Microsurgical anatomy of the anterior cerebral artery and the arterial supply of the cingulate gyrus.

PURPOSE: The cingulate gyrus is a potential surgical area to treat tumours, psychiatric diseases, intractable pain and vascular malformations. The aim of the study was to define the topographic anatomy and arterial supply of the cingulate gyrus located on the medial surface of the cerebral hemisphere. METHODS: We studied thirty-six hemispheres, each hemisected in the midsagittal plane. The vertical thickness of the cingulate gyrus was measured at the anterior commissure (AC), posterior commissure (PC), and genu levels of the corpus callosum. The branches of the anterior and posterior cerebral arteries supplying each zone were noted separately. The arterial pathways were transformed to digital data in AutoCAD to identify the condensation and reduction areas. RESULTS: The mean AC-PC distance was 27.17 ± 1.63 mm. The thinnest region was the genu level of the corpus callosum (10.29 mm). The superior internal parietal artery (SIPA), inferior internal parietal artery (IIPA) and pericallosal artery (PrCA) supplied all zones of the cingulate gyrus. The anterior zone received the greatest supply. The arterial condensation and reduction areas on both sides of cingulate gyrus and its x, y, and z coordinates specified. CONCLUSIONS: The target cingulotomy (TC) area was determined for anterior cingulotomy. The properties of the TC area are that the thinnest region of the cingulate gyrus is supplied relatively less than other areas and is close to the anterior cingulotomy areas in the literature. The arterial reduction area (ARA) was found to be suitable for corpus callosotomy in terms of avoiding haemorrhage.

Transient Receptor Potential Melastatin 3 Is Functionally Expressed in Oligodendrocyte Precursor Cells and Is Upregulated in Ischemic Demyelinated Lesions.

Oligodendrocyte precursor cells (OPCs) are glial cells that differentiate into oligodendrocytes and myelinate axons. The number of OPCs is reportedly increased in brain lesions in some demyelinating diseases and during ischemia; however, these cells also secrete cytokines and elicit both protective and deleterious effects in response to brain injury. The mechanism regulating the behaviors of OPCs in physiological and pathological conditions must be elucidated to control these cells and to treat demyelinating diseases. Here, we focused on transient receptor potential melastatin 3 (TRPM3), a Ca2+-permeable channel that is activated by the neurosteroid pregnenolone sulfate (PS) and body temperature. Trpm3+/Pdgfra+ OPCs were detected in the cerebral cortex (CTX) and corpus callosum (CC) of P4 and adult rats by in situ hybridization. Trpm3 expression was detected in primary cultured rat OPCs and was increased by treatment with tumor necrosis factor α (TNFα). Application of PS (30-100 µM) increased the Ca2+ concentration in OPCs and this effect was inhibited by co-treatment with the TRP channel blocker Gd3+ (100 µM) or the TRPM3 inhibitor isosakuranetin (10 µM). Stimulation of TRPM3 with PS (50 µM) did not affect the differentiation or migration of OPCs. The number of Trpm3+ OPCs was markedly increased in demyelinated lesions in an endothelin-1 (ET-1)-induced ischemic rat model. In conclusion, TRPM3 is functionally expressed in OPCs in vivo and in vitro and is upregulated in inflammatory conditions such as ischemic insults and TNFα treatment, implying that TRPM3 is involved in the regulation of specific behaviors of OPCs in pathological conditions.

Median pericallosal artery with double proximal origin: case report and clinical consideration.

A 76-year-old male patient underwent magnetic resonance angiography of the head and neck vessels due to a recent incident of transitory ischemic attack. Cerebral angiogram uncovered the double proximal origin of the median unpaired pericallosal artery from the duplicated anterior communicating complex. The vessel curved around the corpus callosum and irrigated the paracentral lobule and the medial parietal cortical areas. The main trunks of the anterior cerebral arteries showed a branching pattern of the marginal callosal arteries, supplying orbital and frontal territories. The pre-communicating segment of the left anterior cerebral artery was identified as hypoplastic. The co-existence of the duplicated anterior communicating artery, with the medial pericallosal artery ascending from it, represents a potential danger for both open and endovascular surgery on the anterior circle of Willis as the deep half of this complex is obscured from the surgeon's eyes. Thorough interpretation of preoperative radiographic images and understanding of the developmental mechanisms of such variability are vital. The described branching arrangement of the anterior communicative region and possible mechanisms of migration with following fusion of the pericallosal arteries are discussed in this paper.

Outcome, Prognostic Factors, and Follow-Up Results After Subarachnoid Hemorrhage from Pericallosal Artery Aneurysms.

OBJECTIVE: Pericallosal artery aneurysms (PAAs) are usually rare (2%-5%), and treatment is challenging for both surgical and endovascular modalities. We performed this analysis to determine the outcome and prognostic factors after subarachnoidal hemorrhage (SAH) caused by ruptured PAAs. METHODS: A total of 32 patients with ruptured PAA were admitted to our hospital between 1999 and 2014, added to our prospective database, and analyzed retrospectively. Outcome was measured based on the modified Rankin Scale (mRS) at 6 months after ictus (favorable mRS score, 0-2 vs. unfavorable mRS score, 3-6). RESULTS: Only 16 (50%) patients had a good clinical status at admission (World Federation of Neurological Surgeons Grading System [WFNS] grades I-III), whereas 12 patients (37.5%) were comatose (WFNS grade V). In 18 patients (56%), intracerebral hemorrhage was confirmed, in 18 patients (56%) cerebrospinal fluid drainage was required immediately after admission, and in 5 cases (16%) decompressive craniectomy was performed. There were 17 patients (53.1%) who achieved a favorable outcome (mRS score 0-2) at follow-up. Unfavorable outcome was associated with smoking, cerebral infarction, and worse admission status after multiple logistic regression analysis. CONCLUSIONS: Poor admission status, cerebral infarction, and smoking seem to be crucial factors for unfavorable outcome after SAH from PAA.

Induction of Genes Expressed in Endothelial Cells of the Corpus Callosum in the Chronic Cerebral Hypoperfusion Rat Model.

BACKGROUND: Cerebrovascular white matter lesions (WMLs) are associated with cognitive impairment in patients with subcortical vascular dementia. We performed a comprehensive gene expression analysis to elucidate genes associated with WML development in a chronic cerebral hypoperfusion rat model. METHODS: Brains of rats with bilateral carotid ligation (2VO, n = 10) and sham-operated rats (n = 5-10/group) were removed on days 1, 7, or 28 after surgery. Total RNA isolated from the corpus callosum was evaluated by microarray analysis and quantitative reverse transcription-polymerase chain reaction. RESULTS: On days 7 and 28, WMLs exhibited histologic changes. On day 7, 16 genes were differentially expressed between groups. mRNA levels of Ptprb, Kcnj8, Crispld2, Bcl6b, and Gja5 were differentially expressed in 2VO rats on day 7, but then returned to normal, whereas mRNA levels of Vwf and Trappc6a were upregulated after day 7. Immunohistochemistry showed that GJA5 and vWF were detected in endothelial cells, KCNJ8 in endothelial cells and astrocytes, CRISPLD2 in neurons and astrocytes, and TRAPPC6A in neurons. CONCLUSION: Our findings indicate novel genes that may be associated with WML development in the chronic cerebral hypoperfusion rat model, and suggest an important role of neurovascular dysfunction in the pathophysiology.

Angiographic factors influencing the success of endovascular treatment of arteriovenous malformations involving the corpus callosum.

OBJECTIVE: Arteriovenous malformations (AVMs) of the corpus callosum are rare lesions, accounting for 9-11% of brain AVMs. Microsurgical resection of such lesions is difficult because of their deep location, and also because of possible neuropsychological disasters resulting from extended callosal resection. The introduction of endovascular and radiation therapies has fundamentally changed the outcome of these lesions. METHODS: We prospectively collected clinical and angiographic data on cerebral AVMs from 1995. We reviewed data from patients treated for an AVM of the corpus callosum and identified the factors influencing the endovascular approach of such lesions. RESULTS: 38 patients (mean age 31 years) were consecutively treated by endovascular techniques. 78.9% (30 cases) of patients presented with intracranial hemorrhage. 15 AVMs (39.5%) were anterior, 18 (47.4%) were posterior, and five (13.1%) were holocallosal. The Spetzler-Martin grade was I in two cases (5.2%), II in 20 cases (52.6%), III in nine cases (23.7%), IV in six cases (15.8%), and V in one case (2.6%). The nidus was compact in 19 cases (50%), diffuse in 13 (34.2%), and multifocal in six (15.8%). Both anterior and posterior circulation branches fed 14 nidi (36.8%). Venous drainage was superficial in three cases (7.9%), deep in 28 (73.7%), and both in seven cases (18.4%). 104 sessions were performed, with a procedural complication rate of 6.7%. Mean follow-up was 43.6 months, with the last modified Rankin Scale score <3 in 33 cases (86.8%). 22 patients (57.9%) were totally cured. Univariate analysis of factors influencing the success of endovascular treatment showed that Spetzler-Martin grade ≥3 (p=0.046), nidus >30 mm (p=0.02), extension in an eloquent area (p=0.03), and holocallosal type (p0.005) significantly diminished the chances of cure of the AVM. CONCLUSIONS: AVMs of the corpus callosum seems to be difficult to treat with endovascular therapy alone. The goal of embolization should be prevention of (re) bleeding and a decrease in nidus size. Our experience regarding this sub-pathology suggests that a combination of endovascular therapy and radiotherapy may be the best option.

Apoptosis signal-regulating kinase 1 is a novel target molecule for cognitive impairment induced by chronic cerebral hypoperfusion.

OBJECTIVE: There are currently no specific strategies for the treatment or prevention of vascular dementia. White matter lesions, a common pathology in cerebral small vessel disease, are a major cause of vascular dementia. We investigated whether apoptosis signal-regulating kinase 1 (ASK1) might be a key molecule in cerebral hypoperfusion, associated with blood-brain barrier breakdown and white matter lesions. APPROACH AND RESULTS: A mouse model of cognitive impairment was developed by inducing chronic cerebral hypoperfusion in white matter including the corpus callosum via bilateral common carotid artery stenosis (BCAS) surgery. BCAS-induced white matter lesions caused cognitive decline in C57BL/6J (wild-type) mice but not in ASK1-deficient (ASK1(-/-)) mice. Phosphorylated ASK1 increased in wild-type mouse brains, and phosphorylated p38 and tumor necrosis factor-α expression increased in corpus callosum cerebral endothelial cells after BCAS in wild-type mice but not in ASK1(-/-) mice. BCAS decreased claudin-5 expression and disrupted blood-brain barrier in the corpus callosum of wild-type but not ASK1(-/-) mice. Cerebral nitrotyrosine was increased in wild-type and ASK1(-/-) BCAS mice. Cerebral phosphorylated ASK1 did not increase in wild-type mice treated with NADPH-oxidase inhibitor. A p38 inhibitor and NADPH-oxidase inhibitor mimicked the protective effect of ASK1 deficiency against cognitive impairment. Specific ASK1 inhibitor prevented cognitive decline in BCAS mice. In vitro oxygen-glucose deprivation and tumor necrosis factor-α stimulation caused the disruption of endothelial tight junctions from wild-type mice but not ASK1(-/-) mice. CONCLUSIONS: Oxidative stress-ASK1-p38 cascade plays a role in the pathogenesis of cognitive impairment, through blood-brain barrier breakdown via the disruption of endothelial tight junctions. ASK1 might be a promising therapeutic target for chronic cerebral hypoperfusion-induced cognitive impairment.

Endovascular coiling as the first treatment strategy for ruptured pericallosal artery aneurysms: results, complications, and follow up.

We apply endovascular coiling as the first treatment option for ruptured pericallosal artery aneurysms. We conducted a retrospective analysis of the clinical and radiological outcomes of this treatment strategy and morphological factors associated with the success of endovascular coiling, to assess the safety and feasibility of our management strategy. From January 2003 to January 2012, we attempted endovascular coiling as the first-intention treatment for 30 consecutive patients with ruptured pericallosal artery aneurysms including those with intracerebral hematoma. Twenty-seven cases of ruptured pericallosal artery aneurysms were successfully embolized with coiling whereas three failures required surgery. Four patients experienced periprocedural complications including thromboembolic event in two and hematoma enlargement after coiling in two. A maximum aneurysm diameter of <3 mm was most strongly associated with failure of endovascular coiling. Of the 27 coil-treated aneurysms, immediate angiographic results showed complete aneurysm occlusion in 19 cases, neck remnant in 6, and residual aneurysm in 2. One patient had a major aneurysm recurrence that was uneventfully reembolized. Sixteen of our 30 patients had good outcomes (modified Rankin scale [mRS] 0-2), 7 had moderate disability (mRS 3), and 4 had severe disability (mRS 4-5) at 3 months after treatment. The management strategy for coiling as the first-intention treatment for ruptured pericallosal artery aneurysms has the potential to become an acceptable alternative to surgical clipping for selected cases, although a larger study population and longer follow-up periods are needed before definitive conclusions can be drawn.

Microvascular damage is involved in the pathogenesis of heroin induced spongiform leukoencephalopathy.

OBJECTIVE: To investigate whether microvascular damage is involved in the pathogenesis of heroin induced spongiform leukoencephalopathy (HSLE). METHODS: The brain tissues were collected from 4 HSLE patients and 5 controls and then fixed in 4% paraformaldehyde. The frontal lobe, corpus callosum and cerebellum were separated. The expressions of myelin base protein (MBP) and CD34 were detected by immunohistochemistry. TUNEL staining was applied to detect cell apoptosis. The correlation between microvascular changes and pathological vacuoles was evaluated. RESULTS: No obvious abnormalities were found in the brain of controls. Immunohistochemistry for MBP showed the collapse and fracture of myelin sheath and vacuole formation in the subcortical white matter, corpus callosum, and cerebellar white matter of HSLE patients. TUNEL staining showed the number of apoptotic cells in the cerebellar white matter and corpus callosum of HSLE patients was significantly higher than that in controls (F = 389.451, P < 0.001). Masson's trichrome staining revealed vacuolar degeneration in the cerebral white matter of HSLE patients, and the vacuoles were distributed around the microvessels. Immunohistochemistry revealed CD34 positive cells were seldom found besides the vessels in the cerebellar white matter and corpus callosum of HSLE patients, but a variety of CD34 positive cells was found in the vascular wall of controls (F = 838.500, P < 0.001). CONCLUSION: Apoptosis of oligodendrocytes may be related to the HSLE. Cerebral vascular injury and microcirculation dysfunction are involved in the pathogenesis of HSLE. The interrelation between apoptosis of oligodendrocytes and the microvascular damage are required to be studied in future investigations.

Transarterial balloon assisted Onyx embolization of pericallosal arteriovenous malformations.

SUMMARY: Preliminary experience using a balloon assisted technique (BAT) for embolization of arteriovenous malformations (AVM) is reported. Two patients with large pericallosal AVMs were successfully embolized with Onyx under Scepter C balloon catheter flow arrest. CLINICAL PRESENTATION: One patient presented with a large intraventricular hemorrhage and hydrocephalus. The second patient presented with a long history of seizures and a small intracerebral hemorrhage. Both patients demonstrated extensive interhemispheric AVMs with multiple arterial feeders, predominantly from the pericallosal arteries. INTERVENTION: A Marathon microcatheter was navigated into the target arterial feeders and a Scepter C occlusion balloon catheter was inflated immediately proximal. Under flow arrest, Onyx was injected via the microcatheter with excellent nidal penetration. In both cases, there was complete angiographic obliteration of the treated component of the AVM. CONCLUSIONS: Onyx embolization under balloon catheter flow arrest allows for greater nidal penetration of embolic material and improved reflux control. The technique is limited by the current deliverability of balloon catheters and the potential risk for earlier embolization of dangerous anastomosis.

Callosal warning syndrome.

OBJECTIVE: To report the clinical and imaging findings in a patient with an initial fluctuating disconnection syndrome due to corpus callosal ischemia that ultimately culminated in infarction with persistent symptoms. CASE REPORT: A 40-year-old, hypertensive, right-handed man presented with transient, stereotyped symptoms of corpus callosal disconnection (intermanual conflict, apraxia, dysgraphia and construction difficulties in his left hand). Serial magnetic resonance imaging scans demonstrated the ischemic nature of the initial fluctuating symptoms and later showed callosal infarction when the symptoms were persistent. Magnetic resonance angiogram did not reveal significant stenosis or occlusion of the internal carotid or proximal portion of anterior cerebral arteries. Patient received standard treatment for ischemic stroke and at follow-up 1 month later, had mild left hand apraxia, dysgraphia and construction difficulties. CONCLUSION: The case highlights the unusual occurrence of crescendo transient ischemic attacks culminating in infarction in the location of corpus callosum. We have termed this novel stroke syndrome as 'callosal warning syndrome' as the temporal profile was quite indistinguishable from that of relatively well-known stroke warning syndromes in the location of internal capsule and pontine tegmentum.

Clip assisted use of gelatin-thrombin matrix sealant as a rescue procedure to treat a hidden arterial tear.

Major intracranial arteries can be injured during tumor removal. Surgeons routinely manage this event by using either microvascular direct repair, by-pass of the wounded segment or the placement of a sutureless device. These procedures, however, are not always possible due to artery brittleness, deep operating field, vascular configuration, or restricted viewing field. In this particular case, we illustrate an example of innovative use of gelatin-thrombin matrix sealant used to repair a hidden tear of pericallosal-callosomarginal bifurcation. A 49-year-old man underwent resection of a recurrent left frontal glioma. During an attempt to remove a firmly attached portion of the tumor, a tear occured in the pericallosal-callosomarginal bifurcation. The wall defect was repaired with a temporary vascular clip placed on the pericallosal artery and gelatin-thrombin matrix sealant sprayed over the tear. An intraoperative indocyanine videoangiography showed patency of both the pericallosal and callosomarginal arteries. Gelatin-thrombin matrix sealant is useful to control bleeding from an artery when the viewing field is restricted. In some cases, however, blood outflow must first be reduced in order to allow clot formation.

Corpus callosum arteriovenous malformation with persistent trigeminal artery.

A 13-year-old boy presented with an intracerebral haematoma secondary to a large corpus callosal arteriovenous malformation (AVM) with an associated persistent trigeminal artery, and was treated with Gamma-Knife Radiosurgery for the AVM. This report discusses the embryological basis, radiological features and various classifications of this rare vascular anomaly.

Minimally invasive endoscopic transventricular hemispherotomy for medically intractable epilepsy: a new approach and cadaveric demonstration.

OBJECT: Surgery for medically intractable epilepsy secondary to unihemispheric pathology has evolved from more aggressive hemispherectomy to less aggressive variations of hemispherotomy. The authors propose a novel minimally invasive endoscopic hemispherotomy that should give results comparable to conventional open craniotomy and microsurgery. METHODS: Endoscopic transventricular hemispherotomy was performed in 5 silicon-injected cadaveric heads in the authors' minimally invasive neurosurgery laboratory. The lateral ventricle was accessed endoscopically through a frontal and occipital bur hole. White matter disconnections were performed to unroof the temporal horn and to disconnect the frontobasal region, corpus callosum, and fornix. RESULTS: Using an endoscopic transventricular approach, all white matter disconnections were successfully performed in all 5 cadavers. CONCLUSIONS: The authors have demonstrated the feasibility of endoscopic transventricular hemispherotomy in a cadaveric model. The technique is simple and could be useful in a subgroup of patients with parenchymal volume loss and ventriculomegaly.

[A case of A3-A3 bypass and proximal clipping for a ruptured left A1 dissecting aneurysm].

A 58-year-old woman was admitted to our hospital with sudden onset of headache. CT and angiogram revealed subarachnoid hemorrhage due to a dissecting aneurysm at the left A1 segment. ACoA was not identified. We performed proximal clipping with A3-A3 bypass for preventing the recurrence of the hemorrhage and for reducing ischemia in the territory of the left ACA. After the operation, CT revealed the infarctions in the corpus callosum, the left medial frontal lobe and the genu of the internal capsule. But the postoperative angiogram demonstrated no aneurysm and the opacification of the recurrent artery of Heubner and the part of perforating branches. A3-A3 bypass was patent. The patient experienced a good recovery without recurrence of bleeding.

Limb-shaking transient ischemic attack masquerading as lumbar radiculopathy from pericallosal artery stenosis treated successfully with intracranial angioplasty and stenting.

The pericallosal artery is rarely associated with intracranial atherosclerotic disease and, until recently, was usually not amenable to endovascular therapy with balloon angioplasty and stenting. We present an elderly patient with postural left leg-shaking episodes secondary to pericallosal artery stenosis, which was treated initially with primary intracranial balloon angioplasty, and subsequently, angioplasty and stenting as a result of recurrent stenosis. Both procedures were preformed without complications, and the patient remained free of symptoms on 6-month follow-up. This case demonstrates unique clinical and neuroendovascular aspects; the isolated postural leg-shaking transient ischemic attacks, initially mistaken for radiculopathy and local joint etiology, were found later to be cerebrovascular ischemic in origin. Moreover, the correlation between the findings of computed tomography perfusion and angiography localized the lesion into the medial frontal lobe and pericallosal artery territory. In addition, the technical aspect provides insight into the current state of neuroendovascular techniques, addressing the difficulty of access into very small and distal intracranial arteries affected by stenosis.

Extended intracranial applications for ethylene vinyl alcohol copolymer (Onyx): mycotic and dissecting aneurysms. Technical note.

The authors describe the off-label use of Onyx for embolization of fusiform mycotic and dissecting intracranial aneurysms based on their experience with 3 patients treated at the University of Utah Hospital from 2006 through 2007. Technical success in occluding the parent artery/aneurysm was achieved in all patients. There were no complications. The authors conclude that Onyx can be used to achieve occlusion of fusiform mycotic and dissecting intracranial aneurysms in conjunction with parent artery occlusion.

Self-closing surgical clips for use in pericallosal artery-pericallosal artery side-to-side bypass.

The authors demonstrate the feasibility of a new procedure to create intracranial interrupted microvascular anastomosis. Self-closing nitinol surgical clips were used for a pericallosal artery-pericallosal artery side-to-side bypass in a 52-year-old man harboring an unruptured large aneurysm located on the right A2 segment. The outflow artery was found to arise from the dome of the aneurysm, which was considered unsuitable for stand-alone clip ligation or coil occlusion. After bypass patency was intraoperatively confirmed using near-infrared indocyanine green videoangiography, the aneurysm and feeding artery were embolized with coils and safely occluded. Both postoperative courses were uneventful. The patient was discharged neurologically intact on the 5th postembolization day. Postprocedure angiography demonstrated no ipsilateral aneurysm filling and excellent bilateral distal outflow from the left anterior cerebral artery.