Erdheim-Chester disease of the central nervous system. Report of two cases.

The authors report two cases of Erdheim-Chester disease (ECD), an illness of unknown pathogenesis. Generally, this disease process involves the metaphyseal and diaphyseal portions of the long bones, the lungs, and the retroperitoneum; however, other tissues may be involved including the central nervous system (CNS). To date only two cases of CNS-related ECD have been reported. The present report adds to the literature by documenting two more recent cases of ECD involving the CNS. The clinical presentations of these cases, their radiological findings with special reference to magnetic resonance imaging, pathological determination, and clinical management are briefly reviewed.

Misdiagnosis of symptomatic cerebral aneurysm. Prevalence and correlation with outcome at four institutions.

BACKGROUND AND PURPOSE: It is not known what fraction of patients with symptomatic cerebral aneurysms are misdiagnosed at initial medical presentation. It is also not clear whether misdiagnosed patients more frequently deteriorate before definitive aneurysm diagnosis and therapy or achieve a poorer outcome than correctly diagnosed patients. METHODS: We reviewed records of consecutive patients with symptomatic cerebral aneurysms managed by four tertiary-care neurosurgical services during a recent 19-month period. Clinical course and outcome were analyzed according to misdiagnosis or correct diagnosis at initial medical evaluation. RESULTS: Fifty-four of 217 patients (25%) were misdiagnosed at initial medical evaluation, including 46 of 121 patients (38%) initially in good clinical condition (clinical grade 1 or 2). Forty-six of 54 patients (85%) in the misdiagnosis group were initially grade 1 or 2 compared with 75 of 163 patients (46%) with correct initial diagnosis (P < .01). Twenty-six of 54 misdiagnosed patients (48%) deteriorated or rebled before definitive aneurysm treatment compared with 4 of 165 correctly diagnosed patients (2%) (P < .001). Among patients initially presenting as clinical grade 1 or 2, overall good or excellent outcome was achieved in 91% of those with correct initial diagnosis and 53% of patients with initial misdiagnosis (P < .001). Deterioration before correct diagnosis accounted for 16 of 67 patients (24%) with poor or worse final outcome in this series. CONCLUSIONS: Patients in good clinical condition with symptomatic cerebral aneurysms were commonly misdiagnosed. Misdiagnosed patients were more likely than correctly diagnosed patients to deteriorate clinically and had a worse overall outcome. Misdiagnosed cases accounted for a significant fraction of overall poor outcomes among consecutive cases of symptomatic aneurysms.

Relaxometry of noncalcified human meningiomas. Correlation with histology and solids content.

RATIONALE AND OBJECTIVES: Resected meningiomas were examined by relaxometry and light microscopy to evaluate the potential of magnetic resonance imaging (MRI) for identifying histologic subtypes and for discriminating among benign, radiation therapy-induced, and malignant meningiomas. METHODS: The magnetic field dependence of 1/T1 of water protons (nuclear magnetic relaxation dispersion [NMRD] profile) and the water content (dry weight) were measured for 67 specimens, and the data were compared with histology. Only noncalcified, nonhemorrhagic meningiomas are reported. RESULTS: No correlations were found between NMRD profiles, dry weight, and any histologic subtype, in contrast to an analogous study of astrocytomas. Rather, meningiomas have a broader variability of dry weight and 1/T1 than related parenchyma but a much narrower range than all grades of astrocytomas. The mean value of 1/T1, at all fields, is slightly higher in meningiomas--and the mean water content about the same--as adult cortical gray matter. CONCLUSION: Meningiomas are frequently isointense with cortex, and histologic subtypes cannot be differentiated at any magnetic field strength by MRI using only T1- or proton density-weighted MRI.

Correlation of intracranial pressure and transcranial Doppler resistive index after head trauma.

PURPOSE: To investigate the usefulness of transcranial Doppler ultrasonography in the evaluation of intracranial pressure changes after head injury. METHODS: Transcranial Doppler examinations and intracranial pressure measurements using intraparenchymal monitors were performed in 12 cases of closed head injury. Twenty-four sets of data, including the Glasgow Coma Scale, intracranial pressure, transcranial Doppler, and carbon dioxide pressure were compared. The side-to-side difference in the resistivity index was also assessed. RESULTS: There was a significant correlation between increased pressure values and resistivity index when comparing measurements from the same side. There was no correlation between carbon dioxide pressure and any transcranial Doppler parameter or intracranial pressure measurement. No significant correlation was found between the resistivity index and the Glasgow Coma Scale. End diastolic velocity was a stronger determinant of resistivity index than peak systolic velocity. CONCLUSION: The relationship of ipsilateral measurements of intracranial pressure to resistivity index is valid. The resistivity index must be analyzed within the context of the particular disease studied, especially with respect to the hemodynamic alterations. Initial findings suggest that intracranial pressure monitoring cannot be replaced by serial transcranial Doppler measurements in the treatment of the patient with acute head injury.

Variation of the magnetic relaxation rate 1/T1 of water protons with magnetic field strength (NMRD profile) of untreated, non-calcified, human astrocytomas: correlation with histology and solids content.

The magnetic relaxation rate 1/T1 of tissue water protons was measured over a wide range of magnetic field strengths (NMRD profile) for 92 fresh surgical specimens of astrocytomas to search for correlations of 1/T1 with tumor histology, as determined by light microscopy, and to assess the diagnostic potential of NMRD profiles for grading astrocytomas. A third goal was to elucidate the molecular determinants of 1/T1. Each specimen was histologically graded and inspected for evidence of mineral deposits (Ca, Fe); its dry weight was determined and expressed in % of original wet weight. To minimize variability not directly related to tumor grade, this initial report is limited to NMRD profiles of 47 non-calcified, non-hemorrhagic, untreated astrocytomas. For these, the mean value of 1/T1 at very low magnetic field strengths was found to increase with increasing grade of malignancy; no clear correlation could be demonstrated at high fields where most imaging is done. The spread of 1/T1 for different grades of malignancy is large, however, and the overlap significant, even at the lowest field, so that astrocytomas can not be graded by NMRD profiles alone. Average 1/T1 and average dry weight increase with grade of malignancy; but the variability of 1/T1 among specimens of the same dry weight is large, indicating that at least one other cellular parameter, not variable in normal tissue, influences 1/T1 strongly. We hypothesize that this parameter reflects changes at the molecular level in size distribution, mobility, or intermolecular interaction of cytoplasmic proteins. Which specific changes are induced by malignant transformation in astrocytomas remains to be investigated.

Headache characteristics in aneurysmal subarachnoid hemorrhage.

To investigate the nature of the headache accompanying aneurysmal subarachnoid hemorrhage, a retrospective study was conducted. Fifty-four patients and 54 controls completed questionnaires regarding headache, medical history, and family history, in an attempt to derive further information regarding symptoms and factors that might be predictive of aneurysmal subarachnoid hemorrhage. Factors that appear to be of importance in evaluating headache caused by subarachnoid hemorrhage include ominously severe headache, a history of vigorous physical activity precipitating headache, syncope or transient lethargy accompanying headache, previous medical attention for headache, a family history of aneurysmal subarachnoid hemorrhage, or catastrophic central nervous system event at an early age. An algorithm for the management of serious headache is suggested.

Magnetic field dependence of 1/T1 of human brain tumors. Correlations with histology.

The authors have measured the magnetic field dependence of 1/T1 (nuclear magnetic relaxation dispersion, or NMRD profiles) of water protons of histologically characterized samples of astrocytomas, meningiomas, and lymphomas. The goal was to elucidate the determinants of 1/T1 of brain tumors at the cellular level and, in particular, to search for a possible correlation of the profiles with neoplastic properties, including degree of malignancy. Because of the recently demonstrated contribution of myelin to 1/T1 of white matter, careful histologic analyses were performed to correct for its presence. The range of magnitude of the profiles of differing types and grades of tumors correlates with the range of water content of these tumors; the correlation of water content with cellularity (density of cell nuclei in a histologic preparation), in turn, produces correlations of 1/T1 with tumor type. For all the tumors studied, 1/T1 is proportional to solids content; the constant of proportionality is relatively insensitive to tumor type and, for astrocytomas, grade of malignancy; and is about the same as that of normal gray matter. For low- and intermediate-grade astrocytomas that contain myelin, the myelin-specific contribution to 1/T1 has to be considered to make manifest the underlying correlations, which are best demonstrated at low fields, where the background contribution of water and dissolved oxygen is minimal. At high fields, where most imaging is done, a change in oxygen partial pressure, as for example from ischemia in very malignant tumors, is sufficient to alter 1/T1 significantly, reducing the intrinsic correlation between histology and 1/T1.

Occipitocervical fusion for reduction of traumatic periodontoid hypertrophic cicatrix. Case report.

Periodontoid hypertrophic cicatrix resulting from trauma, as demonstrated by magnetic resonance (MR) imaging, is essentially the same as that seen in rheumatoid arthritis. Recent reports suggest that, in rheumatoid arthritis, occipitocervical fusion without transoral decompression of the pannus is adequate for resolution of this anterior lesion. A case of traumatic periodontoid cicatrix is presented in which posterior fusion resulted in reduction of the anterior mass lesion, clearly demonstrated by MR imaging. The etiology of periodontoid hypertrophic scarring, both traumatic and rheumatoid, is discussed in light of MR findings, and treatment implications are considered.

Giant pediatric aneurysm treated with ligation of the middle cerebral artery with the Drake tourniquet and extracranial-intracranial bypass.

Saccular intracranial aneurysms occur infrequently in children, and the incidence of pediatric giant aneurysms is statistically in the same proportion as in adults. The management of these giant aneurysms can be treacherous. This paper presents a case of a 9-year-old boy with a giant aneurysm of the right middle cerebral artery that was successfully managed by ligation of the middle cerebral artery using a Drake tourniquet with the patient awake and by augmentation of the middle cerebral artery circulation with superficial temporal artery-middle cerebral artery anastomosis without excision of the lesion.

Aggressive physiologic monitoring of pediatric head trauma patients with elevated intracranial pressure.

The management of pediatric patients with severe head trauma often requires aggressive physiologic monitoring and treatment. As intracranial pressure (ICP) increases, so does mortality. Yet attempts to decrease elevated ICP can cause physiologic and hemodynamic problems. In this retrospective analysis of 25 patients treated with ICP monitoring alone, ICP measurements plus mannitol, or ICP measurements plus pentobarbital (PB) induced coma/mannitol, survival rates were higher than predicted, particularly among the most severely injured. These results were apparently due to the intensive care and aggressive monitoring. Although barbiturates are known to decrease ICP, the adverse effects encountered, including hypotension, cardiovascular depression and arrhythmias, often outweigh the benefits. Hemodynamic abnormalities are unpredictable and monitoring with Swan-Ganz catheter is useful in managing patients with PB-induced comas. Many failures of PB therapy in pediatric patients may be related to undiagnosed decreases in cardiac output, resulting in decreased cerebral blood flow, even with well-controlled ICP.

Primary amoebic meningoencephalitis: a report of two cases and antibiotic and immunologic studies.

In the summer of 1978, two children who had recently been swimming in freshwater lakes in Florida died from primary amoebic meningoencephalitis. Despite early and intensive treatment with amphotericin B, both patients died three to five days after the onset of illness. Amoebae were observed in wet preparations of cerebrospinal fluid and in sections of cerebral tissue and were identified as Naegleria fowleri by the indirect immunofluorescent antibody technique. The amoebae were highly virulent in mice. The isolate of N. fowleri was extremely sensitive in vitro to amphotericin B (minimal inhibitory concentration [MIC], 0.15 microgram/ml), somewhat sensitive to miconazole (MIC, 25 micrograms/ml), and resistant to rifampin (MIC, less than or equal to 100 micrograms/ml). Treatment with amphotericin B (7.5 mg/kg of body weight per day) administered intraperitoneally protected 60% of the mice. Lower doses of amphotericin B alone or in combination with miconazole (100 mg/kg) or rifampin (220 mg/kg) were not protective. These results suggest that amphotericin B remains the single effective agent in treatment of primary amoebic meningoencephalitis.