A Patient with a Unilateral Insular Lesion Showing Bilaterally Reduced Perception of Noxious Stimulation.

No study has reported a unilateral localized cerebral lesion of the posterior insula bilaterally reducing noxious stimuli perception. A 57-year-old man with an infarct involving the right posterior insula presented with reduced somatosensory response in the upper and lower left extremities. Furthermore, there was a reduced response to noxious stimulation in the right upper and lower limbs. We noted reductions in pain, noxious heat and cold perceptions, and sensitivity to increasing temperature. Other somatic sensations, including non-noxious temperatures, remained intact in the right upper and lower extremities. These findings in our patient with a unilateral insular lesion indicated a bilaterally reduced perception of noxious stimulation.

Relationship Between Body-Specific Attention to a Paretic Limb and Real-World Arm Use in Stroke Patients: A Longitudinal Study.

Learned nonuse is a major problem in upper limb (UL) rehabilitation after stroke. Among the various factors that contribute to learned nonuse, recent studies have focused on body representation of the paretic limb in the brain. We previously developed a method to measure body-specific attention, as a marker of body representation of the paretic limb and revealed a decline in body-specific attention to the paretic limb in chronic stroke patients by a cross-sectional study. However, longitudinal changes in body-specific attention and paretic arm use in daily life (real-world arm use) from the onset to the chronic phase, and their relationship, remain unknown. Here, in a longitudinal, prospective, observational study, we sought to elucidate the longitudinal changes in body-specific attention to the paretic limb and real-world arm use, and their relationship, by using accelerometers and psychophysical methods, respectively, in 25 patients with subacute stroke. Measurements were taken at baseline (TBL), 2 weeks (T2w), 1 month (T1M), 2 months (T2M), and 6 months (T6M) after enrollment. UL function was measured using the Fugl-Meyer Assessment (FMA) and Action Research Arm Test (ARAT). Real-world arm use was measured using accelerometers on both wrists. Body-specific attention was measured using a visual detection task. The UL function and real-world arm use improved up to T6M. Longitudinal changes in body-specific attention were most remarkable at T1M. Changes in body-specific attention up to T1M correlated positively with changes in real-world arm use up to T6M, and from T1M to T6M, and the latter more strongly correlated with changes in real-world arm use. Changes in real-world arm use up to T2M correlated positively with changes in FMA up to T2M and T6M. No correlation was found between body-specific attention and FMA scores. Thus, these results suggest that improved body-specific attention to the paretic limb during the early phase contributes to increasing long-term real-world arm use and that increased real-world use is associated with the recovery of UL function. Our results may contribute to the development of rehabilitation strategies to enhance adaptive changes in body representation in the brain and increase real-world arm use after stroke.

Practical use of a simple technique, insertion of wet cotton pledgets into the tumor resection cavity in transsphenoidal surgery of pituitary tumors, for a better comparison between pre- and intraoperative high-field magnetic resonance images.

BACKGROUND: Intraoperative high-field magnetic resonance imaging (iMRI) is a useful modality for immediate intraoperative quality control. With iMRI, a surgeon can confirm whether tumor remnants exist during surgery; which makes it possible to add further resection, obtain a higher resection rate, and improve the cure rate. It is sometimes difficult to evaluate the existence of tumor remnants when the tumor resection cavity is collapsed. In this study, we reported a simple technique for comparing pre- and intraoperative MR images. PATIENTS AND METHODS: Thirty-five consecutive patients with pituitary adenoma underwent endoscopic endonasal transsphenoidal surgery using iMRI. Twenty-six patients had adenomas with suprasellar extension, and 9 had intrasellar adenomas. Nine adenomas had cavernous sinus invasion. Eight patients had endocrine-active, and 27 endocrine-inactive tumors. The simple technique included wet cotton pledgets inserted into the resection cavity to easily and precisely compare pre- and intraoperative MR images. Furthermore, we evaluated the efficacy of iMRI using our method on determining the extent of tumor resection in this study. RESULTS: The first iMRI scan showed that 12 of 35 patients had some tumor remnants, and 23 patients did not. Eight of these 12 patients with tumor remnants had cavernous sinus invasion. Three cases received further tumor resection after iMRI and had a gross total removal. CONCLUSIONS: We presented our initial results after using a simple method in high-field iMRI during endoscopic transnasal transsphenoidal pituitary surgery. This procedure allowed us to obtain valuable information to determine the extent of tumor resection and to precisely visualize the parasellar structures.

Usefulness of multimodal examination and intraoperative magnetic resonance imaging system in glioma surgery.

Extensive surgical removal of tumor tissue can contribute to longer survival for patients with gliomas. Intraoperative magnetic resonance (iMR) imaging is important for safe and maximal resection of brain tumors. A new operating room equipped with a 1.5-T MR imaging system and neuronavigation opened at Yamagata University Hospital in 2008. Using this new suite, we have safely treated over 200 cases. Use of iMR imaging improved glioma resection rates in 25 (34%) of 73 cases, and gross total resection was achieved in 48 patients (66%). Motor evoked potential (MEP) monitoring was performed in combination with iMR imaging for 32 gliomas. MEP monitoring was successful in 30 cases (94%). Transient decreases in MEP amplitude were seen in two patients. One patient showed transient motor weakness and another showed improvement of motor function. The iMR imaging system provides useful information for tumor resection that allows intraoperative modification of surgical strategies. Combining MEP monitoring with iMR imaging appears to offer the most effective method for safe glioma surgery near eloquent areas.

[Long-term outcomes of surgical treatment for epidermoid].

OBJECTIVE: Surgical strategies for epidermoids in our department is that the tumor capsule and surrounding arachnoid membrane should be sharply dissected and resected as much as possible. However, if total resection is not possible, because of the danger of surgical morbidity, partial resection should be carried out. The present study reports on long-term outcomes of surgical treatment for intracranial epidermoid in our department. METHODS: Since 1994, intracranial epidermoids have been resected in 13 patients in our department. The mean age at the time of surgery was 50.2 years and the mean postoperative follow-up period was 75.8 months. Surgical outcome, postoperative morbidity, Karnofsky Performance Status (KPS) during long-term follow-up, hydrocephalus, and regrowth rate were investigated. RESULTS: Among the 13 patients, 5 underwent total resection, 5 subtotal resection, and 3 partial resection. No permanent morbidity occurred and KPS did not worsen postoperatively in any of the patients. Surgery for hydrocephalus was performed in 3 patients. However, hydrocephalus had been suspected before surgery in each patient. Regrowth occurred in 1 patient, showing malignant transformation 1 year after total resection. No regrowth during long-term follow-up was observed in the other 12 patients, and none showed exacerbation of KPS. CONCLUSION: The present study indicates that regrowth does not necessarily occur in patients with epidermoids. Although total resection is ideal, to avoid any surgical morbidity is even more important. Partial resection should be performed if total resection is impossible.

Frequent IDH1/2 mutations in intracranial chondrosarcoma: a possible diagnostic clue for its differentiation from chordoma.

Mutations in the genes encoding isocitrate dehydrogenase (IDH) 1/2 have been detected in a significant proportion of diffuse gliomas and in a small fraction of acute myeloid leukemia (AML) cases. Recently, in an examination of various types of mesenchymal tumor, IDH1/2 mutations were only found in cartilaginous tumors including central conventional and periosteal enchondromas/chondrosarcomas. The frequency of IDH1/2 mutations was 56%, and the IDH1 R132C mutation, which is not common in diffuse gliomas or AML, accounted for 40% of these mutations. In this study, we investigated the IDH1/2 mutation status of intracranial chondrosarcomas and chordomas, which are morphologically similar and affect similar regions of the cranial cavity. Of the 13 chondrosarcomas analyzed, six (46.1%) displayed IDH1/2 mutations (the predominant type was IDH1 R132C). Also, an IDH2 mutation (R172S) was observed in one case. Conversely, none of the ten chordomas analyzed displayed any IDH1 or IDH2 mutations. Our data suggest that the IDH1/2 mutation status could be valuable for distinguishing intracranial chondrosarcomas from chordomas.

Atypical teratoid rhabdoid tumor located in the pineal region following prophylactic irradiation for acute lymphoblastic leukemia.

Atypical teratoid rhabdoid tumor (AT/RT) is a rare entity. In the central nervous system, AT/RT generally arises from the posterior fossa of infants and behaves aggressively. AT/RT is reported to arise from the infratentorial region (63%) and other sites, such as the suprasellar region, cerebellopontine angle, and spinal cord. The pineal region is rare (6%) as a site of origin. Radiation-induced brain tumors are well known. In this report, we present a case of a pineal region tumor causing acute hydrocephalus that could be pathologically diagnosed as AT/RT following prophylactic cranial irradiation for acute lymphoblastic leukemia.

The alterations of oligodendrocyte, myelin in corpus callosum, and cognitive dysfunction following chronic cerebral ischemia in rats.

Although the white matter lesions, so called leuko-araiosis, often seen in elderly people have been gaining attention due to their association with cognitive dysfunction (CD) and high risk of incident stroke, the pathological significance of these lesions still remains controversial. Therefore, in the present study, we investigated the alterations in oligodendrocytes (OLG), including oligodendrocytes progenitor cells (OPCs), myelin, and CD following chronic cerebral ischemia in rats. SD rats were subjected to bilateral common carotid artery occlusion. Immunohistochemical staining was performed at 2, 4, 6, 8, and 12weeks after the induction of ischemia with anti-NG2 (OPCs), anti-GST-π (OLG), and anti-MBP antibodies in paramedian corpus callosum (CC). CD was assessed by the Morris water maze test. There was a significant decrease in the number of GST-π positive cells at 2weeks after the start of ischemia compared with that seen in the sham group. There was a significant increase of the number of NG2 positive cells at 4weeks in the ischemia group compared with the sham group. In the ischemic group, the amount of MBP was observed to have decreased significantly at each time point compared with the sham group. CD was observed in the ischemic group than that in the sham group at all time points. Our results indicate that remyelination is strongly correlated with the recovery of cognitive dysfunction following chronic cerebral ischemia.

Intraoperative magnetic resonance imaging in the successful surgical treatment of an arteriovenous malformation--case report.

A 44-year-old female presented with left occipital arteriovenous malformation (AVM) manifesting as sudden onset of severe headache. Magnetic resonance (MR) imaging and conventional angiography showed the left occipital AVM with hemorrhage. Intraoperative MR imaging (iMR imaging) and intraoperative time-resolved imaging of contrast-kinetics (iTRICKS) at 1.5 T revealed complete removal of the nidus of the AVM without conventional catheter angiography. Conventional catheter angiography is commonly used in preoperative and intraoperative examination of AVMs, and for documentation of the surgical outcome, but less-invasive techniques are desirable for both preoperative screening and intraoperative examination. iMR imaging with iTRICKS is less invasive and safer than conventional angiography for both brain tumor surgery and AVM surgery.

Technical notes on endoscopic transnasal transsphenoidal approach for clival chondrosarcoma.

Although there are various operative approaches for clival tumors, a transsphenoidal approach is one of choices when the main tumor extention is in an anterior-posterior direction with a slight lateral extension. However, this approach sometimes provides only narrow and deep operative field. Recently, endoscopic transnasal transsphenoidal approach is quite an effective approach for clival tumors because of the improvement of surgical instruments, image guidance systems, and techniques and materials of wound closure. In this paper, we describe the effectiveness, technical problems, and solution of this approach based on our experiences with two clival chondrosarcomas that was removed by endoscopic transnasal transsphenoidal approach.

Abscess formation associated with pituitary adenoma: A case report: Changes in the MRI appearance of pituitary adenoma before and after abscess formation.

BACKGROUND: Pituitary abscess is an extremely rare finding. The abscess may arise as a primary pituitary lesion or be associated with parasellar pathology. It is important for pituitary abscess treatments to perform early diagnosis. In this report, we describe a case of pituitary adenoma in which MRI findings changed during the follow-up period and strongly suggested progression to pituitary abscess arising from adenoma. CASE DESCRIPTION: In a 73-year-old female, pituitary adenoma had been incidentally detected; MRI showed typical findings of pituitary adenoma, and we had followed up the pituitary lesion and clinical symptoms. Six months later, she had oculomotor nerve palsy and symptoms of hypopituitarism. Hematological examination revealed inflammation and hypopituitarism. MRI showed striking changes in the signal intensity of the pituitary lesion, and strongly suggested occurrence of sinusitis and pituitary abscess ascribed to pituitary adenoma. She was admitted and endoscopic transsphenoidal surgery was performed. The sellar floor was destroyed, and yellowish-white creamy pus was observed. A histopathological study using hematoxylin-eosin staining showed adenoma and inflammatory cells. Aerobic, anaerobic, and fungal cultures were negative. Antibiotics were administered and hormonal replacement was started. Neurological and general symptoms were improved, and postoperative MRI revealed complete evacuation of abscess and removal of tumor. CONCLUSIONS: Pituitary abscess within invasive pituitary adenoma is a rare entity, and shows high mortality. Early diagnosis of pituitary abscess is very important for the prompt surgery and initiation of treatment with antibiotics. In our case, changes in MRI findings were helpful to diagnose pituitary abscess, and endoscopic transsphenoidal surgery was an optimal surgical treatment.

[Detection of acute subdural hemorrhage using intraoperative MR imaging during glioma surgery: a case report].

Intraoperative MRI (iMR) and neuronavigation have substantially changed the principles of surgery for brain tumors. iMR provides updated information on anatomical data and unanticipated brain events, thereby allowing safer and more accurate surgery. We herein report a case of unanticipated intracranial hemorrhage in an iMR imaging suite. The patient was a 53-year-old man with a chief complaint of generalized convulsion. MRI showed a lesion in the right temporal lobe about 6.0 cm in diameter. The tumor was resected using an iMR system and neuronavigation. The first iMR images showed a residual tumor in the medial temporal lobe. No brain events were detected at this time. We obtained updated navigation data and performed additional resection. After completion of the planned tumor resection, additional iMR images were taken. The second iMR images confirmed that the tumor had been completely removed, but they also revealed a contra-lateral subdural hemorrhage. After expedited closure of the original incision, left unilateral craniotomy was performed and the hematoma was evacuated. Fortunately, the patient had no new neurological deficits. The use of iMR imaging allowed the complete removal of the tumor and facilitated prompt and effective identification of an unanticipated life-threatening complication.

[Intracranial extraskeletal mesenchymal chondrosarcoma arising from falx: a case report and literature review].

Intracranial extraskeletal mesenchymal chondrosarcoma is a very rare tumor that affects young adults. We report a 31-year-old woman with a huge intracranial extraskeletal mesenchymal chondrosarcoma. She presented with a history of right homonymous hemianopsia for 6 months. Computed tomography scans demonstrated a heterogeneously enhanced mass, in the right occipital region, which was lobulated and contained areas of calcification. Magnetic resonance imaging demonstrated a large mass (67 mm) of heterogenous intensity that showed enhancement and was attached to the falx cerebri. The patient underwent right occipital craniotomy and subtotal removal of the tumor. At operation, the tumor was found to arise in the falx cerebri and the cranial vault was not involved. Pathologic examination revealed a mesenchymal chondrosarcoma. She underwent conventional radiotherapy after surgery and remained free of progression at the 20-month follow up. We review previously reported cases of extraskeletal intracranial mesenchymal chondrosarcoma and discuss imaging diagnosis, treatment strategies, and outcome.

[Case report: spontaneous rupture of an asymptomatic intracranial dermoid].

We report a rare case of spontaneous rupture of an asymptomatic, intracranial dermoid cyst. A 64-year-old man complained of transient dizziness. MRI incidentally disclosed a 20-mm-diameter cystic lesion in the left cerebellopontine angle. Since the cyst was asymptomatic, follow-up MRIs were performed. One year later, sudden headache and left oculomotor palsy occurred. MRI showed niveau formation within the cyst and scattered fat droplets within the cerebrospinal fluid space, which indicated a spontaneous rupture of the dermoid cyst. Since hydrocephalus on MRI and gait disturbance appeared 2 months later, the tumor was resected, and a ventriculoperitoneal shunt was inserted. The patient's symptoms disappeared, and there were no postoperative neurological deficits. The pathological diagnosis was dermoid cyst. Only 48 cases of spontaneous rupture of a dermoid cyst have been reported. All were symptomatic, and MRI showed a large cyst. Of these cases, none was detected incidentally. Therefore, this is the first case report of an incidentally found dermoid cyst that ruptured spontaneously. Although asymptomatic, small dermoid cysts are usually followed up by MRI without surgical intervention. The possibility of spontaneous rupture, which may give rise to hydrocephalus, as in this case, should always be kept in mind.

Temporal profile of neurogenesis in the subventricular zone, dentate gyrus and cerebral cortex following transient focal cerebral ischemia.

BACKGROUND: In the adult mammalian brain, it is considered that neurogenesis persists in limited regions such as the hippocampal dentate gyrus (DG) and the subventricular zone (SVZ) of the lateral ventricle. On the other hand, neurogenesis in the cortex after cerebral ischemia and its role in post-stroke recovery have not been clarified yet. In this study, we investigated neurogenesis in the cortex and the spatiotemporal profile of neural progenitors in SVZ and DG of rats subjected to transient focal cerebral ischemia. MATERIALS AND METHODS: Male Sprague-Dawley rats (270-300 g) were subjected to 60 minute middle cerebral artery occlusion. Proliferating cells were labeled by the cumulative administration of BrdU 1, 2, 3, 4, 6 and 8 weeks after ischemia induction (at weeks 1-4, 6 and 8). Double labeling was also performed with antibodies against BrdU and NeuN. RESULTS: BrdU-positive cells proliferated in DG and SVZ of the bilateral hemispheres, and their proliferation peaked at week 3 in SVZ and at week 4 in DG. In the peri-infarct zone of cerebral cortex, BrdU-positive cells co-expressed NeuN from weeks 3 to 8. CONCLUSION: Neurogenesis was observed in the cerebral cortex and proliferation of neural progenitors occurred in SVZ and DG of rats subjected to transient focal cerebral ischemia. Our data might indicate that endogenous dormant neural stem cells residing in the cortex were activated by ischemic insult to induce the proliferation of neural progenitors and differentiation into mature neurons.

Correlation between copper/zinc superoxide dismutase and the proliferation of neural stem cells in aging and following focal cerebral ischemia.

OBJECT: Neural stem cells (NSCs) have been demonstrated in the subventricular zone (SVZ) of the lateral ventricle and the subgranular zone of the hippocampal dentate gyrus (DG). Although aging rats manifest a decrease in NSCs, rats exposed to stress (for example, ischemia, epilepsy, radiation, and trauma) show an increase in these cells. In transgenic mice, the overexpression of human copper/zinc superoxide dismutase (SOD1), an endogenous antioxidant, has been reported to be a protective enzyme against transient focal cerebral ischemia. The authors investigated the correlation between SOD1 and the proliferation of NSCs in aging as chronic oxidative stress (Experiment 1) and acute oxidative stress induced by transient focal cerebral ischemia (Experiment 2) in mice. METHODS: Bromodeoxyuridine (BrdU) was used in the evaluation of NSCs. In Experiment 1, NSCs in the SVZ significantly increased in 16-month-old transgenic mice compared with wild-type mice (p = 0.0001). In Experiment 2, mice were subjected to 30-minute occlusions of the middle cerebral artery. The increase in NSCs in the DG in transgenic mice was significantly greater than that in wild-type mice (p < 0.05). CONCLUSIONS: Results in this study suggest that chronic and acute oxidative stress may inhibit the proliferation of NSCs and that SOD1 may play a key role in NSC proliferation.