Reversible Bilateral Transverse Sinus Occlusion Treated by Lumboperitoneal Shunt in Idiopathic Intracranial Hypertension: A Case Report.

We report a patient with idiopathic intracranial hypertension (IIH) with bilateral transverse sinus occlusion treated by a lumboperitoneal shunt. A 45-year-old woman presented with visual disturbance and chronic headache. Magnetic resonance (MR) venography and three-dimensional computed tomography angiography (3D-CTA) showed occlusion of both transverse sinuses. After the surgery, MR venography and 3D-CTA showed no blockages in both transverse sinuses. This phenomenon reveals that obstruction of the bilateral transverse sinus is a consequence of intracranial hypertension, not just a single cause. Since many patients have an obstruction or stenosis of the venous sinus, there are some reports of endovascular treatment. Sinus reconstruction is usually effective, but it is not effective in some cases. Reversal of sinus occlusion suggests that endovascular therapy for IIH is inadequate in some cases.

Acoustic neuromas associated with sudden sensorineural hearing loss.

BACKGROUND: Several studies have reported sudden sensorineural hearing loss (SHL) as an initial symptom of acoustic neuromas (ANs). AIMS/OBJECTIVES: We aimed to retrospectively evaluate the incidence of SHL and the associated rates of post-treatment improvement in patients diagnosed with ANs. MATERIALS AND METHODS: We analysed the clinical data of 686 patients with ANs and examined tumour size, correlation with hearing loss, number of episodes of SHL, extent of auditory recovery, and associated audiogram patterns. RESULTS: Among 686 enrolled patients with ANs, 232 (86 with intracanalicular and 146 with extrameatal tumours) experienced SHL at some point in their clinical history. The incidence of SHL was not significantly associated with tumour size. Of the 172 patients analysed, 119, 44, and 9 patients experienced one, two, or three or more episodes of SHL, respectively. Confirmed auditory recovery occurred in 61%, 45.3%, and 33.3% of the patients after the first, second, or third or later episodes of SHL, respectively. The audiograms of 78/172 (45.3%) patients showed a typical trough-shaped pattern of hearing loss at medium-level frequencies. CONCLUSIONS AND SIGNIFICANCE: Among patients with ANs, 7.7% experienced two or more episodes of SHL. The recovery rate of SHL decreased with each successive occurrence.

Usefulness of T2 Relaxation Time for Quantitative Prediction of Meningioma Consistency.

BACKGROUND: Meningioma consistency is one of the most critical factors affecting the difficulty of surgery. Although many studies have attempted to predict meningioma consistency via magnetic resonance imaging findings, no definitive method has been established, because most have been based on qualitative evaluations. Therefore, the present study examined the potential of the T2 relaxation time (T2 value), a tissue-specific quantitative parameter, for assessment of meningioma consistency. METHODS: Eighteen surgically treated meningiomas in 16 patients were included in the present study. Preoperatively, the T2 values of all meningiomas were calculated pixel by pixel, and a T2 value distribution map was generated. A total of 27 tumor specimens (multiple specimens were procured if heterogeneous) were taken from these meningiomas, with each localization identified intraoperatively using image guidance. The consistency of the specimens was measured with a durometer, originally a device for measuring the hardness of material such as elastic rubber, and their water content was subsequently measured using wet and dry measurements. RESULTS: A significant correlation was found between the T2 values of the matched locations identified by image guidance intraoperatively and the consistency measured using the durometer (r = -0.722; P < 0.01) and the water content (r = 0.621; P = 0.01). In addition, the water content correlated significantly with the durometer consistency (r = -0.677; P < 0.01). CONCLUSIONS: The T2 values could be a reliable quantitative predictor of meningioma consistency, and the T2 value distribution map, which elucidated the internal structure of the tumor in detail, could provide helpful information for surgical resection.

Balloon Test Occlusion of the Carotid Artery: Internal Validation of Predictive Results.

AIM: To develop a protocol of balloon test occlusion (BTO) to perform single-photon emission computed tomography (SPECT) only in cases that require it by using mean stump pressure (MSTP). MATERIAL AND METHODS: BTO was performed in 52 consecutive patients (derivation group). Using the derivation group data, a protocol was created and applied to 55 consecutive patients (validation group). RESULTS: In the derivation group, all patients with MSTP ≥65 mmHg had an ischemic tolerance, whereas those with MSTP ?45 mmHg were considered ischemic intolerant. Based on these results, we developed a protocol wherein MSTP between 45 mmHg and 65 mmHg was defined as "ischemic borderzone" and SPECT was performed in these cases. Using this protocol, BTO was performed in the validation group and 19 patients were treated with parent artery occlusion with or without bypass. In two cases that did not follow the protocol, the occurrence of hypoperfusion caused cerebral infarction after treatment. However, if this protocol had been followed for all cases, no false-negative cases of BTO would have occurred. CONCLUSION: By measuring MSTP and identifying the approximate ischemic tolerability, the current protocol can identify cases requiring SPECT, which is particularly reliable but complicated. Moreover, this protocol would be especially useful for reducing false-negative cases of BTO.

A Case of Sarcoidosis-lymphoma Syndrome: Importance of Brain Biopsy.

Sarcoidosis is occasionally associated with malignant lymphoma. Cases of sarcoidosis associated with malignant lymphoma are called sarcoidosis-lymphoma syndrome. We report a 63-year-old man with sarcoidosis associated with primary central nervous system lymphoma (PCNSL). Definitive diagnosis by clinical and radiological findings was difficult. Finally, brain biopsy could produce the correct diagnosis. We could provide appropriate treatment for PCNSL and the patient has survived over 2 years. Thus, it is very important to make an early definitive diagnosis by biopsy for intracranial lesion, because it can prolong survival in patients with sarcoidosis.

Postoperative Headache after Undergoing Acoustic Neuroma Surgery via the Retrosigmoid Approach.

To estimate the duration of postoperative headache after surgery for acoustic neuroma and the effects of age, sex, tumor size, extent of tumor resection, type of skin incision, surgical duration, hearing preservation, and postoperative facial nerve palsy. This retrospective review analyzed clinical data from 97 patients who had undergone surgery for unilateral acoustic neuroma via the retrosigmoid approach >1 year previously. We investigated whether patients had headache at hospital discharge and during attendance at outpatient clinics. We classified postoperative headache as grade 0 (no headache), 1 (tolerable headache without medication), or 2 (headache requiring medication). The period of headache was defined as the interval in days between surgery and achievement of grade 0. The period of medication for headache was defined as the interval in days between surgery and achievement of grade 0 or 1. Kaplan-Meier analysis revealed median durations of medication and headache of 81 and 641 days, respectively. Headache was cured significantly earlier in patients who underwent surgery using a C-type skin incision (P < 0.001). Headache persisted significantly longer among patients who underwent a shorter surgical procedure (P < 0.02). Multivariate analysis confirmed the type of skin incision as a factor independently associated with duration of postoperative headache. Postoperative headache was cured in the majority of patients within about 2 years after surgery. The C-type skin incision is likely beneficial for reducing the duration of postoperative headache, although headache persisted in a small number of patients.

Enlargement of the Internal Auditory Canal and Hearing Preservation in the Middle Fossa Approach for Intracanalicular Vestibular Schwannomas.

OBJECTIVE: The middle fossa (MF) approach is one of the treatment options for patients with intracanalicular vestibular schwannomas. This study investigated whether enlargement of the internal auditory canal (IAC) represents a risk factor for hearing loss in the MF approach. METHODS: Participants comprised 48 patients who underwent resection of intracanalicular vestibular schwannoma using the MF approach at Nagoya City University Hospital. In this retrospective case review, the shape of the IAC on the affected side was compared with the normal side by coronal reconstruction computed tomography images. A difference of > 1 mm was judged as IAC enlargement. Patients were classified into 4 groups: NE, no enlargement; SE, superior enlargement; IE, inferior enlargement; and BE, both superior and inferior enlargement. In addition, pure-tone average (PTA) and speech discrimination score (SDS) were estimated before and after surgery to evaluate hearing. RESULTS: Hearing preservation (PTA ≤ 50 dB; SDS ≥ 50%) was seen in 96% (21/22), 100% (3/3), 50% (8/16), and 29% (2/7) in the NE, SE, IE, and BE groups, respectively. A significant difference in hearing preservation was seen between cases without IE (NE and SE) and cases with IE (IE and BE) (P < 0.0001). IE of the IAC was identified as an independent risk factor for hearing loss by logistic regression analysis (odds ratio, 32.0; 95% confidence interval, 4.2-783.6). CONCLUSIONS: Enlargement of the IAC on coronal reconstruction computed tomography scan before surgery can predict hearing preservation using the MF approach. Patients without IE may represent good surgical candidates for the MF approach.

Preoperative characteristics of auditory brainstem response in acoustic neuroma with useful hearing: importance as a preliminary investigation for intraoperative monitoring.

We classified the results of preoperative auditory brainstem response (ABR) in 121 patients with useful hearing and considered the utility of preoperative ABR as a preliminary assessment for intraoperative monitoring. Wave V was confirmed in 113 patients and was not confirmed in 8 patients. Intraoperative ABR could not detect wave V in these 8 patients. The 8 patients without wave V were classified into two groups (flat and wave I only), and the reason why wave V could not be detected may have differed between the groups. Because high-frequency hearing was impaired in flat patients, an alternative to click stimulation may be more effective. Monitoring cochlear nerve action potential (CNAP) may be useful because CNAP could be detected in 4 of 5 wave I only patients. Useful hearing was preserved after surgery in 1 patient in the flat group and 2 patients in wave I only group. Among patients with wave V, the mean interaural latency difference of wave V was 0.88 ms in Class A (n = 57) and 1.26 ms in Class B (n = 56). Because the latency of wave V is already prolonged before surgery, to estimate delay in wave V latency during surgery probably underestimates cochlear nerve damage. Recording intraoperative ABR is indispensable to avoid cochlear nerve damage and to provide information for surgical decisions. Confirming the condition of ABR before surgery helps to solve certain problems, such as choosing to monitor the interaural latency difference of wave V, CNAP, or alternative sound-evoked ABR.

Interaural Difference of Wave V Predicting Postoperative Hearing in Gardner-Robertson Class II Acoustic Neuroma Patients.

Patients with acoustic neuroma classified in Gardner and Robertson (GR) Class II should be considered to have useful hearing, and patients classified in Class III should be considered to have not-useful hearing. Therefore, it is important for acoustic neuroma surgery to distinguish between postoperative GR Class II and Class III patients by brainstem auditory evoked potentials (BAEPs). We evaluate which BAEP parameter is the best for predicting postoperative GR Class II or III in 36 preoperative GR Class II patients with unilateral acoustic neuroma. Delay in wave V latency, reduction ratio in wave V amplitude, and interaural difference of wave V (IT5) are evaluated by a receiver-operating characteristic (ROC) curve in this study. IT5 is the best distinguishing parameter between postoperative Class II and Class III. IT5 below 1.12 millisecond (msec) should be a good marker to preserve postoperative useful hearing. Thus, comparing the latency of wave V on both sides is important, and surgeons would be able to make more informed decisions during surgery by checking IT5 on BAEPs.

Lumbar peritoneal shunt containing a programmable valve for intracranial hypertension caused by Borden type 1 dural arteriovenous fistulas.

Three male patients underwent lumbar peritoneal (LP) shunt for intracranial hypertension caused by intracranial Borden type 1 dural arteriovenous fistulas (D-AVFs). Endovascular treatment was performed initially, but it was ineffective in all cases. Before LP shunt, the Mariotte blind spot expanded in all cases and severe papilledema was observed in two cases. We managed the opening pressure of the shunt system in accordance with patient symptoms. Mariotte blind spot expansion and papilledema disappeared after LP shunt. Follow-up cerebral angiography revealed spontaneous closure of D-AVFs in one case and aggressive conversion in two cases. D-AVFs were completely closed by transvenous embolization. Because the angioarchitecture of the fistula frequently worsens without deterioration of the symptom after LP shunt, follow-up angiography and additional treatment are important.

Cochlear nerve action potential monitoring with the microdissector in vestibular schwannoma surgery.

We developed a cochlear nerve action potential (CNAP) monitoring technique using a microdissector and compared the results of CNAP and auditory brainstem response (ABR) monitoring. Thirty-six patients underwent vestibular schwannoma resection via the retrosigmoid approach to preserve hearing. Both CNAP with the microdissector and surface ABR were recorded during the operation. We used the microdissector as an intracranial electrode for CNAP monitoring. The CNAP waveform was classified into four types: triphasic, biphasic, positive, and flat. At the completion of the tumor resection, the triphasic waveform was observed in 11 patients and the biphasic waveform was observed in 11 patients. Hearing function was preserved in all of them, although it was preserved in only two patients with other CNAP waveform types. The prognostic value of CNAP is significantly higher than that of ABR. We found that although CNAP with a microdissector does not provide real-time monitoring, with the classification of waveforms it can be used as predictable tool for postoperative hearing more accurately than ABR.

Increase in neurogenesis and neuroblast migration after a small intracerebral hemorrhage in rats.

Neural stem/progenitor cells (NPCs) reside in the subventricular zone (SVZ) and dentate gyrus in the adult mammalian brain. It has been reported that endogenous NPCs are activated after brain insults such as ischemic stroke. We investigated whether proliferation and migration of endogenous NPCs are increased after a collagenase-induced small intracerebral hemorrhage (ICH) near the internal capsule in rats. Bromodeoxyuridin (BrdU) administration for 14 days after ICH (post-labeling) resulted in an increase in the number of BrdU-positive cells as shown in both ipsilateral and contralateral SVZs. BrdU treatment given for 2 days before ICH to label endogenous NPCs (pre-labeling), caused more BrdU-positive cells to be detected in the ipsilateral dorsal striatum (dSTR) compared to those in the contralateral dSTR 14 days after ICH. BrdU- and doublecortin (Dcx)-positive cells were found in the ipsilateral STR. An increase in the number of Dcx-positive migrating immature neurons was found in the dSTR and peri-hemorrhage area 14 days after ICH, and a cluster of Dcx-positive cells was found in the STR around the lesion 28 days after ICH. Matrix metalloproteinase-2 (MMP-2) was strongly expressed in wide area of the injured brain, particularly around the lesion 14 and 28 days after ICH. Dcx- and MMP-2-positive cells were detected in the ipsilateral STR near the lesion. These data suggest that collagenase-induced ICH enhances the proliferation of endogenous NPCs and the migration of newly born neuroblasts toward the hemorrhage area.

Tailor-made orbitocranioplasty for a sphenorbital encephalocele presenting as pulsatile exophthalmos. Case report.

Basal encephaloceles account for only 1.5% of all encephaloceles. Within this group, the sphenorbital type is quite rare but causes herniation of the brain into the orbit, leading to pulsatile exophthalmos and disturbance of visual acuity. The authors present a case of successful orbitocranioplasty for a sphenorbital encephalocele in which they used a skull model in preparation for the operation. A plaster skull model was made from 3D computed tomography (CT) data obtained in a 6-year-old girl with a sphenorbital encephalocele to determine the appropriate size and shape of an implant for repair of the malformation. A hydroxyapatite ceramic implant with high affinity to autologous bone was designed to cover the defect and simultaneously to enlarge the volume of the orbit as well as allow rigid fixation. Postoperative 3D CT scanning demonstrated good placement of the implant, and the patient's pulsatile exophthalmos diminished immediately. The patient's postoperative condition has been good, and she has exhibited no neurological deficit or deformity of the skull around the cranioplasty 30 months after the operation. A skull model using 3D CT data is useful for determining the most appropriate strategy for reconstruction. Hydroxyapatite ceramic implants have high affinity to autologous bone and thus are suitable for children. In cases such as the present one, however, the patient should be observed carefully to ensure that there is not an imbalance between the implant and the still growing autologous skull.

Oral administration of metal chelator ameliorates motor dysfunction after a small hemorrhage near the internal capsule in rat.

Cerebral hemorrhage leads to local production of free iron, radicals, cytokines, etc. To investigate whether a decrease of iron-mediated radical production influences functional recovery after intracerebral hemorrhage (ICH), a modified ICH rat model with a small hemorrhage near the internal capsule (IC) accompanied with relatively severe motor dysfunction was first developed. Then clioquinol (CQ), an iron chelator that reduces hydroxyl radical production, was orally administrated. Injection of different doses of Type IV collagenase (1.4 mul 1-200 U/ml) into the left striatum near the IC in Wistar rats showed that injection of 7.5 U/ml collagenase resulted in a small hemorrhoidal lesion near the IC with relatively severe motor dysfunction (IC model). Retrograde labeling of neurons in the sensory-motor cortex and axons in the corticospinal tract using Fluoro-gold (FG) injection into the spinal cord (C3-C4) showed that few labeled neurons in the sensory-motor cortex were detected in the IC model, FG-labeled axons disappeared, and FG-including ED-1-positive cells appeared within 24 hr in the IC. Assessments of behavior and histologic analysis after oral administration of CQ in the IC model indicated that oral administration of CQ prevented a decrease of FG-labeled neurons, and resulted in better motor-function recovery. CQ inhibited hydrogen peroxide-induced cell toxicity in oligodendrocytes in vitro, but not in neurons. Our data suggests that CQ ameliorated motor dysfunction after a small hemorrhage near the IC by a mechanism that is related to reduction of chain-reactive hydroxyl radical production in oligodendrocytes.

Neurodegeneration of substantia nigra accompanied with macrophage/microglia infiltration after intrastriatal hemorrhage.

Intrastriatal hemorrhage in rats causes neurodegenaration of the substantia nigra (SN) followed by the appearance of ED1(+) cells (macrophage/microglia). ED1(+) cells were observed for at least 8 weeks after hemorrhage. Phosphorylation of p38 mitogen-activated protein kinase (MAPK) was shown in ED1(+) cells with the expression of both brain-derived neurotrophic factor (BDNF) mRNA and BDNF, suggesting that activated-p38 MAPK(+)/ED1(+) cells would produce BDNF and may exhibit trophic effect on the degenerating neurons in the SN. However, in ELISA, BDNF protein decreased significantly in ipsilateral SN at 7 days after hemorrhage, which may be due to a dramatic decrease of BDNF immunoreactive neurons in pars compacta. Data suggest that activation of p38 MAPK in ED1(+) cells infiltrating in ipsilateral SN after hemorrhage may produce BDNF, but that the amount of BDNF produced from ED1(+) cells is insufficient for the rescue of degenerating neurons.

Intracerebral hemorrhage upregulates Na(+)/myo-inositol cotransporter in the rat brain.

We examined the expression of Na(+)/myo-inositol cotransporter (SMIT) in the rat brain after intrastriatal hemorrhage. The expression of SMIT messenger RNA (mRNA) increased around hematoma 3 days after hemorrhage and it returned to control level as hematoma was absorbed. The expression of SMIT mRNA also increased at ipsilateral substantia nigra without blood-brain barrier disruption 7 days after hemorrhage and remained high until 42 days after hemorrhage. Immunohistochemistry revealed that macrophages around hematoma and microglias at ipsilateral substantia nigra were SMIT-positive. These results suggest that the expression of SMIT must be regulated not only by osmolality but also by unknown factors.

[Neural transplantation for cerebral ischemia/infarction--the present situation and prospects].

Cerebral infarction results in multiple symptoms including hemiplegia and cognitive disturbances. The central nervous system has a limited capacity for self-repair, thus there is a great interest in the possibility of repairing the central nervous system by neural transplantation. Two different types of cerebral infarction model are well investigated for neural transplantation. Several kinds of donor cells have been used to try to restore the brain damage after ischemic insult. Reconstruction of neural circuits by transplantation is an ideal goal for the treatment of cerebral infarction, but trophic action of transplantation is also expected. Amelioration of ischemia-induced brain damage and recovery of neural dysfunction are documented. However, there are several factors and problems to be solved for clinical application.