Damage to the left ventral, arcuate fasciculus and superior longitudinal fasciculus-related pathways induces deficits in object naming, phonological language function and writing, respectively.

The anatomic localization of brain functions can be characterized via diffusion tensor imaging in patients with brain tumors and neurological symptoms. The goal of the present study was to evaluate the function of the ventral, arcuate fasciculus (AF) and the superior longitudinal fasciculus (SLF)-related language pathways using these techniques by analyzing 9 patients treated in our hospital between 2007 and 2011. In cases 1-3, the left ventral pathways, namely, the inferior longitudinal fasciculus, uncinate fasciculus or inferior fronto-occipital fasciculus, were mainly damaged, and the common dysfunction experienced by these patients was a deficit in object naming. In cases 4-6, the left SLF was mainly damaged, and the common deficit was dysgraphia. In cases 7-9, the left AF was mainly damaged, and almost all language functions related to phonology were abnormal. These results suggest that the left ventral, AF and SLF-related pathways are closely related to visual, auditory and hand-related language function, respectively.

The right dorsal anterior cingulate cortex may play a role in anxiety disorder and visual function.

Recent investigation suggests that the dorsal anterior cingulate cortex (ACC) is involved in the interplay between cognition and emotion. The present study described three patients who underwent removal of brain tumors just above the right dorsal ACC. These patients had residual tumor following surgery and showed anxiety disorder (AD) both before and after surgery. Visual memory or attention was abnormal before surgery in these patients, but these deficits improved following surgery, possibly due to a decrease in compression of the right dorsal ACC. These results suggest that damage to the right dorsal ACC is involved in AD and well as in deficits in visual memory or attention. Therefore, the right dorsal ACC might play a role in vision-related cognition and emotion, such as anxiety.

The left superior longitudinal fasciculus within the primary sensory area of inferior parietal lobe plays a role in dysgraphia of kana omission within sentences.

Functional neurological changes after surgery combined with diffusion tensor imaging (DTI) tractography can directly provide evidence of anatomical localization of brain function. Using these techniques, a patient with dysgraphia before surgery was analyzed at our hospital in 2011. The patient showed omission of kana within sentences before surgery, which improved after surgery. The brain tumor was relatively small and was located within the primary sensory area (S1) of the inferior parietal lobe (IPL). DTI tractography before surgery revealed compression of the branch of the superior longitudinal fasciculus (SLF) by the brain tumor. These results suggest that the left SLF within the S1 of IPL plays a role in the development of dysgraphia of kana omission within sentences.

Right temporal lobe plays a role in verbal memory.

OBJECTIVES: Comparison of preoperative and postoperative neurological functions in patients undergoing resection of brain tumors, in combination with data from diffusion tensor imaging (DTI) studies, can provide direct evidence of anatomical localization of brain function. The goal of the present study was to use these techniques to characterize memory function of the right temporal lobe in five patients with right temporal lobe brain tumors. METHODS: Memory function was tested using the Wechsler Memory Scale-Revised (WMS-R) before and after surgery in five patients with right temporal lobe brain tumors. Preoperative DTI was performed in four of five cases. RESULTS: In all cases, general and verbal memory, including verbal paired association, significantly improved after surgery (P<0.05). The right inferior longitudinal fasciculus (ILF) was compressed by the tumor in all cases. CONCLUSION: These results suggest that the right temporal lobe plays a role in verbal memory and that this function may be associated with the right ILF.

Damage to the right dorsal anterior cingulate cortex induces panic disorder.

Brain imaging studies suggest that panic disorder (PD) is mediated by several brain regions, including the anterior cingulate cortex (ACC). In the present report we describe a patient who experienced a panic attack during awake surgery (case 1) and another patient who developed PD after surgery and radiotherapy (case 2). In case 1, the patient experienced repeated panic attacks when the tumor at the upper border of right dorsal ACC was removed during awake surgery. In case 2, the patient developed PD at six months after surgery and Cyberknife radiotherapy. MRI examination revealed that the dorsal ACC size was reduced at six months after surgery and that the dorsal ACC was absent at two years after surgery, possibly due to radiotherapy-induced damage by radiotherapy. Profile of mood states (POMS) testing characterized the presence of tension-anxiety as the common abnormal symptom in cases 1 and 2. In conclusion, these results suggest that damage to the right dorsal ACC can induce PD and that this structure likely plays a pathophysiologic role in PD.

Left or right temporal lesion might induce aggression or escape during awake surgery, respectively: role of the amygdala.

OBJECTIVE: Some patients with temporal lobe brain tumours show aggressive or escape behaviour during awake surgery. As the amygdala plays a critical role in coping with stress, we evaluated whether the left or right amygdala was involved in aggressive or escape behaviour in six patients undergoing awake surgery for temporal lobe brain tumours. METHODS: Brain tumours were located in the left temporal lobe in cases 1-3 and in the right temporal lobe in cases 4-6. In cases 1, 2, 4 and 5, the tumours invaded the amygdala. RESULTS: In case 1, the patient showed aggressive behaviour before partial removal of the left amygdala during awake surgery; just after partial removal of left amygdala, the patient was calm and cooperative. In case 2, the patient showed aggressive behaviour when the tumour near the left amygdala was removed. In case 3, the patient showed aggressive behaviour when awakening during awake surgery. In case 4, the patient showed escape behaviour when removal of the tumour near the right amygdala was initiated. In cases 5 and 6, patients showed escape behaviour upon awakening and upon initiation of tumour removal from the temporal lobe. CONCLUSION: In conclusion, these results suggest that left or right temporal lesions might induce aggressive or escape behaviour during awake surgery, respectively, and that the amygdala on the respective side may play a role in these behaviours.

Damage to the upper portion of area 19 and the deep white matter in the left inferior parietal lobe, including the superior longitudinal fasciculus, results in alexia with agraphia.

Analysis of lesions and symptoms in patients with brain tumors combined with information from diffusion tensor imaging provides direct evidence of the anatomical localization of brain function. Using these methods, we evaluated 8 patients who underwent surgery for metastatic brain tumors located in the left occipital lobes between 2007 and 2009. Preoperatively, 4 patients (cases 1-4) had alexia with agraphia while the other 4 patients (cases 5-8) did not. Tractography for the superior longitudinal fasciculus (SLF) was performed before surgery in case 1. The common brain tumors in cases 1-4 were located in the upper portion of area 19, and peritumor edema in that area resulted in compromise of the deep white matter of the inferior parietal lobe (IPL). The SLF was compressed and disrupted in the white matter of the IPL near the upper portion of area 19 in case 1. In cases 5-8, the brain tumors were not located in the upper portion of area 19. These results suggest that damage to the upper portion of area 19 and to the white matter in the left IPL, including the SLF, resulted in alexia with agraphia.

Damage of left temporal lobe resulting in conversion of speech to Sutra, a Buddhist prayer stored in the right hemisphere.

The present study describes a case of a right-handed 74-year-old woman with a brain tumor who showed conversion of speech to Sutra, a Buddhist prayer, which was stored in the right hemisphere according to the Wada test. After surgery, relative improvement in the speech disorder was observed, and frequency of speech production of simple normal words with normal phonology increased. These observations indicate that damage to left temporal lobe resulted in conversion of speech to Sutra, and that Sutra was stored in this patient's right hemisphere.

Combined movement of multi-joint muscles activates a smaller area compared to the sum of areas activated by respective single-joint muscles after restoration of paresis.

Awake surgery provides accurate localization of brain function based on rapid reversible neurological changes during surgical manipulation. In this study, hand clenching rapidly deteriorated due to surgical manipulation during awake surgery and instantly recovered not by hand clenching alone but by combined movement of hand clenching and elbow flexion. Postoperative fMRI (functional MRI) showed a smaller area activated by combined movement of hand clenching and elbow flexion than the sum of areas activated by hand clenching alone and elbow flexion alone. Conversely, the activated area by combined movement of hand clenching and elbow flexion was almost the same as the sum of areas by hand clenching alone and elbow flexion alone in fMRI of normal volunteers. These findings indicate reorganization of the motor area by combined movement including the motor function of previous transient weakness, and might suggest the effectiveness of combined movement to improve motor paresis in rehabilitation.

Deficits in the left inferior longitudinal fasciculus results in impairments in object naming.

The functional characteristics of the left inferior longitudinal fasciculus (ILF) remain unclear. The present study describes a case of a right-handed 74-year-old woman with a brain tumor who showed marked deterioration in object naming ability after invasion of the tumor into the medial region of the left posterior (middle and inferior) temporal lobe just beside the atrium of the lateral ventricle. Diffusion tensor imaging showed possible interruption of the left ILF after invasion of tumor at this site. By contrast, the left superior longitudinal fasciculus (SLF) remained intact after invasion of tumor, and the inferior fronto-occipital fasciculus (IFOF) was already disrupted prior to tumor invasion. These observations indicate that intact ILF function may be required for object naming ability.

Mirror therapy activates outside of cerebellum and ipsilateral M1.

Mirror therapy is effective in the rehabilitation of patients with hemiparesis, but its mechanism is not clear. In this study, a patient with brain tumor (patient 1) who underwent mirror therapy after surgery and showed drastic recovery of hand paresis, a patient with visual memory disturbance (patient 2), and five normal volunteers performed tasks related to mirror therapy in fMRI study. In patient 1 and all normal volunteers, right and left hand clenching with looking at a mirror (eye open) activated outside of cerebellum, while right and left hands clenching with eye closed activated inside of cerebellum. In patient 2, mirror therapy did not activate outside of cerebellum. In patient 1, and 3 out of 5 normal volunteers, the area of right (affected) M1 activated by right and left hands clenching with eye open was more than that by right and left hands clenching with eye closed, and that right M1 was activated by right hand clenching with eye open. In conclusion, mirror therapy facilitate the paresis of patients by activating ipsilateral M1 and outside of cerebellum, which is possibly related to visual memory function.

Continuous intrathecal treatment with methotrexate via subcutaneous port: implication for leptomeningeal dissemination of malignant tumors.

Use of intrathecal (IT) chemotherapy combined with radiotherapy can extend survival of patients with untreated leptomeningeal dissemination of malignant tumors from one month to two to six months. The goal of the present study was to determine the effect of continuous IT (CIT) via a subcutaneous port that was placed using a neuronavigation system. Twenty patients with leptomeningeal dissemination (primary disease: 10 cancers, 6 gliomas and 4 lymphomas) were given 2-7 cycles of continuous IT (CIT) with methotrexate (MTX; 10 mg) administered into the lateral ventricle for 5 consecutive days biweekly. The concentration of MTX in the lateral ventricle was 7 to 10 x 10(-6 )M from Day 1 to 4. Response to this therapy included 6 patients with complete remission, 7 with progressive disease, and 7 with stable disease. Kaplan-Meier analysis revealed a median overall survival of 8 months while the overall survival rate for leptomeningeal specific death or for metastasis from cancer was 13 or 5 months, respectively. Complications of CIT with MTX were relatively low (<0.5%), and nausea and vomiting did not occur in any of the patients. In conclusion, CIT with 10 mg MTX via subcutaneous port for 5 days may improve the therapeutic effect and reduce the complications associated with treatment of leptomeningeal dissemination from malignant tumors. This would be a safe technique with possible implications that bear repeating more patients.

Impairment of inferior longitudinal fasciculus plays a role in visual memory disturbance.

Function of the inferior longitudinal fasciculus (ILF), which connects the anterior temporal and occipital lobes, has not been clearly demonstrated in the human brain. A 47-year-old woman with visual memory disturbance as demonstrated by the Wechsler Memory Scale-Revised presented with possible brain tumor in the right temporal lobe. Diffusion tensor imaging showed partial disconnection of the right ILF, indicating that function of the ILF is highly involved in visual memory.

Delineation of brain tumor margins using intraoperative sononavigation: implications for tumor resection.

PURPOSE: Sonography has been employed for real-time intraoperative delineation of tumor boundaries during resection of brain tumors. However, the variably hyperechoic appearance of brain edema or gliosis surrounding the brain may interfere with accurate depiction of tumor margins. The goal of the present study was to use sononavigation, which provides coregistration between real-time sonograms and MRI scans, to assess the accuracy of sonographic determination of tumor margins. METHODS: Sononavigation was performed on 12 brain tumors (7 metastatic brain tumors, 2 meningiomas, 1 anaplastic oligodendroglioma, 1 anaplastic pilocytic astrocytoma, and 1 anaplastic astrocytoma). Sonograms of tumor margins were categorized into 1 of 3 types: in type 1, the tumor margin was clearly visualized and corresponded to the margin of the enhanced lesion on MR scan in all areas; in type 2, the tumor margin was clearly seen in some areas but was obscure in others due to hyperechoic edema; and in type 3, the tumor margin was indistinguishable from surrounding tissues in all areas. RESULTS: Three metastatic brain tumors and 1 meningioma were categorized as type 1. Three metastatic brain tumors, 1 meningioma, and 1 anaplastic oligodendroglioma were categorized as type 2. The anaplastic pilocytic astrocytoma, 1 metastatic brain tumor (which consisted mainly of necrotic tissue), and the anaplastic astrocytoma were categorized as type 3. These data assist in determining whether the sonographic appearance of tumor margins is accurate and whether to rely on information from either sonography (type 1) or the sononavigation system when resecting tumor types 1, 2, and 3. CONCLUSIONS: Sononavigation can help categorize the sonographic tumor margins into 3 different patterns, and this categorization can assist in determining which imaging modalities are needed to better delineate the tumor margins for subsequent resection.

Accurate characterization of the main trunk of the anterior cerebral artery by means of intraoperative sononavigation with Doppler sonography: implications for brain tumor surgery.

OBJECTIVE: Doppler sonography can be used for real-time intraoperative localization of arteries within or near brain tumors but is less useful for distinguishing between arteries with similar diameters, such as the main trunk and branches of the anterior cerebral artery (ACA). By contrast, sononavigation provides real-time information in alignment with magnetic resonance imaging scans and may be of use in characterizing the identity of individual arteries on Doppler sonographic images. The goal of this study was to determine whether sononavigation can distinguish the main trunk of the ACA from the branches of the ACA on Doppler sonographic images. METHODS: Doppler sonography was used in 3 patients undergoing surgical resection of brain tumors involving the main trunk of the ACA. The location of the main trunk of the ACA was characterized by sononavigation. RESULTS: With these data, tumor resection was performed with preservation of the main trunk of the ACA. Gross total resection was achieved in 1 case. CONCLUSIONS: Intraoperative sononavigation with Doppler sonography accurately localized the main trunk of the ACA and enabled preservation of this structure during tumor resection. This method may be applicable to the characterization of other critical arteries and may allow tumor resection with decreased morbidity.

Decreased vasoreactivity to right cerebral hemisphere pressure in migraine without aura: a near-infrared spectroscopy study.

OBJECTIVE: Several studies have reported changes in cerebrovascular reactivity during the interictal period of migraine. To characterize mechanisms of migraine, we compared changes in total haemoglobin (THbl) and regional oxygen saturation (rSO(2)) of the right and left frontal lobes in response to intracranial pressure changes during the interictal period of migraine. METHODS: Twelve right-handed migraineurs without aura and twelve age- and sex-matched healthy volunteers were asked to perform a head-down maneuver to increase intracranial venous pressure. Initial THbl was designated as 1.0, and all subsequent THbl measurements, which was proportional to the change in cerebral blood flow, were expressed as a value relative to this baseline. RESULTS: The head-down maneuver resulted in a significantly smaller increase in right-sided THbl in migraineurs when compared to volunteers (migraineurs, -0.1+/-0.04; volunteers, 30+/-13; P=0.027), but there was no significant difference in left-sided THbl when comparing migraineurs and volunteers. Further, the head-down maneuver produced a significantly smaller increase in right-sided THbl than in left-sided THbl in migraineurs (right side, -0.1+/-0.04; left side, 0.35+/-0.08; P<0.0001), but produced a significantly greater increase in right-sided THbl than in left-sided THbl in volunteers (right side, 30+/-13; left side, 0.44+/-0.13; P=0.030). The head-down maneuver resulted in a smaller decrease in right-sided rSO(2) in migraineurs when compared to volunteers (migraineurs, -4.1+/-2.2%; volunteers, -16+/-9.1%), but produced a significantly greater decrease in left-sided rSO(2) in migraineurs when compared to volunteers (migraineurs, -1.3+/-1.1%; volunteers, 2.8+/-0.63%; P=0.0037). CONCLUSIONS: These data indicate that pressure-related vasoreactivity is suppressed in the right hemisphere of migraineurs during the interictal period. SIGNIFICANCE: The suppression of vasoreactivity in the right hemisphere might be related to the pathogenesis of migraine.

Head-down manoeuvre in patients with a high symptom score for orthostatic intolerance reveals impaired right brain frontal lobe vasoreactivity.

OBJECTIVE: Autonomic nerve dysregulation produces a sense of impaired well-being and interferes with work performance in affected individuals. In this study, we characterized the pathophysiology of this condition. METHODS: Six patients with high symptom scores for orthostatic intolerance (OI) along with age- and sex-matched normal volunteers were directed to perform a head-down manoeuvre, and the change in cerebral blood flow (CBF) and cerebral oxygen levels (rSO(2)) in the right and left frontal lobes was measured using near-infrared spectroscopy (NIRS). RESULTS: The head-down manoeuvre induced a much greater increase in right-sided total haemoglobin concentration (THbl) in normal volunteers (0.51+/-0.24) when compared to symptomatic patients (0.0+/-0.04) but had no effect on left-sided THbl (P<0.05) in either group. Five of 6 patients showed a gradual decrease in right-sided THbl when assuming a sitting position, and all patients with this pattern complained of symptoms of multiple autonomic dysfunction. Further, this pattern of changes in right-sided THbl was not observed in normal volunteers. CONCLUSIONS: The gradual decrease of THbl with the sitting position and the lack of increase during the head-down manoeuvre in symptomatic patients suggest that these patients have impaired vasoreactivity in the right frontal lobes. SIGNIFICANCE: This impaired vasoreactivity likely reflects dysfunction of the right hemisphere and the sympathetic nervous system in patients with OI.

Fibers connecting the primary motor and sensory areas play a role in grasp stability of the hand.

The goal of this study was to evaluate the function of fibers that connect the hand area of the primary motor and sensory cortices. A 63-year-old male with a metastatic brain tumor located in the left primary motor area underwent awake surgery. During removal of the tumor, the posterior end of the primary motor cortex, including the fibers between the motor and sensory cortex, was resected, as confirmed by 3D reconstruction of fMRI and diffusion tensor imaging (DTI). Preoperative fMRI with right hand clenching revealed activation in the area around the tumor in the primary motor area. Postoperative fMRI with right hand clenching showed posterior shift of the activation to the sensory area. In contrast, 3D reconstruction of fMRI and DTI with left hand clenching showed activation of cortex corresponding to the motor and sensory hand area. Postoperative neurological examination revealed no change in right hand strength, but the patient complained of decrease right hand grasp stability when he concentrated on using his left hand. These findings suggest that the fibers connecting the primary hand motor and sensory areas play a role in the hand grasp stability.