A Headrest Made of Extruded Polystyrene Reduces the Influence of Attenuation Correction on Human Brain SPECT Images.

Previous reports suggest that a headrest made of carbon significantly influences cerebral blood flow in the anterior and posterior regions by image reconstruction and attenuation correction (AC). The present study aimed to develop a headrest that reduces the influence of the AC process on human brain SPECT. Methods: To validate the performance of a headrest made of extruded polystyrene (XPS), 10 healthy controls and 43 patients with cerebrovascular disease underwent 99mTc-ethyl cysteinate dimer SPECT using a carbon headrest and an XPS headrest. We evaluated the anterior-to-posterior and middle-to-posterior ratio of the brain regions in filtered backprojection (FBP) Chang AC, ordered-subset expectation maximization (OSEM) Chang AC, and OSEM CT-based AC. Results: The anterior-to-posterior ratio was significantly higher with the carbon headrest than with the XPS headrest in FBP Chang AC and OSEM Chang AC (P < 0.001). There was no significant difference between the materials in OSEM CT-based AC. The middle-to-posterior ratio did not differ to a statistically significant extent in any correction process. Conclusion: Acquisition of brain SPECT images with an XPS headrest and processing by the FBP or OSEM Chang AC method enables the influence of the headrest to be reduced, especially in anterior and posterior brain regions.

RGB camera-based simultaneous measurements of percutaneous arterial oxygen saturation, tissue oxygen saturation, pulse rate, and respiratory rate.

We propose a method to perform simultaneous measurements of percutaneous arterial oxygen saturation (SpO 2), tissue oxygen saturation (StO 2), pulse rate (PR), and respiratory rate (RR) in real-time, using a digital red-green-blue (RGB) camera. Concentrations of oxygenated hemoglobin (C HbO), deoxygenated hemoglobin (C HbR), total hemoglobin (C HbT), and StO 2 were estimated from videos of the human face using a method based on a tissue-like light transport model of the skin. The photoplethysmogram (PPG) signals are extracted from the temporal fluctuations in C HbO, C HbR, and C HbT using a finite impulse response (FIR) filter (low and high cut-off frequencies of 0.7 and 3 Hz, respectively). The PR is calculated from the PPG signal for C HbT. The ratio of pulse wave amplitude for C HbO and that for C HbR are associated with the reference value of SpO 2 measured by a commercially available pulse oximeter, which provides an empirical formula to estimate SpO 2 from videos. The respiration-dependent oscillation in C HbT was extracted from another FIR filter (low and high cut-off frequencies of 0.05 and 0.5 Hz, respectively) and used to calculate the RR. In vivo experiments with human volunteers while varying the fraction of inspired oxygen were performed to evaluate the comparability of the proposed method with commercially available devices. The Bland-Altman analysis showed that the mean bias for PR, RR, SpO 2, and StO 2 were -1.4 (bpm), -1.2(rpm), 0.5 (%), and -3.0 (%), respectively. The precisions for PR, RR, Sp O 2, and StO 2 were ±3.1 (bpm), ±3.5 (rpm), ±4.3 (%), and ±4.8 (%), respectively. The resulting precision and RMSE for StO 2 were pretty close to the clinical accuracy requirement. The accuracy of the RR is considered a little less accurate than clinical requirements. This is the first demonstration of a low-cost RGB camera-based method for contactless simultaneous measurements of the heart rate, percutaneous arterial oxygen saturation, and tissue oxygen saturation in real-time.

A Case of Coil Embolization with Crossing Y-Configuration Stenting for a Recurrent IC-PC Aneurysm after Clipping.

Objective: We report a case in which coil embolization using crossing Y-configuration stenting was effective for an internal carotid-posterior communicating artery (IC-PC) aneurysm with repeated recurrence after clipping. Case Presentation: The patient was a 57-year-old woman. Nine months after undergoing clipping for a ruptured right IC-PC aneurysm at 55 years of age, she developed a second subarachnoid hemorrhage (SAH) due to recurrence of the aneurysm and underwent clipping at the same site. A third SAH due to rupture of the left IC-PC aneurysm developed 1.5 years after the second clipping. Simultaneously, recurrence of a right IC-PC aneurysm was noted and she was referred to our department. The recurrent right IC-PC aneurysm was considered to have originated from the distal to the initial neck. It was 7 mm in size and had an irregularly shaped wide neck. As it was assumed that there would be marked adhesion due to repeated surgery, we decided to treat the aneurysm by coil embolization instead of direct surgery. Although the aneurysm neck partially involved the posterior communicating artery (Pcom), tight packing with a minimal residual neck was required. Therefore, crossing Y-configuration stenting was deployed on the internal carotid artery and Pcom using two Neuroform Atlas stents, and coil embolization was performed by the jail technique. The recurrent aneurysm was obliterated. There were no deficits or thrombotic complications after surgery. On DSA follow-up, no compaction or recurrence was observed, and the Pcom was well visualized one year later. Conclusion: Coil embolization by crossing Y-configuration stenting is a viable treatment option for a recurrent IC-PC wide neck aneurysm.

Preoperative Apparent Diffusion Coefficient of Peritumoral Lesion Associate with Recurrence in Patients with Glioblastoma.

Additional resection beyond contrast enhanced lesion on MRI is recently considered to prolong survival in glioblastoma. Prediction of future recurrent site in the peritumoral lesion on preoperative MRI could be useful for surgical planning. The objective of this study was to determine if the preoperative ADC value was associated with the site of future recurrence in patients with glioblastoma. We retrospectively analyzed 21 patients with primary GBM. The ADC value on MRI were analyzed before and after operation and at recurrence. The region of interests (ROIs) were set to cover almost the FLAIR high-signal lesion surrounding contrast enhanced lesion. We determined whether the value of ADC on MRI was correlated with the spot of future recurrence. Among 1844 ROIs determined in the FLAIR high-signal lesion on preoperative MRI, new enhanced lesions occurred in 186 sites. The other 1258 sites showed no change or decrease in size on follow up MRI, and the other 400 sites were removed in first operation. The pre-operative ADC values of sites corresponding to future recurrence were significantly lower than that of non-recurrent sites (p <0.001). We suggest that a low ADC values in FLAIR high-signal lesion is corresponding to recurrence, and useful for predicting recurrence of the lesion in cases of GBM. These results will be helpful for planning of surgery or radiation therapy and facilitate future prospective studies on GBM.

A case report: An increased oxygen extraction fraction in remote ischemic lesions after revascularization for moyamoya disease with a progression of posterior cerebral artery stenosis.

The cerebral metabolism, such as the oxygen extraction fraction (OEF), in remote ischemic lesions following revascularization for moyamoya disease (MMD) has not yet been fully elucidated. We herein report a patient with an increased OEF in a remote ischemic lesion after revascularization in a case of adult-onset MMD. A 21-year-old woman suffered from a left parietal lobe infarction due to MMD. At 2 months after onset, left superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and encephalo-myo-synangiosis (EMS) were performed. The postoperative course was uneventful. 15O-positron emission tomography (PET) performed at 2 months after the first operation revealed an increased OEF in the contralateral (right) frontal lobe that was suspected of being possible remote ischemia. The patient underwent right STA-MCA bypass and EMS. 15O-PET at 14 days after the second operation revealed an increased OEF in the contralateral (left) occipital lobe that was suspected of potentially being remote ischemia caused by a watershed shift. Two years after the second surgery, left occipital artery (OA)-posterior cerebral artery (PCA) anastomosis and EMS were performed due to transient right hemianopsia. Neither rebleeding nor ischemic complications occurred 2 years after the third surgery. We need to be alert for the possible progression of PCA stenosis in MMD after revascularization. It might induce remote ischemia after revascularization. OA-PCA bypass is therefore considered to be an effective treatment option in such cases.

Hybrid Surgical and Endovascular Approach via the Contralateral Superficial Middle Cerebral Vein to Occlude Cavernous Sinus Dural Arteriovenous Fistula in a Hybrid Operating Room: A Case Report.

Most cases of cavernous sinus dural arteriovenous fistula (CS-dAVF) are treated via the inferior petrous sinus (IPS) through the transfemoral vein approach, but there are cases where treatment through the superficial middle cerebral vein (SMCV) is required. A hybrid operating room (OR) is useful because it allows for smooth direct surgery and endovascular treatment in a clean surgical field. We herein report a case of simultaneous treatment for CS-dAVF by coil embolization via a contralateral SMCV and middle cerebral artery (MCA) aneurysm by clipping in a hybrid OR. A 68-year-old woman had been suffering from left chemosis and ptosis for 2 months before visiting our hospital. Digital subtraction angiography (DSA) revealed Borden type II and Cognard type II a+b CS dAVF with parenchymal hemorrhaging and an unruptured left M1/M2 junction aneurysm. Since passing through the CS via the femoral vein was unsuccessful, we decided to access the right CS via the left CS through the intercavernous sinus (ICS) via the left SMCV by the pterional approach in a hybrid OR equipped with a multi-axis working system angiography machine. Endovascular treatment via direct cannulation into the contralateral SMCV following craniotomy in a hybrid OR is an optional strategy for treating complicated CS-dAVF.

Arterial spin labeling magnetic resonance imaging at short post-labeling delay reflects cerebral perfusion pressure verified by oxygen-15-positron emission tomography in cerebrovascular steno-occlusive disease.

BACKGROUND: Arterial transit time correction by data acquisition with multiple post-labeling delays (PLDs) or relatively long PLDs is expected to obtain more accurate imaging in cases of the cerebrovascular steno-occlusive disease. However, there have so far been no reports describing the significance of arterial spin labeling (ASL) images at short PLDs regarding the evaluation of cerebral circulation in ischemic cerebrovascular disease. PURPOSE: To clarify the role of short-PLD ASL in cerebrovascular steno-occlusive disease. MATERIAL AND METHODS: Fifty-three patients with cerebrovascular steno-occlusive disease were included in this study. All patients underwent ASL magnetic resonance imaging and 15O-PET within two days of each modality. To compare the ASL findings with each parameter of PET, the right-to-left (R/L) ratio, defined as the right middle cerebral artery (MCA) value/left MCA value, was calculated. RESULTS: There is a significant correlation between the ASL images at a short PLD and the ratio of cerebral blood flow and cerebral blood volume by 15O-PET, which may accurately reflect the cerebral perfusion pressure. A receiver operating characteristic curve analysis indicated that ASL images at PLD 1000 and 1500 ms were more accurate than at PLD 2000-3000 ms for the detection of a ≥10% change in the PET cerebral blood flow. CONCLUSION: ASL images at shorter PLDs may be useful at least as a screening modality to detect the changes in the cerebral circulation in cerebrovascular steno-occlusive disease. We must evaluate ASL images at multiple PLDs while considering the arterial transit time of each case at present.

Influence of a Headrest on Reconstruction and Attenuation Correction of Human Brain SPECT Images.

Previous reports suggest that a headrest significantly influences anterior and posterior cerebral blood flow. The present study aimed to clarify the influence of a headrest on reconstruction and attenuation correction (AC) of brain SPECT images. Methods: We evaluated the influence on cerebral blood flow in the anterior region (brain segments A + B), middle region (segments D + F), and posterior region (segment G) of the brain using filtered backprojection-AC based on the method of Chang (FBP-ChangAC), ordered-subset expectation maximization-ChangAC (OSEM-ChangAC), OSEM CT-based AC (OSEM-CTAC), and OSEM with no attenuation correction (OSEM-NoAC) with and without a headrest. The subjects were 17 healthy volunteers who underwent 99mTc-ECD SPECT. We compared the A + B/G and the D + F/G ratios of 99mTc-ECD SPECT images in each group. Results: For FBP-ChangAC, OSEM-ChangAC, and OSEM-NoAC, there were significant differences in A + B/G ratio between images obtained with a headrest and those obtained without. On the other hand, for OSEM-CTAC, there were no significant differences in A + B/G ratio regardless of whether a headrest was used. For FBP-ChangAC and OSEM-NoAC, there were significant differences in D + F/G ratio between images with a headrest and those without. For OSEM-CTAC and OSEM-ChangAC, there were no significant differences in D + F/G ratio regardless of whether a headrest was used. Conclusion: The influence of a headrest on image reconstruction and AC should be considered if FBP-ChangAC, OSEM-ChangAC, or OSEM-NoAC is used but not if OSEM-CTAC is used.

[A Case of Unruptured Internal Carotid Artery Aneurysm with Improved Endocrinological Function after Treatment].

We experienced a case of unruptured internal carotid artery aneurysm improved endocrinological function after the treatment. A 68-year-old woman was admitted to our hospital complaining of general fatigue, dizziness, and decreased visual acuity. Radiological examination revealed unruptured large aneurysm at the right anterior carotid artery compressing on the pituitary gland. We underwent right STA-MCA bypass and trapping of right internal carotid artery. Post-operative course was uneventful. Although visual function was not improved, her endocrinological function was improved 8 months after surgery by thrombosed and shrunken aneurysm. The mechanism of panhypopituitarism due to aneurysm has been suggested to involve mechanical compression on the pituitary gland, pituitary stalk, or hypophyseal artery. Although it was unclear about the improvement of endocrine function after the treatment of aneurysm, some cases could recover the hypopituitarism after enough follow-up period.

[Intracranial Pseudoaneurysm Arising after Radiotherapy for Oligodendroglioma:A Case Report].

Intracranial pseudoaneurysms arising after radiotherapy for brain tumors are a relatively rare occurrence and associated with high-volume radiotherapy such as stereotactic radiosurgery. Herein, the authors report a rare case of intracranial pseudoaneurysm after conventional radiotherapy for oligodendroglioma. Case:A 46-year-old female incidentally presented with an intracranial hemorrhage from a middle temporal artery aneurysm. Four years earlier, she underwent surgical resection and conventional radiation therapy for oligodendroglioma. The aneurysm was successfully treated with middle cerebral artery(MCA)aneurysm trapping, in conjunction with a parietal branch superficial temporal artery-MCA bypass, to prevent re-rupture. Formation of intracranial pseudoaneurysm after conventional radiotherapy is extremely rare. However, the occurrence of cerebral aneurysm(s), as well as vascular stenosis during follow-up for brain tumors treated with radiotherapy, should be considered.

A case report: C2 radiculopathy induced by neck flexion due to the cord compression of C2 segmental type vertebral artery relieved by microvascular decompression.

BACKGROUND: Decompression of an anomalous vertebral artery (VA) may effectively treat cervical myelopathy/radiculopathy due to resultant spinal cord or nerve compression. Here we report a case of C2 radiculopathy induced by neck flexion due to cord compression of the C2 segmental type VA relieved by microvascular decompression. CASE DESCRIPTION: A 30-year-old female presented with left occipitalgia, sensory abnormalities in the left upper and lower extremities, and neck pain induced by neck flexion. The magnetic resonance imaging (MRI) revealed an abnormal flow void, confirming that the VA was compressing the spinal cord at the C1 level. Three-dimensional computed tomography (3D-CT) showed an anomalous course of the left VA, which entered the spinal canal between the axis and atlas. Microvascular decompression was performed by transposing the artery (e.g., anchoring it to the dura using PTEF): this effectively relieved cord compression. CONCLUSION: An anomalous VA rarely causes cervical radiculopathy induced by neck flexion. When it occurs, microvascular decompression effectively relieves pressure resulting in a resolution of symptoms.

In Vivo Evaluation of Cerebral Hemodynamics and Tissue Morphology in Rats during Changing Fraction of Inspired Oxygen Based on Spectrocolorimetric Imaging Technique.

During surgical treatment for cerebrovascular diseases, cortical hemodynamics are often controlled by bypass graft surgery, temporary occlusion of arteries, and surgical removal of veins. Since the brain is vulnerable to hypoxemia and ischemia, interruption of cerebral blood flow reduces the oxygen supply to tissues and induces irreversible damage to cells and tissues. Monitoring of cerebral hemodynamics and alteration of cellular structure during neurosurgery is thus crucial. Sequential recordings of red-green-blue (RGB) images of in vivo exposed rat brains were made during hyperoxia, normoxia, hypoxia, and anoxia. Monte Carlo simulation of light transport in brain tissue was used to specify relationships among RGB-values and oxygenated hemoglobin concentration (CHbO), deoxygenated hemoglobin concentration (CHbR), total hemoglobin concentration (CHbT), hemoglobin oxygen saturation (StO2), and scattering power b. Temporal courses of CHbO, CHbR, CHbT, and StO2 indicated physiological responses to reduced oxygen delivery to cerebral tissue. A rapid decrease in light scattering power b was observed after respiratory arrest, similar to the negative deflection of the extracellular direct current (DC) potential in so-called anoxic depolarization. These results suggest the potential of this method for evaluating pathophysiological conditions and loss of tissue viability.

[A Case of Lymphocytic Adenohypophysitis Presenting Visual Disturbance in the Third Trimester of Pregnancy].

Lymphocytic hypophysitis(LH)has first been described as an autoimmune endocrinopathy by Goudie in 1962. In particular, lymphocytic adenohypophysitis(LAH)is usually associated with pregnancy and hypopituitarism due to insufficient endocrine of ACTH. However, several cases of LAH in pregnant patients showing only visual disturbances have recently been documented. We treated a patient with LAH presenting only the chiasma syndrome in the third trimester without hypopituitarism. A 27-year-old woman unexpectedly experienced visual disturbance starting in the 28th week of pregnancy. Her symptoms progressed rapidly. MRI revealed a pituitary mass lesion compressing the optic chiasma. In addition, ophthalmological examination revealed bitemporal hemianopsia. The patient underwent endoscopic transsphenoidal surgery(eTSS)during the 30th week of pregnancy. LH was diagnosed histologically during surgery. We performed decompression of optic chiasma. After surgery, the patient's visual field markedly widened and the pituitary mass regressed along with replacement of corticosteroids. In the 37th week of pregnancy, she delivered a healthy baby. We speculate that the reason for the absence of hypopituitarism during pregnancy in patients with LH, especially in the third trimester, might be that the placental endocrine system masks pituitary endocrinopathy. In summary, we report a case of LAH that did not present with hypopituitarism, and eTSS could be performed safely during pregnancy.

A case of Langerhans cell histiocytosis of the skull in which preoperative methionine positron emission tomography was useful in comprehending the spreading of the lesion.

BACKGROUND: The problem with treatments against skull lesions of Langerhans cell histiocytosis (LCH) is that invasions often reach the bones and dura mater, making it difficult to accurately comprehend the range thereof prior to surgery. We herein report that (11)C-methionine positron emission tomography (PET) (Met-PET) carried out prior to surgery was useful in comprehending the spreading of the lesion. CASE DESCRIPTION: A 20-year-old female presented with swelling and dull pain on the left side of the head. A slightly heterogeneously reinforced tumor was observed inside the bone defect in the gadolinium-enhanced T1-wighted image upon magnetic resonance imaging (MRI) and the dura mater contacting the tumor was observed with an enhancing effect. Accumulation was poor in the center of the tumor upon Met-PET, and accumulation with a well-defined border was observed in the border thereof as well as the area adjacent to the brain. Surgical resection was performed; the pathological diagnosis was LCH. An invasion of tumor cells was observed in the dura mater with accumulation observed according to Met-PET. Moreover, the accumulation of tumor cells was observed in the area observed with accumulation inside the bone; however, the center part with poor accumulation lacked tumor cells, with fibrous tissue accounting for most parts. CONCLUSION: Met-PET was believed to be helpful in comprehending the spreading of the tumor in the surroundings of the brain surface for skull lesions.

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.

[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.

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.

[Sacrococcygeal dermal sinus presented bacterial meningitis: a case report].

A rare case of sacrococcygeal dermal sinus suffering from relapsing meningitis is presented. In addition, deference of clinical figure and pathology between sacrococcygeal region and other regions are discussed. A 10 -month-old boy was suffering from relapsing meningitis. Spinal MRI was performed to find occult spinal dysraphism because he had a pit on his hip. The MRI revealed sacrococcygeal dermal sinus. He received surgical resection of dermal sinus based on this findings. Interestingly, different from other dermal sinuses, the dermal sinus runs to caudal direction, and was fused filum terminale with dermoid cyst. This interesting pathological feature of sacrococcygeal dermal sinus seems to come from developmental difference between sacrococcygeal dermal sinus and the other dermal sinuses. Only sacrococcygeal dermal sinus is related with caudal cell mass on its pathogenesis. Because filum terminale is also developed from caudal cell mass, sacrococcygeal dermal sinus seems to be related with filum terminale. Most important differential diagnosis is coccygeal pit that is found in 1 -4% of newborn baby. The clinical feature and pathology got from our case must be very helpful to distinguish sacrococcygeal dermal sinus from coccygeal pit.

[Trends in the incidence of stroke in Yamagata, Japan].

The purpose of this study was to clarify the incidence and features of acute cerebrovascular diseases in Yamagata Prefecture, by comparing with those in other prefectures reported in previous studies. Consecutive 13,639 cases of acute stroke were prospectively registered to Yamagata Society in Treatment for Cerebral Stroke (YSTCS) between January 1, 1998 and December 31, 2002. Cerebral infarction (CI), intracerebral hemorrhage (CH), subarachnoid hemorrhage (SAH) and transient ischemic attack (TIA) were observed in 58.4%, 25.8%, 11.4% and 4.4% of the patients, respectively. The frequencies of CH and SAH (37.2%) in Yamagata Prefecture were higher than those reported in other studies (p < 0.01). In addition, time from onset to admission in Yamagata Prefecture was longer than that reported in others(p< 0.01). This study was one of the largest stroke registration studies in Japan enrolling 13,639 patients. In addition, computed tomography (CT) and/or magnetic resonance image (MRI) was performed on admission in all patients. Diagnosis was made by a neurologist or a neurosurgeon based on CT and/or MRI findings. Our results might accurately reflect current status of stroke patients in Yamagata Prefecture.