Hidehito Koizumi

Postoperative intracerebral hemorrhages: A survey of computed tomographic findings after 1074 intracranial operations

We surveyed computed tomographic findings after 1074 intracranial operations to determine the incidence and etiology of postoperative intracerebral hemorrhages. Medium or large hemorrhages occurred after 42 operations (3.9%). Larger hemorrhages, hemorrhages in the suprasellar region, and hemorrhages associated with other types often preceded a poor outcome. Major etiologies underlying postoperative intracerebral hemorrhages were uncontrolled bleeding from a blind area, difficult dissection of a tumor from the brain, retraction injury, vessel injury from a needle, bleeding from a residual tumor, local hemodynamic changes after removal of a tumor, premature rupture of an aneurysm, and hypertensive putaminal hemorrhage. Hypertension during recovery from anesthesia was another important factor.

Postoperative Extradural Hematomas: Computed Tomographic Survey of 1105 Intracranial Operations

We reviewed the computed tomographic findings after 1055 intracranial operations to determine the incidence of postoperative extradural hematomas. There were 11 medium and 5 large hematomas after 1055 operations (1.0%). Ten of the 16 hematomas were operated upon (10/1055, 0.9%). Four of the 10 hematomas were seen after 278 brain tumor removals (1.4%), another four after 190 aneurysmal operations (2.1%), one after 14 intracerebral hematoma removals (7.1%), and the last one after 251 ventricular shunting or drainage procedures (0.4%). In 4 of the 10 operated hematomas, sites were regional, in five sites were adjacent, and in one the site was distant. All of the five adjacent hematomas extended downward from a lower rim of the operative locus. Causes were analyzed in the three types of the hematomas. In case of the regional hematomas, the causes were incomplete hemostasis of the dura mater or the bone in all four patients, nonperformance of central stay sutures in three, systemic hypertension in one, and hypofibrinogenemia in one. In the adjacent hematomas, we could find dural separation at an edge of craniotomy in all five patients, abrupt collapse of the brain in all, ventricular dilatation in two, and systemic hypertension during immediate postoperative period in two. In one distant hematoma, ventricular dilatation and ventricular shunting procedure were themselves thought to be the causal factors.

Postoperative subdural fluid collections in neurosurgery

After introduction of computed tomography (CT) scanning, subdural fluid collections (SFCs) have been more frequently detected. We encountered 1013 operated cases in which CT scans were performed at an early postoperative stage. Postoperative SFC occurred in 165 of the 1013 operated cases (17%). The incidence of SFC was highest in aneurysm surgery (47%), followed by neurovascular decompression (27%) and brain tumor surgery (22%). In aneurysm surgery, preoperative ventricular dilatation seemed to promote the occurrence of SFC. In tumor surgery, SFC occurred more frequently when the tumor existed in the sellar region. The SFCs decreased or disappeared in most cases on sequential CT scans, but increased in 27 cases. In the latter, maximum thickness of the SFC was seen between 20 and 30 postoperative days. Nineteen of the 27 cases had preoperative ventricular dilatation. Operation for SFC was performed in four cases with clinical symptoms and signs. Three of 169 cases developed into chronic subdural hematomas.

Effects of cilostazol on cerebral vasospasm after aneurysmal subarachnoid hemorrhage: a multicenter prospective, randomized, open-label blinded end point trial

OBJECT Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is a major cause of subsequent morbidity and mortality. Cilostazol, a selective inhibitor of phosphodiesterase 3, may attenuate cerebral vasospasm because of its antiplatelet and vasodilatory effects. A multicenter prospective randomized trial was conducted to investigate the effect of cilostazol on cerebral vasospasm. METHODS Patients admitted with SAH caused by a ruptured anterior circulation aneurysm who were in Hunt and Kosnik Grades I to IV and were treated by clipping within 72 hours of SAH onset were enrolled at 7 neurosurgical sites in Japan. These patients were assigned to one of 2 groups: the usual therapy group (control group) or the add-on 100 mg cilostazol twice daily group (cilostazol group). The group assignments were done by a computer-generated randomization sequence. The primary study end point was the onset of symptomatic vasospasm. Secondary end points were the onset of angiographic vasospasm and new cerebral infarctions related to cerebral vasospasm, clinical outcome as assessed by the modified Rankin scale, and length of hospitalization. All end points were assessed for the intention-to-treat population. RESULTS Between November 2009 and December 2010, 114 patients with SAH were treated by clipping within 72 hours from the onset of SAH and were screened. Five patients were excluded because no consent was given. Thus, 109 patients were randomly assigned to the cilostazol group (n = 54) or the control group (n = 55). Symptomatic vasospasm occurred in 13% (n = 7) of the cilostazol group and in 40% (n = 22) of the control group (p = 0.0021, Fisher exact test). The incidence of angiographic vasospasm was significantly lower in the cilostazol group than in the control group (50% vs 77%; p = 0.0055, Fisher exact test). Multiple logistic analyses demonstrated that nonuse of cilostazol is an independent factor for symptomatic and angiographic vasospasm. The incidence of new cerebral infarctions was also significantly lower in the cilostazol group than in the control group (11% vs 29%; p = 0.0304, Fisher exact test). Clinical outcomes at 1, 3, and 6 months after SAH in the cilostazol group were better than those in the control group, although a significant difference was not shown. There was also no significant difference in the length of hospitalization between the groups. No severe adverse event occurred during the study period. CONCLUSIONS Oral administration of cilostazol is effective in preventing cerebral vasospasm with a low risk of severe adverse events. Clinical trial registration no. UMIN000004347, University Hospital Medical Information Network Clinical Trials Registry.

Immediate postoperative seizures: incidence and computed tomographic findings

Convulsive seizures within 48 hours after intracranial operations using a craniotomy were reviewed. Incidence was 8.9% (44 of 493 operations): 13.5% of brain tumor operations and 3.8% of aneurysmal operations. We demonstrated that preoperative seizures, sites of lesion, sub-therapeutic anticonvulsant levels, and postoperative local organic lesions were important factors causing the immediate postoperative seizures. Among them, a survey of postoperative computed tomography scans disclosed nine intracerebral hemorrhages, eight cases of cerebral edema, and four cerebral infarctions in the 44 patients; such major complications had a significant correlation with postoperative seizures (p less than 0.005).

Recurrence of medulloblastoma 19 years after the initial diagnosis

Abstract A 25-year-old woman presented with recurrent medulloblastoma. She had been diagnosed with cerebellar medulloblastoma and treated for it at the age of 5 years. The new tumor was partially resected and chemotherapy was begun. However, a disseminated tumor of the spine was discovered and, despite radiotherapy, the patient became comatose and died. Histological examination of the tumor specimen showed characteristics similar to those of the first tumor. Late recurrence of medulloblastoma is rare, and a latency period of 19 years is the longest reported. This case violates Collins’ rule and exceeds other proposed periods of risk. Extension of the period of follow-up in patients with medulloblastoma is advocated.

Bony carotid canal hypoplasia in patients with moyamoya disease.

OBJECT The natural history of moyamoya disease is not well known. We have observed that the bony carotid canal is hypoplastic in patients with adult onset moyamoya disease. Bony carotid canal development should represent internal carotid artery (ICA) development, and may stop with the beginning of ICA stenosis. The purpose of this study was to determine the onset of moyamoya disease by measuring the bony carotid canal. METHODS The normal diameter of the bony carotid canal was evaluated on 4-mm thick bone window CT scans of the skull base in 60 Japanese patients aged 20-80 years, who had minor head trauma or headache considered to be unrelated to the skull base or arterial systems. The relationship between age and bony carotid canal development was assessed in a second group of 50 patients aged 0-19 years, including 10 under 2 years, using CT scans with the same parameters. The diameter of the bony carotid canal in 17 Japanese patients with moyamoya disease was measured. RESULTS The normal diameter in adults was 5.27 +/- 0.62 mm (mean +/- SD). The bony carotid canal developed rapidly before approximately 2 years of age. After fusion of the bony suture, the bony carotid canal developed slowly. The mean diameter of the bony carotid canal was 3.31 +/- 0.44 mm in 11 adult patients with adult-onset moyamoya disease. According to the apparent curve of bony carotid canal development, ICA stenosis was assumed to start in early childhood. CONCLUSIONS Our findings suggest that most cases of Asian moyamoya disease may arise in childhood and that many Asian adult patients with moyamoya disease may develop occlusive vasculopathy in childhood.

Subdural hemorrhagic injury after open heart surgery

We report two cases of acute subdural hematoma after cardiac surgery using cardiopulmonary bypass. In both patients, emergency removal and drainage of a subdural hematoma was performed by neurosurgeons, and complete recovery followed. Subdural hemorrhagic brain injury after cardiac surgery is rare and devastating; however, we consider early diagnosis and proper treatment to be effective because organic brain damage did not occur.

Unsuccessful tracer injection in radionuclide cisternography revisited

Since cerebrospinal fluid (CSF) leakage is highlighted as a cause of persistent headache, radionuclide cisternography has been increasingly performed in Japan to confirm the disorder, although the limited ability of the examination should be recognized. We present 3 cases in which failure of a tracer injection was strongly suspected. In 2 cases with chronic symptoms, the tracer appeared to be injected into the epidural space, because of irregular initial accumulation of the tracer and lack of diffusion along the CSF cavity. Another is a case with spontaneous CSF leakage confirmed by MRI, and the tracer was thought to be injected into the leaked fluid accumulated in the spinal epidural space. Tracer in the CSF space rapidly disappeared within several hours in all cases. As such cisternographic images may be misdiagnosed as severe CSF leakage, careful interpretation of images in patients especially with no typical MR findings of CSF leakage is necessary. Excessive tracer clearance from the body suggests such technical failure.

Subdural effusions in the posterior fossa associated with spontaneous intracranial hypotension

BACKGROUND Misdiagnosis of spontaneous intracranial hypotension remains a problem, despite increasing recognition. METHODS Three patients with spontaneous intracranial hypotension presented with typical findings on lumbar puncture, magnetic resonance (MR) imaging, and radioisotope cisternography. All patients showed subdural effusions in the posterior fossa on axial T2-weighted MR imaging. Axial MR images of 112 patients with other conditions were also screened for this finding. RESULTS One of three patients had typical orthostatic headache, and the other two had continuous headache. The finding of subdural effusions in the posterior fossa on axial T2-weighted MR imaging disappeared after treatment. Similar findings were found in 14 of 112 patients with other conditions. Most of the patients were over 60 years old or had dementia or previous radiation therapy. CONCLUSIONS Subdural effusions in the posterior fossa can be identified by T2-weighted axial MR imaging, and are useful for the diagnosis of spontaneous intracranial hypotension and for verifying the effectiveness of treatment.