Exploratory, descriptive data analysis shows that between 1 and 4 months after the last cycle the average sum score for neurological signs and symptoms and VPT had deteriorated compared with 1 month after treatment. Thereafter a gradual but incomplete improvement was seen between 4-12 and 12-24 months after treatment. These changes were seen in all patients regardless of previous treatment with Org 2766 or placebo, but deterioration was less pronounced in patients previously treated with Org 2766. These results suggests that treatment with Org 2766 to prevent a cisplatin-induced neuropathy should possibly be continued up to 4 months after the last cycle of cisplatin.

Subacute progressive sensory ataxic neuronopathy after Rickettsia conorii infection.

A case is presented in which sensory ataxic neuronopathy developed after serologically proven infection with Rickettsia conorii and continued to be progressive after appropriate antibiotic treatment. Electrophysiological studies showed decreasing sensory nerve conduction velocities ending with the absence of sensory nerve action potentials as well as peripheral and cortical somatosensory evoked potentials. Histological studies revealed a profound loss of myelinated fibres due to primarily axonal degeneration. The clinical course and the electrophysiological and histological findings suggest primary involvement of the dorsal root ganglion. Peripheral neuropathy due to infection with R. conorii is rare and usually of the mixed motor and sensory type. We believe this to be the first report of sensory ataxic neuronopathy associated with R. conorii infection.

Isolated spinous process deviation. A pitfall in the interpretation of AP radiographs of the lumbar spine.

A new type of spinous process deviation is described. This variant may cause confusion in the interpretation of anteroposterior (AP) radiographs of the lumbar spine. In the literature, two types of lumbar spinous process deviation (SPD) have been described: 1) SPD due to rotation of the entire vertebra (as in rotatory scoliosis and degenerative arthritis), and 2) SPD as a consequence of developmental asymmetries of the neural arch. The present study demonstrates that spinous process deviation in the AP radiograph is not a reliable diagnostic guide. The authors' quantitative morphologic analysis of computed tomographic (CT) sections of over 200 lower lumbar vertebrae in vivo revealed a third type of SPD, namely isolated deviation of the spinous process, ie, deviation without any associated rotation or asymmetry of the vertebral body or arch. Since the oval shadow cast by the spinous process in AP radiographs is caused by its tip, rather than by its base (as was demonstrated by in vitro tests), it is concluded that the position of the spinous process shadow in AP radiographs cannot be used as a reliable landmark to differentiate between the three types of SPD. This is only possible by means of a CT examination.

Morphometry of lower lumbar vertebrae as seen on CT scans: newly recognized characteristics.

Transaxial computed tomographic (CT) sections represent a new approach to vertebral morphometry, allowing certain measurements to be made in vivo for the first time. The cross-sectional morphology of the bodies and pedicles of L3, L4, and L5 was studied in a series of 213 vertebrae. This revealed that the pedicles of L5 arise more laterally from the body of L5 than from L3. Further, the lateral surfaces of the L5 body are inclined obliquely, unlike those of L3. L4 is transitional in form between L3 and L5, more closely resembling the former. This morphology explains the fact, hitherto unnoticed, that the lateral outlines of the pedicles and the lateral borders of the body of L5 are not normally imaged on plain anteroposterior radiographs. It is evident that pathologic changes of the lateral borders of the body of L5 may be invisible also. In cases of transitional vertebrae in the lumbosacral region the presence or absence of the lateral outlines of the pedicles and of the lateral borders of the vertebral body may be of help in identifying the vertebrae on conventional projections.

The orientation of laminae and facet joints in the lower lumbar spine.

The relationship between the angulation of the facet joints and that of the caudad parts of the corresponding laminae in the transverse plane was investigated with computed tomography (CT) at the vertebral levels L3-L4, L4-L5, and L5-S1. At the level of L3-L4, both the facet joints and the caudad portions of the laminae tend toward a sagittal orientation, while at L5-S1 this is more toward the frontal plane. At the level of L4-L5, they occupy an intermediate position. A highly significant correlation between the orientation of these structures is demonstrated. The caudad parts of the laminae may be considered buttresses for the inferior articular processes of the same vertebra.