Akira Fukamachi

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.

Spontaneous resolution of chronic subdural hematomas.

Four patients with chronic subdural hematomas, all of which resolved spontaneously, were followed from the time of injury to resolution of the chronic subdural hematoma. Periodic computed tomographic (CT) scans showed spontaneous resolution 78, 174, 231, and 326 days after the development of the chronic subdural hematoma, respectively. Features of the CT scans and a possible mechanism of spontaneous resolution are discussed.

The incidence and developmental process of delayed traumatic intracerebral haematomas

SummaryAlthough delayed traumatic intracerebral haematomas (DTICH) have been frequently reported especially after the advent of computerized tomography (CT), the developmental processes of traumatic intracerebral haematomas and the incidence of DTICH have not been described precisely. Based on early sequential CT examinations of 84 intracerebral haematomas for which initial CT scans were performed as early as within 6 hours of injury, we could ascertain four types of the developmental processes: Type I (39%) included the haematomas which were already evident in the initial CT scans, Type II (11 %) the haematomas which were small or medium initially and increased their sizes afterwards, Type III (24%) the haematomas of which admisstion CT scans could not demonstrate any changes at the sites of development of the haematomas, and Type IV (26%) the haematomas of which initial CT scans showed a salt and pepper or flecked high-density appearance. Types III and IV denoted the DTICH and accounted for 50% of all the haematomas. Therefore, DTICH are thought to be not as uncommon as previously reported. Aetiologies and changes in the concepts of the DTICH are discussed, and it is stressed that, in the cases with eventual extra-and intra-cerebral combined haematomas, any surgical treatment of an extracerebral haematoma plays an important role in the development of DTICH.

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.

Giant Serpentine Aneurysm of the Posterior Cerebral Artery

We are reporting an unusual case of a giant serpentine aneurysm of the posterior cerebral artery (PCA). We were unable to find a report in the literature of a similar aneurysm. The microsurgical pterional approach was used for temporary clipping of the P-2 segment of the PCA, and the aneurysm was trapped successfully and excised. The discussion includes the operative approach to the giant serpentine aneurysm.

Spontaneous and evoked activity of sensory neurons and their organization in the human thalamus

Summary1. Several aspects of the thalamic sensory neurons in man were studied by extracellular recording in the course of stereotaxic intervention in 22 cases.2. Among 44 sensory neurons studied, 16 responded to light touch on the contralateral small areas (except for one) of the face or the first finger, 6 responded to strong pressure on the contralateral small parts of the face, 15 responded to the passive and active movement of the contralateral joint and 7 responded to contralateral muscle stretch.3. Although the somatotopic representation in the thalamic area was not so conspicuous it was found that tactile (touch and pressure) neurons were encountered more in the caudal part while the kinesthetic (joint and muscle) neurons were abundant in the rostral part.4. In nucleus ventralis intermedius region, 2 neurons responded to electrical stimulation of the contralateral median nerve with a fixed latency of about 12 msec.5. On several occasions, when the sensory neuron was recorded, this same point was electrically stimulated by the same electrode and the patients experiences thereby caused were asked. Repetitive electrical stimulation at threshold always resulted in paresthesia in exactly the same area of the neurons receptive field and stronger stimulation provoked sense of electric current in many cases.6. About one fourth of the total recorded neurons were discharging spontaneously in burst fashion. Principally, these neurons did not respond to any kind of natural stimuli nor could they be influenced by voluntary effort of the patient.Zusammenfassung1. Verschiedene Aspekte der sensorischen Neurone des Thalamus wurden am Lebenden mit Hilfe extracellulärer Ableitungen im Verlauf eines stereotaktischen Eingriffes in 22 Fällen untersucht.2. Von den 44 untersuchten sensorischen Neuronen reagierten 16 (mit einer Ausnahme) auf leichtes Berühren der kontralateralen, eng begrenzten Gebiete des Gesichtes oder des Daumens, 6 reagierten auf starken Druck der kontralateralen kleinen Gebiete des Gesichtes, 15 reagierten auf passives und aktives Bewegen des kontralateralen Gelenkes, und 7 reagierten auf kontralateralen Muskelzug.3. Obgleich die somatotopische Repräsentation im Gebiet des Thalamus nicht so auffallend war, wurde festgestellt, daß die taktilen Neurone (Berührung und Druck) mehr im caudalen Teil zusammentreffen, während die kinästhetischen (Gelenk und Muskel betreffenden) Neurone im rostralen Teil angehäuft waren.4. Im Gebiet des Nucleus ventralis intermedius reagierten 2 Neurone auf elektrische Reizung des Nervus medianus der gegenüberliegenden Seite mit einer fest bestehenden Latenzzeit von 12 msec.5. Bei mehreren Gelegenheiten, während das sensorische Neuron abgeleitet wurde, wurde derselbe Punkt mit Hilfe derselben Elektrode elektrisch gereizt und der Patient nach seinen dabei empfundenen Erfahrungen befragt. Repetierende elektrische Stimulation an der Reizschwelle resultierte immer in einer Paraesthesie in genau demselben Gebiet des dem Neuron zugehörigen Rezeptionsfeldes, stärkere Reizung rief in vielen Fällen ein Elektrisiergefühl hervor.6. Ungefähr ein Viertel aller registrierten Neurone entluden sich spontan und explosionsartig (burst). Prinzipiell reagierten diese Neurone auf keinen natürlichen Reiz, noch konnten sie durch den Willen des Patienten beeinflußt werden.

Xenon Contrast CT-CBF Measurements in High-Intensity Foci on T2-Weighted MR Images in Centrum Semiovale of Asymptomatic Individuals

BACKGROUND AND PURPOSE White matter lesions (WMLs) on T2-weighted MR images occurring in the centrum semiovale of normal individuals are a subject of great clinical interest. We therefore investigated regional cerebral blood flow (rCBF) of the centrum semiovale among neurologically normal individuals. METHODS One hundred thirty-five neurologically normal subjects were divided into four grades of WML on the basis of their MR images. rCBF values in the centrum semiovale were measured by xenon contrast CT methods. RESULTS Advanced age and associated hypertension were significant risk factors for higher grade WMLs. Centrum semiovale rCBF values on the left side were 24.27 +/- 2.60 mL.100 g-1.min-1 in grade 0, 23.52 +/- 2.78 in grade I, 19.35 +/- 2.81 in grade II, 15.82 +/- 2.05 in grade III, and 11.31 +/- 2.56 in grade IV. Differences were significant between grades (P < .005 between grade 0 and grades II, III, and IV; between grade II and grades III and IV; and between grades III and IV). Patients with hypertension had lower rCBF values than those without in grades 0, I, II, and III, with significant difference in grade I (P < .005). Age-matched studies between patients 61 to 70 years old confirmed a significant difference between WML grades. CONCLUSIONS WMLs in centrum semiovale are associated with greater age, hypertension, and reduced rCBF values.

Intracranial granuloma caused by Aspergillus fumigatus.

A case is reported of intracranial granuloma caused by Aspergillus fumigatus involving the anterior cranial fossa and the frontal lobe. In this case, clinical symptoms developed about 5 years before the diagnosis was made. The final diagnosis was made by a craniotomy. The patient was treated with an extensive excision and chemotherapy, but finally he failed to respond to these treatments. We compile a summary of reported cases with a tabulation of pertinent information and discuss the pathogenesis, prognosis, and difficulty in treating this infection.