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To investigate the diagnostic capability of anterior temporal lobe white matter abnormal signal (ATLAS) for determining seizure focus laterality in temporal lobe epilepsy (TLE) by comparing different MR sequences. This prospective study was approved by the institutional review board and written informed consent was obtained. Three 3D sequences (double inversion recovery (DIR), fluid-attenuated inversion recovery (FLAIR) and T2-weighted imaging (T2WI)) and two 2D sequences (FLAIR and T2WI) were acquired at 3 T. Signal changes in the anterior temporal white matter of 21 normal volunteers were evaluated. ATLAS laterality was evaluated in 21 TLE patients. Agreement of independent evaluations by two neuroradiologists was assessed using κ statistics. Differences in concordance between ATLAS laterality and clinically defined seizure focus laterality were analysed using McNemar’s test with multiple comparisons. Pre-amygdala high signals (PAHS) were detected in all volunteers only on 3D-DIR. Inter-evaluator agreement was moderate to almost perfect for each sequence. Correct diagnosis of seizure laterality was significantly more frequent on 3D-DIR than on any other sequences (P ≤ 0.031 for each evaluator). The most sensitive sequence for detecting ATLAS laterality was 3D-DIR. ATLAS laterality on 3D-DIR can be a good indicator for determining seizure focus localization in TLE. • Magnetic resonance imaging is widely used to investigate temporal lobe epilepsy. • Numerous MR sequences can show anterior temporal lobe white matter abnormal signal. • ATLAS on 3D-DIR can frequently indicate seizure focus laterality in TLE. • 3D-DIR is more sensitive about ATLAS laterality than T2WI or FLAIR.

It is the cortices and the cortico-cortical connections that are involved in manifestation of normal cortical functions as well as production of seizure symptoms. In this sense, presurgical evaluation of patients with intractable partial epilepsy helps us delineate cortical functions and networks at the individual level. In return, the advancement of clinical system neuroscience brought us better understanding and evaluation of clinical epileptology as follows. Electrical cortical stimulation in epilepsy surgery can delineate the cortex responsible for a particular task by making transient focal functional impairment, which is in sharp contrast to chronic stroke lesions that are relatively large and usually associated with cortical plastic compensation. For example, this gold-standard mapping method recently demonstrated the presence of anterior ventral language pathway by revealing active engagement of the anterior part of the superior temporal gyrus in speech perception. Cortico-cortical evoked potential (CCEP) is a new in vivo electrical tract tracing method for presurgical evaluation. It promises to refine our understanding of surgical candidacy, first through a more precise and tailored evaluation of the seizure network in each individual patient, and second through greater understanding of the functional systems of the brain involved, such as language, praxis and cognitive motor control.

Objective To describe a simple technique for preoperative surface localization of intracranial lesions. Methods 11 pills in total, including Alfarol (alfacalcidol) capsules, were affixed to a phantom with adhesive tape and a MRI scan was performed. The visibility of the pills and any spatial errors in determining their locations were evaluated. Between June 2006 and April 2009, we employed Alfarol capsules as a skin marker in MRI in clinical surgical cases. Results Alfarol capsules, whose actual size is 5.6 mm in diameter, were identified as a hyperintense spot at a size of 4.2, 4.2, and 4.5 mm in diameter in T1-weighted, T2-weighted, and FLAIR (fluid attenuated inversion recovery) sequence images, respectively. The size discrepancies were within 1.4 mm. The average spatial errors were 0.7, 0.6, and 0.7 mm in T1-weighted, T2-weighted, and FLAIR sequence images, respectively. Other pills were not identified in the MRI scans. During this 35-month period, 8 patients underwent preoperative MRI-guided localization at our institution. There were 5 men and 3 women in whom 8 biopsies were performed. In all cases, the result of the biopsy was positive and useful for the treatment that followed. No perioperative complications were encountered. Conclusion Alfarol capsule can be used as an external skin marker. Our simple and inexpensive method is a useful addition to preoperative evaluation of superficial intracranial lesions.

Cervical carotid artery aneurysms are rare and sometimes induce not only hemorrhage but also ischemic stroke. Various surgical treatments are reported to prevent hemorrhage and stroke. We report the result of endovascular therapies for 4 patients who had large or giant cervical carotid artery aneurysms. Endovascular therapies were performed for 4 patients and 5 aneurysms, from January 2003 to October 2007. One patient had external carotid artery aneurysm and the other 3 patients had common or internal carotid artery aneurysms. One patient had 2 cervical carotid artery aneurysms. Case 1 had an external carotid artery aneurysm and underwent parent artery occlusion (PAO); the aneurysm was occluded without any event. Case 2 had an internal carotid artery (ICA) aneurysm and also underwent PAO, but the internal carotid artery showed recanalization 2 days later on magnetic resonance image. Therefore, we added endovascular coil embolization and occluded the aneurysm completely. Case 3 had 1 aneurysm and Case 4 had 2 aneurysms on the common carotid artery (CCA) to ICA. Bare metal stents were deployed, followed by endovascular embolization for 2 aneurysms. One aneurysm in Case 4 on which only stenting was performed completely occluded 1 year after procedure. On 2 aneurysms combined stenting and coil embolization were performed. One was completely occluded, and the other had a tiny flow into the aneurysm, only confirmd by cervical ultrasound examination. No procedural complication or neurological symptoms and signs were recognized during these endovascular procedure. Endovascular therapy was effective and safe for the cervical carotid artery areurysms. However, the aneurysm sometimes became recanalized, and it is important to treat the recurrent aneurysm.

Introduction The negative motor area (NMA) is defined as a cortical area where 50 Hz electrical cortical stimulation produces inhibition of the voluntary movement such as finger tapping. The function of NMA has not been well delineated since previous 50 Hz stimulation studies mainly focused on the all or none response, namely, arrest of finger tapping at high current intensity. We hypothesized that NMA plays a role in higher motor behavior such as praxic movements. Our objective was to clarify the praxis-related function of NMA by applying stimulation at smaller intensity to evaluate the effect of stimulation. Methods Subjects were 5 patients with intractable focal epilepsy who underwent implantation of intracranial electrodes in the inferior frontal area for presurgical evaluation (IRB#C1062). After defining NMA with 50 Hz stimulation at high intensity for clinical purpose, stimulation was delivered at the intensity 1–3 mA smaller than that of clinical mapping in the following tasks: finger tapping, reach-to-grasp task, imitation of meaningless finger gesture, and pantomime of tool-use. The stroke of finger tapping, and the maximum aperture and reaching velocity in reach-to-grasp tasks are evaluated quantitatively with 3D motion capture system. Finger gesture and tool-use pantomime were evaluated qualitatively because of technical difficulty in applying the motion capture system. Results NMA was identified in the precentral gyrus in 3 patients, the ventral premotor area in 1 and at their border in 1. In 3 patients with precentral NMA, quantitative analysis revealed the significant decrease of stroke in finger tapping and maximum aperture in grasping, while the reaching velocity did not change significantly. Qualitative analysis showed mild slowing of finger gesture in 1 out of 3 patients but did not change the performance of tool-use pantomime. In the more rostral NMA (in the ventral premotor area and at the border), quantitative analysis also showed the significant decrease of stroke and aperture in finger tapping and grasping, respectively. In addition, reaching velocity was significantly decreased. Qualitative analysis showed either mild slowing (at the border) or arrest of finger gesture (ventral premotor area), and arrest of tool-use pantomime in 1 out of 2 patients (ventral premotor area). Conclusion Precentral NMA seems to play a more role in controlling elementary finger movements than praxic movements, and, when impaired, could be responsible for limb-kinetic apraxia. More rostral NMA is likely associated with more complex movements. These findings suggested functional subdivisions within NMA and may help understand the disability after focal resection of NMA.

A 56-year-old woman with adult idiopathic thrombocytopenic purpura (ITP) diagnosed 17 years previously presented with a fusiform aneurysm manifesting as chronic headache. She had suffered no major hemorrhagic complications, although her platelet counts were between 3.0 × 109/l and 50.0 × 109/l. Magnetic resonance angiography identified a fusiform aneurysm of the right vertebral artery. Endovascular trapping after high-dose gammaglobulin with steroid therapy was performed. The patient received antiplatelet therapy to prevent thromboembolic events. The parent artery and aneurysm were completely occluded with no hemorrhagic complications. Endovascular treatment is considered safe in patients with ITP, although careful periprocedural management of platelet count is required.

In many cases, the prognosis for acute cervical carotid artery occlusion is poor. However, a standard treatment for the acute stage is not yet established. We report here the results of eight consecutive patients (mean age 71.5 years old) in which revascularization mainly by suction thrombectomy was performed under proximal protection during the acute phase. The occlusion sites were the intracranial internal carotid artery in five patients, tandem lesions of the internal carotid origin and intracranial vessel in two patients, and the common carotid artery in one patient. In addition, the subjects who received the treatment had an extent of infarction in MRI/DWI that was 1/3 or less of the internal carotid artery territory. The mean time from the onset to treatment commencement was 7.25 hours (2–28 hours). For the endovascular treatment, a guiding catheter with a balloon was used for proximal protection of the carotid artery. Revascularization was performed mainly by suction thrombectomy, and if a stenosed lesion was observed, PTA/stenting was added. Local fibrinolysis was not performed in combination with the above procedure. The treatment results were complete recanalization in three patients and partial recanalization in three patients. However, recanalization was not achieved in two patients. No hyperfusion syndrome or hemorrhagic infarction was observed postoperatively. All four patients in whom thrombi were successfully aspirated had occlusions proximal to the ophthalmic artery branch. In three of these four patients, complete recanalization was achieved. The revascularization procedure using suction thrombectomy under proximal protection was considered effective against the acute cervical carotid occlusions, in particular, those proximal to the ophthalmic artery branch.

Preoperative glioma grading is important for therapeutic strategies and influences prognosis. Intratumoral heterogeneity can cause an underestimation of grading because of the sampling error in biopsies. We developed a voxel-based unsupervised clustering method with multiple magnetic resonance imaging (MRI)-derived features using a self-organizing map followed by K-means. This method produced novel magnetic resonance-based clustered images (MRcIs) that enabled the visualization of glioma grades in 36 patients. The 12-class MRcIs revealed the highest classification performance for the prediction of glioma grading (area under the receiver operating characteristic curve = 0.928; 95% confidential interval = 0.920–0.936). Furthermore, we also created 12-class MRcIs in four new patients using the previous data from the 36 patients as training data and obtained tissue sections of the classes 11 and 12, which were significantly higher in high-grade gliomas (HGGs) and those of classes 4, 5 and 9, which were not significantly different between HGGs and low-grade gliomas (LGGs), according to a MRcI-based navigational system. The tissues of classes 11 and 12 showed features of malignant glioma, whereas those of classes 4, 5 and 9 showed LGGs without anaplastic features. These results suggest that the proposed voxel-based clustering method provides new insights into preoperative regional glioma grading.

Here, we report three cases of moyamoya disease with a history of Kawasaki disease. A 33-year-old man was found to have stenotic lesions of the internal carotid arteries(ICAs)on both sides at a nearby hospital where he visited complaining of headache and lisping. He had received immunoglobulin therapy for Kawasaki disease at the ages of 1, 2, and 6 years. MRI showed only a chronic ischemic lesion in the white matter. Angiography showed occlusion at the terminal portion of the ICAs on both sides. He was diagnosed with moyamoya disease, but as he had no symptoms and preserved cerebral blood flow (CBF), he was kept under observation. An 8-year-old boy was diagnosed with moyamoya disease and underwent right encephaloduroarteriosynangiosis at a nearby hospital. He had received immunoglobulin therapy for Kawasaki disease at the age of 1 year. His ischemic symptoms worsened. Although MRI detected no apparent ischemic lesion, angiography revealed severe stenosis at the terminal portions of the ICAs on both sides, and 123I-IMP SPECT showed CBF impairment. Bilateral direct bypass was performed. His father was subsequently also diagnosed with moyamoya disease. A 4-year-old girl with epilepsy was diagnosed with moyamoya disease at a nearby hospital. She had been treated with aspirin for Kawasaki disease at the age of 1 year. MRI detected no remarkable ischemic lesions, but angiography revealed mild stenosis at the terminal portions of the ICAs on both sides. Five months later, her ischemic symptoms were worsening with progressing stenotic lesions, and she underwent bilateral direct bypass.

Physiological high frequency activities (HFA) are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections), or different terminal layers (layer IV vs. layer II/III) affect its frequency, we, in the primary somatosensory cortex (SI), compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response) and N80 (late response) of somatosensory evoked potentials (HFA(SEP(N20)) and HFA(SEP(N80))) and compared those overriding N1 and N2 (first and second responses) of cortico-cortical evoked potentials (HFA(CCEP(N1)) and HFA(CCEP(N2))). HFA(SEP(N20)) showed the power peak in the frequency above 200 Hz, while HFA(CCEP(N1)) had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFA(CCEP(N1)) and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions.

There has been a paradigm shift in the understanding of brain function. The intrinsic architecture of neuronal connections forms a key component of the cortical organization in our brain. Many imaging studies, such as noninvasive magnetic resonance imaging (MRI) studies, have now enabled visualization of the white matter fiber tracts interconnecting the functional cortical areas in the living brain. Although such a structural connectome is essential for understanding of cortical function, the anatomical information alone is not sufficient. Practically, few techniques allow the investigation of the excitatory and inhibitory mechanisms of the cortex in vivo in humans. Several attempts have been made to track neuronal connectivity by applying direct electrical stimuli to the brain in order to stimulate subdural and/or depth electrodes and record responses from the functionally connected cortex. In vivo single-pulse electrical stimulation (SPES) and/or cortico-cortical evoked potential (CCEP) were recently introduced to track various brain networks. This article reviews the concepts, significance, methods, mechanisms, limitations, and clinical applications of CCEP in the analysis of these dynamic connections.

Motivation facilitates recovery after neuronal damage, but its mechanism is elusive. It is generally thought that the nucleus accumbens (NAc) regulates motivation-driven effort but is not involved in the direct control of movement. Using causality analysis, we identified the flow of activity from the NAc to the sensorimotor cortex (SMC) during the recovery of dexterous finger movements after spinal cord injury at the cervical level in macaque monkeys. Furthermore, reversible pharmacological inactivation of the NAc during the early recovery period diminished high-frequency oscillatory activity in the SMC, which was accompanied by a transient deficit of amelioration in finger dexterity obtained by rehabilitation. These results demonstrate that during recovery after spinal damage, the NAc up-regulates the high-frequency activity of the SMC and is directly involved in the control of finger movements.

To demonstrate the Bereitschaftspotentials (BPs) over the high lateral convexity in the superior frontal gyrus, movement-related cortical potentials with respect to the middle finger extension were recorded in seven patients with refractory epilepsy who underwent subdural implantation of platinum electrode grids and/or strips covering the high lateral frontal convexity. In two out of the seven patients, BPs were recorded from the electrodes placed on the superior frontal gyrus in the vicinity of the border between the medial and lateral frontal lobes, which were distinct from those recorded from the primary sensorimotor cortex. The results suggest the possible contribution of either the lateral dorsal non-primary motor area or the SMA to the generation of the BPs.

We analyzed ictal motor symptoms in 10 patients diagnosed to have supplementary motor area (SMA) seizures based on ictal encephalographic (EEG) findings and ictal clinical semiology. Inclusion criteria were (1) EEG seizure pattern in the vertex for the scalp recording or in the area over and/or adjacent to SMA for epicortical recording and (2) ictal motor semiology characterized, as previously reported, by sudden and a brief tonic posturing of extremities and trunk mainly occurring during sleep without loss of consciousness. In 50% (5/10) of the patients, tonic posturing began in one part of the body and moved to other part(s) in 5-10s. Unlike Jacksonian march seen in seizures involving the primary sensorimotor area (S1-M1), it spread in no accordance with the somatotopy in S1-M1. The sequential propagation of tonic posturing may represent the somatotopic organization within the SMA proper.

Summary: Purpose: Malformations of cortical development (MCDs) are a frequent cause of refractory epilepsy in humans. The in utero radiation model in rats shares many clinical and histopathologic characteristics with human MCDs. Previous studies reported the presence of clinical seizures in radiated rats, but also suggested a dose-dependent differential effect. Methods: Time-pregnant Sprague–Dawley rats were irradiated on embryonic day E17 with 100 cGy (low dose), 145 cGy (medium dose), 175 cGy (high dose), or were left untreated. Their adult litters were implanted with bifrontal epidural and hippocampal depth electrodes and underwent long-term video-EEG monitoring. After 2 weeks of monitoring, the animals were killed and their brains processed for histological studies. Results: Spikes were most frequently found in the rats that were subjected to low- and medium-dose radiation at E17 and were less frequently seen in the animals that were subjected to high-dose radiation. No interictal spikes were found in any of the control animals. Seizures were recorded in three of five animals of the medium-dose group. Histological studies showed a dose-dependent decrease in cortical thickness as well as an increase of cortical and hippocampal disorganization. Conclusions: In vivo epileptogenicity in radiated animals was present only in mild or moderate MCD. No in vivo epileptogenicity was seen in severe radiation-induced MCD.

In order to clarify the role of the lateral non-primary motor area in the control of voluntary movements, we studied movement-related cortical potentials (MRCPs) by direct epicortical recording from the lateral frontal lobe in nine patients with intractable partial epilepsy as a part of presurgical evaluation. We adopted movement tasks involving different body sites: eye closing, lip pursing, shoulder abduction, middle finger extension, thumb abduction, and foot dorsiflexion. We found that one or two small areas on the caudal lateral convexity of the frontal lobe generated pre-movement potential shifts regardless of the sites of movement (omni-Bereitschaftspotential; "omni-BP"). Such regions were located at or just rostral to the primary motor face area in six subjects, and at or rostral to the primary motor upper extremity area in three. Moreover, half of those areas were identified just adjacent (either rostral or caudal) to the primary negative motor area (PNMA), a cortical area of the lateral frontal lobe where negative motor responses were elicited by electric cortical stimulation. In conclusion, it is suggested that the lateral non-primary motor area plays a significant role, and has a close and direct relationship with other cortical areas in the frontal lobe, just like its counterpart on the mesial frontal cortex (supplementary negative motor area, SNMA).

Background Chordoid glioma of the third ventricle is a rare neuroepithelial tumor characterized by a unique histomorphology within the third ventricular region, but with radiological and histopathological features mimicking benign lesions such as meningioma. We report a case of chordoid glioma of the third ventricle and suggest a useful indicator for accurate diagnosis. Case description A previously healthy 46-year-old woman was admitted to our hospital with mild headache. Neuroimaging revealed a large tumor measuring approximately 18 mm in the suprasellar region, and perifocal edema in the optic tract and internal capsule on magnetic resonance imaging. Laboratory findings revealed no pituitary dysfunction including diabetes insipidus. Gross total resection of the tumor was performed by the interhemispheric translamina terminalis approach. Histological findings revealed nests of regular epithelioid cells with large nuclei and abundant eosinophilic cytoplasm within myxoid stroma. Immunohistochemical studies demonstrated diffuse cytoplasmic expression of glial fibrillary acidic protein (GFAP) and CD34, and strong nuclear staining for thyroid transcription factor 1 (TTF-1). We, therefore, histologically classified the tumor as chordoid glioma of the third ventricle. Headache improved immediately postoperatively, and follow-up neuroimaging after 12 months showed no signs of recurrence. Conclusions Chordoid glioma of the third ventricle is a very rare tumor that is difficult to diagnose on routine neuroimaging. Accurate diagnosis requires detailed analysis of neuroimaging and immunohistochemical studies using CD34 and TTF-1 staining.

Sleep‐induced changes in human brain connectivity/excitability and their physiologic basis remain unclear, especially in the frontal lobe. We investigated sleep‐induced connectivity and excitability changes in 11 patients who underwent chronic implantation of subdural electrodes for epilepsy surgery. Single‐pulse electrical stimuli were directly injected to a part of the cortices, and cortico‐cortical evoked potentials (CCEPs) and CCEP‐related high‐gamma activities (HGA: 100–200 Hz) were recorded from adjacent and remote cortices as proxies of effective connectivity and induced neuronal activity, respectively. HGA power during the initial CCEP component (N1) correlated with the N1 size itself across all states investigated. The degree of cortical connectivity and excitability changed during sleep depending on sleep stage, approximately showing dichotomy of awake vs. non‐rapid eye movement (REM) [NREM] sleep. On the other hand, REM sleep partly had properties of both awake and NREM sleep, placing itself in the intermediate state between them. Compared with the awake state, single‐pulse stimulation especially during NREM sleep induced increased connectivity (N1 size) and neuronal excitability (HGA increase at N1), which was immediately followed by intense inhibition (HGA decrease). The HGA decrease was temporally followed by the N2 peak (the second CCEP component), and then by HGA re‐increase during sleep across all lobes. This HGA rebound or re‐increase of neuronal synchrony was largest in the frontal lobe compared with the other lobes. These properties of sleep‐induced changes of the cortex may be related to unconsciousness during sleep and frequent nocturnal seizures in frontal lobe epilepsy. Hum Brain Mapp, 2015. © 2015 Wiley Periodicals, Inc.

“Formes frustes” of encephalopathy associated with anti-NMDAR antibody have been recently described in cases of chronic epilepsy. We report a young woman with a parietal lesion and anti-NMDAR antibody who acquired bilateral, secondary epileptogenesis in the temporal lobes within a period as short as six years. Removal of the primary epileptogenic lesion of oligoastrocytoma in the right parietal lobe resulted in seizure freedom, disappearance of secondary foci, and substantial decrease of the antibody titre. Chronic exposure to anti-NMDAR antibody, albeit at a low titre, may have resulted in a smoldering chronic course and relatively early acquisition of “reversible” secondary foci without development of a high degree of epileptogenicity and structural changes.

The superior parietal lobule (SPL) and the medial parietal cortex are associated with integration of various kinds of information. Little is known about connections from the superior and medial parietal cortices in humans. Our objective is to delineate their connectivity by means of cortico-cortical evoked potential (CCEP). Subjects were eight patients who underwent chronic subdural electrode placement covering the dorso-lateral (SPL) or medial parietal cortices. Single-pulse electrical stimuli were delivered and CCEPs were obtained from the frontal and parietal areas by averaging electrocorticograms time-locked to stimuli. SPL stimulation elicited 75 CCEPs at the precuneus, precentral gyrus, the dorsal premotor area (dorsal PM). The precuneus elicited 66 CCEPs in the inferior parietal lobule (IPL), dorsal premotor area (PM) and SPL. The posterior cingulate cortex elicited 36 CCEPs at the middle cingulate cortex, SPL and the precuneus. This study demonstrated reciprocal connections between the superior and medial parietal cortices. While the precuneus tends to connect with the lateral frontal area, posterior cingulate cortex with medial frontal area. These findings would account for functional differentiation between these areas, and may help us understand seizure propagation in patients with parietal lobe epilepsy.

OBJECTIVE: 68Ga-DOTATOC positron emission tomography (PET)/CT ((68)Ga-DOTATOC PET/CT) has currently been the most sensitive imaging modality for neuroendocrine tumors expressing somatostatin receptors (Poeppel, 2011). The aim of this pilot study was to validate molecular imaging of pineal parenchymal tumor with (68)Ga-DOTATOC PET/CT. PATIENTS AND METHODS: Two patients, who were diagnosed with pineal parenchymal tumor of intermediate differentiation (PPTID), underwent (18)F-FDG-PET/CT and (68)Ga-DOTATOC PET/CT. Image scan was performed 30 and 60 minutes after venous injection of the tracers, (18)F-FDG and (68)Ga-DOTATOC, respectively. The maximum standardized uptake value (SUVmax) was measured. The expression of somatostatin receptor subtype 2 (SSTR2) was immunohistochemically analyzed in tumor specimens. RESULTS: The strong uptakes of both tracers were detected in PPTID. The SUVmax of FDG-PET and (68)Ga-DOTATOC was 26.2 and 37.2 in a case, 11.6 and 23.6 in the other, respectively. Immunohistochemical study revealed the high expression of SSTR2 in PPTID specimens. CONCLUSION: It is not easy to distinguish between pineal parenchymal tumor and other tumors including germ cell tumor, meningioma, and glioma by using CT and MRI (Kakigi, 2014). Our results suggest that the uptake of (68)Ga-DOTATOC is correlated with SSTR2 expression and it could be useful for detection of pineal parenchymal tumors.

Two functional brain-mapping techniques, functional magnetic resonance imaging (fMRI) and cortical stimulation by chronically implanted subdural electrodes, were used in combination for presurgical evaluation of three patients with intractable, partial motor seizures. Brain mapping was focused on characterizing motor-related areas in the medial frontal cortex, where all patients had organic lesions. Behavioral tasks for fMRI involved simple finger and foot movements in all patients and mental calculations in one of them. These tasks allowed us to discriminate several medial frontal motor areas: the presupplementary motor areas (pre-SMA), the somatotopically organized SMA proper, and the foot representation of the primary motor cortex. All patients subsequently underwent cortical stimulation through subdural electrodes placed onto the medial hemispheric wall. In each patient, the cortical stimulation map was mostly consistent with that patient's brain map by fMRI. By integrating different lines of information, the combined fMRI and cortical stimulation map will contribute not only to safe and effective surgery but also to further understanding of human functional neuroanatomy.

Summary: Purpose: The study goal was to evaluate the clinical usefulness of intravenous EEG recording by placing wire electrodes in the cavernous sinus (CS) and the superior petrosal sinus (SPS) in patients with intractable temporal lobe epilepsy (TLE), with special emphasis on the ictal recording. Methods: We placed Seeker Lite- 10 guide wire as electrodes in the bilateral CS, SPS, or both to simultaneously record both ictal and interictal EEGs with the scalp EEG in five patients with TLE. In addition, in one patient, we averaged interictal scalp and intravascular EEG time-locked to the epileptiform discharge recorded from the CS/SPS-EEG to further delineate the relationship of the spikes between scalp and intravenous recording. Results: In four of five patients, clinically useful recording was obtained to determine ictal focus. We recorded habitual seizures in three patients, and the detailed characteristics of ictal epileptiform discharges were shown. The averaged waveform of interictal epileptiform discharges clarified the spike distribution in the scalp EEGs, which was otherwise undetectable in the single trace. All of the patients completed the intravenous EEG monitoring without any neurological or psychological problems. Conclusions: The CS/SPS-EEG is a relatively noninvasive method that is useful for the detection of ictal focus and its spreading pattern and thus for the selection of surgical candidate among patients with intractable TLE. Although the number of seizures detected during the short monitoring period may be limited, due to the advantages of its safety and simplicity, it is worth trying for potential surgical candidates before more invasive examinations are applied. A further study with a larger number of patients is needed to estimate its practical risk.

To clarify the mechanism by which inhibitory motor responses such as cortical negative myoclonus are generated in humans, three patients with medically intractable partial epilepsy (two with frontal lobe epilepsy and one with parietal lobe epilepsy) were studied by means of direct cortical stimulation with a single electric pulse through subdural electrodes. All underwent chronic long-term video/EEG monitoring, cortical mapping by 50 Hz electric cortical stimulation and recording of cortical somatosensory evoked potentials with chronically implanted subdural grid electrodes (3 mm in diameter and centre-to-centre distance of 1 cm) to map both epileptogenic and functional zones. After these clinical evaluations, cortical stimulation by single electric pulse (0.3 ms duration, 1 Hz) was carried out through pairs of subdural electrodes located at the primary sensorimotor area (MI-SI), pre-supplementary motor area (pre-SMA) and lateral negative motor area (lateral NMA), while surface EMG was recorded from the muscles of the contralateral hand. The results showed that (i) in all subjects, single pulse stimulation of MI-SI elicited a motor evoked potential (MEP) followed by a silent period (SP) in the contralateral distal hand muscles, the latter lasting 300 ms after the stimulus. The duration of SP was proportional to the size of the preceding MEP. In one subject, SP without any preceding MEP was elicited, and, in another subject, there was a short SP immediately before MEP in the contralateral thenar muscle. (ii) Following the stimulation of either pre-SMA or lateral NMA, no SP was observed. It is concluded that the inhibitory mechanism within the MI-SI, but probably not in the non-primary motor areas, either closely linked to or completely independent of excitation, most likely plays an important role in eliciting brief negative motor phenomena such as cortical negative myoclonus or SP.

We investigated movement-related change in the cortical EEG signal by simultaneous recording from the primary sensorimotor area (S1-M1) and the supplementary motor area proper (SMA proper) in four patients with intractable partial epilepsy. By the use of temporal spectral evolution (TSE) analysis, the change in background cortical activity in relation to self-paced finger/wrist extension was compared among the SMA proper, S1 and M1. All three areas showed a decrease in the amount of activity for the frequency range between 10 and 40 Hz before the onset of movement [event-related desynchronization (ERD)]. The SMA proper showed earlier onset of ERD for 18-22 Hz activity (-3.4 +/- 0.5 s, mean +/- standard deviation) than M1 (-1.7 +/- 0.7 s) and S1 (-1.4 +/- 0.5 s). The degree of ERD in S1 was greatest for 10-14 Hz and that in M1 for 18-22 Hz, whereas in the SMA proper ERD was observed throughout the frequency bands from 10 to 40 Hz. Neither the degree nor the onset time of ERD in the SMA proper was lateralized to either the ipsilateral or the contralateral side with respect to the movement. A transient increase in activity after movement [event-related synchronization (ERS)] was observed in all three areas. In the SMA proper, two out of four subjects showed ERS for frequency bands below 40 Hz with both ipsilateral and contralateral movements. By contrast, in S1 and M1, ERS was recorded for frequency bands between 20 and 90 Hz, and was predominantly associated with the contralateral movement. The present study suggests that the background cortical activity in the SMA proper has a specific temporal pattern with respect to self-paced movement, and that the SMA proper is involved in motor preparation earlier than S1-M1 in a bilaterally organized manner.

We described autosomal dominant familial temporal lobe epilepsy in a Japanese family in which three individuals (one man and his two children) were affected. Their seizures commonly consisted of auditory symptoms and infrequent nocturnal generalized seizures. Repeated EEGs did not provide confirmative epileptiform discharges, but cranial MRI in one patient showed mild left hippocampal atrophy, and decreased glucose metabolism in the left temporal area was demonstrated by 18F-deoxyglucose positron emission tomography (FDG-PET). A confirmative diagnosis in one of the patients by FDG-PET was helpful for diagnosis in other patients in the same family. Seizure onset was adolescent commonly among the three patients, but better seizure control was achieved in the father as compared with the two children.

To clarify the somesthetic functions of the supplementary motor area (SMA), we recorded the cortical potentials following the median nerve electric stimulation directly from the SMA and investigated the modulation caused by voluntary movements in two patients with intractable SMA seizures. The evoked potentials over the SMA consisted of positive (61.5 ms) and negative (100.0 ms) peaks, which were enlarged by voluntary movements of the stimulated hand. The present finding is in strong contrast with the attenuation (gating) of the response at the primary sensorimotor area (SM1) and suggests that the voluntary movements differently modulate the somatosensory functions of SMA and SM1.

Objective—To investigate somesthetic functions of the perisylvian cortex. Methods—Somatosensory evoked magnetic fields (SEFs) and somatosensory evoked potentials (SEPs) of the perisylvian cortex were recorded directly from subdural electrodes in a patient with a left frontal brain tumour. Results—The most prominent SEP components after electrical stimulation of the right and left hands and the right foot were double peaked negativity recorded just above the sylvianfissure (latency 80 to 150 ms), respectively (N1a and N1b). Generator sources for the magnetoencephalographic counterparts of those peaks (N1a(m) and N1b(m)) were both localised at the upper bank of the sylvian fissure, and those of N1a(m) were more anteromedially located than those of N1b(m). Conclusions—These findings suggest the existence of at least two separate somatosensory areas within the human perisylvian cortex. (J Neurol Neurosurg Psychiatry 1997;63:501‐505)

Modality specificity of human primary somatosensory cortex was studied by recording somatosensory evoked potentials (SEPs) from subdural electrodes in a patient with intractable focal motor seizure. A newly developed device was used for selectively activating proprioception. The spatial and temporal distributions of proprioception-related SEPs elicited by brisk passive flexion movement at the proximal interphalangeal (PIP) joint of the middle finger (4 degrees in 25 ms) were quite different from those to cutaneous sense evoked by electric stimulation of the digital nerve at the same site. It was for the first time demonstrated that proprioception-related SEPs following passive finger movement do not originate in area 3b, which was clearly activated by cutaneous stimulation, and that other sites at the sensorimotor cortex such as areas 2, 3a and 4 possibly contribute to the cortical processing of proprioception.

Summary Purpose To quantitatively compare the diagnostic capability of double inversion-recovery (DIR) with F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) for detection of seizure focus laterality in temporal lobe epilepsy (TLE). Methods This study was approved by the institutional review board, and written informed consent was obtained. Fifteen patients with TLE and 38 healthy volunteers were enrolled. All magnetic resonance (MR) images were acquired using a 3T-MRI system. Voxel-based analysis (VBA) was conducted for FDG-PET images and white matter segments of DIR images (DIR-WM) focused on the whole temporal lobe (TL) and the anterior part of the temporal lobe (ATL). Distribution of hypometabolic areas on FDG-PET and increased signal intensity areas on DIR-WM were evaluated, and their laterality was compared with clinically determined seizure focus laterality. Correct diagnostic rates of laterality were evaluated, and agreement between DIR-WM and FDG-PET was assessed using κ statistics. Key Findings Increased signal intensity areas on DIR-WM were located at the vicinity of the hypometabolic areas on FDG-PET, especially in the ATL. Correct diagnostic rates of seizure focus laterality for DIR-WM (0.80 and 0.67 for the TL and the ATL, respectively) were slightly higher than those for FDG-PET (0.67 and 0.60 for the TL and the ATL, respectively). Agreement of laterality between DIR-WM and FDG-PET was substantial for the TL and almost perfect for the ATL (κ = 0.67 and 0.86, respectively). Significance High agreement in localization between DIR-WM and FDG-PET and nearly equivalent detectability of them show us an additional role of MRI in TLE.

The preservation of language function during brain surgery still poses a challenge. No intraoperative methods have been established to monitor the language network reliably. We aimed to establish intraoperative language network monitoring by means of cortico‐cortical evoked potentials (CCEPs). Subjects were six patients with tumors located close to the arcuate fasciculus (AF) in the language‐dominant left hemisphere. Under general anesthesia, the anterior perisylvian language area (AL) was first defined by the CCEP connectivity patterns between the ventrolateral frontal and temporoparietal area, and also by presurgical neuroimaging findings. We then monitored the integrity of the language network by stimulating AL and by recording CCEPs from the posterior perisylvian language area (PL) consecutively during both general anesthesia and awake condition. High‐frequency electrical stimulation (ES) performed during awake craniotomy confirmed language function at AL in all six patients. Despite an amplitude decline (≤32%) in two patients, CCEP monitoring successfully prevented persistent language impairment. After tumor removal, single‐pulse ES was applied to the white matter tract beneath the floor of the removal cavity in five patients, in order to trace its connections into the language cortices. In three patients in whom high‐frequency ES of the white matter produced naming impairment, this “eloquent” subcortical site directly connected AL and PL, judging from the latencies and distributions of cortico‐ and subcortico‐cortical evoked potentials. In conclusion, this study provided the direct evidence that AL, PL, and AF constitute the dorsal language network. Intraoperative CCEP monitoring is clinically useful for evaluating the integrity of the language network. Hum Brain Mapp 35:4345–4361, 2014. © 2014 Wiley Periodicals, Inc.

Summary Background and purpose Cortical venous reflux (CVR) in dural arteriovenous fistulas (AVFs) is a well-known risk factor for intracranial hemorrhage. However, the impact of the angiographic characteristics of CVR on the risk of intracranial hemorrhage remains unclear. This study retrospectively reviewed the angioarchitectural features of CVR to assess their influence on the risk of intracranial hemorrhage in dural AVFs. Patients and methods We retrospectively evaluated 68 consecutive patients with dural AVFs treated at our hospital between September 2001 and February 2010. In all cases, the angioarchitectural features of CVR were analyzed using cerebral angiography with a special focus on the venous drainage pattern of dural AVFs. “Loop-like formation” was defined as at least one CVR forming a curvature and connection adjacent to the original arteriovenous shunt point. Results Ten dural AVF patients (14.7%) presented with intracranial hemorrhage. All ten dural AVFs with intracranial hemorrhage showed CVR with a “loop-like formation” on angiography. This association was found to be statistically significant (P Conclusion “Loop-like formation” in CVR may be a risk factor for intracranial hemorrhage resulting from dural AVF. This angioarchitectural feature of venous drainage may be a useful prognostic indicator, and hence should be a point of focus during treatment decisions.

It is now recommended that magnetic resonance imaging (MRI) or computed tomography (CT) be carried out in all patients with at least partial- and hopefully also generalized epilepsy to help identify intracranial lesions, such as hippocampal sclerosis, focal cortical dysplasia, brain tumor, cavernous malformation, and arteriovenous malformation. In order to identify epileptic focus, other neuroimaging tools, such as positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetoencephalography (MEG), are also useful, because an epileptogenic area is not necessarily located within these intracranial lesions. With regard to epilepsy surgery, neuroimaging is also required for the identification of functionally essential cortices, such as motor and language areas. MEG and functional MRI are noninvasively, and tractography with diffusion-weighted imaging (DWI) is also useful for visualizing relevant white matter tracts. Recently, it has been reported that the cortico-cortical network plays an important role in preservation of brain function. Thus, cortico-cortical evoked potentials (CCEP) and resting state fMRI are candidate methods to help clarify brain network. While good seizure control is an important treatment outcome for patients with intractable partial epilepsy, the preservation of brain function is equally important. For this reason, further development and clinical application of sophisticated imaging technique are required.

Background Arachnoid cysts originating from the velum interpositum are very rare, and their existence as a clinicopathologic entity remains controversial. We report a case of a patient with an arachnoid cyst of the velum interpositum presenting with memory disturbance, focusing on the anatomical origin of the lesion and the physiological mechanisms causing memory disturbance. Case description A 65-year-old man with a large cystic lesion in the velum interpositum experienced progressive memory disturbance and enlargement of the lesion 6 months before referral to our institution. Neuropsychological evaluation on admission demonstrated severe memory disturbance. Radiological examination did not reveal hydrocephalus, but the bilateral fornices and thalami were compressed by the cyst. The patient underwent endoscopic cystoventriculostomy via the frontal horn of the right lateral ventricle through a frontal burr hole. Histopathology of the sample was consistent with that of an arachnoid cyst, and the endoscopic findings suggested that the cyst originated from the tela choroidea, which covers the velum interpositum. The symptoms resolved after surgery with significant improvement in neuropsychological test scores. Conclusion Arachnoid cysts of the velum interpositum are rare but distinct clinicopathologic entities that originate from the tela choroidea. The lesions can cause memory disturbance without hydrocephalus due to compression of the fornices and thalami, but this can be reversed by surgery.