Clinical study of cerebral blood flow in bilateral chronic subdural hematoma measured by 99mTc-HMPAO SPECT]

Cerebral blood flow(CBF) in 34 patients with bilateral chronic subdural hematoma was measured by 99mTc-HMPAO SPECT before operation. The regional CBF was measured in 26 regions of the 10 cortical regions, putamen, thalamus and cerebellar hemisphere on both sides. According to the thickness of subdural hematoma, the thicker hematoma side was measured and examined as the thick hematoma side, and the other side as the thin hematoma side. Thirty four cases with bilateral chronic subdural hematoma were classified into four groups on the basis of clinical symptoms: 13 cases with headache(headache group), 10 cases with hemiparesis(hemiparesis group), 5 cases with tetraparesis(tetraparesis group) and 6 cases with consciousness disturbance or dementia(consciousness disturbance group), and into two groups according to the degree of midline brain shift on MRI: 14 cases of non-shifted group and 20 cases of shifted group. The average CBF of 34 patients in each region indicated a regional CBF reduction in the frontal, parietal and occipital cortices on the thin hematoma side, and in the putamen on the thick hematoma side. In the headache group, the regional CBF reduction on the thin hematoma side was found in the frontal, parietal and occipital cortices compared with the corresponding regions on the thick hematoma side, and in thalamus on the thick hematoma side. In the hemiparesis and tetraparesis groups, there was no statistically significant CBF reduction between the thick and thin hematoma sides. In the consciousness disturbance group, the CBF reduction in whole brain was remarkably significant. By the degree of the midline brain shift, the CBF reductions between the thick and thin hematoma sides were observed. Namely, in the shifted group, the CBF reductions were noted in the frontal, parietal and occipital cortices in the thin hematoma side, and in the putamen in the thick hematoma side. We concluded that the CBF reduction of bilateral chronic subdural hematoma was bilaterally found in the hemiparesis and tetraparesis groups, and which was finally observed in whole brain in the consciousness disturbance group.     

Regional differences in cerebral vascular response to PaCO2 changes in humans measured by positron emission tomography.

Hypercapnia and hypocapnia produce cerebral vasodilation and vasoconstriction, respectively. However, regional differences in the vascular response to changes in Paco2 in the human brain are not pronounced. In the current study, these regional differences were evaluated. In each of the 11 healthy subjects, cerebral blood flow (CBF) was measured using 15O-water and positron emission tomography at rest and during hypercapnia and hypocapnia. All CBF images were globally normalized for CBF and transformed into the standard brain anatomy. t values between rest and hypercapnia or hypocapnia conditions were calculated on a pixel-by-pixel basis. In the pons, cerebellum, thalamus, and putamen, significant relative hyperperfusion during hypercapnia was observed, indicating a large capacity for vasodilatation. In the pons and putamen, a significant relative hypoperfusion during hypocapnia, that is, a large capacity for vasoconstriction, was also observed, indicating marked vascular responsiveness. In the temporal, temporo-occipital, and occipital cortices, significant relative hypoperfusion during hypercapnia and significant relative hypoperfusion during hypocapnia were observed, indicating that cerebral vascular tone at rest might incline toward vasodilatation. Such regional heterogeneity of the cerebral vascular response should be considered in the assessment of cerebral perfusion reserve by hypercapnia and in the correction of CBF measurements for variations in subjects' resting Paco2.     

Regional volume changes of the brain in migraine chronification

The pathophysiology of migraine is complex.Neuroimaging studies reveal functional and structural changes in the brains of migraine patients.We sought to explore regional volume differences in intracranial structures in patients with episodic and chronic migraine.Sixteen episodic migraine patients,16 chronic migraine patients,and 24 normal controls were recruited and underwent 3.0 T MRI scanning.The volumes of 142 brain regions were calculated by an automatic volumetric algorithm and compared with clinical variables.Results demonstrated that the volumes of specific regions in the frontal and occipital lobes,and the right putamen,were increased and the volume of the fourth ventricle was decreased in the episodic migraine patients compared with controls.The volumes of the left basal forebrain,optic chiasm,and,the fourth ventricle were decreased in the chronic migraine patients,while the occipital cortex and the right putamen were larger.Compared to episodic migraine patiants,chronic migraine patients displayed larger left thalamus and smaller frontal regions.Correlation analysis showed that headache frequency was negatively correlated with the volume of the right frontal pole,right lateral orbital gyrus,and medial frontal lobes and positively correlated with the volume of the left thalamus.The sleep disturbance score was negatively correlated with the volume of the left basal forebrain.This suggests that migraine patients have structural changes in regions associated with pain processing and modulation,affective and cognitive processing,and visual perception.The remodeling of selective intracranial structures may be involved in migraine attacks.This study was approved by the Ethics Committee of Chinese PLA General Hospital(approval No.S2018-027-02)on May 31,2018.     

Relation between brain displacement and local cerebral blood flow in patients with chronic subdural haematoma

OBJECTIVES: To evaluate the relation between brain displacement, clinical signs and symptoms, and local cerebral blood flow (lCBF) in patients with chronic subdural haematoma (CSDH). METHODS: Forty five patients (age range 58-87 years, mean 71.9 (SD 8.4)) with unilateral CSDH were studied. Patients were categorised into three groups: I, headache (n=16); II, paresis (n=14); and III, mental change (n=15). T1 weighted MR images were obtained in all patients preoperatively. Quantitative values of maximum haematoma thickness, midline shift, and brain rotation angle were measured on axial and coronal MR images. In 21 patients, lCBF was measured by Xe enhanced CT. Values for lCBF were obtained in selected regions of interest in the frontal cortex, thalamus, and hemisphere on both the haematoma and contralateral sides. RESULTS: The lCBF reduction in the ipsilateral frontal cortex showed the best linear correlation with haematoma thickness (r=0.57), whereas the reduction in the ipsilateral thalamus had the most significant correlation with pineal shift (r=0.65) and third ventricle incline (r=0.67). In patients with paresis, lCBF decreased significantly on the ipsilateral side of both the frontal cortex and thalamus (p<0.05), whereas patients with mental change showed a significant reduction of lCBF on both sides of the thalamus (p<0.01) and in the ipsilateral frontal cortex (p<0.01). CONCLUSIONS: The lCBF reduction and clinical symptoms correlated well with local brain displacement in patients with CSDH. The lCBF in the central cerebral area including the thalamus was reduced in patients with clinical signs. The mental changes found were thought to derive from mild impairment of consciousness due to upper brain stem displacement.     

A case of interhemispheric subdural empyema with sinusitis diagnosed by diffusion-weighted MRI]

The patient was a 29-year-old man with sinusitis. He was admitted with high grade fever, headache, vomiting and disturbance of consciousness. Neurological examination revealed nuchal rigidity, aphasia, right hemiparesis, right sensory disturbance and bilateral Babinski signs. A nonenhanced CT on admission showed a low density area in the interhemispheric fissure. Gadolinium-enhanced MRI and DWI showed an interhemispheric subdural empyema and sinusitis. Neurological deficits gradually improved, after he underwent urgent surgical drainage of sinusitis followed by antibiotics therapy. About three weeks later, he developed right hemiparesis and disturbance of consciousness, and MRI demonstrated the expansion of interhemispheric subdural empyema. Therefore, he underwent surgical drainage of interhemispheric subdural empyema. He was discharged from our hospital without neurologic deficit. We suggest that MRI, in particular DWI, is a useful additional imaging modality for the diagnosis of interhemispheric subdural empyema.     

Brain gamma-aminobutyrate aminotransferase (GABA-T) and monoamine oxidase (MAO) in patients with Alzheimer's disease

Summary Activities of Gamma-aminobutyrate aminotransferase (GABA-T) and Monoamine oxidase (MAO)-A and-B were estimated in postmortem brains from 6 control subjects without psychiatric or neurologic disorders and 8 histopathologically verified cases of patients with Alzheimer's disease and senile dementia of Alzheimer type (AD/SDAT). The enzyme activities were examined in four cortical brain regions, three nuclei in the basal ganglia, thalamus and white matter. GABA-T activities in the cortical regions (frontal, parietal, occipital and temporal cortices) and nucleus caudatus were significantly lowered in the AD/SDAT patients. The MAO-A activities were significantly increased in the occipital cortex, caudate nucleus, thalamus and white matter in the AD/SDAT patients. No significant differences were found in the other regions (frontal cortex, parietal cortex, temporal cortex, putamen and globus pallidus). The MAO-B activities in three cortical regions (frontal, parietal and occipital cortices), thalamus and white matter were significantly increased in the AD/SDAT patients, whereas no difference was apparent in the other regions. The changed activities could not be correlated with age or postmortem time. The present results are the first describing decreased GABA-T activities as well as increased MAO-A activities in brain from patients with AD/SDAT, while the results with MAO-B support previous findings. A possible connection was found between the order of magnitude of the changes in enzyme activities and the severity of the disease.     

Kernohan's notch phenomenon in chronic subdural hematoma: MRI findings.

We report two cases of Kernohan's notch phenomenon secondary to chronic subdural hematoma detected by MRI. In the first case, the patient was drowsy with an oculomotor palsy and a hemiparesis ipsilateral to the chronic subdural hematoma. MRI in the post-operative period showed no abnormal signal or deformity of the crus cerebri. The neurological signs immediately resolved after trephination. In the second case, the patient was admitted with progressive decrease in their level of consciousness and ipsilateral hemiparesis with the chronic subdural hematoma. MRI on admission revealed an abnormal signal in the contralateral crus cerebri against the chronic subdural hematoma. After surgery, the mental state gradually recovered to normal with some degree of residual hemiparesis. In patients with chronic subdural hematoma, a compressive deformity of the crus cerebri, without abnormal signal on MRI, may predict a better neurological recovery in patients with Kernohan's notch phenomenon.     

Cerebral blood flow and metabolism in multi-infarct dementia

Cerebral blood flow and oxygen metabolism were studied in three aged normal volunteers and 10 patients with multi-infarct dementia (MID) by Positron Emission Tomography using O-15. The diagnosis of MID was done according to the Loeb's modified ischemic score and X-ray CT findings. The MID patients, whose X-ray CT showed localized low density areas in the subcortical white matter and basal ganglia and thalamus, were studied. No occlusion was observed at anterior cerebral artery and/or middle cerebral artery on cerebral angiography. All cases of MID were mild dementias. Regional CBF, rOEF and rCMRO2 were measured by the steady state technique described by Terry Jones et al. The values of rCBF in MID patients were significantly low compared with those of aged normal subjects in frontal, temporal, occipital, parietal cortices and thalamus. The values of CMRO2 in MID were significantly low in frontal, temporal, occipital cortices and thalamus compared with normal subjects'. The OEF was 0.46 in aged normal subjects, and 0.52 in MID patients. The MID patients in the early stage of dementia showed the increased oxygen extraction fraction, and this fact suggests that ischemia is a significant pathogenic mechanism in the production and progression of multi-infarct dementia. The decrease of CBF and CMRO2 in MID compared from normal subjects' were most remarkable in frontal cortex. The impairment of mental functions in MID should be caused by the decreased neuronal activities in frontal association cortex.     

A case of duret hemorrhage demonstrated by computed tomography]

Brainstem hemorrhage in descending transtentorial herniation is well known as Duret hemorrhage. However, CT or MRI rarely reveals Duret hemorrhage. The authors report a case of brainstem hemorrhage after craniotomy of spontaneous acute subdural hematoma. A 47-year-old man suffered sudden onset of severe headache and progressive consciousness disturbance. Initial CT scan demonstrated a right acute subdural hematoma and a marked shift of the midline structures to the left. Emergency craniotomy was performed but he remained comatose. CT scan after 8 days showed multiple petechial hemorrhages in the brainstem. We reported a rare case of Duret hemorrhage diagnosed by CT scan. Duret hemorrhage is almost fatal.     

Structural and functional brain alterations in patients with idiopathic rapid eye movement sleep behavior disorder

ObjectiveTo investigate structural and functional alterations in patients with idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) compared with healthy controls.MethodsTwenty-seven patients with polysomnography-confirmed iRBD and 33 healthy subjects were recruited. All subjects underwent a 3-tesla structural and resting-state functional magnetic resonance imaging (fMRI) examination. Voxel-based morphometry (VBM) analysis was performed to assess grey matter alterations between groups. The amplitude of low-frequency fluctuations (ALFF) was calculated and then compared to measure differences in spontaneous brain activity. Correlations were performed to explore associations between imaging metrics and clinical characteristics in iRBD patients.ResultsCompared with healthy controls, patients with iRBD had decreased grey matter volume in the frontal, temporal, parietal, occipital cortices as well as increased grey matter volume in cerebellum posterior lobe, putamen, and thalamus. Patients with iRBD also exhibited increased ALFF values in the right parahippocampal gyrus. Olfaction correlated with ALFF value changes in occipital cortices.ConclusionsPatients with iRBD had widespread decreases of grey matter volume. Increases of grey matter volume in cerebellum, putamen, and thalamus may suggest a compensatory effect, while the altered ALFF values in parahippocampal gyrus and occipital cortices may play a role in the underlying process of neurodegeneration in this disorder.     

Infected subdural hematoma

A case is presented in which Escherichia coli seeded a pre-existing chronic subdural hematoma. A 77-year-old woman was admitted to our hospital because of lethargy, left hemiparesis and fever. Drainage through a burr hole was performed with the diagnosis of bilateral chronic subdural hematoma. Operative findings revealed the infected subdural hematoma on the right side and non-infected subdural hematoma on the left side. Cultures of the subdural hematoma grew Escherichia coli. In view of the pyuria, the etiology of the infected subdural hematoma was postulated to be a urinary tract infection. In the majority of 14 reported cases, the causative organisms were Escherichia coli, Salmonella, and the systemic sources of infection included the urinary tract, gastrointestinal disease, or were unknown. The possibility of infected subdural hematoma should be considered when computed tomography findings suggestive of chronic subdural hematoma exist in a patient with signs of infection.     

Traumatic acute subdural hygroma mimicking acute subdural hematoma.

Subdural hygroma is a frequent delayed complication of head trauma. Most hygromas are clinically 'silent' and a few cases have shown slow deterioration in the chronic stage. We report a case of subdural hygroma showing unique radiological findings and rapid deterioration. A 74-years-old female presented with a mild headache and consciousness disturbance after head injury. Computed tomography showed a midline shift as a result of two components piling up in the subdural space; the outer components showed low density, the inner components high density. Magnetic resonance imaging demonstrated that these two subdural components were subdural hygroma and subarachnoid hematoma. Simple burr hole irrigation, rather than large craniotomy, was thought to be more appropriate treatment to reduce the mass effect. Simple burr hole irrigation was performed to remove the subdural hygroma and the patient showed an excellent recovery. Careful examination of the radiological findings prevented an unnecessary procedure in this case. A possible mechanism of this phenomenon is discussed.     

Neuroimaging findings of hemiconvulsions, hemiplegia, epilepsy (HHE) syndrome]

A 32-year-old man with hemiconvulsions, hemiplegia, epilepsy (HHE) syndrome is described. He was well developed with a normal pregnancy and delivery, but at age 10 months, he had status epilepticus during a febrile illness. Thereafter, he was noted to have left hemiparesis and mental retardation with recurrent hemiconvulsions. Magnetic resonance (MR) images showed atrophy and degeneration of the right cerebral cortex and white matter, homolateral thalamus, caudate nucleus, and hippocampus, with hyperintensities in both T2-weighted (TR/2200, TE/90) and proton (TR/2200, TE/30) images. There were also slight bilateral cerebellar atrophies. Quantitative single photon emission computed tomographic (SPECT) images using technetium-99m-ethyl cysteinate dimer (99mTc-ECD) revealed markedly reduced cerebral blood flow (CBF) in the right cerebral hemisphere, homolateral thalamus, caudate nucleus and bilateral cerebellum. Bilateral putamen and the medial occipital lobe showed normal findings on MR images and normal regional CBF in SPECT images. We suppose these selective neuronal injures in this case of HHE syndrome will be mainly due to histotoxic factors in epileptic brain damage.     

Traumatic posterior fossa hematoma

The traumatic posterior fossa hematoma was regarded as relatively rare thing, but recently, as the result of the prevalence of CT scanners, the number of reported cases is increasing. We report nine cases of traumatic posterior fossa hematoma. We divided into two categories: one was the acute epidural hematoma, the other was the acute subdural hematoma with cerebellar contusion. Five were cases of the acute epidural hematoma, three were cases of the acute subdural hematoma with cerebellar contusion and a case had both an epidural and a subdural hematoma. All the cases had struck the occipital region and had the occipital bone fracture. The prognosis of the five cases of the acute epidural hematoma was excellent, but that of the four cases of the acute subdural hematoma with cerebellar contusion was poor and they all died inspite of the removal of the hematoma executed in three cases. We estimated that the hitting forth was extremely strong in cases of the subdural hematoma with cerebellar contusion, and that the momentary deformity of the occipital bone might injure the cerebellum directly. Once a hematoma was produced in the posterior fossa, it oppresses the brainstem and causes the acute hydrocephalus, so the state of consciousness and respiration deteriorate suddenly. In cases of the acute epidural hematoma, appropriate surgical intervention could save the patients and resulted in good outcome. But in some cases of the fulminant type acute epidural hematoma of the posterior fossa caused by tearing the sinuses, though we have not experienced, patients die before the diagnosis and treatment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Contralateral acute subdural hematoma occurring after removal of calcified chronic subdural hematoma.

Supratentorial craniotomy for a nontraumatic lesion complicated by an acute subdural hematoma on the opposite side is rare. A 47-year-old woman presented with progressive headache and dizziness with no significant past history. Neuroimaging studies revealed a very large calcified chronic subdural hematoma over the entire right hemisphere with prominent mass effect. Despite a near total excision of the hematoma including the inner membranes by a large craniotomy with meticulous dissection, the brain parenchyma remained depressed. The dead space was therefore filled with saline and the operation was completed as usual. Repeat computed tomography scan for signs of left tentorial herniation demonstrated an acute contralateral subdural hematoma with severe shift of midline structures. We propose a prevention strategy for this event, which has not been previously described. We also discuss possible mechanisms involved in this unexpected complication.     

Mild hypothermia for hemispheric cerebral infarction after evacuation of an acute subdural hematoma in an infant

The use of mild hypothermia to treat hemispheric infarction after evacuation of an acute subdural hematoma in an infant is reported. The patient, a 2-year-old boy, presented with a deteriorating level of consciousness after a fall from a tree. Computed tomography (CT) scan revealed an acute subdural hematoma on the right side with marked midline shift, and emergency evacuation of the hematoma was performed. The postoperative course was uneventful until the patient's intracranial pressure (ICP) rose and his condition deteriorated 3 days after surgery. CT scan revealed a hemispheric infarction on the injured side. Mild hypothermia was induced to control the ICP and protect the brain. While the hypothermia was effective in lowering the elevated ICP, it failed to arrest progression of the infarction. The patient was discharged with mild disability 2 months after the injury. No serious complications occurred during or after the hypothermia. Our experience indicates that hypothermia can be a useful procedure for controlling the ICP in children with severe traumatic brain injury including acute subdural hematoma, although its capability to protect the brain from severe, progressive ischemia appears to be limited.     

Non-persistent "doll phenomenon" in a patient with right thalamic infarction]

An 81-year-old right-handed woman was admitted because of acute dysarthria and left hemiparesis. She had lived herself without aids until the admission. On neurological examination she was confused and disoriented. She was ambulant, but had mild dysarthria and mild left hemiparesis. Neuropsychological tests showed severe impairment of memory, mild impairment of visual cognition, decreased fluency of word recall and mild paramnesia, but no acalculia, agraphia, aphasia or apraxia. MRI of the brain showed small infarction in the right anterior thalamus. 123I-IMP SPECT demonstrated a decrease in CBF of the thalamus, basal ganglia and frontal lobe on the right. During admission, she always played with a doll as if she took it as a real baby. This peculiar symptom. "doll phenomenon" continued for approximately three months later. The "doll phenomenon" usually appears in demented patients with diffuse mental deterioration or dysfunction of the frontal lobe. The present patient had not been demented until the onset of the thalamic infarction, and disturbance of cognition caused by the right thalamic infarction probably produced the "doll phenomenon".     

CBF/CBV maps in normal volunteers studied with 15O PET: a possible index of cerebral perfusion pressure

Local cerebral perfusion pressure (CPP) is a primary factor controlling cerebral circulation and previous studies have indicated that the ratio of cerebral blood flow (CBF) to cerebral blood volume (CBV) can be used as an index of the local CPP. In this study, we investigated whether the CBF/CBV ratio differs among different brain structures under physiological conditions, by means of ¹⁵O positron emission tomography. Nine healthy volunteers (5 men and 4 women; mean age, 47.0 ± 1.2 years) were studied by H₂ ¹⁵O bolus injection for CBF measurement and by C¹⁵O inhalation for CBV measurement. The CBF/CBV ratio maps were created by dividing the CBF images by the CBV images after anatomical normalization. Regions of interest were placed on the CBF/CBV maps and comparing the regions. The mean CBF/CBV ratio was highest in the cerebellum (19.3 ± 5.2/min), followed by the putamen (18.2 ± 3.9), pons (16.4 ± 4.6), thalamus (14.5 ± 3.3), cerebral cortices (13.2 ± 2.4), and centrum semiovale (11.5 ± 2.1). The cerebellum and putamen showed significantly higher CBF/CBV ratios than the cerebral cortices and centrum semiovale. We created maps of the CBF/CBV ratio in normal volunteers and demonstrated higher CBF/CBV ratios in the cerebellum and putamen than in the cerebral cortices and deep cerebral white matter. The CBF/CBV may reflect the local CPP and should be studied in hemodynamically compromised patients and in patients with risk factors for small-artery diseases of the brain.     

阿尔茨海默病的脑血流灌注研究

目的探讨AD患者脑血流灌注的特征性变化。方法选择20例确诊AD患者和10例认知正常者,对所有入组对象行SPECT脑血流灌注显像检查,对所得图像进行视觉分析和半定量分析,比较两组对象各脑区血流灌注情况的差异,并比较AD患者左、右脑叶脑血流灌注的差异。结果 (1)视觉分析结果显示,AD组以颞叶或顶叶脑血流灌注减低为主,各占55%,其中双侧颞顶叶血流灌注减低者占15%,单侧颞顶叶血流灌注减低占20%。正常认知组SPECT影像学表现各异,额叶、颞叶、顶叶、枕叶、丘脑、基底节血流灌注减少情况均存在,各占10%。但无双侧颞顶叶血流灌注减少者,40%表现完全正常。(2)半定量分析结果显示,AD组在右额叶、双侧颞顶叶、右枕叶血流灌注显著低于正常认知组(P<0.05),以右侧颞叶血流灌注降低最明显,左右颞顶叶血流低灌注程度对比无显著性差异。结论 AD患者的SPECT特征性表现为双侧对称性颞顶叶血流低灌注,其中右侧颞叶血流灌注下降最严重。     

Occlusion of a perforating artery, by descending tentorial herniation after head injury, supplying deep cerebral structure--report of 4 cases and their CT evaluation

Four cases with descending tentorial herniation (DTH) after head injury which showed thalamic, mesencephalic and basal ganglionic low density areas (LDAs) manifesting a infarction in postoperative CT films are reported, and a possible mechanism are discussed in this paper. Case 1: Bilateral acute subdural hematoma with left DTH showed LDAs in the anterior part of the bilateral thalami, left occipital lobe and midbrain. The estimated occluded arteries included the anterior thalamoperforating artery(AThA), posterior cerebral artery and midbrain perforator. Case 2: Right acute epidural hematoma with DTH showed LDAs in the anterior part of the right thalamus and in the left globus pallidus. The estimated occluded arteries included the AThA and anterior choroidal artery. Case 3: Right acute epidural hematoma with DTH showed LDAs in the anterior part of the left thalamus, and in the left midbrain tegmentum. The estimated occluded artery was the interpeduncular thalamoperforating artery (IThA). Case 4: Right chronic subdural hematoma with DTH showed LDA mainly in the left thalamus except for the superior thalamic region. The estimated occluded arteries included the AThA and/or IThA and thalamogeniculate artery. Cases 1 and 4 were adult males and cases 2 and 3 were infant males, and the prognosis was good in the infant males, and poor in the adult males. Each of the 4 cases showed no loss of consciousness just after the head injury while 3 out of them deteriorated within several hours, and one was a case of chronic subdural hematoma.(ABSTRACT TRUNCATED AT 250 WORDS)