Takatoshi Sorimachi

Research into the Physiology of Cerebrospinal Fluid Reaches a New Horizon: Intimate Exchange between Cerebrospinal Fluid and Interstitial Fluid May Contribute to Maintenance of Homeostasis in the Central Nervous System

Cerebrospinal fluid (CSF) plays an essential role in maintaining the homeostasis of the central nervous system. The functions of CSF include: (1) buoyancy of the brain, spinal cord, and nerves; (2) volume adjustment in the cranial cavity; (3) nutrient transport; (4) protein or peptide transport; (5) brain volume regulation through osmoregulation; (6) buffering effect against external forces; (7) signal transduction; (8) drug transport; (9) immune system control; (10) elimination of metabolites and unnecessary substances; and finally (11) cooling of heat generated by neural activity. For CSF to fully mediate these functions, fluid-like movement in the ventricles and subarachnoid space is necessary. Furthermore, the relationship between the behaviors of CSF and interstitial fluid in the brain and spinal cord is important. In this review, we will present classical studies on CSF circulation from its discovery over 2,000 years ago, and will subsequently introduce functions that were recently discovered such as CSF production and absorption, water molecule movement in the interstitial space, exchange between interstitial fluid and CSF, and drainage of CSF and interstitial fluid into both the venous and the lymphatic systems. Finally, we will summarize future challenges in research. This review includes articles published up to February 2016.

The Striate Artery, Hematoma, and Spot Sign on Coronal Images of Computed Tomography Angiography in Putaminal Intracerebral Hemorrhage

Background and Purpose— A spot sign is a bright spot on computed tomography angiography source images, which is predictive of hematoma growth in spontaneous intracerebral hemorrhage, although the cause of the spot sign is unclear. Our aim was to investigate the spot sign seen on computed tomography angiography and a striate artery, which is a presumed site of intracerebral hemorrhage bleeding origin in the putamen. Methods— In consecutive cases of spontaneous intracerebral hemorrhage in the putamen, spot signs and striate arteries were evaluated. Coronal reformat images of computed tomography angiography were created to visualize the striate arteries. Acute deterioration, defined as hematoma enlargement, emergency hematoma removal, or death within the day of admission, was reviewed. Results— Of the 141 patients undergoing computed tomography angiography, 15 of the 30 patients (50%) who had spot signs showed an intrahematoma striate artery (termed spot and tail sign), which was a linear density extending from the middle cerebral artery toward the spot sign. Acute deterioration occurred more frequently in patients who had a spot and tail sign compared with patients who had spot signs without intrahematoma striate arteries (P<0.05). Multivariate analysis revealed that hematoma volume, spot signs, and intrahematoma striate arteries were independent predictors of acute deterioration (P<0.05). Conclusions— The presence of a spot and tail sign, assumed to indicate active bleeding from the striate artery, could be a more sensitive predictor of acute deterioration than the presence of a simple spot sign.

Chronic subdural haematoma associated with disturbance of consciousness: significance of acute-on-chronic subdural haematoma

Abstract Objective: Detailed features of chronic subdural haematoma (cSDH) associated with disturbance of consciousness and acute-on-chronic subdural haematoma (a/cSDH), in which acute subdural haematoma overlaps cSDH, remain poorly understood. The object of this study was to clarify both characteristics of cSDH associated with disturbance of consciousness and the significance of a/cSDH. Methods: Clinical factors and computed tomography (CT) findings were retrospectively investigated in 349 consecutive patients admitted between 2006 and 2013 and diagnosed with cSDH. Results: Glasgow Coma Scale (GCS) was ≤u20098 in 21 patients (6.0%) and 9–14 in 29 patients excluding aphasia and/or dementia (8.3%). Multiple logistic regression analysis indicated that a/cSDH, female sex and haemodialysis were significantly related to severe disturbance of consciousness (GCSu2009≤u20098). Predictors for a/cSDH observed in 29 patients (8.3%) were trauma history within 7u200adays before admission, high prothrombin time–international rate, and use of anticoagulants and/or antiplatelets. Unfavourable outcomes were observed in 29 of 299 patients (9.7%) without consciousness disturbance, compared to 27 of 50 patients (54%) with consciousness disturbance. Predictors of unfavourable outcome were consciousness disturbance, increase in age, malignancy, trauma history within 7u200adays and haemodialysis. Discussion: Disturbance of consciousness associated with cSDH, often caused by either a/cSDH or concomitant disease, frequently resulted in unfavourable outcomes. As a result, in cSDH patients associated with disturbance of consciousness, underlying conditions, especially a/cSDH, which is often caused by haemostatic abnormality, should be clarified and managed.

Risks and benefits of CT angiography in spontaneous intracerebral hemorrhage

BackgroundFew studies have examined the risk of computed tomography angiography (CTA) during the acute phase of spontaneous intracerebral hemorrhage (ICH), while the benefits of CTA in ICH have been well-documented. The present study investigated both the benefits of identifying spot signs, which are supposed to indicate hematoma enlargement after admission, and risks of CTA performed during the acute phase of ICH.MethodsWe retrospectively assessed 323 consecutive patients with spontaneous ICHs admitted to our hospital between April 2009 and March 2012 and who underwent CTA on admission.ResultsIn 80 patients (24.7xa0%), spot signs were demonstrated on CTA source images. Multivariate analysis revealed two independent factors correlated with presence of the spot sign: age and hematoma volume (pu2009<u20090.05 each). The presence of spot sign was associated with unfavorable outcomes at discharge and hematoma growth after admission (pu2009<u20090.05 each). Adverse events related to CTA occurred in 17 patients (5.2xa0%), including transient renal dysfunction in 16 patients and allergy to contrast medium in one patient. All adverse events completely resolved within 1xa0week.ConclusionsPresence of the spot sign indicated the possibility of hematoma growth and unfavorable outcomes. A small number of adverse events occurred in association with CTA, but without any permanent deficits. Given the potential benefits and risks, we believe that CTA performed at admission in all patients with ICH is beneficial to improve the outcomes.

Chronic Subdural Hematomas Associated with Arachnoid Cysts: Significance in Young Patients with Chronic Subdural Hematomas

Although arachnoid cysts (ACs) are associated with chronic subdural hematomas (CSDHs), especially in young patients, the detailed features of CSDHs associated with ACs remain poorly understood. The objective of this study was to clarify the relationship between the location of CSDHs and ACs and the significance of ACs in young patients with CSDHs. We retrospectively assessed 605 consecutive patients 7 years of age and older who were diagnosed with a CSDH between 2002 and 2014. Twelve patients (2%) had ACs, and 10 of the 12 patients were 7–40 years of age. Patients with ACs as a complication of CSDHs were significantly younger than those without ACs (p < 0.05). Three different relationships between the location of CSDHs and ACs were found: a CSDH contacting an AC, an ipsilateral CSDH apart from an AC, and a CSDH contralateral to an AC. In 21 patients with CSDHs who were 7–40 years of age, 10 (47.6%) had ACs (AC group) and 7 (33.3%) had no associated illnesses (non-AC group). All 10 young patients with ACs showed ipsilateral CSDHs including a CSDH apart from an AC. All 17 patients in both the AC and non-AC groups showed headache but no paresis at admission. The pathogenesis of CSDHs associated with ACs may be different among the three types of locations. The clinical characteristics of patients with a combination of a CSDH and an AC including headache as a major symptom may be attributed to young age in the majority of patients with ACs.

Cerebral Infarction following Acute Subdural Hematoma in Infants and Young Children: Predictors and Significance of FLAIR Vessel Hyperintensity.

A phenomenon of cerebral infarction following acute subdural hematoma (ASDH) in infants and young children, termed cerebral infarction following ASDH (CIASDH), has been well recognized, though both its mechanisms and risk factors have been poorly understood. The purpose of the present study was to investigate the predictors for CIASDH in a population of ASDH, and to evaluate the imaging studies to presume the mechanisms of CIASDH. We retrospectively examined consecutive children 6 years of age or younger, who were diagnosed with ASDH and were admitted to our hospital between 2000 and 2014. In 57 consecutive children with ASDH, 12 (21.1%) developed CIASDH. The multivariate analysis revealed five predictors for CIASDH: presence of seizure, consciousness disturbance at admission, absence of skull fracture, hematoma thickness ≥ 5 mm on computed tomography (CT), and midline shift ≥ 3 mm on CT (p < 0.05). In three of six patients (50%) undergoing magnetic resonance (MR) imaging/fluid-attenuated inversion recovery (FLAIR) within 5 days of admission, serpentine hyperintensities in the subarachnoid space (FLAIR vessel hyperintensities) were demonstrated. MR angiography showed neither occlusion nor stenosis of the cerebral arteries. Single photon emission CT performed at admission in one patient showed a cerebral blood flow reduction in the ASDH side. All the children with CIASDH showed unfavorable outcomes at discharge. Children showing multiple predictors at admission should be carefully observed for development of CIASDH. Evaluation of the imaging studies suggested that a blood flow disturbance in the level of peripheral arteries to microcirculation was one candidate for possible mechanisms to induce the CIASDH.

Predictors of early vs. late permanent shunt insertion after aneurysmal subarachnoid hemorrhage

Objective: Numerous studies have identified different predictors for secondary hydrocephalus after aneurysmal subarachnoid hemorrhage (SAH), although predictors regarding timing of the shunt operation have never been reported. Predictors for an early shunt, which was defined as a shunt operation performed ≤30 days after SAH onset, and for a late shunt, performed at >40 days, were investigated. Methods: A total of 735 consecutive SAH patients admitted to our hospital between 2003 and 2014 who underwent surgery for ruptured aneurysms within five days of onset were retrospectively assessed. Results: Secondary hydrocephalus developed in 225 patients, including 70 with an early shunt and 96 with a late shunt. Multivariate analysis showed that predictors for secondary hydrocephalus were age ≥70 years, World Federation of Neurosurgical Society (WFNS) grade IV-V, Fisher grade 3–4, intraventricular hemorrhage, anterior cerebral artery aneurysms, and external drainage for acute hydrocephalus (p < 0.05). In the early and late shunt groups, multivariate analysis indicated that early shunt was significantly associated with coil embolization, and late shunt was correlated with middle cerebral artery aneurysms and cerebral infarction due to vasospasm (p < 0.05). Discussion: The difference in the predictors between the early and late shunts implied that the mechanisms of secondary hydrocephalus differed between the early and late shunt groups. Knowledge of the associated risk factors might help to predict the timing of the shunt operation for early rehabilitation planning in the future.

Transvenous embolization of cavernous sinus dural arteriovenous fistula through a thrombosed inferior petrosal sinus utilizing 3D venography

Objective We report a new technique in approaching the cavernous sinus through an occluded inferior petrosal sinus (IPS) using three-dimensional (3D) venography. Case presentation A patient diagnosed with arteriovenous fistula of the right cavernous sinus underwent transvenous embolization. The IPS was not detectable on angiogram. Retrograde injection of contrast with 3D imaging of the internal jugular vein clearly demonstrated the remnant of the IPS. By referring to the images obtained, catheterization of the cavernous sinus by way of the IPS was performed without difficulties. Conclusion Three-dimensional venography for detecting the entrance to the IPS is a useful method and easy to perform. We believe that this technique should be considered whenever the access to an occluded IPS is necessary.

Acute subdural hematoma caused by a ruptured cavernous internal carotid artery giant aneurysm following abducens nerve palsy: case report and review of the literature

The authors report a 61-year-old female patient with a giant cavernous aneurysm in the right internal carotid artery (ICA) leading to acute subdural hematoma (ASDH) 7xa0days after the occurrence of abducens nerve palsy. She underwent ICA occlusion associated with high-flow bypass. In all five reported patients with a cavernous ICA aneurysm causing ASDH, the size of the aneurysm was giant and cranial nerve signs preceded the rupture. When a patient with a symptomatic cavernous ICA giant aneurysm experiences sudden-onset headache and/or consciousness disturbance, rupture of the aneurysm should be differentiated, even though a cavernous ICA aneurysm rarely causes ASDH.

Chronic Subdural Hematoma in Women

OBJECTIVEnSex differences in various diseases recently have been recognized as an important factor in the approach to more efficient preventive and therapeutic medicine. We clarified sex differences in the clinical characteristics of chronic subdural hematoma (CSDH) by comparing men and women with CSDH, as there is a well-known male predominance in the prevalence of CSDH.nnnMETHODSnClinical factors and computed tomography findings were investigated retrospectively in 490 consecutive patients admitted to our hospital between 2006 and 2015 who were diagnosed with CSDH.nnnRESULTSnOn univariate analysis, women were significantly older than men (P < 0.05). In women, premorbid impaired activities of daily living, consciousness disturbance, acute-to-chronic subdural hematoma, and death as outcomes at discharge were significantly more frequent than in men (Pxa0<xa00.05). In contrast, women had less frequent instances of good recovery and less alcohol intake (P < 0.05). Multivariate analysis demonstrated female sex as an independent predictor of consciousness disturbance at admission. Female sex also was identified as a predictor of death at discharge.nnnCONCLUSIONSnWe demonstrated sex differences in the clinical characteristics of CSDH. In the future, management of patients with CSDH with regard to sex differences in disease characteristics could be expected to improve the outcomes of women, which have been worse than in men.