[Two cases of cervical carotid artery stenosis with high risk post-operative hyperperfusion treated with dexmedetomidine after carotid endarterectomy].

Dexmedetomidine is a central alpha2 adrenoceptor agonist recently shown to be a safe and acceptable sedative agent for patients requiring sedation after brain surgery. We report two patients successfully treated by carotid endarterectomy (CEA) with postoperative management under dexmedetomidine anesthesia for transient ischemic attack (TIA) resulting from severe stenosis of the internal carotid artery (ICA). Case 1: A 75-year-old man was admitted to our hospital with aphasia and weakness of the right side of his body. Although no evidence of acute cerebral infarction was obtained on magnetic resonance imaging (MRI)/diffusion-weighted image (DWI), MR angiography (MRA) revealed severe stenosis of the left cervical ICA. (123)I-IMP-single photon emission tomography (SPECT) and transcranial Doppler (TCD) revealed marked reduction of cerebral blood flow in the left cerebral hemisphere. Although CEA induced hyperperfusion, aggressive control of blood pressure under dexmedetomidine anesthesia enabled effective management of the resulting hyperperfusion syndrome. The patient was discharged without neurological deficits. Case 2: A 68-year-old man was admitted to our hospital with amaurosis fugax and numbness of the right side of his body. Although no evidence of acute cerebral infarction was obtained on MRI/DWI, MRA disclosed severe stenosis of the left cervical ICA. (123)I-IMP-SPECT revealed extremely low perfusion and disturbance of vascular reactivity in the territory of the left ICA. Although conservative therapy was performed, crescendo TIA was noted. Revascularization using CEA was therefore performed. After surgery, hyperperfusion was observed in the same fashion as in case 1, and again aggressive control of blood pressure under dexmedetomidine anesthesia enabled effective management of the resulting hyperperfusion syndrome. The patient was discharged 1 month postoperatively without neurological deficits. Dexmedetomidine is a safe and acceptable sedative drugs preventing hyperperfusion syndrome after CEA.

Bilateral vertebral artery dissecting aneurysm with subarachnoid hemorrhage treated with staged bilateral vertebral artery coil occlusion: a case report.

BACKGROUND: Vertebral artery dissecting aneurysm is now increasingly recognized as a cause of posterior circulation stroke in young adults. Here, we report a case of bilateral VADA with SAH, treated by bilateral coil occlusion using GDCs. CASE DESCRIPTION: A 64-year-old woman was admitted to our hospital with consciousness disturbance (Hunt and Kosnik: grade 4). Computed tomography showed diffuse SAH with a thick hematoma in the left C-P angle. Magnetic resonance angiography, 3D-CTA, and cerebral angiography revealed bilateral VADAs. First, the ruptured left VADA involving the PICA and a perforating branch was treated by occluding the lower half of the VADA and the proximal VA with GDCs in the acute stage. Thereafter, the residual VADA and contralateral VADA exhibited enlargement on cerebral angiography and MRA for 2 months after the initial surgery; thus, the right VADA was occluded by GDCs just proximal to the right PICA after confirming BTO tolerance. CONCLUSION: Staged bilateral VA coil occlusions combined with BTO may be one of the treatment strategies for bilateral VADA with SAH in cases presenting surgical difficulty due to anatomical factors or severe grade of SAH.

Altered brain and gut responses to corticotropin-releasing hormone (CRH) in patients with irritable bowel syndrome.

Stress is a known trigger of irritable bowel syndrome (IBS) and exacerbates its gastrointestinal symptoms. However, underlying the physiological mechanism remains unknown. Here, we investigated hypothalamic-pituitary-adrenal (HPA) axis, colonic motility, and autonomic responses to corticotropin-releasing hormone (CRH) administration as well as brain activity alterations in IBS. The study included 28 IBS patients and 34 age and sex-matched healthy control subjects. IBS patients demonstrated greater adrenocorticotropic hormone (ACTH) responses to CRH than control subjects. Male IBS patients had greater increases in colonic motility than male HCs after CRH. Female IBS patients showed altered sympathovagal balance and lower basal parasympathetic tone relative to female control subjects. Brain responses to rectal distention were measured in the same subjects using functional magnetic resonance imaging, and their associations with individual ACTH responses to CRH were tested. A negative association between ACTH response to CRH and activity in the pregenual anterior cingulate cortex (pACC) during rectal distention was identified in controls but not in IBS patients. Impaired top-down inhibitory input from the pregenual ACC to the HPA axis may lead to altered neuroendocrine and gastrointestinal responses to CRH. Centrally acting treatments may dampen the stress induced physical symptoms in IBS.

Delayed hemorrhage from completely obliterated arteriovenous malformation after gamma knife radiosurgery.

A 43-year-old female was treated with gamma knife radiosurgery (GKS) for right frontal arteriovenous malformation (AVM) manifesting as absence seizures. Complete nidus obliteration was confirmed on angiography 4 years after GKS. However, she experienced recurrence of her previous seizures and delayed hemorrhage occurred within the treated nidus, despite absence of abnormalities by repeated angiography 81 months after GKS. She was treated conservatively and discharged home without neurological deficits. The risk of hemorrhage from obliterated AVM is significantly reduced but not eliminated after radiosurgery. Recanalization of thrombus that is too small to detect by neuroimaging may result in delayed hemorrhage.

[Two cases of main trunk artery occlusion associated with multiple cerebral aneurysms].

We report 2 cases of multiple aneurysms (AN) associated with main trunk artery occlusion. CASE 1: A 52-year-old male was admitted to our hospital with dysarthria and weakness of the right side of the body. Computed tomography (CT) showed cerebral infarction in the left corona radiata. MR angiography and conventional angiography showed occlusion of the left middle cerebral artery (MCA) and saccular aneurysms (ANs) at the origin of the anterior communicating artery (A-com) and bifurcation of the right MCA. Subsequent 123I-IMP-single photon emission tomography (SPECT) revealed marked reduction of cerebral blood flow and disturbed reactivity to acetazolamide in the left cerebral hemisphere. Superficial temporal artery (STA)-MCA anastomosis was performed to improve cerebral blood flow and reduce hemodynamic stress for AN of the A-com and right MCA. At 5 months after the first operation, neck clipping was performed successfully for the non-ruptured A-com AN and right MCA AN. CASE 2: A 65-year-old male was admitted to our hospital. CT revealed subarachnoid hemorrhage (SAH), and 3D-computed tomographic angiography (CTA) and cerebral angiography showed basilar top AN, A-com AN and right MCA AN associated with right internal carotid artery occlusion. Right ACA and MCA territories were visualized from the A-com artery and posterior cerebral artery. STA-MCA anastomosis was performed to improve cerebral blood flow and reduce hemodynamic stress for ANs. In the same operation, successful neck clipping was performed for BA top AN and right MCA AN. In such cases as these, particularly in ischemic cases associated with main trunk artery occlusion, it was important to consider surgery for AN after STA-MCA anastomosis in anticipation of improved cerebral blood flow and reduce hemodynamic stress for AN.

[Case of clipping of a ruptured aneurysm of the posterior cerebral artery (P2) via the transchoroidal-fissure approach].

A 59-year-old female was found to be drawn in a swimming pool and transferred to our hospital. The patient was comatose on admission (Hunt & Kosnk: Grade IV). Computed tomography (CT) showed diffuse subarachnoid hemorrhage (SAH) with thick hematoma in the left ambient cistern. Conventional cerebral angiography and 3D-digital subtraction angiography revealed aneurysms (ANs) of the left posterior cerebral artery (P2), and bifurcation of the left internal carotid and posterior communicating arteries (IC-PC). Successful neck clipping was performed the same day through the temporal horn via the insula for ruptured P2 AN, and the non-ruptured IC-PC AN was also obliterated using a pterional approach. Postoperative course was uneventful except for initial disturbance of consciousness and aphasia. The patient was discharged with no neurological deficit 1 month after surgery. This approach may be preferable in cases involving high positioned PCA AN in the ambient cistern, particularly in the acute phase of severe SAH, as the brain is protected from the detrimental effects of strong temporal retraction and a wider working space is provided.

[A case of rheumatoid factor-positive hypertrophic spinal pachymeningitis].

A 54-year-old female was admitted to our hospital with the complaint of progressive gait disturbance, starting with left abdominal pain 1 month previously. She developed acute paraparesis and stocking-anesthesia type sensory disturbance within a few days. MR imagings on admission, revealed an encircled subdural mass at the Th1-9 vertebral level, and her spinal cord was compressed at several places at the Th5-6. The subdural mass showed low intensity on T1 and T2 weighted image, and was homogenously enhanced after Gd-DTPA administration. Laboratory data revealed elevation of rheumatoid factor, CH50, C3, C4, and C-reactive protein. An emergency operation was performed by left hemilaminectomy from Th4 to Th6. The subdural mass was resected as far as possible, followed by dural plasty and initiation of steroid intraoperatively. Histopathologic examination of the resected lesion documented a hypertrophic pathymeningitis. Postoperatively, her neurological findings were improved immediately, followed by adjuvant therapy. Recurrence was not present on radiographic images 3 years after surgery. Laboratory data normalized within 4 months. Hypertrophic pachymeningitis is a rare case, and it is difficult to diagnose preoperatively. If there are subdural mass lesions at the multiple vertebral levels, we should suspect this disease. Treatment by immediate decompressive surgery and continuous adjuvant therapy was effective in our case.

[A case of high-aged idiopathic spinal cord herniation from dural defect].

Idiopathic spinal cord herniation was assumed to be a rare disease. However, the incidence of discovering this condition appears to have been increasing recently with advances in neuroradiological diagnosis using magnetic resonance imaging (MRI) and computed tomographic myelogram (CTM). We present herein an operated case of high-aged idiopathic spinal cord herniation. A 71-year-old female presented with spastic paresis of the right lower limb and sensory disturbance of pain and temperature below the level of the left Th4 dermatome, consistent with Brown-Séquard syndrome. MRI and CTM revealed right ventral displacement of the spinal cord and dilatation of the dorsal subarachnoid space at Th2/3. Laminectomy of Th1-3 was performed, herniated spinal cord was untethered and repositioned, and the dural defect was sealed with GORE-TEX dura substitute. Postoperative MRI revealed normal location of the spinal cord and neurological state improved slightly. The patient was discharged 1 month after the operation. Among many cases of spinal cord herniations, this is considered to be a rare case of idiopathic spinal cord herniation in an elderly patient.

[Currarino triad: a case report].

The authors report a case of Currarino triad with a combination of anterior sacral meningocele and mature teratoma, sacral body deformity, anorectal stenosis, and tethered cord. A newborn girl suffered from vomiting, abdominal distension and constipation. Initially, a diverting colostomy was performed at the age of one month. 7 months later, at the age of 8 months, we performed posterior sagittal anorectoplasty (PSARP): As a result, extirpation of teratoma, excision of meningocele, untethering of the spinal cord, and anorectoplasty were achieved simultaneously without complication. We suggest the use of an MRI to specify the presence of anosacral and spinal cord anomalies in patients with intractable constipation and we recommend combined pediatric and neurosurgical assessment and management for all cases of Currarino triad.