[A Dumbbell-Type Thoracic Spinal Lipoma: A Case Report].

Spinal lipomas are rare, accounting for less than 1% of all spinal tumors. Most are associated with spinal dysraphism. Spinal lipomas without spinal dysraphism are uncommon;they are typically subpial tumors. Some tumors are located both inside and outside the dura mater (so-called "dumbbell-type"). Herein, we report a patient with a dumbbell-type thoracic spinal lipoma. A man in his 50's complained of progressive gait disturbance, dysesthesia in his left leg, and hyperesthesia in his right leg. His symptoms were worsened by exercise. CT and MRI revealed a thoracic spinal lipoma extending from the spinal cord to the intervertebral foramen at the Th 6-8 level. He underwent partial tumor removal and untethering. Postoperatively he reported gradual symptom abatement. Dumbbell-type spinal lipomas are very rare. Besides partial removal of the tumor, untethering should be considered when symptoms are associated with tethering of the spinal cord.

A case of cervical juxtafacet cyst with extensive rim enhancement on Gd-DTPA MRI.

The authors reported a case of cervical juxtafacet cyst with extensive rim enhancement on gadolinium-diethylenetriamine pentaacid magnetic resonance imaging. Operative finding revealed the epidural space around the mass filled with abundant venous plexus. Histological examination demonstrated that cyst wall was composed of the well-vascularized fibrous connective tissue with some inflammatory changes. We speculate that extensive rim enhancement of juxtafacet cyst may be attributed not only to the chronic inflammatory changes of cyst wall, but to engorged venous plexus within the widened epidural space.

Semiquantitative analysis of indocyanine green videoangiography for cortical perfusion assessment in superficial temporal artery to middle cerebral artery anastomosis.

BACKGROUND: Postoperative hyperperfusion may lead to severe neurological complications after superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. However, there are no reliable modalities to predict the occurrence of postoperative hyperperfusion during surgery. The purpose of this study is to evaluate whether a semiquantitative analysis of indocyanine green (ICG) videoangiography could be useful in predicting postoperative hyperperfusion after STA-MCA anastomosis. METHODS: This study included seven patients who underwent STA-MCA anastomosis due to occlusive carotid artery diseases. During surgery, ICG videoangiography was performed before and after bypass procedures, and ICG intensity-time curves were semiquantitatively analyzed to evaluate hemodynamic changes by calculating maximum intensity, time to peak (TTP), and blood flow index (BFI). RESULTS: Maximum intensity significantly increased from 252.6 ± 132.5 to 351.7 ± 151.9 after bypass (p < 0.001). TTP was significantly shortened from 12.9 ± 4.4 s to 9.8 ± 3.7 s (p < 0.001). Furthermore, BFI significantly increased from 33.9 ± 28.1 to 74.6 ± 88.4 (p < 0.05). Postoperative hyperperfusion was observed in five of seven patients 1 day after surgery. The ratio of BFI before and after bypass procedures was significantly higher in patients with postoperative hyperperfusion than those without, 2.5 ± 1.1 and 1.5 ± 0.4, respectively (p = 0.013). CONCLUSIONS: These findings suggest that semiquantitative analysis of ICG videoangiography is helpful in predicting occurrence of hyperperfusion after STA-MCA anastomosis in patients with occlusive carotid artery diseases.

[Non-invasive quantitative EMG: invention of the "Clustering Index (CI)" method].

There have been few previous studies trying to evaluate neuromuscular disorders using surface electro myography (SEMG). The greatest obstacle to such an approach must be the difficulty in identifying individual motor unit potentials (MUPs) on the SEMG signal under voluntary contraction because of their dense overlap. We tried to solve this problem by reducing the overlap of MUPs using appropriate electrode setting, as well as by developing a new method of interference pattern analysis. The tibialis anterior muscle was examined in our first study. A new method to analyse SEMG signal, the Clustering Index (CI) method, achieved 100% and 61% sensitivities for neurogenic and myopathic patients, and 97% specificity for control subjects. In the second study, the abductor digiti minimi muscle was examined. Subjects were 29 spinal and bulbar muscular atrophy patients and 27 controls. The CI method was compared with the motor unit number estimation, and the amplitude of compound muscle action potential. As results, the CI method achieved the best sensitivity and among these three techniques. The CI method is a novel, simple, and quantitative analysis method without using any special equipments, and is promising as a non-invasive complement to needle EMG.

Favorable outcome after radical resection and subsequent local irradiation of malignant peripheral nerve sheath tumor in the cervical spine.

A 25-year-old man presented with malignant transformation to malignant peripheral nerve sheath tumor (MPNST) in the cervical spine associated with neurofibromatosis type 1. He presented with a 3-week history of rapidly increasing weakness and numbness in all four extremities. Magnetic resonance (MR) imaging of the cervical spine demonstrated a dumbbell-shaped tumor, which compressed the spinal cord at the C2-3 level. The tumor was excised, mainly within the spinal canal to decompress the spinal cord. The histological diagnosis was benign neurofibroma. Three months after surgery, he rapidly developed progressive tetraparesis and MR imaging revealed marked regrowth of an extradural mass into the spinal canal. At reoperation, the regrown mass in the spinal canal was totally excised. The histological diagnosis revealed MPNST. He underwent radiation therapy, with a total dose of 32 Gy, for approximately 3 weeks after the second surgery, but MR imaging showed tumor regrowth within the spinal canal, and his condition deteriorated. The decision was made to remove the tumor radically, including the involved facet and extradural lesion. Posterior fusion using a pedicle screw was performed one month later. He manifested no additional neurological deficits. He has been free of relapse for 46 months. Radical resection remains the most effective treatment for MPNST, although complete removal with a clear tumor margin is often impossible in practice.

Intraoperative dual monitoring during carotid endarterectomy using motor evoked potentials and near-infrared spectroscopy.

BACKGROUND: Carotid endarterectomy (CEA) is a useful procedure to prevent subsequent ischemic stroke in patients with severe stenosis of internal carotid artery. However, lowering of morbidity is still essential to keep its clinical significance. This study aimed to evaluate the validity of dual monitoring using transcranial motor evoked potential (MEP) and near-infrared spectroscopy (NIRS) during CEA. METHODS: Transcranial MEP and NIRS monitoring were conducted in 20 consecutive CEAs. MEP was recorded in the contralateral extremities. Regional cerebral saturation of oxygen (rSO(2)) was continuously measured in the ipsilateral forehead. The changes of MEP amplitudes and rSO(2) during cross-clamping of carotid artery were compared in each case. RESULTS: The amplitudes of MEP significantly decreased when rSO(2) reduced to more than 20% during carotid clamping. There was a significant correlation between the changes of MEP amplitude and rSO(2) during carotid clamping in a quadratic manner (P < .001, r = 0.821). However, NIRS could not detect critical cerebral ischemia in 1 patient with cerebral infarction in the ipsilateral frontal lobe. On the other hand, MEP could not identify it in 1 patient with severe motor deficit. No perioperative complication occurred. CONCLUSIONS: These findings strongly suggest that both MEP and NIRS can detect critical cerebral ischemia during CEA in most patients. Dual MEP and NIRS monitoring may further increase the sensitivity to identify it, being valuable to prevent perioperative complications due to cerebral ischemia during CEA.

Clinical and radiographic characteristics of upper lumbar disc herniation: ten-year microsurgical experience.

Upper and lower lumbar disc herniation apparently have different background, symptoms, and operative results. This retrospective study reviewed the clinical records of 403 patients (409 discs) who underwent lumbar microdiscectomy performed by different surgeons at our institute between 1999 and 2009. The 290 male (72.0%) and 113 female (28.0%) patients were aged from 19 to 77 years (mean 44 years). Demographics, symptoms, and static and dynamic radiographic and magnetic resonance images obtained at the L1-2, L2-3, L3-4, L4-5, and L5-S1 intervertebral levels were analyzed. Of the 409 herniations, 3 were at L1-2, 9 at L2-3, 21 at L3-4, 166 at L4-5, and 210 at L5-S1. The mean age at herniation at L1-2 and L2-3 levels was 55.7 years. Patients with herniation of discs at L3-4 or above were significantly older than patients who suffered herniation at L4-5 or below (p < 0.0001), and the incidence of urinary disturbance was significantly higher in patients with herniation at L1-2 and L2-3 levels (p = 0.0013). The incidence of degenerative scoliosis was significantly higher in patients with herniation at L1-2 and L2-3 than in those with herniated discs at L3-4 or below (p < 0.0001). Patients with upper lumbar disc herniation were older and manifested a higher incidence of urinary disturbance. A high incidence of degenerative scoliosis was noted in the course of prolonged degenerative processes.

"Clustering Index method": a new technique for differentiation between neurogenic and myopathic changes using surface EMG.

OBJECTIVE: To establish a non-invasive and quantitative analysis method using single-channel surface EMG (SEMG) for diagnosing neurogenic and myopathic changes. METHODS: The subjects consisted of 66 healthy controls, 12 patients with neurogenic diseases, and 18 patients with myopathic diseases. The tibialis anterior muscle was examined using a belly to the adjacent bone lead. From each subject, 20-40 signals of 1 s length were collected of various strengths. A new parameter, the "Clustering Index (CI)", was developed to quantify the uneven distribution of the SEMG signal, and was plotted against the SEMG area. The results were expressed as the Z-score of each subject calculated using linear regression from the normative data. RESULTS: When ±2.5 was used as the cut-off value of the Z-score, the specificity was 95%, whereas the sensitivity was 92% (11/12) and 61% (11/18) for the neurogenic and myopathic patients, respectively. There was no overlap of the Z-score values between the neurogenic and myopathic groups. CONCLUSIONS: The CI method achieved a reasonably high diagnostic yield in detecting neurogenic or myopathic changes. SIGNIFICANCE: This is a new simple and quantitative analysis method using SEMG with good reproducibility, and is promising as a non-invasive complement to needle EMG.

Lumen morphology in mild-to-moderate internal carotid artery stenosis correlates with neurological symptoms.

BACKGROUND: Several prospective studies have shown that carotid endarterectomy can reduce the risk for subsequent ischemic stroke in patients with 70-99% stenosis of the internal carotid artery (ICA). However, its benefits are still controversial in less than 70% stenosis of the ICA. There is increasing evidence that carotid lumen irregularities may correlate with neurological symptoms. Recent development of computed tomography angiography (CTA) can provide adequate information on the carotid plaque morphology. In this study, therefore, we aimed to clarify whether carotid lumen morphology estimated by CTA correlates with neurological symptoms in patients with 30-69% ICA stenosis. METHODS: This study included 67 carotid stenotic lesions with 30-69% ICA stenosis in 52 consecutive patients. These 67 lesions were examined by CTA from the viewpoints of the degree of stenosis, the prevalence of ulceration, and lumen morphology. Multivariate analysis was performed to detect significant predictors for the occurrence of ipsilateral ischemic events. RESULTS: Multivariate analysis showed that the irregular shape of the carotid lumen was the most powerful variable to predict symptomatic lesion in 30-69% ICA stenosis. CONCLUSIONS: These findings suggest that the morphology of carotid plaque may be associated with the occurrence of ipsilateral ischemic events in 30-69% ICA stenosis.

Clinical characteristics and outcomes in carotid endarterectomy for internal carotid artery stenosis in a Japanese population: 10-year microsurgical experience.

Few studies have explored the significance of carotid endarterectomy (CEA) in long-term prognosis in Japanese patients. In the present study, we precisely elucidated the demographic and radiologic data, surgical morbidity and mortality, and long-term outcome in 135 Japanese patients who underwent a total of 142 CEAs due to 70%-99% stenosis of the internal carotid artery at our hospitals over a 10-year period. The prevalence of risk factors was similar to those found in previous studies in Western countries. Surgical mortality (0.7%) and morbidity (2.8%) were relatively low. Blood flow studies done immediately after CEA revealed postoperative hyperperfusion in 8 patients (5.6%), but none of these patients exhibited related symptoms. Over the mean follow-up period of 38.7 months, a total of 9 patients died (6.7%), due mainly to malignancies. Cerebrovascular events occurred in 12 patients (8.5%), including ipsilateral ischemic stroke in 2 (1.4%). In addition, 11 patients (8.2%) developed vascular disorders in other organs, including coronary artery disease and chronic renal failure. Follow-up radiologic examination revealed restenosis of >50% in 3 carotid arteries (2.1%). Stenosis of the contralateral carotid arteries progressed to >70% in 12 patients (9.2%). This study strongly suggests that microsurgical CEA is feasible and effective in preventing subsequent ipsilateral ischemic stroke in Japanese patients; however, long-term medical and radiologic surveillance is essential to reduce the incidence of ischemic stroke in other areas and of vascular disorders in other organs to improve prognosis.

[Can cerebral blood flow measurement predict clinical outcome in the acute phase in patients with artherosclerotic occlusive carotid artery disease?].

It has been thought that the clinical course of patients with acute carotid occlusive disease depends on their collateral cerebral blood flow (CBF) and duration of ischemia. However, there have been few clinical reports to prove this hypothesis. Therefore, we performed CBF study in patients with artherosclerotic carotid occlusive disease in the very acute phase, and precisely assessed the prognosis of those patients under intensive medical therapy. This prospective study included a total of 44 patients (72+/-13 years) who were admitted to our hospital between April, 2007 and December, 2008. To evaluate their initial CBF, single photon emission computed tomography (SPECT) studies were performed within 6 hours after the onset. All patients included in this study were medically treated and were periodically followed up by neurological and radiological examination. Moreover, in patients with reduced CBF (ipsilateral CBF/contralateral CBF x 100: %CBF< 80%), dobutamine-induce hyperdynamic therapy was performed. Multivariate analysis was performed to detect significant predictors for the occurrence of further cerebral infarction. Multivariate analysis showed that the occurrence of further infarction was associated with older age and smaller %CBF. Of 44 patients, 21 experienced further cerebral infarction within 10 days after onset. Fourteen out of 15 patients with %CBF< 60% developed cerebral infarction. This study showed that the prognosis of the patients with artherosclerotic carotid occlusive disease in the acute phase is associated with their initial residual CBFs. It may be difficult to stop the developed cerebral infarction in those patients with %CBF< 60% despite intensive medical therapy.

[A case of brainstem variant of reversible posterior leukoencephalopathy syndrome].

A rare case of a brainstem variant of reversible posterior leukoencephalopathy syndrome (RPLS) is reported. A 34-year-old man with a past history of untreated chronic renal failure and hypertension was admitted to our hospital complaining of severe nuchal headache lasting for about four days. His neurological examination was normal, however physical examination revealed his blood pressure was 216/120 mmHg. Computed tomography imaging (CT) showed his brain stem with a low attenuation. Magnetic resonance imaging (MRI) revealed extensive hyperintensity and enlargement of the midbrain and pons on T2 weighted and fluid attenuated inversion-recovery (FLAIR) image. However, there was no abnormal lesion seen in either bilateral occipital lobe. Diffusion-weighted image (DWI) was normal at the brainstem, but apparent diffusion coefficient (ADC) values were slightly elevated at the left midbrain. There was no contrast enhancement. His symptom and radiological finding improved soon after his blood pressure was controlled. A repeated MRI taken two weeks later showed complete resolution of the lesion. RPLS associated with predominant involvement of the brainstem and sparing of the supratentorial region is rare, but it should be differentiated from brain stem infarction, pontine glioma, central pontine myelinolysis and infective encephalitis, since the neulological consequences are potentially fully reversible after adequate and prompt treatment.

Cervical myelopathy by C1 posterior tubercle impingement in a patient with DISH.

STUDY DESIGN: A unique case of a patient with diffuse idiopathic skeletal hyperostosis (DISH) associated with C1 posterior tubercle impingement resulting in spinal canal stenosis and cervical myelopathy. OBJECTIVE: To describe an uncommon mechanism of spinal cord compression in patient with DISH. SUMMARY OF BACKGROUND DATA: The neurologic deficits due to cervical DISH are relatively rare and a few cases of cervical spinal cord compression due to atlantoaxial subluxation, odontoid fracture, pseudotumor, ligamentous hypertrophy, and basilar impression have been reported. To the best of our knowledge, there has been no other report of a patient with DISH causing C1 posterior tubercle impingement and cervical myelopathy. METHODS: A 75-year-old Japanese man, first diagnosed as hyperostosis of anterior and posterior longitudinal ligament 25 years ago, presented with gradual progression of numbness in both lower extremities, disturbed precise hand motion and urinary function. DISH, OPLL, and C1 posterior tubercle impingement was diagnosed by radiograph, CT, and MRI. Hyperintense signal in the C1 spinal cord on T2 weighted sequence was observed. RESULT: Laminectomy from C1-C3 was performed. Myelocompression and myelopathy improved after the surgical intervention. Multilevel fusion of the subaxial cervical spine and increase of the mechanical stress on the craniocervical segment may leads to partial damage of the ligaments and resulted in C1 posterior arch impingement. CONCLUSION: This is the first report of unique C1 posterior tubercle impingement and myelopathy caused by DISH. We should keep it in mind that DISH can cause serious problems in the upper cervical spine even after 25 years of interval.

An automated ROI setting method using NEUROSTAT on cerebral blood flow SPECT images.

OBJECTIVE: We have developed a method to automatically set regions of interest (ROI) (automated ROI) on cerebral blood flow single-photon emission computed tomography (SPECT) images with morphological information specific to the subjects. The objective was to set ROIs automatically without losing individual morphological information in the SPECT images and then evaluate its validity and clinical applicability. METHODS: We constructed the volume of interest (VOI) template on the standardized brain generated by NEUROSTAT to determine the regions for ROIs to be set. Assuming patients with cerebral vascular disease, the VOI template was constructed so that the ROIs were drawn for the major vascular regions and 17 regions in total within the hemisphere, basal ganglia, thalamus, cerebellar cortex, cerebellar vermis, and pons. By comparing the major vascular occlusion models, the accuracy of region setting by the VOI template was evaluated for validation. Using the anatomical standardization of NEUROSTAT and inverse transformation, the automated ROI transformed the VOI template into the individual brain shape and then the VOI template was extracted from each slice to determine ROIs. An evaluation was made by visually investigating the effect of a different image quality and cerebral blood flow tracers using brain phantom and clinical data. The regional cerebral blood flow (rCBF), determined by the manual setting method of ROI (manual ROI) and automated ROI, was compared. We also compared automated ROI with other morphological images using clinical data. RESULTS: The VOI templates accurately showed the region with the reduced blood flow in the major vascular occlusion model, which validated the proper ROI setting. The brain phantom study demonstrated that ROI settings were least influenced by matrix size, image quality, and image rotation. The observation with the clinical data also indicated that the variation in cerebral blood flow tracers little affected the ROI settings. The comparison with manual ROI revealed a strong correlation between the two ROI settings, and the mean values within both ROIs were similar. The comparative evaluation with morphological images, obtained by magnetic resonance imaging (MRI), verified the accurate setting of ROI. CONCLUSIONS: The automated ROI achieved successful automatic ROI settings without distorting individual SPECT images. The automated ROI is not affected by the differences in the image quality or the cerebral blood flow tracers, which suggests versatile applicability. Thus, the use of automated ROI may eliminate the interoperator and interfacility variability in ROI setting and improve objectivity and reproducibility. It also allows comparative evaluation at the same transverse level with images acquired with other modalities such as MRI and is expected to enhance the clinical diagnosis.

[Natural course of the carotid artery contralateral to carotid endarterectomy in Japan].

There are few studies that describe long-term outcome of the carotid artery contralateral to carotid endarterectomy (CEA) in Japan. This study, therefore, was aimed at assessing the incidence and clinical features of patients whose contralateral carotid artery showed progression to significant stenosis (more than 70%). This study included 130 patients who underwent CEA for internal carotid artery stenosis between 1998 and 2007. During follow-up periods of a mean of 34.3 months, MR angiography or 3-dimenional CT angiography was performed every 6 or 12 months. Risk factors including hypertension, diabetes mellitus, hyperlipidemia, and coronary artery disease were also evaluated to clarify the significant predictors for disease progression of the carotid artery contralateral to CEA. The results were that, the carotid artery contralateral to CEA showed disease progression to significant stenosis (> 70%) in 12 of 130 patients (9.2%). The interval between CEA and disease progression of the carotid artery contralateral to CEA ranged from 13 to 103 months (mean, 50.7 months). Of these 9 patients underwent CEA for contralateral carotid artery stenosis to prevent ischemic stroke. Multiple logistic regression analysis revealed that there were no predictors for disease progression of the carotid artery contralateral to CEA during follow-up periods. This is the first report that has analyzed the incidence and clinical features of disease progression of the carotid artery contralateral to CEA in Japan. Its incidence is not low in Japan, and careful long-term follow-up would be essential to prevent additional stroke occurrence in patients who undergo CEA.

Radiculopathy caused by lumbar epidural venous varix: case report.

A 33-year-old man presented with a rare case of lumbar epidural venous varix causing radiculopathy manifesting as sciatica exacerbated during bowel movements. The left straight-leg raising test was positive and patellar tendon reflex was lost. Lumbar magnetic resonance imaging showed a mass lesion in the epidural space at the L4 level just anterior to the dural sac on the left, appearing as hypointense on T(1)- and hyperintense on T(2)-weighted images, with ring-like enhancement with gadopentetate dimeglumine. He underwent surgery under a preoperative diagnosis of cystic nerve sheath tumor. After left hemilaminectomy, intraoperative ultrasonography showed a low echoic mass lesion ventral to the L4 nerve root. The mass was dark blue with a smooth wall. Tearing of the wall resulted in continuous bleeding. After removal of the lesion, we confirmed that the dura of the nerve root was intact. Histological examination of the surgical specimen confirmed venous tissue. The postoperative course was excellent. Lumbar epidural varix is difficult to diagnose preoperatively. Lumbar epidural varix should be considered if the lesion is smaller on preoperative than intraoperative imaging, or disappears with bleeding cessation, as this may avoid unnecessary widening of the operative field. The correct preoperative diagnosis remains difficult, so we recommend surgical removal and histological confirmation.

Characteristics and distribution of somatosensory evoked potentials in the subthalamic region.

OBJECT: The aim of the present study is to evaluate the topographical distribution of somatosensory evoked potentials (SSEPs) in the subthalamic area, including the zona incerta (ZI). Determination of this distribution may help in the correct placement of deep brain stimulation (DBS) leads. METHODS: Intraoperative SSEPs were recorded from contacts of DBS electrodes at 221 sites in 41 patients: three patients with essential tremor and 38 with Parkinson disease who underwent implantation of DBS electrodes for the relief of severe tremor or parkinsonism. RESULTS: Two distinct SSEPs were recorded in the subthalamic area. One was a monophasic positive wave with a mean latency of 15.8 +/- 0.9 msec, which the authors designated subthalamic P16. Using both cephalic and noncephalic references, subthalamic P16 was only recorded in the ventral part of the ZI (mean 6.6 +/- 1.3 mm posterior to the midcommissure point, 4.8 +/- 1.2 mm inferior to the anterior commissure-posterior commissure line, and 9.7 +/- 0.6 mm lateral to the midline). When bipolar recordings were made, the traces showed a phase reversal at the caudal part of the ZI. The second potential is a positive-negative SSEP recorded throughout the entire subthalamic area. The mean latencies of the initial positive peak and the major negative peak were 13.6 +/- 1.1 msec and 16.4 +/- 1.1 msec, respectively. Several small notches were superimposed on the peaks, and their amplitudes were largest at the contact close to the medial lemniscus. CONCLUSIONS: The results indicate that intraoperative SSEPs from DBS electrodes are helpful in refining stereotactic targets in the thalamus and subthalamic areas.

[Deep brain stimulation of the posterior subthalamic area (Zi/Raprl) for intractable tremor].

Tremor in the proximal arm muscle, trunk, or legs is often resistant to the standard stereotactic surgery of the thalamic ventrointermediate nucleus. We have performed deep brain stimulation (DBS) of the posterior subthalamic area for those intractable tremors. The white matter area between the red nucleus and the subthalamic nucleus was targeted on the T2-weighted MR-CT fused image. Inhibitory effect on the tremor was tested with macrostimulation. The somatosensory-evoked potential recorded through DBS contacts demonstrated characteristic biphasic pattern. Eight cases with severe essential tremor and 18 of tremor-dominant Parkinson disease were treated with unilateral DBS of the area including the zona incerta and the prelemniscal radiation (Zi/Raprl). Tremors including the proximal part have been well controlled for 24 months after the operation. The stimulation parameters have been almost stable during the follow-up period. There was no obvious adverse effect of stimulation. We conclude that Zi/Raprl-DBS is a safe and effective treatment on Parkinsonian and essential tremor.

Cystic meningioangiomatosis.

A case of cerebral meningioangiomatosis with rare cyst formation is reported. A 14-year-old boy without any stigmata of neurofibromatosis type 2 presented intractable complex partial and generalized seizures since the age of 12 years. Neuroradiological studies showed an abnormal cystic mass with calcification in the left frontal lobe of the cerebrum. The tumor was located in the leptomeninges and cerebral cortex. The patient underwent surgical treatment because medical treatment with phenytoin and sodium valproate was not sufficient to control the seizures. An intraoperative electrocorticogram revealed that epileptic foci were recorded from the cortex, which was adjacent to the lesion. Histopathology showed specific features of meningioangiomatosis with meningioma-like nodules. The patient did not have any seizures with anticonvulsants after surgery. It is important to distinguish meningioangiomatosis from other possible cortical lesions and epileptic foci should be carefully considered before resection, because it is a benign and surgically manageable cause of seizures.

Two-year follow-up of chronic stimulation of the posterior subthalamic white matter for tremor-dominant Parkinson's disease.

OBJECTIVE: To determine the efficacy and safety of unilateral deep brain stimulation on the posterior subthalamic white matter, including the zona incerta (ZI) and the prelemniscal radiation (PRL), for tremor-dominant parkinsonian patients and to determine the exact location of electrodes that were most effective. METHODS: Eight parkinsonian patients with severe resting tremor underwent unilateral stimulation of the ZI/PRL by use of stereotactic guidance. Electrophysiological targeting was obtained by macrostimulation and by somatosensory evoked potentials recorded directly through a quadripolar deep brain stimulation lead. Postoperative computed tomographic scans and magnetic resonance images were performed to confirm anatomic location of the electrode. Parkinsonian motor disabilities were evaluated by use of the Unified Parkinson's Disease Rating Scale in the medication-off state before surgery and every 6 months after electrode implantations. RESULTS: The mean location of the clinically effective contacts was in the posterior subthalamic white matter, including the ZI and the PRL (mean, 5.6 +/- 1.2 mm posterior to the midcommissural point, 3.2 +/- 1.1 mm inferior to the anterior commissure-posterior commissure line, and 10.5 +/- 1.2 mm lateral to the midline). At 24 months after operation, ZI/PRL stimulation resulted in significant improvement in mean Unified Parkinson's Disease Rating Scale motor score by 44.3%, contralateral tremor by 78.3%, contralateral rigidity by 92.7%, and contralateral akinesia by 65.7% above the "off-stimulation" scores. Handwriting, posture, and gait were also improved. There were no or only mild adverse events. CONCLUSION: Unilateral ZI/PRL stimulation is a reliable and long-term therapeutic modality and can be considered another surgical target for the treatment of tremor-dominant Parkinson's disease.