Joon Ho Song

Is It Possible to Evaluate the Parameters of Cervical Sagittal Alignment on Cervical Computed Tomographic Scans

Study Design. Retrospective study. Objective. The purpose of this study was to analyze the relationship of the parameters of cervical sagittal alignment between those obtained from cervical CT and those obtained from radiography, as well as to determine which parameter would help predict physiological lordosis of the cervical spine. Summary of Background Data. Sagittal balance in the cervical spine is as important as the pelvic incidence and is related to the concept of T1 slope. However, many articles including this article based on unclear cervical x-ray radiographs could weakly explain the parameters. To overcome the fundamental limitation of x-ray radiographs, Hallym University Sacred Heart Hospital reported the strong correlation between T1 slope and cervical lordosis on the cervical dimensional CT scans like result by checking by the cervical x-ray radiographs. Methods. A retrospective analysis of data from 50 asymptomatic adults in whom both cervical CT scans and cervical radiograph were obtained at the same time. The T1 slope, Cobb angle C2–C7, neck tilt, and thoracic inlet angle (TIA) obtained from the CT scans and radiographs were assessed. Results. The T1 slope on x-ray was significantly correlated with the T1 slope on CT. The mean of the T1 slope on x-ray was larger than the mean of the T1 slope on CT (3.3° ± 6.1°). More cervical spine lordosis was evident on the cervical radiograph than on the cervical CT scan (5.93° ± 9.0°). No significant difference was seen between the TIA on x-ray and the TIA on CT (TIA on x-ray − TIA on CT, −0.1 ± 7.6, P = 0.959). Conclusion. This difference may be due to the differing effect of gravity upon the spine between the upright versus the supine position. Accordingly, TIA and T1 slope may be used as a guide for the assessment of sagittal balance of the cervical spine. Level of Evidence: N/A

Therapeutic Considerations of Percutaneous Sacroplasty for the Sacral Insufficiency Fracture

Sacral insufficiency fracture is a debilitating injury not easily found in general radiologic examinations and is rarely diagnosed, since its symptoms are obscure. It is known to frequently occur in patients with osteoporosis, but the treatment has not yet been established and various kinds of treatment methods are being attempted. Sacroplasty is sometimes performed by applying percutaneous vertebroplasty which is known to be a less invasive treatment. Since the course of diagnosis of sacral insufficiency fracture is difficult and clear guidelines for treatments have not yet been established, many spine surgeons fail to diagnose patients or speculate on treatment methods. We report our experience in diagnosing a sacral insufficiency fracture in a 54-year-old healthy female patient using MRI and treating her with sacroplasty. From a therapeutic point of view, we then cover the usefulness, effects and characteristics relating to the complications of sacroplasty, along with literature review.

T1 slope and degenerative cervical spondylolisthesis.

Study Design. Retrospective analysis. Objective. The main objectives of this study were to analyze and compare cervical sagittal parameters, including the T1 slope, in a population of 45 patients with degenerative cervical spondylolisthesis (DCS) and to compare these patients with a control group of asymptomatic population. Summary of Background Data. Sagittal balance in the cervical spine is as important as the pelvic incidence and is related to the concept of T1 slope. Compared with degenerative lumbar spondylolisthesis, there are few studies evaluating DCS, and characteristic changes of the cervical sagittal parameters (including T1 slope) in patients with DCS are not well studied. Methods. We identified 45 patients with DCS (5.8%) from a database of 767 patients, using cervical radiograph in a standing position. All had radiograph and computed tomographic scan at the same time. Cervical sagittal parameters were analyzed on computed tomographic scan in a standardized supine position. The following cervical sagittal parameters were measured: T1 slope, neck tilt, thoracic inlet angle, and cervical lordosis (C2–C7 angle). The DCS group was compared with a control group of 45 asymptomatic age- and sex-matched adults to the DCS group, who were studied in a recently published study. Results. Of our initial group of 767 patients, 45 with anterolisthesis (5.8%) were included for this study. The T1 slope was significantly greater for DCS (26.06° ± 7.3°) compared with the control group (22.32° ± 7.0°). No significant difference of the neck tilt, thoracic inlet angle, and C2–C7 angle was seen between the DSC group and the control group. Therefore, the T1 slope of the DSC group was significantly greater than that of the control group (P < 0.005). Conclusion. The DCS group was characterized by a greater T1 slope than the control group; therefore, we suggest that a high T1 slope may be a predisposing factor in developing DCS. Level of Evidence: 3

The Effect of Lumbar Spinal Muscle on Spinal Sagittal Alignment: Evaluating Muscle Quantity and Quality.

BACKGROUND The majority of earlier studies of the parameters of sagittal balance did not consider the influence of spinal muscles on spinal sagittal alignment. OBJECTIVE To analyze the relationship between the paraspinal muscle (quantity and quality) and sagittal alignment in elderly patients. METHODS We reviewed 50 full-spine lateral standing radiographs and lumbar magnetic resonance images of elderly patients at a single center. The radiographic parameters examined were thoracic kyphosis, lumbar lordosis (LL), sagittal vertical axis, pelvic tilt, sacral slope, and pelvic incidence (PI). The lumbar muscularity (LM; quantity) and fatty degeneration ratio (FD; quality) in the paraspinal muscle were measured at the L3 level on magnetic resonance images. The relationships between the parameters, LM, and FD were analyzed with the Pearson correlation coefficient and multiple linear regression. RESULTS Pearson analysis demonstrated that the FD had significant correlations with age (r = 0.393), thoracic kyphosis (r = -0.559), pelvic tilt (r = 0.430), sagittal vertical axis (r = 0.488), and PI - LL (r = 0.479, P < .05), and a close negative correlation was found between the FD and LL (r = -0.505, P < .01). The LM had significant correlations with the LL (r = 0.342) and PI - LL (r = -0.283, P < .05). Regression models that controlled for confounding factors such as body mass index confirmed the correlations between the above parameters and FD (P < .05). CONCLUSION The quality of the paraspinal muscle could be one of the various factors that influence sagittal balance. ABBREVIATIONS BMI, body mass indexCSA, cross-sectional areaFD, fatty degeneration ratioLL, lumbar lordosisLM, lumbar muscularityPI, pelvic incidencePT, pelvic tiltSC, subcutaneous fatSS, sacral slopeSVA, sagittal vertical axisTK, thoracic kyphosisVB, vertebral body.

Adenocarcinoma arising from intracranial recurrent mature teratoma and featuring mutated KRAS and wild‐type BRAF genes

Malignant transformation or recurrence of intracranial mature teratoma is an extremely rare occurrence, compared to the usual ovarian counterpart. Previously, yolk sac tumor elements have been considered to be selective progenitors of enteric‐type adenocarcinoma arising from intracranial germ cell tumors. However, the present case demonstrates the occurrence of enteric‐type adenocarcinoma in recurrent intracranial mature cystic teratoma 12 years after gross total removal, a case of which has not previously been documented in the literature. The 11.5‐cm long, dura mater‐based tumor on the right fronto‐temporal lobe displaced the brain; however, the patient had no neurologic symptoms or discomfort other than pus‐like discharge on the scalp. Microscopic examinations revealed a small focus of adenocarcinoma and dysplastic colonic mucosa in the mature cystic teratoma. No immature elements were seen. The cystic wall was almost denuded and showed an exuberant xanthogranulomatous reaction with foreign‐body type giant cells engulfing keratin materials and cholesterol clefts, suggesting that chronic inflammation due to repeated cyst wall rupture and the previous resection may contribute to malignant transformation. The adenocarcinoma showed strong immunohistochemical expression of CK20 and p53, but CK7 in patches. The molecular profile of the adenocarcinoma showed a mutation in KRAS and wild‐type BRAF, which might be associated with malignant transformation of intracranial mature teratomas. In conclusion, the intracranial mature teratomas should require long‐term follow‐up, and clinicians, radiologists and pathologists should be aware of the potential for malignant progression of recurrent intracranial mature cystic teratoma despite gross total resection and no neurologic symptoms.

Clinical Aspects of Cerebral Venous Thrombosis: Experiences in Two Institutions

Objective Cerebral venous thrombosis (CVT) is a rare condition for which few clinical reviews have been conducted in Korea. Our aim was to investigate, risk factors, clinical presentations/courses, and outcomes of 22 patients treated for CVT at two centers. Materials and Methods A retrospective analysis was conducted, selecting 22 patients diagnosed with and treated for CVT at two patient care centers over a 10-year period (January 1, 2004 to August 31, 2015). Patient data, pathogenetic concerns (laboratory findings), risk factors, locations, symptoms, treatments, and clinical outcomes were reviewed. Results Mean patient age at diagnosis was 54.41 ± 16.19. Patients most often presented with headache (40%), followed by seizure (27%) and altered mental status (18%). Focal motor deficits (5%), visual symptoms (5%), and dysarthria (5%) were less common. Important predisposing factors in CVT included prothrombotic conditions (35%), infections (14%), hyperthyroidism (18%), trauma (14%), and malignancy (4%). By location, 9 patients (40%) experienced thrombosis of superior sagittal sinus predominantly, with involvement of transverse sinus in 20 (90%), sigmoid sinus in 12 (40%), and the deep venous system in 5 (23%). Treatment generally consisted of anticoagulants (63%) or antiplatelet (23%) drugs, but surgical decompression was considered if warranted (14%). Medical therapy in CVT yields good functional outcomes. Conclusion Mean age of patients with CVT in our study exceeded that reported in Europe or in America and had difference in risk factors. Functional outcomes are good with use of antithrombotic medication, whether or not hemorrhagic infarction is evident.

The Effect of Different Pillow Heights on the Parameters of Cervicothoracic Spine Segments

Objective To investigate the effect of different pillow heights on the slope of the cervicothoracic spine segments. Methods A prospective analysis of data from 16 asymptomatic adults (aged 20 to 30 years) was carried out. Exclusion criteria were history of injury or accident to the cervicothoracic spine, cervicothoracic spine surgery, or treatment for neck symptoms. We used three different pillow heights: flat (0 cm), 10-cm, and 20-cm pillows. Cervical sagittal parameters, measured with radiography, included; C2-7 Cobbs angle, T1 slope (T1S), thoracic inlet angle (TIA), and neck tilt (NT). Statistical analyses were performed using Spearman correlation coefficients. Results As the height of the pillow increased, the T1S & C2-7 Cobbs angle increased while the NT values tended to decrease. The TIA values, however, remained constant. Additionally, there was a statistically significant sex difference in T1S with the 0-cm pillow (p=0.01), and in NT with the 20-cm pillow (p=0.01). Conclusion From the data obtained in this study, we recommend that the most suitable pillow height is 10 cm, considering the normal cervical lordosis.

The Effect of the Pedicle-Facet Angle on Degenerative Cervical Spondylolisthesis.

Objective To measure the orientation of the facet joints of cervical spine (C-spine) segments in the sagittal plane, known as the pedicle-facet (P-F) angle, and to use these measurements to evaluate the relationship between the P-F angle and the amount of vertebral anterolisthesis in patients with degenerative cervical spondylolisthesis (DCS). Methods A retrospective case-control study was performed including 30 age- and sex-matched patients with DCS and 30 control participants. Anterior-posterior and lateral view radiographs of the C-spine were obtained in a standing position. The P-F angle at all cervical levels and the amount of anterolisthesis at C4-5 were measured from lateral view plain radiographs. Results The P-F angles at C4-5 were 141.14±7.14° for the DCS group and 130.53±13.50° (p=0.012) for the control group, and at C5-6 were 137.46±8.53° for the DCS group and 128.53±16.01° for the control group (p=0.001). The mean P-F angle at C4-5 did not correlate with the amount of anterolisthesis (p=0.483). The amount of anterior slippage did correlate with age (p<0.001). Conclusion The P-F angle was intrinsically higher at C4-5, compared to C5-6, in both the DCS and control groups, which might explain the increased likelihood for anterolisthesis of C4. Higher P-F angles in the DCS group may be a predisposing factor to slippage. The P-F angle may interact with age to increase incidence of anterolisthesis with increasing age.

Ruptured Total Intrameatal Anterior Inferior Cerebellar Artery Aneurysm

Among the distal anterior inferior cerebellar artery (AICA) aneurysms, a unique aneurysm at the meatal loop inside the internal auditory meatus is extremely rare. The authors report a case of surgically treated total intrameatal AICA aneurysm. A 62-year-old female patient presenting with sudden bursting headache and neck pain was transferred to our department. Computed tomography and digital subtraction angiography showed subarachnoid hemorrhage at the basal, prepontine cistern and an aneurysm of the distal anterior inferior cerebellar artery inside the internal auditory meatus. Surgery was performed by retrosigmoid craniotomy with unroofing of the internal auditory meatus. The aneurysm was identified between the seventh and eighth cranial nerve in the meatus and was removed from the canal and clipped with a small straight Sugita clip. After operation the patient experienced transient facial paresis and tinnitus but improved during follow up.

Epidemiology and Risk Factors for Bicycle-Related Severe Head Injury: A Single Center Experience

Objective Head injury is the main cause of death and severe disability in bicycle-related injuries. The purpose of this study was to compare the demographic characteristics and injury mechanisms of bicycle-related head injuries according to the severity and outcome and determine the main risk factors and common types of accompanying injuries. Methods A total of 205 patients who were admitted to the neurosurgery department of our hospital for bicycle-related head injuries between 2007 and 2016 were analyzed. We categorized the patients into two groups according to severity and outcome of head injury, and then identified the differences in age, sex, and cause of injury between the two groups. Results Collisions with a motor vehicle increased the risk of severe head injury (p=0.011), resulted in poor outcomes (Glasgow Outcome Scale [GOS] ≤3; p=0.022), and caused more accompanying chest/abdominal (p<0.001) and pelvic/lower extremity injuries (p=0.001) than other mechanisms. Older age and high grade of head injury severity resulted in poor outcomes (p=0.028 and p<0.001, respectively), and caused more accompanying chest/abdominal injuries (p<0.032 and p<0.001, respectively) compared with younger age and low grade of head injury severity. Conclusion In bicycle-related head injuries, collision with motor vehicle is one of the most important risk factor for high grade of head injury severity and outcome. In addition, bicycle-related head injuries are often accompanied by injuries of other parts of the body.