Intracranial ictal onset zone in nonlesional lateral temporal lobe epilepsy on scalp ictal EEG

OBJECTIVE

To determine the ictal focus and the role of seizure characteristics, fluorodeoxyglucose (FDG) PET, and subtraction ictal SPECT in patients diagnosed as having nonlesional lateral temporal lobe epilepsy by long-term scalp video-EEG monitoring.

METHODS

The authors studied 33 consecutive patients with nonlesional neocortical epilepsy who had a scalp ictal onset zone localized in the temporal lobe and good surgical outcome after focal neocortical resection. All patients were evaluated using intracranial recordings prior to resection. Semiology, FDG-PET, and ictal-interictal subtraction SPECT were used to verify the diagnostic role of these methods in the localization of epileptic foci.

RESULTS

The ictal onset zones, confirmed by intracranial study, were the lateral temporal (22 patients), parietal (5), frontal (3), temporoparietal (2), and occipital (1) areas. FDG-PET analyzed by statistical parametric mapping correctly localized the epileptogenic lobe in 18 of 33 patients and subtraction ictal SPECT correctly localized it in 13 of 25 patients. However, in patients with extratemporal ictal onset zones, FDG-PET and ictal SPECT in combination correctly localized the epileptogenic lobe in only 3 of 11 cases.

CONCLUSIONS

An extratemporal ictal onset zone was encountered in patients with nonlesional lateral temporal lobe seizures based on scalp video-EEG monitoring. FDG-PET and subtraction SPECT had localizing value in no more than half of patients.

Iatrogenic spinal epidermoid tumor. A complication of spinal puncture in an adult

A case of an intraspinal epidermoid tumor following a lumbar puncture (LP) is described. This tumor developed 5 years after a LP in a man aged 31 years. The majority of epidermoid tumors reported are late complications of spinal puncture during the early neonatal period. To the best of our knowledge, this case is the third oldest patient, whose symptoms presented relatively early after the initial LP. He was successfully treated by surgery. Pathologic diagnosis revealed an epidermoid cyst. The relation between LP and epidermoid tumor and the possible risk factors involved are discussed.

Differential features of metabolic abnormalities between medial and lateral temporal lobe epilepsy: quantitative analysis of (18)F-FDG PET using SPM

Because limited resection could yield an equally good surgical outcome as standard anterior resection in temporal lobe epilepsy (TLE), the differentiation of medial from lateral TLE is important. We tried to find the differential features in metabolic abnormalities between medial and lateral TLE groups using quantitative analysis including statistical parametric mapping (SPM).

METHODS

We examined 113 (18)F-FDG PET scans of TLE patients who had surgically and pathologically proven lesions and a good surgical outcome (78 medial TLE, 35 lateral TLE). Each scan was compared with those of 22 healthy control subjects to detect hypometabolic regions using a t test of the SPM method and interhemispheric asymmetry using 2-group, 2-condition analysis on SPM. Group analysis was performed between medial and lateral TLE using mirrored PET images. The sensitivity was defined as the detection rate of hypometabolism in the ipsilateral temporal lobes, and the specificity was defined as the nondetection rate in the contralateral lobes. The extent of the hypometabolism was calculated as the number of significant voxels, and the severity was calculated by the asymmetry index (ASI), in the medial or lateral temporal lobes on Statistical Probabilistic Anatomical Map template images.

RESULTS

The hypometabolism in the temporal lobes was detected ipsilateral to the seizure focus in 76% of the TLE patients (76% in medial TLE, 77% in lateral TLE) but on the contralateral temporal lobes in 32% of the patients. After considering interhemispheric temporal asymmetry, the sensitivity was found to be 89%, and the specificity was 91% without differences between the medial and lateral TLE groups. In both medial and the lateral TLE, the hypometabolism was more prominent in the lateral cortical structures than in the medial structures. The hypometabolism in the medial temporal structures was found less frequently in the lateral TLE group, and the extent of the hypometabolism was significantly larger in the medial TLE group. ASIs of the medial temporal structure and superior temporal gyrus of lateral temporal structure were significantly higher in the medial TLE.

CONCLUSION

SPM analysis of (18)F-FDG PET in TLE patients could localize accurately the seizure focus and helped in the discrimination of the medial TLE from the lateral TLE. We suggest the lateral TLE, rather than the medial TLE, should be considered when glucose metabolism is relatively preserved in the medial temporal structures.

Intracranial ganglioglioma: preoperative characteristics and oncologic outcome after surgery

In order to investigate the clinical characteristics, neuroimaging findings, pathological features, treatment, and outcomes, and to provide valuable guidance for the diagnosis and management of intracranial gangliogliomas, 34 cases of intracranial gangliogliomas were retrospectively analyzed. This study included 23 males and 11 females. Age at operation ranged from 17 days to 50 years. All patients had preoperative magnetic resonance imaging (MRI). Computed tomography (CT), magnetic resonance spectroscopy (MRS), 18F-FDG-PET (positron emission tomography), and 99Tc-HMPAO-SPECT (single photon emission computed tomography) were also performed in some cases. All pathological specimens and all available neuroimages were re-evaluated. The follow-up period varied from 12 to 89 months (mean 36 months). Seizure was the most common presenting symptom (85%). Tumor calcification was detected by CT scan in six of 11 cases. Seventeen gangliogliomas (50%) showed cystic components and 18 tumors (53%) were enhanced on MRI. All temporal lobe gangliogliomas were located intracortically and most of them had poor demarcation on MRI. In comparison with the contralateral normal area, the gangliogliomas showed a reduced Cho/Cr and NAA/Cr ratio, and an increased Cho/NAA ratio. On 18F-FDG-PET, gangliogliomas were usually hypometabolic. HMPAO-SPECT indicated tumor hypoperfusion or isoperfusion. A gross total resection was achieved in 25 patients. Tumor progression was observed in three patients who underwent an incomplete tumor resection. Two of them underwent a malignant transformation to a glioblastoma. Twenty-seven patients could carry on their normal life activity with the Karnofsky Performance Scale (KPS) of more than 80. Even though ganglioglioma is a slowly growing benign tumor, which could be demonstrated by magnetic resonance spectroscopy (MRS), PET, and SPECT, there is a chance of malignant transformation, especially in cases of incomplete tumor resection. Gangliogliomas should be resected gross totally, if feasible, to achieve the best long-term outcomes.

Spinal cord hemangioblastoma: surgical strategy and clinical outcome

BACKGROUND AND AIM

The authors present a retrospective analysis of 14 patients treated for spinal cord hemangioblastoma (SCH). This study was conducted to evaluate and compare the difference of functional outcomes associated with the extent of surgical removal of the tumor.

METHODS

Eleven patients were male and three were female, with a mean age of 37.2 years (19-62 years). Pre- and postoperative magnetic resonance imaging was performed in all cases. Preoperative angiography was performed in 11 cases and preoperative embolization in four. The follow-up period ranged from 15 to 161 months (median, 47 months).

RESULTS

Thirteen patients had intramedullary tumor, and the remaining one had an extradural lesion. All patients underwent surgical removal, and total removal (TR) was achieved in 10 cases. In four patients with preoperative embolization, intraoperative bleeding was minimal and TR was possible. In three of four patients without TR, their functional outcomes were aggravated postoperatively. At the last follow-up (15-161 months), eight patients were improved, three were stationary, and three deteriorated. All patients who showed improvements underwent TR. The statistical analysis showed that TR produced a significantly better outcome than incomplete removal (p = 0.015).

CONCLUSION

TR resulted in a better outcome for SCH. Preoperative embolization could be effective in the reduction of intraoperative bleeding and facilitate TR with an improved surgical outcome.

Surgical approach to anterior compression in the upper thoracic spine

OBJECT

The anterior upper thoracic spine (T1-3) is difficult to access because most neurosurgeons are unfamiliar with the anatomy. This study was performed to evaluate the different surgical options by retrospectively analyzing data on operations performed for anterior upper thoracic compression at the authors' institution.

METHODS

Eighteen patients underwent surgery between November 1993 and May 2001. There were eight men and 10 women; their mean age was 55 years (range 28-80 years). All patients presented with pain and/or neurological deficits. The causes of anterior compression were diverse, although metastatic spinal tumor was most common. The approach chosen was primarily dictated by the axial involvement of the lesion. Anterior approaches, mainly the transmanubrium approach, were performed in six and posterior approaches in 12. In all cases except one, in which only an iliac bone graft was placed, instrumentation was used. The mean follow-up period was 11.4 months (range 1-57 months). One postoperative death occurred. Postoperative follow-up imaging studies, especially plain radiography, demonstrated no instrumentation failure. Improvement was shown in eight patients, an aggravation of symptoms in one, and stable clinical status in eight.

CONCLUSIONS

Decompression may be achieved on the anterior side of the upper thoracic spine if the operative approach is scrupulously chosen; this choice involves consideration of the locations of the lesion, the nature of the primary disease, and the surgery-related risk.

(18)F-FDG PET in localization of frontal lobe epilepsy: comparison of visual and SPM analysis

The sensitivity of (18)F-FDG PET to localize epileptogenic zones in frontal lobe epilepsy was evaluated by both visual assessment and statistical parametric mapping (SPM).

METHODS

Twenty-nine patients with frontal lobe epilepsy were examined. All patients showed good outcome after surgical resection (Engel class I or II). On pathologic examination, 22 patients had cortical dysplasia, 4 had tumors, 1 had cortical scars, and 2 had an old infarct. Hypometabolic lesions were found on (18)F-FDG PET images by both visual assessment and SPM analysis. On SPM analysis, the cutoff threshold was varied and sensitivity to find epileptogenic zones was compared.

RESULTS

MRI showed structural lesions in 15 patients and normal findings in 14. (18)F-FDG PET correctly localized the epileptogenic zones in 16 patients (55%) by visual assessment. The sensitivity of (18)F-FDG PET was 36% in patients without structural lesions on MRI and 73% in patients with structural lesions. On SPM analysis, using an uncorrected probability value of 0.005 as the threshold, the sensitivity of SPM analysis was 66%, which was not statistically different from the sensitivity of visual assessment. The sensitivity decreased according to the decrease in probability value.

CONCLUSION

(18)F-FDG PET was sensitive in localizing epileptogenic zones by revealing hypometabolic areas in nonlesional patients with frontal lobe epilepsy as well as in lesional patients. SPM analysis showed a comparable sensitivity to visual assessment and could be used as an aid in diagnosing epileptogenic zones in frontal lobe epilepsy.

Photoreceptor inner segments in monkey and human retina: mitochondrial density, optics, and regional variation

The present work quantifies aspects of photoreceptor structure related to mitochondria, inner segment dimensions, and optical properties, as a basis for furthering our understanding of rod and cone function. Electron-microscopic analyses were performed on the retina of one stumptail macaque (Macaca arctoides) to obtain stereological measurements of ellipsoid mitochondrial density, and sizes and shapes of outer and inner segments. In addition, the distribution of mitochondria and the optical properties of human foveal cones were examined with electron microscopy and Nomarski differential interference contrast (NDIC) imaging. Mitochondria comprised 74-85% of cone ellipsoids and 54-66% of rod ellipsoids in macaque. Ellipsoid volume increased with eccentricity by 2.4-fold for rods and more than 6-fold for cones over eccentricities to 12.75 mm, while the volume of the outer segment supported by the ellipsoid was essentially constant for both rods and cones. Per unit volume of outer segment, cones contained ten times as much mitochondria as rods. In human fovea, as in the rest of the retina, most cone mitochondria were located in the distal inner segment. In the foveal center, however, there are also mitochondria in the myoid, as well as in the outer fiber, proximal to the external limiting membrane (ELM). Analyses of the optical aperture of human foveal cones, the point at which their refractive index clearly differs from the extrareceptoral space, showed that it correlated well with the location of mitochondria, except in the foveal center, where the aperture appeared proximal to the ELM. While mitochondria have an important metabolic function, we suggest that the striking differences between rods and cones in mitochondrial content are unlikely to be determined by metabolic demand alone. The numerous cone mitochondria may enhance the waveguide properties of cones, particularly in the periphery.

Multifocal primary CNS T cell lymphoma of the spinal cord

The majority of primary central nervous system lymphomas (PCNSL) are of B cell origin, and those of T cell origin are a distinct rarity. Furthermore, spinal cord involvement of T cell PCNSL is extremely rare and only a small number of cases have been reported. The authors report a case of multifocal T cell PCNSL mainly involving the intramedullary (IM) portion ofthe spinal cord in a 57-year-old woman. Neurological examination showed right leg weakness and hypesthesia below the T10 level. Magnetic resonance images revealed multiple well enhancing masses in the IM portion ofthe cervical and thoracic spinal cord and the cerebellum. Cytological examination of the cerebrospinal fluid revealed no malignant cells. As the mass at the C7 level was the largest among multiple masses, open biopsy was performed at that level. Histopathological examination confirmed malignant peripheral T cell lymphoma, unspecified (PTCL-U), small- and medium-sized cell type. Clinical and laboratory investigations failed to reveal any evidence of lymphomatous deposits elsewhere in the body. After biopsy, the patient received cranio-spinal irradiation, which included the whole brain and the spinal neuraxis. The clinical course, pathological findings and treatments are discussed and a review of the literature included.

Surgical outcome and prognostic factors of spinal intramedullary ependymomas in adults

The goal of treatment for spinal ependymoma is complete removal with minimal postoperative neurological deficit. The authors correlated the results of surgical management for spinal cord ependymoma with the rate of postoperative disease progression and the prognostic factors. Thirty-one cases of spinal ependymomas, surgically treated between 1979 and 1998, were retrospectively analyzed. The authors reviewed clinical features, radiological characteristics and operative findings for the surgical outcome analysis. Thirty-five percent of patients with preoperative Nurick's grade better than grade 4 showed improvement in functional status, whereas no improvement was observed in patients with preoperatively poorer functional status (P = 0.05). The proportion of complete surgical removals was influenced by tumor location (40% in cases around the conus versus 97% in other regions, P = 0.003) and histology (42% in the myxopapillary subtype versus 97% in the non-myxopapillary subtype, P = 0.001). Disease progression was observed in six cases, the mean progression free interval after surgical removal was 83 months and the 5-year progression free rate was 70%. Disease progression was found in two out of 23 cases from the complete removal group and in four out of eight cases from the incomplete removal group (P = 0.008). In the aspect of disease progression, the only statistically significant factor by multivariate analysis was the surgical extent of removal (P = 0.010). Of those patients where there was incomplete removal, radiation therapy lead to improved clinical results, which were not statistically significant (P = 0.27). In the surgical treatment of spinal cord ependymoma, preoperative functional status and the extent of removal were the significant prognostic factors influencing postoperative outcome. Early diagnosis is vital and complete removal of the tumor should be attempted in all surgical treatment of spinal ependymoma.

Supratentorial ganglioglioma and epilepsy: postoperative seizure outcome

Ganglioglioma is increasingly recognized as being a cause of epilepsy. However, controversy still exists regarding the type of surgery required for optimal seizure control. To find out the factors associated with seizure outcome and to clarify treatment guidelines, a retrospective analysis of 29 epileptic patients who had pathologically proven gangliogliomas that were operated on at our institute during a 13-year period, was performed. There were 23 temporal and six extratemporal gangliogliomas, with a mean age of 16.5 years at surgery. Epilepsy was medically intractable in 14 (48.3%) patients. There were 26 temporal and six extratemporal resections including three re-operations. Three patients underwent intracranial electroencephalography (EEG) recordings (invasive monitoring). Intraoperative electrocorticography (ECoG) was performed in four patients. The mean duration of follow-up after surgery was 36.5 months. The Fisher's Exact test (two-tailed) was used to assess the association between the seizure outcome and several preoperative and operative parameters. Surgical treatment rendered most patients (75.9%, 22/29) seizure free. All three patients who underwent re-operation were seizure-free postoperatively. Eleven (47.8%) of the 23 temporal lobe gangliogliomas were associated with cortical dysplasia. Postoperative incomplete seizure control was associated with the presence of cortical dysplasia (p < 0.001). Good seizure outcome is expected in patients with gangliogliomas, despite years of medically intractable epilepsy, once the tumor is resected. Invasive monitoring/intraoperative electrocorticography is recommended for patients with suspected cortical dysplasia on MRI or for the patients with persistent epilepsy after ganglioglioma resection.

Diagnostic performance of [18F]FDG-PET and ictal [99mTc]-HMPAO SPECT in occipital lobe epilepsy

PURPOSE

We investigated whether interictal F-18 fluorodeoxyglucose positron emission tomography ([18F]FDG-PET) or ictal [99mTc]-HMPAO single-photon emission computed tomography (SPECT) was useful to find epileptogenic zones in occipital lobe epilepsy (OLE).

METHODS

We reviewed visually and quantified patterns of hypometabolism in interictal [18F]FDG-PET and those of hyperperfusion in ictal SPECT in 17 OLE patients (27 plus minus 6.8 years old; M/F, 10/7; injection time, 30 plus minus 17 s). OLE was diagnosed based on invasive electroencephalography, surgery, and postsurgical outcome (Engel class I in all at an average of 26 months after surgery).

RESULTS

Epileptogenic zones were correctly localized in nine (60%) of 15 patients by interictal [18F]FDG-PET, and asymmetric indices corroborated visual diagnosis. Epileptogenic hemispheres were correctly lateralized in 14 (93%) of 15 patients on [18F]FDG-PET. Epileptogenic hemispheres were correctly lateralized in 13 (76%) of 17 patients using ictal SPECT, but localization was possible in only five (29%) patients. Interictal [18F]FDG-PET was helpful in two of the patients who showed no abnormality on magnetic resonance imaging (MRI) and no possible localization with ictal SPECT.

CONCLUSIONS

In OLE, ictal SPECT was helpful in lateralization, but less helpful in localization. Interictal [18F]FDG-PET was helpful in localization or lateralization of epileptogenic zones, even in patients with ambiguous MRI or ictal SPECT findings.

Neuroimaging findings of cortical dyslamination with cytomegaly

PURPOSE

Our aims were to identify (a) the characteristic magnetic resonance imaging (MRI) findings of cortical dyslamination with cytomegaly, including dysplastic and destructive lesions; (b) the relationship between MRI findings and pathologic characteristics; (c) the diagnostic role of functional neuroimaging studies in patients with these pathologies.

METHODS

The series consisted of 23 adult patients who had proven cortical dyslamination with cytomegaly. The abnormalities found on MRI were subdivided according to the patterns of involvement. They also were compared with the patients' pathologic characteristics. With visual qualitative analysis, [18F]fluorodeoxyglucose with positron emission tomography (FDG-PET), and ictal single-photon emission computed tomography (SPECT), observations were classified as localizing, lateralizing, nonlateralizing, false-localizing, and false-lateralizing. The standard for correct localization of neuroimages was defined to be the resected lobe.

RESULTS

Focal abnormalities were found in 14 cases by MRI. Six cases showed typical MRI findings of focal cortical dysplasia, with focal areas of cortical thickening with or without poor grey-white matter differentiation. Focal subcortical high signal intensities on T2-weighted images occurred in two cases. Six patients had the focal destructive pattern. Three of eight cases with normal MRI and four of eight cases with the nondestructive cortical dysplasia pattern had balloon cells. However, these were not found in six patients with the destructive MRI pattern. FDG-PET localized the pathologic lobe in 13 (65%) of 20 cases, and ictal SPECT achieved this in 11 (61.1%) of 18 cases. FDG-PET and ictal SPECT also correctly localized the pathologic lobe in four and two cases with normal MRI, respectively.

CONCLUSIONS

Two distinct patterns of abnormal MRI were found in the pathology of cortical dyslamination with cytomegaly. These dysplastic and destructive patterns might reflect different pathogeneses, such as the time of insult. FDG-PET and ictal SPECT have confirmatory and independent diagnostic roles in localizing epileptogenic foci.

Surgical treatment for thoracic spinal stenosis

OBJECTIVES

To describe the underlying causes, surgical results and prognostic factors in thoracic stenosis causing myelopathy.

METHODS

The underlying causes and surgical results were analyzed retrospectively in 28 cases of thoracic spinal stenosis which caused myelopathy. Degenerative spondylosis was the most common cause, and three cases were associated with systemic diseases. Decompressive laminectomy was performed in 24 cases, anterior decompression in five cases, and combined decompression in one case. Ossification of ligamentum flavum was found in 18 cases, facet hypertrophy in 13, ossification of posterior longitudinal ligament in six, and ventral spur in four. Postoperatively 16 patients improved and four patients worsened. Follow-up ranged from 2 months to 5 years and 8 months). Statistical analysis was performed using a chi(2) test to investigate the relationship between subjects. Multivariant analysis (general linear model) was used to determine the factors which influence surgical outcome.

RESULTS

There were neurological improvements in 16 patients, in whom Nurick grade changed from 3.3 preoperatively to 1.8 postoperatively. Eight patients showed no significant change in functional grade and four patients deteriorated after decompressive laminectomy. The group of which initial symptom duration was less than 2 years showed better results (P=0.006). The group with sufficient decompression and no additional proximal stenosis had better treatment outcome (P=0.005, P=0.002).

CONCLUSION

Chronic severe myelopathy caused by thoracic spinal stenosis can be reversible with appropriate decompression. Surgical outcome was dependent on initial symptom duration, sufficient decompression and presence of additional proximal stenosis.

SPONSORSHIP

This study was supported by a grant No. 02-1997-071-0 from the Seoul National University Hospital Research Fund.

Comparative analysis of MR imaging, positron emission tomography, and ictal single-photon emission CT in patients with neocortical epilepsy

BACKGROUND AND PURPOSE

MR imaging, positron emission tomography (PET), and single-photon emission CT (SPECT) play important roles in presurgical localization of epileptic foci. However, comparative study of these imaging methods for cases of neocortical epilepsy has been limited. The purpose of this study was to compare the sensitivities of these three imaging methods for presurgical localization of neocortical epileptogenic foci.

METHODS

We studied 117 consecutive patients who underwent surgery for intractable neocortical epilepsy. The pathologic substrates were neuronal migration disorder (n = 77), tumor (n = 15), and others (n = 25). MR imaging was compared retrospectively with (18)F-fluorodeoxyglucose PET and ictal technetium-99m hexamethylpropyleneamine oxime SPECT regarding their capability to correctly localize the epileptogenic foci. The pathologic findings were used as the standard of reference.

RESULTS

Overall, MR imaging, PET, and ictal SPECT correctly localized the lesions for 59.8%, 77.7%, and 70.3% of the patients, respectively, with a 38% concordance rate among the three methods. PET was most sensitive (71-100%) in detecting all substrates. MR imaging was as sensitive (100%) as PET in detecting tumor but was least sensitive (48.1%) in detecting neuronal migration disorder. Ictal SPECT was more sensitive (75.8%) than MR imaging in detecting neuronal migration disorder. Patients with imaging abnormalities achieved good outcomes in 81.4% of the cases, in contrast to 59.5% for those without imaging abnormalities (P <.05).

CONCLUSION

PET and ictal SPECT were overall more sensitive than was MR imaging, despite the low concordance rate and variable sensitivity depending on substrates. The detection of abnormalities by MR imaging was associated with good outcome. PET or ictal SPECT can be well used as complementary tools, particularly in cases of negative MR imaging findings.

Lateralizing ability of single-voxel proton mr spectroscopy in hippocampal sclerosis: comparison with mr imaging and positron emission tomography

BACKGROUND AND PURPOSE

Proton MR spectroscopy (MRS) is still in the early stages in the evaluation of epilepsy, and comparisons with MR imaging and positron emission tomography (PET) in the same patients have rarely been documented. The purpose of this study was to evaluate the lateralizing ability of single-voxel MRS in comparison with MR imaging and PET in patients with hippocampal sclerosis.

METHODS

Thirty-three patients with intractable temporal lobe epilepsy whose MR imaging diagnosis was unilateral hippocampal sclerosis and who underwent anterior temporal lobectomy and had good postsurgical outcome over 1-year follow-up were included in the study. MR spectra were obtained from the hippocampus bilaterally, using the point-resolved spectroscopy sequence. Metabolite ratios of NAA/Cho and NAA/Cr were calculated from the relative peak height measurements. An NAA/Cho ratio of 0.8 or less and an NAA/Cr ratio of 1.0 or less were regarded as abnormal. The MRS results were compared retrospectively with those of MR imaging and PET as to the ability to lateralize the epileptogenic focus.

RESULTS

The sensitivity of MRS and PET (concordance with MR imaging) was 85% each in the lateralization of the ipsilateral lesion side. Bilateral abnormalities were seen in 30% of the patients. False-lateralization rates for MRS and PET were 3% and 6%, respectively. The concordance rate of MRS and PET was 73%, when comparing the results of the ipsilateral lesion side.

CONCLUSION

MRS may be used as an adjunct tool in the evaluation of hippocampal sclerosis, like PET, although its sensitivity has to be improved and the clinical significance of bilateral abnormality is still to be determined.

Intramedullary spinal cord astrocytoma in adults: postoperative outcome

Intramedullary spinal cord astrocytomas are relatively rare and usually low-grade lesions with a long natural history. The rarity of the condition and its indolent clinical course has made the evaluation of treatment efficacy difficult. To clarify postoperative outcome and prognostic factors, we performed a retrospective analysis of intramedullary spinal cord astrocytomas in a single institute. Twenty-eight patients were surgically treated between 1978 and 1999; of median age 36 years (range, 19-68 years); nineteen patients were males and nine females. All patients presented with pain and neurological deficits. The cervical cord was involved in fifteen patients, cervico-thoracic in five, thoracic in six and thoraco-lumbar in two. Gross total removal was performed in three patients, subtotal removal in six, partial removal in fourteen and biopsy only in five. Nineteen patients received radiation therapy postoperatively. The mean follow-up period was 31.9 months (range, 0.5-184 months). Low-grade astrocytomas were found in 18 cases, anaplastic astrocytoma in three cases and glioblastomas in seven cases. The median survivals of patients with low- and high-grade astrocytoma were 184 months and 8 months, respectively (p < 0.05). The median survivals of irradiated and non-irradiated patients with low-grade astrocytoma were 184 months and 102 months. Neither the extent of resection, nor radiation influenced the survival rate. In summary, the histological grade was the most significant predictor of survival in patients with astrocytoma of the spinal cord.

Incidence and clinical profile of extra-medial-temporal epilepsy with hippocampal atrophy

We tried to investigate the incidence and the clinical profile of intractable epilepsy with hippocampal atrophy and ictal onset zones located in areas other than the hippocampus (extra-medial-temporal epilepsy; EMTE). We included patients who had hippocampal atrophy confirmed by MRI but with extra-medial-temporal ictal onset zones as verified by invasive intracranial electrodes or video-EEG monitoring. The case histories, interictal EEG, ictal semiology, other MRI findings in addition to hippocampal atrophy, and results of ictal SPECT and PET scans were evaluated. Results were compared with those of surgically proven medial temporal lobe epilepsy with hippocampal atrophy recruited during the same period. 8.5% of the intractable epilepsy patients with hippocampal atrophy had extra-medial temporal epileptogenic zones. A history of encephalitis and hemiconvulsion-hemiparesis were significantly common in the EMTE group. Most of the interictal EEGs of EMTE patients showed extratemporal irritative zones. MRI, ictal SPECT, and FDG-PET seemed to be helpful at localizing the true epileptogenic zones. The predominant EMTE seizure type was focal motor seizure with secondary generalization. Some portion of intractable epilepsy patients with hippocampal atrophy had extra-medial-temporal epileptogenic foci and careful analysis of semiology and neuroimagings could yield clues to correct diagnosis.

Cerebral dissection from syringomyelia demonstrated using cine magnetic resonance imaging. Case report

A 16-year-old boy presented at the authors' emergency department with a sudden deterioration of respiration. He had been paraparetic for 3 years and had become quadriplegic 2 days previously. Magnetic resonance images revealed a Chiari I malformation and a hydromyelic cavity extending from C-1 to T-11. Rostrally, a small cylindrically shaped lesion extended from the cervicomedullary junction to the left semioval center. The patient made a dramatic neurological recovery following suboccipital craniectomy and upper cervical laminectomies with augmentation duraplasties followed by placement of a syringoperitoneal shunt.

Analysis of radiation workers' dose records in the Korean National Dose Registry

Data are presented on the externally received personal dose equivalent for radiation workers who used the Korea Radioisotope Association's personal monitoring and dose record keeping service since 1984, and provide initial statistics on Korean workers who have been exposed to ionising radiation in different occupations. The total number of workers registered during the period of 1984 to 1999 was 64,518. The number increased steadily and the accumulated dose also increased. The proportion of radiation workers by occupation was 38.4% for nuclear power plants, 20.3% for industrial organisations and 12.4% for non-destructive industry. The annual collective dose of radiation workers was 31.72 man.Sv in 1999. The mean annual dose by sex was 1.49 mSv for males and 0.56 mSv for females and the mean annual dose for a worker was 1.41 mSv with the highest mean dose being received by non-destructive industry (3.53 mSv). Very few workers (0.8%) received more than 20 mSv (2 rem) and only one more than 50 mSv, the legal limit for an annual dose increase. There has been a steady decline in the mean dose since 1984, showing a significant decrease in dose with time (p<0.001). The data showed that radiation protection in Korea was improving, though annual doses were still higher than other countries.

The clinical usefulness of ictal surface EEG in neocortical epilepsy

PURPOSE

Localizable scalp EEGs, during ictal episodes, appear to be rare in neocortical epileptic syndromes. However, studies based on large numbers of patients are also rare. This study aims to identify the characteristic patterns of variable neocortical epilepsies and to evaluate their clinical usefulness in the localization of epileptogenic focuses.

METHODS

We retrospectively assessed 394 noninvasive ictal recordings from 86 patients who subsequently underwent invasive study and resective surgery. Ictal EEGs were recorded using a video-EEG monitoring system with electrodes placed according to the International 10-20 system, with additional anterior temporal electrodes. The ictal recordings were analyzed according to localizing accuracy and frequency characteristics. The durations of discrete or regional ictal rhythms were also measured.

RESULTS

The percentage of discrete or regional EEGs was 23% in frontal lobe epilepsy, 52% in lateral temporal lobe epilepsy, 70% in occipital lobe epilepsy, and 10% in parietal lobe epilepsy. In order of frequency, the localizable ictal rhythms were theta, beta, alpha, delta, and rhythmic spike-and-wave. The duration of discrete or regional ictal rhythms was significantly shorter in frontal lobe epilepsy and parietal lobe epilepsy than in other epilepsies. Ictal beta activity was the most common rhythm in discrete-patterned EEGs. Structural lesions found on MRI did not significantly affect the localization of epileptogenic focuses in the patients. The type of seizure was not related to the degree of localization, with the exception of simple partial seizure.

CONCLUSIONS

Ictal surface EEG was clinically helpful in the localization of epileptogenic focuses in at least some neocortical epileptic syndromes.

Intramedullary spinal cord ganglioglioma: a report of five cases

We report five cases of ganglioglioma in various locations. The tumours were removed with gross total resection in most cases without any further neurological deterioration. Without any additional treatment, no evidence of recurrence or regrowth of tumours was observed in the mean follow-up period of 4.1 years. We suggest that intramedullary spinal cord gangliogliomas be resected totally due to the high risk of recurrence and regrowth rate of the tumours with subtotal resection in the long term considering especially that these tumours affect predominantly young patients.

Inhibitory effect of sodium salicylate on nitric oxide production from TM4 sertoli cells

Nitric oxide (NO) has been proposed to play a role in a variety of inflammatory diseases. Sodium salicylate (NaSal) is the most commonly used anti-inflammatory agent. We investigated whether NaSal can diminish the production of NO in TM4 Sertoli cells. TM4 Sertoli cells produced a small amount of NO upon treatment with recombinant interferon-gamma (rIFN-gamma). The effect of rIFN-gamma was enhanced markedly by the addition of recombinant TNF-alpha (rTNF-alpha) in a dose-dependent manner. NaSal (10 and 20 mM) significantly inhibited NO production from TM4 Sertoli cells induced by rIFN-gamma plus rTNF-alpha. In addition, rIFN-gamma in combination with rTNF-alpha showed a marked increase of the expression of inducible NO synthase (iNOS) protein. Western blot analysis revealed that NaSal (10 and 20 mM) blocked a step of iNOS protein synthesis. The rIFN-gamma plus rTNF-alpha-induced nuclear factor-kappaB (NF-kappaB) activation was significantly blocked by NaSal (10 and 20 mM). On the other hand, neither staurosporine nor polymyxin B significantly inhibited NO production from TM4 Sertoli cells induced by rIFN-gamma plus rTNF-alpha. The present results indicate that NaSal inhibits rIFN-gamma plus rTNF-alpha-induced NO production in TM4 Sertoli cells via the signal transduction pathway of NF-kappaB activation.

The lateralizing and surgical prognostic value of a single 2-hour EEG in mesial TLE

We investigated 109 patients who received anterior temporal lobectomy for intractable mTLE by post-operative follow-up for at least 11/2 years. We reviewed pre-operative 2-hour interictal EEGs, counted interictal epileptiform discharges (IEDs), and compared the lateralization of IEDs with the side of surgery and surgical outcome. Twenty of 22 patients who had no spikes and 44 of 51 who had unitemporal spikes became seizure free after surgical resection. The correct lateralization of the epileptogenic side was possible in 90. 9% of the patients with unitemporal IEDs. In 12 seizure-free patients of 15 patients with less than 70% predominance of IED in one temporal lobe, the positive predictive value of the lateralization was 41.7%. In 16 seizure-free patients of 21 with more than 70% preponderance of IED in one lobe, the positive predictive value was 81.3%. Surgical outcome of patients with unitemporal and bitemporal IEDs were not significantly different. Interictal scalp EEG can be used as a lateralizing tool in mTLE when the temporal IEDs appear with more than 70% preponderance in one side. Although the presence of bitemporal IEDs often causes confusion in terms of the correct lateralization, it does not affect the surgical outcome.

Intradural extramedullary tuberculoma of the spinal cord: a case report

Intradural extramedullary (IDEM) tuberculoma of the spinal cord is uncommon entity and moreover, few reports have been documented on concurrent IDEM and intracranial tuberculomas. Authors report a case of IDEM spinal tuberculoma having intracranial lesion simultaneously. A 49-year-old woman suffered from paraparesis and urinary incontinence while being given medical treatment for tuberculous meningitis. Magnetic resonance imaging (MRI) revealed an IDEM mass lesion between the T1 and T2 spinal levels, and multiple intracranial tuberculous granulomas. Surgical resection of the IDEM tuberculoma followed by anti-tuberculous medication resulted in good outcome.