Spectral power and coherence analysis of sleep EEG in AIDS patients: decrease in interhemispheric coherence.

Fifteen patients aged between 26 and 55 years with the acquired immunodeficiency syndrome (AIDS) and various cerebral manifestations of the disease underwent an all-night sleep electroencephalogram (EEG) registration. The recordings of 15 age-matched volunteers were examined as controls. Sleep stages were determined visually and the following spectral analysis was based on corresponding artifact-free 40-second periods. The sampling rate was 64 second-1, the spectral resolution was 0.25 Hz and the frequency ranged from 0.25-24 Hz. The power density spectra of eight EEG derivations (left and right frontopolar, frontal, central and occipital; reference montage to the ipsilateral Cb electrodes) and the coherence spectra of interhemispheric (interfrontal, interoccipital) and intrahemispheric (frontooccipital, left and right) channel pairs were computed. The power density of the patients in the 11.5-13-Hz frequency range of nonrapid eye movement (NREM) sleep was considerably lower than that of the controls (p < 0.05 and p < 0.01 at left and right frontal derivations, two-tailed Mann-Whitney U test). The power density of rapid eye movement (REM) sleep showed no consistent differences between the two groups. The interfrontal coherence of the whole frequency range below 12 Hz was markedly lower in the patient group. This applied to NREM sleep and also to REM sleep (p < 0.01 and p < 0.001 for different frequency bands between 1 and 12 Hz in NREM and REM sleep). Possible relations to clinical features are discussed.

Oxalate-induced encephalitis after infusions of sugar surrogates.

The case of a 55-year-old female with oxalate-induced lethal encephalitis following infusions of sugar surrogates is reported. Renal failure and subsequent central coma developed following the use of xylitol, fructose and sorbitol above the recommended dosages. The patient died due to raised intracranial pressure. Cerebral damage was caused by encephalitis due to calcium oxalate crystals. Oxalosis induced by sugar surrogates may be explained either by dose-dependent toxic effects or genetically fixed intolerance.

Wernicke's encephalopathy--causes to consider.

Wernicke's encephalopathy (WE) is a thiamine deficiency disorder and is characterized clinically by the triad of ocular abnormalities, ataxia and disturbances of consciousness. We report on 3 patients with WE, of whom 2 had insufficient thiamine substitution. In the first patient symptoms disappeared during thiamine substitution. In the second patient acute WE was the terminating event in the sequence of parenteral nutrition, lactic acidosis and cardio-pulmonary decompensation. Possibly due to hereditary deficits WE developed in the third patient despite sufficient thiamine substitution. Attention to thiamine deficiency should be paid in all patients with history of alcoholism, malnutrition, malabsorption, tumors, inflammation, other severe diseases and in parenteral hyperalimentation. In order to prevent WE thiamine should be substituted with at least 100 mg/day i.v. or i.m.

Hyperostosis in meningiomas: MR findings in patients with recurrent meningioma of the sphenoid wings.

PURPOSE: We used MR imaging to analyze retrospectively the pattern of hyperostosis occurring concomitantly with recurrent sphenoid wing meningiomas. METHODS: Bone involvement was compared in 12 corresponding CT and MR studies of 10 female patients with sphenoid wing meningiomas recurrence after earlier surgical treatment. Four of these had histologically confirmed meningiomatous infiltration of the bone. RESULTS: All patients had CT findings of localized hyperostosis of parts of the sphenoid wings. MR revealed inhomogeneous areas of slightly increased signal intensity in hyperostotic bone on T2-, proton density- and T1-weighted sequences. In nine of 10 patients, segments of the hyperostotic bone showed different degrees of gadolinium enhancement. CONCLUSIONS: Because earlier studies have revealed high incidences of meningiomatous bone infiltration in sphenoid wing meningiomas, and because infiltration was confirmed in four of our patients, we postulate that the gadolinium enhancement in the area of hyperostosis may be related to meningiomatous bone infiltration.

MR of brain involvement in progressive facial hemiatrophy (Romberg disease): reconsideration of a syndrome.

PURPOSE: To gain further insight into the pathogenesis of progressive facial hemiatrophy, a sporadic disease of unclear etiology characterized by shrinking and deformation of one side of the face. METHODS: We investigated possible brain involvement. MR of the head and face was performed in three female patients with progressive facial hemiatrophy. The central-nervous-system findings were correlated to a clinical protocol and a review of the literature. RESULTS: One patient with epilepsy had abnormal brain findings confined to the cerebral hemisphere homolateral to the facial hemiatrophy. These consisted of monoventricular enlargement, meningocortical dysmorphia, and white-matter changes. CONCLUSIONS: These MR findings, and corresponding neuroradiologic data disclosed by the review, indicate that homolateral hemiatrophy occasionally occurs in a subgroup of patients with progressive facial hemiatrophy. The MR features do not seem consistent with an underlying simple or nutritive atrophic process. We propose chronic localized meningoencephalitis with vascular involvement as a possible underlying cause of the occasional brain involvement in progressive facial hemiatrophy.

[The sacral perineural system--are there radiological criteria for an indication for surgery? First results and literature survey]. / Sakrale Perineuralzysten--gibt es radiologische Kriterien für eine Operationsindikation? Eigene Ergebnisse und Literaturübersicht.

PURPOSE: To establish recommendations for diagnostic imaging of cystic lesions of the sacral region and to evaluate for potential predictors of therapeutic outcome. METHODS: Conventional imaging of the lumbar spine, conventional CT, myelography, post myelo-CT and MRI were performed in 7 symptomatic [corrected] patients. All patients underwent operative decompression and histological examination. The radiographic examinations were reevaluated retrospectively and correlated with the postoperative outcome. RESULTS: In one patient the differential diagnosis of a neurinoma could not be excluded with CT and CT-myelography alone. In all 7 patients MRI provided a definite diagnosis and a precise presentation of the cyst extension. A complete postoperative remission of symptoms was noticed in 4, a partial remission in three cases. The correlation of cyst extension, cyst shape, and the communication with the subarachnoid space did not provide predictive information concerning operative outcome. CONCLUSION: MR can be used as the sole imaging tool for demonstration of cystic lesions. Relevant disadvantages in comparison to myelography and myelo-CT were not evident. No imaging modality could predict the value of surgical intervention.

Vasculitic, hypoxic-ischemic leukoencephalopathy.

The case of a 67-year-old woman with terminal renal insufficiency, who developed extensive encephalopathy with predominant involvement of the white matter is reported. The encephalopathy was the consequence of preexisting hypertensive alterations, acidosis, hypoxia, ischemia, bacteremia and varicella-zoster meningoencephalitis. The vasculitic alterations associated with meningoencephalitis had a major influence on the development and the extent of the leukoencephalopathy.

Otorhinolaryngological complications of progressive facial hemiatrophy (Romberg's disease).

Progressive facial hemiatrophy (PFH) is characterized by slowly progressive atrophy of subcutaneous tissue. Bone, muscles, nerves, the eye, and the brain may be affected by atrophy. Four patients suffering from various otorhinolaryngological complications of PFH or Romberg's disease are reported. Unilateral hearing loss could be located in the inner ear of one patient by audiologic examination. Localized bone destruction and disintegration of a portion of the anterior wall of the frontal sinus were observed in a patient after more than three decades. Marked shrinking of the homolateral parotid gland and homolateral masticatory spasm are reported as further otorhinolaryngological manifestations. The various complications of PFH call for close interdisciplinary cooperation.

Superficial siderosis of the central nervous system.

We report on three patients with superficial siderosis of the central nervous system. The main clinical findings were progressive dementia, hearing loss and ataxia in combination with repeated xanthochromia of the cerebrospinal fluid. Diagnosis was made in one patient with magnetic resonance imaging (MRI), which showed a hyperintense rim around the surface of the cerebellum and the spinal cord. In the two other cases necropsy disclosed superficial iron and hemosiderin deposits on the surface of the brain. The etiology either was idiopathic or secondary to chronic intracranial bleeding by an angioma or after multiple head injuries. Superficial siderosis should be taken into account as one reason for dementia.

[Magnetic resonance of brain involvement in progressive facial hemiatrophy (Romberg's disease). Reconsideration of a syndrome]. / Ressonância magnética do envolvimento cerebral na hemiatrofia facial progressiva (doença de Romberg). Reconsideração de uma síndrome.

UNLABELLED: Progressive facial hemiatrophy (PFH) is a sporadic disease of unclear etiology, characterized by shrinking and deformation of one side of the face. Reports and interpretations of CNS involvement in PFH, as deduced from the occurrence of seizures in some patients and documented by pneumoencephalography and CT findings in small series of patients, are contradictory. We examined three female patients with PFH, one with partial epilepsy, with the view to gaining further insight into the pathogenesis of the disease. METHODS: Routine MR examinations of the head and face were performed. RESULTS: Only the patient with epilepsy showed pathological findings, confined to the cerebral hemisphere homolateral to the facial hemiatrophy, and including monoventricular enlargement, meningo-cortical dysmorphia and white matter changes. CONCLUSIONS: The MR morphology, and corresponding neuroradiological and histopathological findings disclosed by a review of the literature, indicate that homolateral hemiatrophy is a typical finding for a subgroup of PFH patients, but do not support the model of a simple or nutritive atrophic process. We reconsider chronic localized meningo-encephalitis with vascular involvement as possible underlying cause of the occasional brain involvement in PFH.

[Subperiostal hematoma of the orbit and epidural hematoma in patients with skull-brain trauma]. / Subperiostales Orbitahämatom und epidurales Hämatom bei Patienten mit Schädel-Hirn-Trauma.

Subperiostal hematomas (SPOH) of the orbit are mostly of traumatic origin, but may occur spontaneously. In patients with frontal and temporal extradural hematomas, concomitant SPOH of the ipsilateral orbit have sporadically been observed. We report clinical and radiological findings of a patient and a review of the literature and discuss the development of SPOH.

[Effects of flurazepam on disturbed sleep in patients with AIDS]. / Die Wirkung von Flurazepam auf den gestörten Schlaf von Patienten mit AIDS.

Polysomnograms were recorded of twelve patients with acquired immune deficiency syndrome (AIDS) during different stages in an open design. During the first night no hypnotics were administered, during the second night 30 mg flurazepam per os were given. Flurazepam affected mainly the NREM parameters. The times "awake" during the night were reduced, sleep stage 2 showed an increase, and the effective sleep time was also increased. The increase in sleep spindle density was remarkable, however, delta sleep and generation of K-complexes were not affected. Flurazepam did not affect REM sleep at all. The amount of REM sleep showed a slight increase. REM distribution during the night did not show the "bell shaped" increase and the decrease in the morning; the degree of the illness correlated with a flattening of REM distribution.

[Cerebral manifestations of progressive facial hemiatrophy (Romberg's disease). Nuclear spin tomographic findings and literature review]. / Zerebrale Manifestation der progressiven fazialen Hemiatrophie (Romberg-Erkrankung). Kernspintomographische Befunde und Literaturübersicht.

Progressive facial hemiatrophy (PFH) is a sporadic disease of unknown etiology. It is characterized by shrinking and deformation of one side of the face. Potential CNS involvement has repeatedly been suspected in some patients, but is still a matter of controversy. In this article we describe the clinical and MR imaging findings of the CNS in three female patients with PFH and present a comprehensive review of the literature. One of three PFH patients had partial epilepsy. MRI showed ventricular enlargement, white matter lesions, flattening of the cortical surface and meningeal adhesions homolateral to the facial hemiatrophy. Two other patients had completely normal intracranial findings. These findings confirm that cerebral hemiatrophy occurs in a subgroup of PFH patients. The MRI pattern, however, does not seem to be consistent with a simple atrophic or malnutritional process. We consider chronic localized meningoencephalitis with vascular involvement as a possible underlying mechanism for the occasional CNS involvement in PFH.

[How can Romberg disease be evaluated by means of MRI?]. / Was bringt die Magnetresonanztomographie in der Beurteilung der Romberg-Erkrankung?

Romberg disease, also known as progressive facial hemiatrophy (PFH), is an uncommon disease with progressive facial asymmetry as the major symptom. It is a atrophic process of the subcutaneous fatty tissue whose etiology is unknown. Skin, muscles and bones can be secondarily afflicted. With MRI evaluation we were able to show in 14 patients with PFH thinner subcutaneous fat, as well as flattening of the dermis in 12 of the 14. We divided the patients into three stages by the means of the MRI findings and found tendency towards concurrence between the MRI stage and the clinical stage.

Regional association of developmental venous anomalies with angiographically occult vascular malformations.

This study reviews the neuroradiological findings of 43 patients with a developmental venous anomaly in order to discuss the clinical significance of this entity. All patients underwent unenhanced and contrast-enhanced computer tomography and magnetic resonance tomography, as well as selective angiography, and were followed for at least 2 years. In 40% (17 of 43) of patients a cryptic vascular malformation was found in the proximity to the developmental venous anomaly. Neurological symptoms were present in 8 of 17 patients (47%) in this group. Patients with an isolated developmental venous anomaly had symptoms in 19% (5 of 26), but none of them had experienced a hemorrhage. Magnetic resonance was the most sensitive method for the diagnosis of both types of lesions and alterations of the adjacent parenchyma. These results further support that developmental venous anomalies represent a clinically benign entity. However, patients with an association of a developmental venous anomaly and a cryptic vascular malformation are at risk for hemorrhage from their angiographically occult vascular malformation. Magnetic resonance proved to be the imaging modality of choice for both entities and is appropriate for diagnosis and follow-up.

MRA in patients with cerebrovascular disease. Considerations of clinical effectiveness.

OBJECTIVE: To establish in which clinical contexts cerebral MR angiography (MRA) is routinely carried out in a neurological university department and to describe its clinical impact. MATERIAL AND METHODS: Medical records, reports of findings and documentation of imaging examinations carried out in all 69 patients referred to the Department of Radiology from the Department of Neurology between 1995 and 1998 for cerebral MRA were evaluated. The clinical impact of all imaging findings was assessed on the basis of the medical records. RESULTS: Circulatory disturbances in the vertebrobasilar arteries (n = 34) were the most frequent indication for investigation. MRA followed CT or duplex sonography in 66 of the 69 patients with a mean delay of 8 days. MRA was considered diagnostically inferior to conventional MR in 11 cases, comparable in 30 and superior in 25. Comparing MRA and duplex sonography, the corresponding figures were 12, 29 and 23. In retrospect, 56 MRAs were judged unnecessary. CONCLUSION: Controlled clinical studies on optimal use of MRA are needed to avoid wasting resources and to exploit the method's full diagnostic potential in appropriate cases.

High-resolution magnetic resonance imaging in patients with facial haemiatrophy.

The aim of this clinical study was to evaluate the use of high-resolution magnetic resonance imaging (MRI) in the diagnosis of facial haemiatrophy. A total of 14 patients with clinically suspected facial haemiatrophy were investigated using high-resolution MRI. The T1- (500/25) and T2- (2200/50) weighted images were analysed visually and numerically. The results of the affected skin portions were compared with the contralateral skin and correlated with the clinical results. The subcutis could not be delineated by high-resolution MRI in 9 patients with facial haemiatrophy. The dermis was not discernible in 6 cases and was "smooth" in a further 6 patients. The signal-to-noise ratio of affected skin portions and contralateral skin or clinical severity did not correlate. The higher the clinical severity, the more pronounced was the magnetic resonance ratio between dermis and subcutis thickness. Thus high-resolution MRI is a useful method for objective description of pathological changes in clinically suspected facial haemiatrophy.

[Visual motor coordination of AIDS patients, HIV-positive asymptomatic probands and healthy persons during video-tracking]. / Visuomotorische Koordinationsleistung von AIDS-Patienten, HIV-positiven asymptomatischen Probanden und Gesunden im Videotracking.

Here we investigated the applicability of a computer-aided video-tracking as a method for evaluating potential deficits of neural information processing in patients with AIDS and those showing only positive HIV-seroreactivity. Video-tracking was accompanied with a simultaneous recording of EEG. Eight HIV-positive asymptomatic volunteers and eight AIDS-patients with cerebral manifestation of the disease participated in the pilot study. Two groups of eight normals each served as a control. Video-tracking performance of the HIV-positive volunteers and AIDS-patients significantly differed (p less than 0.05) from those of the healthy volunteers. Although the AIDS-patients' performance tended to be worse than that of the HIV-group, this difference was not significant. Power spectrum analysis of the EEG-data indicated that the diminished performance of the two test groups (AIDS and HIV-positives), accompanied by an increased spectral power across the entire frequency range measured in the study, could be an expression of an enhanced synchronization in cortical neuronal networks. The synchronization in turn could be a sign of possible organic brain damage resulting from HIV-infection. In conclusion, we suppose that video-tracking measures parameters which may indicate early deficits of information processing in CNS.

[Spectral power density and coherence in sleep EEG in patients with acquired immunodeficiency syndrome]. / Spektrale Leistungsdichte und Kohärenz im Schlaf-EEG bei Patienten mit dem erworbenen Immunschwächesyndrom.

15 male AIDS-patients from 26 to 55 years (mean 41.8 +/- 8.5) with various cerebral manifestations had a whole-night-sleep-EEG registration. As control the recordings of 15 age-matched volunteers (26-55 years, mean 41.8 +/- 9.8) were examined. Spectral characteristics of elementary EEG-epochs of 40 s length were computed, and sleep staging was performed visually for these intervals. The spectral power density of eight EEG-derivations (left and right frontopolar, frontal, central and occipital electrodes, reference montage to the ipsilateral Cb) were measured (sampling rate 64(-1) s, spectral resolution .25 Hz, frequency range from .25 to 24 Hz). Interhemispherical coherences of the frontal and occipital derivation pairs, and intrahemispherical fronto-occipital coherences of the left and right hemisphere, were computed. In the patients the frontal power density of NREM sleep showed lower values in the frequency range of 10 to 14 Hz. In central and in occipital derivations the power density between 12.5 and 15 Hz was lower in the patients, but the difference was less accentuated. The spectral power density of REM sleep showed similar characteristics in both groups. The interhemispherical frontal coherence of the whole frequency range below 13 Hz was markedly lower in the patient group. This was true for the NREM sleep, and, slightly less, for the REM sleep, too. The interoccipital spectral coherence was generally slightly lower in the patient group; the difference was most clearly in the 12.5 to 15 Hz range of NREM sleep.

MR anatomy and small lesions of the eye: improved delineation with a special surface coil.

To develop an improved investigation protocol for MRI studies of intraocular lesions, imaging with a small surface coil (diameter 6 cm) was compared with a standard surface coil (diameter 11 cm). Both coils were assessed initially on an eye phantom and then by studying 22 patients with uveal melanoma and similar lesions of the eye. The influence of bandwidth and field or view (FOV) were systematically studied and evaluated quantitatively. A smaller bandwidth improved image quality independent of surface coil size. The subsequent secondary increase in chemical shift artefact was acceptable. Smaller FOVs (60-80 mm) necessitated the use of a smaller surface coil. A smaller bandwidth also proved to be advantageous with the use of the smaller surface coil. In conclusion, a smaller-diameter surface coil improves MR imaging of ocular lesions. Pulse sequences with a small bandwidth maintain an acceptable signal-to-noise ratio when the FOV is reduced.