Cerebral Arteriovenous Malformation With Ipsilateral Middle Cerebral Artery Occlusion: A Case Report.

We report the case of a 29-year-old man who presented with a sudden headache. Computed tomography showed a small intraventricular hemorrhage in the left lateral ventricle. Cerebral angiograms suggested rupture of a coexisting feeder aneurysm in the left temporal cerebral arteriovenous malformation (AVM). The left proximal middle cerebral artery, a major feeding artery, was occluded near the AVM, with development of abnormal blood supply, such as in moyamoya-like vessels to the nidus. After endovascular embolization of the coexisting feeder aneurysm and feeding arteries, the patient underwent volume-staged Gamma Knife radiosurgery (GKS). Follow-up angiograms performed 4.5 years after the last GKS confirmed complete disappearance of the AVM. Around 4.8 years after GKS, the patient required surgical intervention to develop delayed cyst formation; however, the postoperative course was uneventful.

A Recurrent Large Posterior Cerebral Artery Aneurysm Successfully Treated with Parent Artery Occlusion Using Somatosensory-Evoked Potential: A Case Report.

Objective: Treatment of large posterior cerebral artery (PCA) aneurysm involving the P1-P2 segment is difficult by both neurosurgery and endovascular treatment. Balloon occlusion test (BOT) to identify precise peripheral collateral flow is difficult prior to parent artery occlusion (PAO). Besides, PAO at the aneurysm at this location can cause peripheral cortical infarction of the occipital and temporal lobes and/or perforator infarction involving the midbrain and thalamus perfused by the perforating artery arising from the P1-P2 segment. However, detection of the perforator during PAO is difficult. Case Presentation: The patient was a 49-year-old woman. At the age of 43 years, a right large PCA aneurysm was discovered in the right P1-P2 segment. A simple technique coiling was performed. As recurrence was identified 1 year later, embolization was performed using a same procedure. Since further recurrences were later found, a third round of treatment was planned. Somatosensory-evoked potential (SEP) was recorded as intraoperative electrophysiological monitoring. Tortuosity of the right PCA was observed at the aneurysm neck and the distal right PCA could not be secured. We could neither perform stent-assisted coil embolization nor BOT in the right PCA. Hence, we inflated the balloon in the basilar artery and checked the collateral circulation routes retrograde into the right PCA from the right middle cerebral artery via a leptomeningeal anastomosis. PAO was performed on the right P1-P2 segment at the aneurysm neck. The signal of the SEP was not decreased, and the aneurysm was not visualized. Another coil was added to strengthen the PAO to the right P1 segment, which decreased the SEP amplitude in the extremities by 3 minutes after. As the last coil was thought to be occluding the perforator branching from the right P1 segment, it was removed without detaching. The SEP amplitude began to improve and recovered by 9 minutes after. There was no postoperative deficit. No recurrence of aneurysm was observed on MRA 9 months postoperatively. Conclusion: During PAO at the P1 segment of large PCA aneurysm involving the P1-P2 segment, SEP may be helpful to prevent perforator infarction, even if perforating artery originating from the proximal portion of the aneurysm was not detected by angiography.

Usefulness of the middle cerebellar peduncle approach for microsurgical resection of lateral pontine arteriovenous malformation.

Surgical treatment of brainstem arteriovenous malformation (AVM) is challenging and associated with a higher risk of complications and a lower rate of gross-total resection. The authors present their experience with the surgical management of lateral pontine AVM using the middle cerebellar peduncle approach. All cases presented with neurological deficits that were caused by hemorrhage before surgery. In all cases, the AVM was not visualized on postoperative angiography, and there was no deterioration of neurological symptoms. In this video, the authors report the treatment results of one case and describe the technique with a review of the literature. The video can be found here: https://youtu.be/bFvEMtMnrKw.

[Ruptured Posterior Inferior Cerebellar Artery Communicating Artery Aneurysm:A Case Report].

The posterior inferior cerebellar artery(PICA)communicating artery is a fine tortuous artery that interconnects the bilateral vermian branches of the distal PICAs. Aneurysms of this anastomotic vessel have been reported in only seven cases(including ours)in the available literature. The PICA communicating artery supplied collateral blood flow to the contralateral vermian territory in all seven cases. A 51-year-old man presented with a rare PICA communicating artery aneurysm(which manifested as a hematoma in the fourth ventricle)and mild subarachnoid hemorrhage at the cerebellomedullary fissure. Angiography revealed a hypoplastic right PICA and a PICA communicating artery from the left PICA that supplied the right vermian territory; the ruptured aneurysm originated from this vessel. Aneurysm trapping is associated with the risk of cerebral infarction of the right vermian territory. We concluded that the distal part of the telovelotonsillar segment could be sacrificed because the right anterior inferior cerebellar artery and the superior cerebellar artery would supply collateral blood flow; therefore, we attempted trapping in this case. A bilateral midline suboccipital approach was used, and we detected a reddish fusiform aneurysm at the top of a hairpin curve of the PICA communicating artery in the uvula of the cerebellar vermis. The aneurysm was trapped and removed without complications. Histopathological evaluation confirmed findings of a true aneurysm. Congenital vulnerability of the arterial wall and hemodynamic stress are considered contributors to PICA communicating artery aneurysms. Preservation of the affected vessel is difficult in patients in whom aneurysmal clipping is challenging. Other vessels tend to establish collateral blood flow to the contralateral vermian territory in such cases. Trapping is a simple and effective therapeutic strategy for these aneurysms.

Five Cases of High-grade Arteriovenous Malformation Treated by Presurgical Embolization through the Anterior Choroidal Artery.

Objective: In cases of cerebral arteriovenous malformation (AVM) in which perforators are involved as feeder, hemostasis is difficult during surgical removal and postoperative hemorrhage may develop. If possible, presurgical embolization should be performed. However, when the anterior choroidal artery (AChA) is the feeder, the risk of embolization is particularly high, and there are few reports describing this situation. Authors report the treatment results of five cases of AVM in which a single operator performed presurgical embolization through the AChA and describe the technique with a review of the literature. Case Presentations: Of the five total cases (three men and two women; average age was 43.4 years [28-68 years]), one case presented with hemorrhage, two with epilepsy, the other ones with headache and trigeminal neuralgia, respectively. The lesions were located in the frontal lobe in one case and in the temporal lobe in four cases. On the Spetzler-Martin (SM) grading scale, four cases were grade III and one was grade IV. The eloquent area was involved within the nidus in four cases. Multimodal treatment was planned because all cases were high-grade AVM. Authors thought that performing presurgical embolization through the AChA would reduce the overall risk of treatment and performed the presurgical embolization. The embolization was possible in all cases, and the AVM was not angiographycally visible through the AChA in three cases. The blood flow through the AChA was reduced in two cases. All cases were awake immediately after embolization and no case had neurological symptom after embolization. CT or MRI after embolization revealed asymptomatic infarction in two cases. The AVM was removed safely without difficulty including hemostasis. Conclusion: In this series, there were no morbidity and embolization was performed relatively safely. Embolization through the AChA was suggested to be an effective treatment, but careful consideration is required in each individual case.

Titanium Mesh Implant Exposure Due To Pressure Gradient Fluctuation.

OBJECTIVE: Titanium mesh implants (TMIs) are used for various purposes in craniotomy. Although delayed implant exposure and thinning of the overlying skin are well-known complications, the mechanism has not yet been elucidated. We reviewed our cases and propose a mechanism for TMI exposure. METHODS: From 2009 to 2018, we treated 14 patients with delayed titanium implant exposure after craniotomy. The exposed titanium implant was a TMI in 4 patients, a titanium mesh plate in 6 patients, and a titanium fixation plate with holes in 4 patients. We reviewed the preoperative computed tomography (CT) scans and operative findings. RESULTS: The interval between craniotomy and implant exposure was 13 years (range, 5-27). Implant exposure occurred at the temporal region in 7 patients, frontal region in 6 patients, and parietal region in 1 patient. The skin ulcer size ranged from 0.25 to 10 cm2 (mean, 1.95). In the patients with TMI exposure, the dura was expanded, and no residual epidural space was identified on the CT scans; however, epidural dead space was revealed on the CT scan in the patients with titanium mesh plate or titanium fixation plate exposure. CONCLUSIONS: We believe that the key factor resulting in delayed titanium mesh exposure is the pressure gradient between the atmosphere and the intracranial space. Fluctuation of this gradient exerts dynamic stress on the tissue in the mesh holes and the adjacent tissue, resulting in tissue damage and implant exposure.

Lumbar Degenerative Spondylolisthesis: Changes in Surgical Indications and Comparison of Instrumented Fusion With Two Surgical Decompression Procedures.

STUDY DESIGN: Single-center retrospective case series. OBJECTIVE: To compare outcomes of instrumented fusion and two methods of decompression for degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: There is no consensus on the surgical indications or optimum techniques for lumbar degenerative spondylolisthesis. METHODS: We analyzed the data of 140 patients treated by fusion (n = 80; mean follow-up, 77.9 months) or decompression (n = 60; mean follow-up, 38.0 months) and examined changes in surgical indications over a 12-year period. We compared the outcomes of instrumented fusion with the outcomes of two decompression techniques, the first employing a unilateral approach for bilateral decompression and the second employing a bilateral approach for contralateral decompression, with contralateral foraminal decompression as needed. Postoperative evaluation was made at the final follow-up visit beginning in 2007 by analyzing patient interviews and neurological examination data. We compared results with the Japanese Orthopedic Association symptom score before surgery and at final follow-up. RESULTS: Surgical indications for fusion narrowed over time, with fusion used less frequently and decompression used more frequently. Similar decreases in clinical symptoms, including low back pain, were achieved with all methods. In the decompression groups, preoperative slip distance and instability, and postoperative slip progression or development of instability, did not correlate significantly with clinical outcome. Slip progression occurred in 8 of 10 levels in patients with preoperative translation ≥5 mm, but these patients showed no increase in instability, defined as translation ≥ 2 mm, at final follow-up. CONCLUSION: Our findings raise a question about the value of the radiologic criteria for performing fusion used in the late period, namely translation ≥5 mm and/or rotation ≥ 10°. If discogenic pain is excluded, decompression alone may be suitable even for patients with severe low back pain and translation ≥5 mm. LEVEL OF EVIDENCE: 4.

[Stent-in-Stenting for In-Stent Stenosis after Carotid Artery Stenting:A Report of 2 Cases].

Standard strategy for the treatment of subacute in-stent stenosis after carotid artery stenting remains controversial. We report the successful application of stent-in-stenting in 2 patients with subacute in-stent stenosis of the internal carotid arteries (ICA). The postoperative courses of both patients were uneventful, and the patency of the ICA was confirmed at the 2-year follow-up. In this study, medical treatment was not effective, and therefore, stent-in-stenting was used as an alternative treatment for subacute in-stent stenosis.

Masseteric nerve transfer for short-term facial paralysis following skull base surgery.

BACKGROUND: Nerve transfers have been widely used to reanimate paralyzed facial muscles after irreversible proximal injuries to the facial nerve. The author has developed a technique involving masseteric nerve transfer combined with cross-facial nerve grafting for treating skull base surgery-induced facial paralysis. This paper aims to demonstrate that this procedure is effective and causes negligible donor site morbidity. METHODS: Seven patients who developed facial paralysis after the removal of skull base tumors were treated with masseteric nerve transfer combined with cross-facial nerve grafting with the aim of reanimating the midface. The mean period of preoperative paralysis was 6 months. The follow-up period ranged from 22 to 65 months (mean: 46 months). The patients were evaluated with physical examinations and video analysis. RESULTS: Successful reanimation of the midface was achieved in all patients except one, whose muscle tone recovered. On average, facial motion developed 4 months after the nerve transfer. Only minimal coordinated eyelid movement was seen during biting. None of the patients experienced impaired masticatory function or visible wasting of the masseter muscle. All of the patients who recovered the ability to contract their paralyzed muscles were able to close their eyes tightly during biting; however, none of the patients have been able to achieve an effortless spontaneous smile. CONCLUSIONS: Masseteric nerve transfer is an alternative method for selective reanimation of the midface and does not cause donor site morbidity.

[Chronic subdural hematoma organized over a short period of time with spontaneous intracranial hypotension: a case report].

Spontaneous intracranial hypotension (SIH) can develop after cerebrospinal fluid (CSF) leakage and is accompanied by various symptoms, including headache and neck pain. In recent years, cases of chronic subdural hematoma (CSDH) that develop concomitantly with SIH have been encountered occasionally. Although various reports regarding the priority of treatment exsist, a conclusive opinion has yet to be given. Here, we present a rare case of CSDH that developed concomitantly with SIH in which the hematoma became organized over a short period of time. Organized CSDH results from impairment of the microcirculation due to metabolic or circulatory dysfunction or inflammation after trepanation. The disease is believed to require craniotomy for treatment, while SIH is frequently treated with an epidural blood patch, which may require repeated procedures to achieve success. If CSF leakage cannot be improved, the concomitant CSDH may become organized. Therefore, it is important to thoroughly discuss the therapeutic options in individual cases.

[Endonasal endoscopic chiasmapexy for secondary empty sella syndrome following fenestration of a Rathke's cleft cyst].

Drainage by fenestration of the cyst wall via the transsphenoidal apporach is the most commonly used treatment for symptomatic Rathke's cleft cyst (RCC). The same procedure is usually adopted for recurrence of RCC. We have encountered a case of secondary empty sella syndrome presented with visual field defects after repeated surgery for RCC. Secondary empty sella syndrome following the surgery of RCC is rare. The condition was explained by the mechanism that the optic nerve adhered to the cyst wall and it was tethered downward as the cyst shrank after the surgery. We treated the patient via the endonasal endoscopic transsphenoidal approach by placing holed silicone plates under the sellar floor to elevate the sellar contents and the optic nerve. Silicone plate is hard enough to support the sella and the small holes on it would facilitate drainage of the cyst contents. This method has proved useful as chiasmapexy for secondary empty sella syndrome after the surgery of RCC.

Endonasal endoscopic transsphenoidal chiasmapexy with silicone plates for empty sella syndrome: technical note.

Silicone plates sutured together to form blocks were used for extradural elevation of the sella floor in two patients who underwent chiasmapexy for visual disturbance associated with empty sella syndrome. A 36-year-old woman had been treated for prolactinoma for about 19 years with bromocriptine and then presented with left visual disturbance. A 79-year-old man presented with right blurred vision of unknown cause other than empty sella. The sella turcica was accessed via the endonasal transsphenoidal approach under endoscopic guidance. The bony sellar floor was opened with a drill. Two or three pieces of 1-mm-thick silicone plate were sutured to make a block. Two or three blocks were inserted into the epidural space to elevate the sellar contents. Visual symptoms improved in both patients. Silicone is biocompatible and not absorbable. Silicone plates are elastic and easy to handle during insertion, but firm enough to support the sella. The elevation can be adjusted by changing the number of plates in the block. The endonasal endoscopic approach is minimally invasive and particularly suitable for transsphenoidal extradural chiasmapexy for empty sella syndrome.

Suture knot on the repair splint: a simple method to facilitate reconstruction of the sella turcica during endonasal endoscopic transsphenoidal surgery. Technical note.

Reconstruction of the sellar floor after pituitary tumor removal is sometimes difficult because the repair graft is difficult to handle in the narrow space. This is especially problematic if the endonasal endoscopic approach is used. The authors devised a technique to facilitate this procedure by placing a suture knot on the repair splint. This allows the material to be grasped securely with forceps and improves manipulation even within the narrow nasal cavity. This technique has proved useful when performing the endonasal endoscopic approach, and it is also expected to be useful when conducting the conventional sublabial transsphenoidal approach.

[Pachymeningoencephalitis: case report].

A 59-year-old man presented with generalized convulsion. MR imaging demonstrated a homogeneously enhanced dural lesion infiltrating the parenchyma in the right parietal region. He had no history of sinusitis and the lesion a resembled malignant tumors, so surgical treatment was performed. The histopathological studies showed pachymeningitis extending to the cerebral parenchyma, so the diagnosis of pachymeningoencephalitis was made. After the operation, the patient had no neurological deficits and anticonvulsant therapy was continued. We report the third case of idiopathic local pachymenigoencephalitis that we could range extensively in the world. The clinical features and pathogenesis are discussed.