Changes of regional cerebral blood flow after deep brain stimulation in cervical dystonia.

INTRODUCTION: Cervical dystonia is considered as a network disorder affecting various brain regions in recent days. Presumably, deep brain stimulation (DBS) of the internal segment of globus pallidus (GPi) may exert therapeutic effects for cervical dystonia through modulation of the aberrant brain networks. In the present study, we investigated postoperative regional cerebral blood flow (rCBF) changes after GPi DBS using single-photon emission computed tomography (SPECT) to identify significant activity changes in several relevant brain areas of cervical dystonia patients. METHODS: A total of 9 patients with idiopathic cervical dystonia were recruited, and SPECT scans were conducted at baseline and 3 months after the bilateral GPi DBS. Voxel-wise changes of rCBF were analyzed using Statistical Parametric Mapping. Symptom severity of dystonia was measured using Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) at the baseline, and 1 week, and 3 months after GPi DBS. RESULTS: At the 3-month follow-up after DBS, rCBF was increased in the left pons and right postcentral gyrus and decreased in the left middle frontal gyrus, left cerebellum, right putamen and pallidum, and left thalamus (p < 0.001). Severity of cervical dystonia assessed by TWSTRS was significantly decreased at 1-week and 3-month follow-up (p = 0.004). CONCLUSIONS: Clinical improvement of cervical dystonia after GPi DBS may be accompanied by rCBF changes in several brain areas of the cortico-basal ganglia-cerebellar network which are important for sensorimotor integration.

Outcome of pallidal deep brain stimulation for treating isolated orofacial dystonia.

BACKGROUND: Isolated orofacial dystonia is a rare segmental neurological disorder that affects the eye, mouth, face, and jaws. Current literature on pallidal surgery for orofacial dystonia is limited to case reports and small-scale studies. This study was to investigate clinical outcomes of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in patients with isolated orofacial dystonia. METHODS: Thirty-six patients who underwent GPi DBS at Incheon St. Mary's Hospital, The Catholic University of Korea, between 2014 and 2019 were included in this study. Burke-Fahn-Marsden Dystonia Rating Scale, Unified Dystonia Rating Scale, and Global Dystonia Severity Rating Scale were retrospectively retrieved for analysis before surgery, at 6-month follow-up as short-term outcome, and at follow-up over 1 year (12 months to 69 months) as long-term results. RESULTS: Mean total BFMDRS-M scores at the three time points (baseline, 6 months, and over 1 year follow-up) were 11.6 ± 4.9, 6.1 ± 5.2 (50.3 ± 29.9% improvement, p < 0.05), and 4.3 ± 4.2 (65.0 ± 24.2% improvement, p < 0.05), respectively. In terms of UDRS and GDS, improvement rates were 45.1% (p < 0.001) and 47.7% (p < 0.001) at 6 months, and 63.8% (p < 0.001) and 65.7% (p < 0.001) at over 1 year after surgery, respectively. CONCLUSIONS: Bilateral GPi DBS in isolated orofacial dystonia can be effective if conservative treatment option fails. Its benefit is not only observed in a short term, but also maintained in a long-term follow-up.

Neuromodulation for Trigeminal Neuralgia.

Clinical studies on neuromodulation intervention for trigeminal neuralgia have not yet shown promising results. This might be due to the fact that the pathophysiology of chronic trigeminal neuropathy is not yet fully understood. Chronic trigeminal neuropathy includes trigeminal autonomic neuropathy, painful trigeminal neuropathy, and persistent idiopathic facial pain. This disorder is caused by complex abnormalities in the pain processing system, which is comprised of the affective, emotional, and sensory components, rather than mere abnormal sensation. Therefore, integrative understanding of the pain system is necessary for appropriate neuromodulation of chronic trigeminal neuropathy. The possible neuromodulation targets that participate in complex pain processing are as follows : the ventral posterior medial nucleus, periaqueductal gray, motor cortex, nucleus accumbens, subthalamic nucleus, globus pallidus internus, anterior cingulate cortex, hypothalamus, sphenopalatine ganglion, and occipital nerve. In conclusion, neuromodulation interventions for trigeminal neuralgia is yet to be elucidated; future advancements in this area are required.

Clinical Outcomes after Spinal Cord Stimulation According to Pain Characteristics.

OBJECTIVE: Spinal cord stimulation (SCS) is an effective treatment for chronic neuropathic pain. However, its clinical efficacy in regard to specific types of pain has not been well studied. The primary objective of this study was to retrospectively analyze the clinical outcomes of paddle-type SCS according to the type of neuropathic pain. METHODS: Seventeen patients who underwent paddle-lead SCS at our hospital were examined. Clinical outcomes were evaluated pre- and postoperatively (3 months, 1 year, and last follow-up) using the Neuropathic Pain Symptom Inventory (NPSI). The NPSI categorizes pain as superficial, deep, paroxysmal, evoked, or dysesthesia and assess the duration of the pain (pain time score). Changes in NPSI scores were compared with change in Visual analogue scale (VAS) scores. RESULTS: After SCS, the pain time score improved by 45% (independent t-test, p=0.0002) and the deep pain score improved by 58% (independent t-test, p=0.001). Improvements in the pain time score significantly correlated with improvements in the VAS score (r=0.667, p=0.003, Spearman correlation). Additionally, the morphine milligram equivalent value was markedly lower after vs. before surgery (~49 mg, pared t-test, p=0.002). No preoperative value was associated with clinical outcome. CONCLUSION: The NPSI is a useful tool for evaluating the therapeutic effects of SCS. Chronic use of a paddle-type spinal cord stimulation improved the deep pain and the pain time scores.

Range of voluntary neck motility predicts outcome of pallidal DBS for cervical dystonia.

BACKGROUND: The effectiveness of pallidal deep brain stimulation (GPi DBS) for cervical dystonia has been extensively described, but controversies exist about which prognostic factor is clinically useful. We previously reported that classification of tonic- or phasic-type cervical dystonia is useful for predicting clinical prognosis; however, the approach used by physicians to distinguish between the two types remains subjective. OBJECTIVE: The aim of this study was to develop a prognostic factor of GPi DBS for cervical dystonia. METHODS: By identifying distributions of range of motion scores between phasic- and tonic-type cervical dystonia, a new prognostic factor group was developed based on whether the patients could voluntarily move their head to the opposite side against dystonic motions. The prognosis for GPi DBS in the two groups was analyzed according to the time sequence. RESULTS: Patients who were able to move their head past the midline had a better long-term prognosis after GPi DBS than did those who could not. In the early post-operative phase, there were no significant differences in the clinical outcomes between the two groups. CONCLUSION: A range of voluntary neck motility with respect to the midline is an objective factor that is useful in predicting the prognosis of patients with cervical dystonia. This result renders needs for future study addressing neuroplastic changes in the brain network caused by GPi DBS.

Neuropsychological consequences of pallidal deep brain stimulation altering brain networks.

The purpose of this study was to evaluate postoperative changes in the neuropsychological function of cervical dystonia patients who had undergone deep brain stimulation (DBS) of the internal segment of the globus pallidus (GPi) and to investigate how DBS affects neuropsychological function by altering the neural networks of the brain. In 12 cervical dystonia patients, the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) was used to measure the preoperative and postoperative status of cervical dystonia, and the Seoul Neuropsychological Screening Battery was used to gather neuropsychological data. The data were analyzed using a Wilcoxon signed-rank test. The average improvement in the TWSTRS score at the time of the postoperative neuropsychological battery was 56.1 ±â€¯26.8%. In the neuropsychological battery, inhibitory control, as evaluated by the Stroop test, was significantly decreased after GPi DBS. The average pre-/postoperative Stroop test word and color reading correct response score were 107.9/99.2 (P = 0.043) and 85.3/75.8 (P = 0.032), respectively. The observed neuropsychological consequence of GPi DBS in this study, i.e., decreased inhibitory control, implies that electrical stimulation of the GPi may alter brain networks via the centromedian-parafascicular nuclear complex, suppressing the inhibitory control function of the prefrontal cortex.

Electrophysiological interpretations of the clinical response to stimulation parameters of pallidal deep brain stimulation for cervical dystonia.

OBJECTIVE: Deep brain stimulation (DBS) at the posterolateral ventral portion of the globus pallidus internus (GPi) has been regarded as a good therapeutic modality. Because the theoretical principle behind the stimulation parameters is yet to be determined, this study aimed to interpret analyses of the stimulation parameters used in our department based on an electrophysiological review. METHODS: Nineteen patients with medically refractory idiopathic cervical dystonia who underwent GPi DBS were enrolled. The baseline and follow-up parameters were analyzed according to their dependence on time after DBS. The pattern of changes in the stimulation parameters over time, the differences across the four active contacts, and the relationship between the stimulation parameters and clinical benefits were evaluated. RESULTS: Mean age and disease duration were 50.9 years and 54.7 months, respectively. Mean follow-up duration was 22.6 months. The amplitude and frequency exhibited significant increasing temporal patterns, i.e., a mean amplitude and frequency of 3.1 V and 132.2 Hz at the initial setting and 4.0 V and 142.6 Hz at the last follow-up, respectively. The better clinical response group (clinical improvement rate of 65-100 %) used a narrower pulse width (mean value of 78.4 µs) than the worse clinical response group (clinical improvement rate of 5-60 %, mean of value of 88.6 µs). Active contact at the GPe was used more often in the worse clinical response group than in the better response group. CONCLUSIONS: Based on electrophysiological considerations, these patterns of stimulation parameters could be interpreted. This interpretation was based on a theoretical understanding of the mechanisms of action of DBS, i.e., that the abnormal neural signal is substituted by an induced neural signal, which is generated by therapeutic DBS.

Side predilections of offending arteries in hemifacial spasm.

The side predilections of various offending arteries in hemifacial spasm (HFS) have not been well studied. The relationship between clinical and radiological features of HFS and offending arteries were investigated in the present study. A retrospective analysis of 370 patients who underwent microvascular decompression for HFS was performed. The patients were divided into four groups based on the offending arteries, namely anterior inferior cerebellar artery (AICA), posterior inferior cerebellar artery (PICA), vertebral artery, and multiple offending arteries. Affected side, age at onset, presence of hypertension, and sigmoid sinus area and dominance were compared between groups. The mean age of patients with a left HFS was significantly greater than that of patients with a right HFS (P=0.009). The AICA affected primarily the right side and PICA and multiple offending arteries the left side (P<0.001). Side of sigmoid sinus dominance was significantly different among groups (P<0.001). The offending arteries in HFS may be related to these differences. AICA was associated with right-sided symptoms, younger age at onset, and presence of left dominant sigmoid sinus, while PICA was associated with left-sided symptoms, older age at onset, and smaller right sigmoid sinus area.

Different clinical course of pallidal deep brain stimulation for phasic- and tonic-type cervical dystonia.

BACKGROUND: Dystonia has been treated well using deep brain stimulation at the globus pallidus internus (GPi DBS). Dystonia can be categorized as two basic types of movement, phasic-type and tonic-type. Cervical dystonia is the most common type of focal dystonia, and sequential differences in clinical outcomes between phasic-type and tonic-type cervical dystonia have not been reported. METHODS: This study included a retrospective cohort of 30 patients with primary cervical dystonia who underwent GPi DBS. Age, disease duration, dystonia direction, movement types, employment status, relevant life events, and neuropsychological examinations were analyzed with respect to clinical outcomes following GPi DBS. RESULTS: The only significant factor affecting clinical outcomes was movement type (phasic or tonic). Sequential changes in clinical outcomes showed significant differences between phasic- and tonic-type cervical dystonia. A delayed benefit was found in both phasic- and tonic-type dystonia. CONCLUSIONS: The clinical outcome of phasic-type cervical dystonia is more favorable than that of tonic-type cervical dystonia following GPi DBS.

Correlating Parkinson's disease motor symptoms with three-dimensional [(18)F]FP-CIT PET.

PURPOSE: To investigate the correlation between the striatal three-dimensional location and the Unified Parkinson's Disease Rating Scale (UPDRS) motor score in the context of idiopathic Parkinson's disease (PD) through radiolabeled N-(3-fluoropropyl)-2ß-carboxymethoxy-3ß-(4-iodophenyl) nortropane positron emission tomography/computed tomography (FP-CIT PET/CT). MATERIALS AND METHODS: In this cross-sectional study, we assessed the UPDRS motor score and performed FP-CIT PET/CT in patients with PD. Thirty-eight patients with idiopathic PD [average 70 years of age (range 49-86); male:female ratio 12:26] were enrolled. The correlation between FP-CIT PET/CT and the UPDRS III scores was investigated after the transformation of PET images by an alternative method using MATLAB. RESULTS: Left caudate nucleus uptake negatively correlated with UPDRS items 18, 20 (face), 22 (right arm and leg), 23, 24 (right side), 26 (right side), 27, 30, and 31, while right caudate nucleus uptake positively correlated with items 18, 22 (left arm), 26, and 29. Putamen uptake correlated with items 22 and 25. Left caudate nucleus uptake positively correlated with axial and akinetic-rigidity symptoms. CONCLUSIONS: FP-CIT uptake in specific basal ganglia structures strongly correlated with the UPDRS III motor score. Among these, the left caudate nucleus exhibited the strongest relationship with axial and akinetic-rigidity PD symptoms.

Effectiveness of selective peripheral denervation in combination with pallidal deep brain stimulation for the treatment of cervical dystonia.

BACKGROUND: Selective peripheral denervation (SPD) and deep brain stimulation of the globus pallidus (GPi-DBS) are available surgical options for patients with medically refractory cervical dystonia (CD). There are few data available concerning whether patients who have unsatisfactory treatment effects after primary surgery benefit from a different type of subsequent surgery. The aim of this study was to assess whether combining these surgical procedures (SPD plus GPi-DBS) was effective in patients with unsatisfactory treatment effects after their initial surgery. METHODS: Forty-one patients with medically refractory idiopathic CD underwent SPD and/or GPi-DBS. Patients who were dissatisfied with their primary surgery (SPD or GPi DBS) elected to subsequently undergo a different type of surgery. These patients were assessed with the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS). RESULTS: SPD alone and GPi-DBS alone were performed in 16 and 21 patients, respectively. Four patients had unsatisfactory treatment effects after the initial surgery and subsequently underwent another type of surgery. Among them, two patients with persistent dystonia after SPD subsequently underwent GPi-DBS, and two other patients who had insufficient treatment effects following GPi-DBS were subsequently treated with SPD. All of these patients experienced sustained improvement from the combined surgical procedures according to the TWSTRS score during a long-term follow-up of 12-90 months. CONCLUSIONS: Patients with unsatisfactory treatment effects after an SPD or GPi-DBS experienced improvement from subsequently undergoing other types of surgery. Therefore, combined surgical procedures are additional surgical options with good outcomes in the treatment of patients with residual symptoms after their initial surgery.

Association Factors for CT Angiography Spot Sign and Hematoma Growth in Korean Patients with Acute Spontaneous Intracerebral Hemorrhage : A Single-Center Cohort Study.

OBJECTIVE: This study was conducted to clarify the association factors and clinical significance of the CT angiography (CTA) spot sign and hematoma growth in Korean patients with acute intracerebral hemorrhage (ICH). METHODS: We retrospectively collected the data of 287 consecutive patients presenting with acute ICH who arrived within 12 hours of ictus. Baseline clinical and radiological characteristics as well as the mortality rate within one month were assessed. A binary logistic regression was conducted to obtain association factors for the CTA spot sign and hematoma growth. RESULTS: We identified a CTA spot sign in 40 patients (13.9%) and hematoma growth in 78 patients (27.2%). An elapsed time to CT scan of less than 3 hours (OR, 5.14; 95% CI, 1.76-15.02; p=0.003) was associated with the spot sign. A CTA spot sign (OR, 5.70; 95% CI, 2.70-12.01; p<0.001), elevated alanine transaminase (GPT) level >40 IU (OR, 2.01; 95% CI, 1.01-4.01; p=0.047), and an international normalized ratio ≥1.8 or warfarin medication (OR, 5.64; 95% CI, 1.29-24.57; p=0.021) were independent predictors for hematoma growth. Antiplatelet agent medication (OR, 4.92; 95% CI, 1.31-18.50; p=0.019) was significantly associated with hematoma growth within 6 hours of ictus. CONCLUSION: As previous other populations, CTA spot sign was a strong predictor for hematoma growth especially in hyper-acute stage of ICH in Korea. Antithrombotics medication might also be associated with hyper-acute hematoma growth. In our population, elevated GPT was newly identified as a predictor for hematoma growth and its effect for hematoma growth is necessary to be confirmed through a further research.

Spinous process morphometry for interspinous device implantation in Korean patients.

OBJECTIVE: To analyze the interspinous distance and the height, length, and thickness of the lumbar spinous process for interspinous device implantation in Korean patients. METHODS: Morphometric data obtained from plain radiographs of the lumbar and sacral spine were analyzed. The study included 60 matched subjects who visited an outpatient clinic for back pain. Exclusion criteria included collapsed intervertebral disc, lumbarization, and sacralization. There were 34 men and 26 women; age range was the 20s to 70s, with 10 subjects in each decade. The interspinous distance and height, length, and thickness of the lumbar spinous process were obtained on lateral radiographs using an image analysis program (M-view 5.4; Marotech). RESULTS: The largest interspinous distance was at L2-3, with a mean of 12 mm (range 6-22 mm), and the smallest distance was at L5-S1, with a mean of 8 mm (range 3-16 mm). The interspinous distance became shorter from L1-2 to L5-S1. A negative correlation was noted between age and interspinous distance in the L1-5 levels (L1-2, y=-0.11x+17.27, r2=0.34, P<0.0001; L2-3, y=-0.07x+15.68, r2=0.12, P=0.0058; L3-4, y=-0.08x+14.39, r2=0.27, P<0.0001; L4-5, y=-0.05x+11.65,r2=0.096, P=0.0158; L5-S1, y=-0.02x+9.25, r2=0.028, P=0.1982). CONCLUSIONS: There is a decreasing trend in the interspinous distance in the L1-5 levels with advancing years. Taking progressive collapse of the interspinous distance with the aging process into consideration, interspinous implants should be carefully selected in younger patients.

Electrophysiologic investigation during facial motor neuron suppression in patients with hemifacial spasm: possible pathophysiology of hemifacial spasm: a pilot study.

OBJECTIVE: To evaluate the pathophysiological mechanism of hemifacial spasm (HFS), we performed electrophysiological examinations, such as supraorbital nerve stimulation with orbicularis oris muscle recording and lateral spread tests, after suppressing the patient's central nervous system by administering intravenous diazepam. METHODS: Six patients with HFS were recruited. Supraorbital nerve stimulation with orbicularis oris muscle recording and the lateral spread test were performed, followed by intravenous application of 10 mg diazepam to achieve facial motor neuron suppression. Subsequently, we repeated the two electrophysiological experiments mentioned above at 10 and 20 minutes after the patients had received the diazepam intravenously. RESULTS: Orbicularis oris muscle responses were observed in all patients after supraorbital nerve stimulation and lateral spread tests. After the diazepam injection, no orbicularis oris muscle response to supraorbital nerve stimulation was observed in one patient, and the latencies of this response were evident as a slowing tendency with time in the remaining five patients. However, the latencies of the orbicularis oris muscle responses were observed consistently in all patients in the lateral spread test. CONCLUSION: Our results suggest that ectopic excitation/ephaptic transmission contributes to the pathophysiological mechanisms of HFS. This is because the latencies of the orbicularis oris muscle responses in the lateral spread test were observed consistently in the suppressed motor neuron in our patients.

Intraoperative facial electromyography and brainstem auditory evoked potential findings in microvascular decompression for hemifacial spasm: correlation with postoperative delayed facial palsy.

BACKGROUND: Delayed facial palsy (DFP) after microvascular decompression (MVD) in patients with hemifacial spasm (HFS) is not uncommon, but the cause remains unknown. OBJECTIVES: To assess whether intraoperative electromyography (EMG) and brainstem auditory evoked potential (BAEP) can predict DFP after MVD. METHODS: Between September 2009 and February 2011 we examined 86 patients, 9 of whom (10.4%) developed DFP after MVD on the same side. All patients underwent MVD and were followed-up for a median period of 13 months (range 6-22). We retrospectively examined intraoperative facial EMG and BAEP findings using our MVD patients' registry. We excluded secondary HFS and immediate postoperative facial palsy after MVD in this study. We assessed the prevalence and clinical characteristics of DFP and compared EMG and BAEP findings between DFP and non-DFP groups. RESULTS: All patients recovered completely, with a mean time to recovery of 37.8 days (range 22-57). There were no significant differences between DFP and non-DFP patients in terms of the amplitude and latency of intraoperative EMG and BAEP. CONCLUSION: The usefulness of intraoperative facial EMG and BAEP is limited and cannot predict DFP after MVD for HFS. We speculate that DFP after MVD is not associated with permanent nerve damage according to the EMG findings.

Comparison of treatment results between selective peripheral denervation and deep brain stimulation in patients with cervical dystonia.

BACKGROUND/AIMS: Cervical dystonia (CD) is the most common form of focal dystonia. The treatment options for CD include medical therapy and surgery. The 3 basic types of CD are tonic, phasic and tremulous. Selective peripheral denervation (SPD) and globus pallidus internus (GPi) deep brain stimulation (DBS) have been developed as therapeutic options for the treatment of CD. METHODS: Between 1997 and 2009, 24 patients with CD underwent operations: either SPD (n = 16) or DBS (n = 8). The mean follow-up period was 29.5 months (range = 2-59). The mean age at onset of symptoms was 46.6 years (range = 27-65). The patients were evaluated with the subjective scores and the Toronto Western Spasmodic Torticollis Scale scores. RESULTS: All patients showed gradual improvement after SPD and DBS. No statistically significant differences were seen between the SPD group and the DBS group. However, there was a trend toward greater pain reduction in the DBS group (p = 0.094). CONCLUSION: Both the SPD group and the DBS group showed successful improvement in their Toronto Western Spasmodic Torticollis Scale scores as well as subjective scores. The GPi DBS group showed a remarkable improvement on the pain scale and there was a trend toward greater pain reduction in the DBS group.

Serious complication of cement augmentation for damaged pilot hole.

Polymethl methacrylate (PMMA) screw reinforcement is frequently used in osteoporotic bone as well as in damaged pilot holes. However, PMMA use can be dangerous, since the amount of applied cement is uncontrolled. A 47-year-old male with traumatic cervical spondylolisthesis at C6-7 underwent anterior cervical plate fixation. During repeated drilling and tapping for false trajectory correction, a pilot hole was damaged. Although it was an unconventional method, PMMA augmentation was tried. However, PMMA was accidentally injected to the cervical spinal cord owing to lack of fluoroscopic guidance. The PMMA was surgically removed after corpectomy and durotomy. The patient had left side hemiparesis (Grade 2/5) immediately post operation. The patient improved spontaneously (Grade 4/5) except for 4th and 5th digit extension. Here, we report a rare complication of PMMA extrusion in the spinal cord during a damaged pilot hole injection, which has not previously been described.

Effect of various surgical modalities in recurrent or persistent trigeminal neuralgia.

BACKGROUND/AIMS: In recurrent or persistent idiopathic trigeminal neuralgia (TN) after initial operation, additional surgical procedures may be required. There are numerous articles reporting the outcomes of additional surgical treatment and it is unclear how best to treat patients with recurrent or persistent TN. We evaluated the subsequent therapeutic options for recurrent or persistent TN. METHODS: The study was a retrospective study. The authors reviewed 29 patients (15 female/14 male) who underwent retreatments for recurrent or persistent symptoms after an initial operation. RESULTS: The mean follow-up duration was 56.4 months (range 12-78.7) from final treatment. Patients underwent a mean of 2.3 retreatments with a mean period of 26 months (range 1-72) between treatments. Final treatments were as follows: microvascular decompression (MVD) in 12 patients, percutaneous rhizotomy in 10, and radiosurgery in 7. Of the 29 patients, after final treatments, 9 patients (31%) achieved excellent results and 15 (52%) good results. Failure results were seen in 17% of patients with recurrent TN. CONCLUSION: In this study the authors demonstrate that percutaneous rhizotomy is recommended for most patients with recurrent pain after MVD, and MVD can be effective in patients with a history of failed percutaneous procedures. Radiosurgery can be utilized to treat those that have not responded to other surgical modalities.

Association of methylenetetrahydrofolate reductase (MTHFR 677C>T and 1298A>C) polymorphisms and haplotypes with silent brain infarction and homocysteine levels in a Korean population.

PURPOSE: Methylenetetrahydrofolate reductase (MTHFR) is the main regulatory enzyme for homocysteine metabolism. In the present study, we evaluated whether the MTHFR 677C>T and 1298A>C gene polymorphisms are associated with SBI and plasma homocysteine concentration in a Korean population. MATERIALS AND METHODS: We enrolled 264 patients with SBI and 234 healthy controls in South Korea. Fasting plasma total homocysteine (tHcy) concentrations were measured, and genotype analysis of the MTHFR gene was carried out. RESULTS: The plasma tHcy levels were significantly higher in patients with SBI than in healthy controls. Despite a significant association between the MTHFR 677TT genotype and hyperhomocysteinemia, the MTHFR 677C>T genotypes did not appear to influence susceptibility to SBI. However, odds ratios of the 1298AC and 1298AC + CC genotypes for the 1298AA genotype were significantly different between SBI patients and normal controls. The frequencies of 677C-1298A and 677C-1298C haplotypes were significantly higher in the SBI group than in the control group. CONCLUSION: This study demonstrates that the MTHFR 1298A>C polymorphism is a risk factor for SBI in a Korean population. The genotypes of 677C>T and 1298A>C polymorphisms interact additively, and increase the risk of SBI in Korean subjects.

Stereotactic spine radiosurgery for intradural and intramedullary metastasis.

OBJECT: Stereotactic radiosurgery (SRS) has become an important treatment alternative to surgery for a variety of spinal lesions. However, the use of SRS in the management of intradural intramedullary (IDIM) metastasis remains controversial. The aim of this study was to determine the clinical efficacy and safety of SRS for treatment of IDIM metastasis. METHODS: Nine patients with 11 IDIM metastases treated with SRS at Henry Ford Hospital were retrospectively reviewed. The mean age at presentation was 50 years, with a range of 14-71 years. There were 4 intradural extramedullary and 7 intramedullary lesions. The radiosurgery procedure used techniques of image-guided and intensitymodulated radiation. The mean treatment dose was 13.8 Gy, with a range of 10-16 Gy. All patients had clinical follow-up (except in 1 lesion), with an emphasis on initial symptoms and ambulatory status, and 8 patients (9 lesions) had imaging studies. The median follow-up duration was 10 months. RESULTS: The presenting symptoms were improved in 8 (80%) of 10 evaluable lesions, unchanged in 1 case, and worsened in 1 case. Radiographic responses were seen as follows: complete response in 2 (22%) of 9; partial response in 3 (33%) of 9; stable disease in 3 (33%) of 9; and progressive disease in 1 (11%) of 9. After radiosurgery, 7 patients (78%) remained ambulatory until the last follow-up visit. The overall median survival time after SRS was 8 months, with a range of 2-19 months. No radiation toxicity was detected clinically during the follow-up period. CONCLUSIONS: Despite the fact that this was a small series of patients with IDIM metastasis who had limited treatment options, SRS appears to be an effective and safe method of treating patients with these lesions.