'Gangliocytomas' of the pituitary: a heterogeneous group of lesions with differing histogenesis

Hamartomatous or neoplastic ganglion cells in the sella turcica are an unusual cause of symptoms. They have been reported in association with a functioning or nonfunctioning pituitary adenoma, with pituitary cell hyperplasia, and occasionally as masses unassociated with an adenoma, again with variable endocrinologic findings. Fewer than 50 cases of intrasellar ganglion cell lesions have been reported in the literature, only six of them associated with Cushing's syndrome. We describe the clinicopathologic features of another eight patients, three of whom presented with acromegaly, four with apparently nonfunctioning adenohypophyseal masses, and one with Cushing's syndrome. On histology, six of them were found to have sparsely granulated growth hormone (GH)-producing adenomas with ganglion cell areas, one appeared to have a gangliocytoma not associated with an adenoma, whereas the eighth had a ganglion cell lesion in the posterior pituitary. The morphologic and immunohistochemical findings suggest that the ganglion cell component of seven of these tumors has resulted from neuronal differentiation in a GH-producing adenoma, despite the lack of demonstrable adenoma in one case. A true sellar "gangliocytoma" or hamartoma of ectopic hypothalamic-type neurons appears to be a rarer explanation for the presence of ganglion cells in a pituitary biopsy.

Multifocal inflammatory demyelinating neuropathy: a distinct clinical entity?

BACKGROUND

Several patients have been reported with an asymmetric sensory or sensorimotor demyelinating neuropathy not fulfilling the diagnostic criteria for chronic inflammatory demyelinating polyneuropathy or multifocal motor neuropathy.

OBJECTIVE

To present the clinical, electrophysiologic, radiologic, and pathologic features of six patients with an asymmetric sensory or sensorimotor demyelinating neuropathy.

RESULTS

All six patients were initially affected in only one limb; in four patients the neuropathy progressed to other limbs in an asymmetric fashion during several years. On electrophysiologic examination, evidence of multifocal demyelination and conduction block in motor and sensory nerves was found in all patients. MRI of the brachial plexus revealed swollen nerves and an increased signal intensity on T2-weighted imaging in four patients. A biopsy sample taken from the brachial plexus of one patient revealed evidence of inflammation. All patients showed a beneficial response to IV immunoglobulin treatment. Thirty-four similar patients have been reported previously, many of whom were initially diagnosed as having various other (nontreatable) diseases.

CONCLUSIONS

The authors propose calling this neuropathy "multifocal inflammatory demyelinating neuropathy" and considering it as a distinct clinical entity to facilitate early diagnosis of this treatable disorder.

Proton magnetic resonance spectroscopy of temporal lobe white matter in patients with histologically proven hippocampal sclerosis

The purpose of this study was to assess temporal lobe white matter changes accompanying hippocampal sclerosis on magnetic resonance (MR) imaging using single-voxel 1H MR spectroscopy and to strengthen the hypothesis that these white matter changes are caused by myelin alterations. In 11 patients with histologically proven hippocampal sclerosis, preoperative coronal fluid-attenuated inversion recovery images were visually assessed by two experienced neuroradiologists for hippocampal signal increase and size decrease, atrophy of collateral white matter, and temporal lobe gray/white matter demarcation loss. Single-voxel 1H MR spectroscopy of the white matter of each anterior temporal lobe was also performed, excluding the amygdala and hippocampus. The N-acetyl-aspartate (NAA)/choline and NAA/creatine ratios were calculated. In 12 healthy volunteers both temporal lobes were spectroscopically examined. In all patients the excised hippocampi were histologically assessed for the presence of sclerosis, and the excised neocortical temporal lobes were examined for gray and white matter abnormalities. MRI abnormalities were found on the right in six patients, on the left in four, and one scan was normal. Hippocampal signal increase was seen in nine patients, hippocampal size decrease in ten, atrophy of collateral white matter in nine, and gray/white matter demarcation loss in six. A significant decrease in the NAA/choline ratio was found in temporal lobe white matter ipsilateral to the pathologic hippocampus (symptomatic side), compared with the contralateral, asymptomatic side (P < 0.01), and also compared with controls (P < 0.001). The ipsilateral NAA/creatine ratio was also significantly decreased (P < 0.05) compared with the contralateral side and the control subjects (P < 0.001). Histological examination showed hippocampal sclerosis to a different degree in all patients. Neither gliosis nor cortical dysplasia was found in the ipsilateral, symptomatic temporal lobe. Significant decrease in the mean of NAA/choline ratios is found in temporal lobe white matter of patients with histologically confirmed hippocampal sclerosis. As this indicates neuronal loss or dysfunction, the number of axons may be reduced, with associated decrease in myelin density.

Immunohistochemical characterization of mossy fibre sprouting in the hippocampus of patients with pharmaco-resistant temporal lobe epilepsy

Hippocampal sclerosis (HS) is a common derangement in many patients with temporal lobe epilepsy. As a result of neuronal cell loss in the hilar region of the hippocampus, it is proposed that mossy fibres sprout and re-innervate new regions of the dentate gyrus. This sprouting may cause recurrent excitation that may lead to the generation of seizures. Here, we determined neuronal density, and synaptophysin and glial fibrillary acidic protein (GFAP) immunoreactivity in hippocampal specimens from patients with pharmaco-resistant temporal lobe epilepsy. Patients were classified into two groups: those with severe and those with no HS. Non-epileptic autopsy tissue served as controls. Mossy fibre sprouting was investigated in these two groups of epilepsy patients using Timm's staining and an immunohistochemical staining of the presynaptic growth-associated protein B-50 (also known as GAP-43, neuromodulin, F1). B-50 immunoreactivity in the different sub-areas of the hippocampus was quantified by image analysis. Our results show the following: (i) in both groups of temporal lobe epilepsy patients, there was a significant loss in cell number in all major hippocampal sub-areas compared with autopsy control tissue; (ii) in HS patients, when compared with non-HS patients, there was a further decline in the number of principal cells in all hippocampal sub-areas analysed, which was associated with an increase in GFAP immunoreactivity; (iii) the decline in cell density was accompanied by a reduced number of synaptic terminals; (iv) in the HS group, there were sprouted mossy fibres in the supragranular layer (SGL) of the dentate gyrus; (v) there was an increase in synaptophysin immunostaining in the SGL indicating that functionally active nerve terminals were formed; and (vi) B-50 immunoreactivity was also increased in the SGL in the HS group compared with the non-HS and control groups. These data showed that all temporal lobe epilepsy hippocampi investigated had severe neuronal cell loss which was most dramatic in the HS group, where it was accompanied by a severe loss of synapses. In the HS group, mossy fibre sprouting into the SGL was found. The increase in B-50 immunoreactivity in the SGL indicated that there was still active sprouting. This sprouting was accompanied by an increased density of synapses, indicating that mossy fibre terminals are not only anatomically present, but probably also functional. Thus, functional glutamatergic mossy fibre terminals are in the right position to synapse on to the dendrites of granule cells and thus may contribute to the onset of seizures.

Prognostic relevance of MIB-1 immunoreactivity, S-phase fraction, 5-bromo-2'-deoxyuridine labeling indices, and mitotic figures in gliomas

Prognostic relevance of cell proliferation markers was evaluated in 27 glioma patients. By 1) flow cytometry (FCM), i.e., S-phase fraction (SPF), and BrdUrd-labeling index (LIfcm); 2) immunohistochemistry (IHC), i.e., BrdUrd-labeling index (LIihc) and MIB-1 immunoreactivity (MIB-1 LIihc); and 3) histologic examination, i.e., the presence or absence of cells in mitoses, were assessed. A longer local progression free survival (LPFS) was significantly associated with low SPF, low LIfcm, and low MIB-1 LIihc. For LIihc, no significant association was found. LIfcm appeared to be a more promising prognosticator than MIB-1 LIihc. In comparison with this marker, the presence or absence of mitotic figures appeared to be an even stronger prognosticator. Prognostic significance of LIfcm appeared to be of importance in low-grade gliomas. The number of patients in our study is limited. Our findings were: 1) the presence or absence of cells in mitoses (M-phase activity) appeared to be of more prognostic significance than LIfcm (S-phase activity) and MIB-1 LIihc (non-G0-phase activity); 2) of the tested experimental cell proliferation markers, LIfcm appeared to be of more prognostic significance than MIB-1 LIihc, SPF, and LIihc; and 3) LIfcm is likely to be an important prognosticator in low-grade gliomas and is, therefore, not definitive and only of potential interest.

Prognostic relevance of cell proliferation markers and DNA-ploidy in gliomas

The prognostic significance of clinically, histologically and flow cytometrically derived parameters was assessed in 49 glioma patients. With flow cytometry, DNA-index, S-phase fraction (SPF), 5-bromo-2'-deoxyuridine (BrdUrd)-labelling index (LI), and potential doubling time (Tpot) were determined. After univariate analysis of clinical variables such as, age, seizures as initial symptom, and duration of first symptom were found to be significantly associated both with proliferation rate and with local progression free survival (LPFS). Cytomorphological features such as, the presence or absence of mitosis, necrosis, and endothelial proliferation, were separately analysed and appeared to be significantly associated with LPFS. With respect to the cell proliferation markers, we observed a longer LPFS to be associated with a low SPF, a low LI, and a short Tpot. We did not observe a significant association between DNA-ploidy and LPFS. After multivariate analysis both of high and of low grade tumours, we found that neither LI, SPF, nor age had additional prognostic significance for cells in mitoses. We also demonstrated, that necrosis and endothelial proliferation had no additional prognostic significance to that for cells in mitoses. In the subgroup of low grade gliomas, in contrast to high grade gliomas, we noted prognostic significance for LI. We concluded, that i) the presence or absence of cells in mitoses was the strongest single prognosticator in gliomas, ii) in low grade gliomas LI holds prognostic significance.

Overexpression of nerve growth factor and basic fibroblast growth factor in AIDS dementia complex

Although neurotrophic factors are currently considered as treatment for neurodegenerative diseases, little is still known about their presence in the central nervous system under pathological conditions. We investigated the expression of the neurotrophic molecules NGF, bFGF, BDNF and IGF-1 in brain tissue of patients suffering from AIDS dementia complex. In contrast to IGF-1 and BDNF, NGF and bFGF mRNA levels were significantly elevated. Strong NGF immunoreactivity was found in perivascular areas and was colocalized with infiltrating macrophages, whereas intense bFGF staining was found in cells with characteristic astrocytic morphology. These data suggest that the induction of NGF and bFGF alone appears to be insufficient as a compensatory mechanism to prevent ADC.

Pontocerebellar hypoplasia associated with respiratory-chain defects

Pontocerebellar hypoplasias are congenital disorders of brain morphogenesis which include such diverse etiologies as carbohydrate-deficient glycoprotein syndrome type 1, cerebromuscular dystrophies (Walker-Warburg syndrome, Fukuyama syndrome, muscle-eye-brain disease) and at least two types of autosomal recessive neurodegenerations known as pontocerebellar hypoplasia type I and II. Pontocerebellar hypoplasia type 1 is a lethal phenotype and clinical features include congenital contractures, respiratory insufficiency, central and peripheral motor dysfunction and spinal anterior horn degeneration. Type 2 is characterized by progressive microcephaly, extrapyramidal dyskinesia and normal spinal cord findings. In this paper, we describe a girl, born at 33 weeks of gestation, presenting with respiratory insufficiency and multiple contractures. MRI scan of the brain demonstrated pontocerebellar hypoplasia and cortical and diffuse periventricular white matter abnormalities. Postmortem examination showed pontocerebellar hypoplasia with extensive gliosis of the periventricular white matter and of the basal ganglia with normal spinal cord findings. Histology of skeletal muscle was normal. Biochemical analysis demonstrated multiple deficiencies of respiratory chain enzymes in skin fibroblasts. This case demonstrates a lethal phenotype of pontocerebellar hypoplasia without spinal cord abnormalities associated with a respiratory-chain disorder. The diagnostic workup in a patient whose brain image shows pontocerebellar hypoplasia should include a search for respiratory-chain impairment.

Acromegaly: report of two patients with an unusual presentation

The presenting features of functionally active pituitary tumours depend on the specific hormone which is overproduced. Growth hormone (GH) producing tumours usually present with the clinical manifestations of acromegaly due to excessive GH secretion or symptoms resulting from mass effects of the enlarging tumour. The changes in physical features and the increase in tumour size are usually insidiously slow and therefore, recognition of the disease is delayed. In this report two patients with acromegaly are described with an atypical presentation due to acute onset of symptoms. The first patient presented with central diabetes insipidus. The diagnosis acromegaly was made on physical examination. The second patient presented with a generalized seizure during sleep. On CT-scanning a large tumour protruding into the left temporal lobe connected to the pituitary gland was seen. Immunohistochemistry of the tumour after partial transcranial resection confirmed the clinical diagnosis of acromegaly. At a later stage transsphenoidal resection of the pituitary tumour was performed with full recovery and without loss of pituitary function.

New MRI findings in Creutzfeldt-Jakob disease: high signal in the globus pallidus on T1-weighted images

We report a 49-year-old woman with Creutzfeldt-Jakob disease (CJD). In addition to typical high-signal lesions on proton-density and T2-weighted images there was high signal in the globus pallidus bilaterally on T1-weighted images. The latter feature has not been described previously and probably due to deposition of prion protein, as found at autopsy.

MR contribution in surgery of epilepsy

The contribution of MR imaging in patients with drug-resistant epilepsy considered for surgical therapy is discussed. In this review we focus on: (a) focal abnormalities (mesial temporal sclerosis, focal migration disorders, hamartomatous lesions and low-grade tumours, phakomatosis and vascular malformations) associated with therapy-resistant partial epilepsy, requiring resective surgery; (b) abnormalities leading to generalized seizures that require more drastic surgical procedures, such as callosotomy and functional hemispherectomy; and (c) localisation of implanted depth-electrodes.

Fast fluid-attenuated inversion recovery (FLAIR) compared with T2-weighted spin-echo in the magnetic resonance diagnosis of mesial temporal sclerosis

RATIONALE AND OBJECTIVES

The authors compare coronal fast fluid-attenuated inversion recovery (FLAIR) with coronal T2-weighted spin-echo (SE) magnetic resonance (MR) techniques in the diagnosis of mesial temporal sclerosis (MTS).

METHODS

In this prospective study, the authors assessed MR scans of 30 patients with drug-resistant temporal lobe epilepsy (based on clinical symptomatology and electroencephalographic registrations) with MR features suggestive of MTS. MR scans of age-, sex-, and scanner-matched patients, referred for MR assessment of white matter disease, without a history of epilepsy and with no visible abnormalities on MR, were used as controls. In 16 patients the MR diagnosis was confirmed by histologic abnormalities consistent with MTS. Coronal T2 SE and FLAIR images of patients and controls were presented to two experienced radiologists in random order for independent blinded review. Hippocampal and associated extrahippocampal temporal lobe abnormalities were used for the diagnosis of MTS.

RESULTS

The sensitivity of observer A was 97% for the T2 SE sequence and 100% for the FLAIR; the specificity of observer A for both techniques was 100%. The sensitivity of observer B was 53% for T2 SE and 83% for FLAIR; the specificity for observer B was 93% for the T2 SE and 100% for FLAIR.

CONCLUSION

Coronal FLAIR images provide a similar or increased yield in the detection of MTS compared with T2-weighted SE images.

Relevance of temporal lobe white matter changes in hippocampal sclerosis. Magnetic resonance imaging and histology

RATIONALE AND OBJECTIVES

To evaluate the diagnostic relevance of ipsilateral atrophy of the collateral white matter in the parahippocampal gyrus (ACWMp) and temporal lobe gray/white matter demarcation loss (GWDL) on magnetic resonance imaging in patients with histologically confirmed hippocampal sclerosis. In the second part of this investigation, histologic specimens were analyzed to find an explanation for GWDL.

METHODS

Retrospective visual assessment of hippocampal signal intensity and size and of ACWMp and GWDL was performed using 4- to 5-mm coronal T2-weighted spin-echo magnetic resonance images of 80 patients with histologically proven hippocampal sclerosis and of 30 age-matched controls without epilepsy. Frequency of occurrence and likelihood ratios of ACWMp and GWDL were calculated and their contribution to the diagnosis of hippocampal sclerosis was assessed, particularly in patients with no or restricted hippocampal abnormalities (either high signal or smaller size) on magnetic resonance imaging. The second part of the study involved the morphologic histologic assessment of neocortical temporal lobe specimens of all patients. Myelin density was evaluated in specimens of a subgroup of six patients with hippocampal sclerosis and GWDL on MRI and six patients with hippocampal sclerosis without GWDL.

RESULTS

ACWMp was found in 68% and GWDL in 65% of patients with hippocampal sclerosis on magnetic resonance imaging. Both features had an infinite positive likelihood ratio. Sixty-two patients (77.5%) had concomitant hippocampal signal increase and smaller size. Eighteen patients (22.5%) had no or restricted hippocampal abnormalities on magnetic resonance imaging. When using ACWMp and GWDL as additional diagnostic parameters, 13 of these 18 patients were more unambiguously diagnosed as having hippocampal sclerosis. No significant morphologic differences were found between GWDL-positive and GWDL-negative specimens. A significantly lower average myelin stain was found in the white matter of the GWDL-positive group compared to the GWDL-negative group.

CONCLUSIONS

ACWMp and GWDL can improve the visual diagnosis of hippocampal sclerosis, particularly in patients with no or restricted hippocampal abnormalities. These results suggest that loss of myelin may be the underlying cause of GWDL in association with hippocampal sclerosis.

Early-onset but not late-onset endothelin-A-receptor blockade can modulate hypertension, cerebral edema, and proteinuria in stroke-prone hypertensive rats

-The ability of endothelin receptor blockade to prevent and to treat established cerebral and renal injury was explored in salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP) with the endothelin receptor subtype-A antagonist A127722. SHRSP were subjected to 1% NaCl intake. The start of treatment with A127722 (35 and 70 mg. kg-1. d-1, respectively) was either synchronized with salt loading or initiated after the first observation of cerebral edema with T2-weighted magnetic resonance imaging. In untreated control animals median survival was 54 days (range, 32 to 80 days) after the start of salt loading. Early-onset A127722 treatment increased median survival to 233 days (range, 92 to 407 days; P<0.05 versus controls) with 35 mg/kg and to 124 days (range, 97 to 169 days; P<0.05 versus control) with 70 mg/kg. The development of cerebral edema was prevented, and systolic blood pressure and proteinuria were dose-dependently reduced. However, all rats in the 70-mg/kg treatment group developed hemorrhages in the basal ganglia shortly before death. Late-onset A127722 treatment failed to affect survival, systolic blood pressure, or proteinuria. Nevertheless, cerebral edema was reduced but not as well as in early-onset treatment. Development of hypertension, cerebral edema, and proteinuria was prevented in SHRSP when A127722 treatment was initiated at the start of salt-loading. However, A127722 treatment did not prolong survival in SHRSP with cerebral edema. This suggests that in SHRSP the endothelin A receptor participates actively in the development of increased blood pressure and initiation of organ damage but participates minimally in established malignant hypertension and progression of target-organ damage.

Bilateral temporal lobe necrosis after radiotherapy: confounding SPECT results

A patient with seizures and a contrast-enhancing temporal lesion after radiation therapy for a chondrosarcoma of the nasal septum is described. To differentiate between radiation necrosis and recurrent tumor, thallium-201 (201Tl) SPECT was used. 201Tl SPECT revealed high local accumulation suggesting tumor growth; however, pathologic examination demonstrated focal necrosis with reactive changes but without tumor. The 201Tl SPECT findings in this patient demonstrate a possible diagnostic pitfall in differentiating recurrent tumor from radiation necrosis.

Enalapril prevents imminent and reduces manifest cerebral edema in stroke-prone hypertensive rats

BACKGROUND AND PURPOSE

Stroke-prone spontaneously hypertensive rats (SHRSP), subjected to high NaCl intake, show severe hypertension, organ damage, and early death. Preventive treatment with an angiotensin-converting enzyme (ACE) inhibitor is known to reduce mortality. Previously we found that proteinuria always precedes cerebral edema in SHRSP. Hence, in this study ACE inhibition was started later, ie, directly after manifestation of either proteinuria or cerebral edema.

METHODS

SHRSP were subjected to 1% NaCl intake. Group 1 served as a control. In group 2 early-onset treatment with the ACE inhibitor enalapril was initiated after proteinuria was >40 mg/d. In group 3 late-onset ACE inhibition was started after the first observation of cerebral edema with T2-weighted MRI. Cerebral edema was expressed as the percentage of pixels with an intensity above a defined threshold.

RESULTS

In controls median survival was 54 days (range, 32 to 80 days) after start of salt loading. The terminal level of cerebral edema was 19.0+/-3.0%. Under early-onset enalapril, median survival increased to 320 days (range, 134 to 368 days; P<0.01 versus group 1). Cerebral edema was prevented in all but 1 rat. Systolic blood pressure was slightly and transiently reduced at day 14. Proteinuria was markedly reduced (52+/-7 versus 190+/-46 mg/d in group 1 at day 7; P<0.05). Under late-onset enalapril, median survival was 264 days (range, 154 to 319 days; P<0.01 versus group 1). Cerebral edema decreased to baseline levels (9.6+/-2.9 at day 0 to 3.4+/-0.5% at day 3; (P<0.05). Ultimately cerebral edema reoccurred in 6 of the 8 rats. SBP decreased slightly at day 7 only. Proteinuria decreased from 283+/-27 at day 0 to 116+/-22 mg/d at day 7 (P<0.05). Complete remission of the original locus of cerebral edema was confirmed histologically.

CONCLUSIONS

In SHRSP with proteinuria, treatment with an ACE inhibitor both prevented the development of cerebral edema and reduced manifest cerebral edema and proteinuria. Survival was markedly prolonged. These findings support the use of ACE inhibition for treatment in hypertensive encephalopathy.

Recurrent subdural haematoma as the primary and sole manifestation of chronic lymphocytic leukaemia

An 81-year-old man with a recurrent subdural haematoma as the first and only manifestation of chronic lymphocytic leukaemia (CLL) is described. Microscopic examination of the encapsulated haematoma showed leukaemic infiltration and the diagnosis was confirmed by bone marrow aspiration and by pathological examination of the brain at autopsy.

Ultraviolet-B induced hyperplasia and squamous cell carcinomas in the cornea of XPA-deficient mice

In Xeroderma Pigmentosum (XP) patients, due to a defective repair of UV-induced DNA damage, neoplastic changes occur in sunlight-exposed areas of the skin and eyes. There are seven complementation groups in XP (XP-A to XP-G). Recently, we have generated XPA-deficient mice (group-A XP) by gene targeting in embryonic stem cells. In order to evaluate UV-B sensitivity, XPA-deficient mice (n = 20), wild type (n = 7) and heterozygous mice (n = 13) were exposed to low daily doses of UV-B for 14 weeks at a cumulative dose of 22 kj m-2 (250-400 nm). For a period of 32 weeks, the mice were checked twice a week for the development of pathology. The UV-B treatment induced eye abnormalities in the XPA-deficient mice. Initially, photophobia was noticed, followed by a loss of transparency of the cornea, eventually affecting nearly all XPA-deficient mice (19 out of 20). In 12 out of 19 mice, the pathology progressed to give eye protrusion. Histology of these eyes showed hyperplasia and squamous cell carcinomas of the corneal epithelium. No eye-lesions were found in control (wild-type and heterozygous) mice that were exposed to the same UV-B dose. The corneal abnormalities found in the XPA-deficient mice appear to be similar to those found in human XP patients. These results confirm the role of the functional XPA gene in protecting the cornea from pathology by UV-B irradiation. In addition, they suggest that the XPA-deficient mouse is a suitable animal model for the study of XPA ocular disorders.

Absence of characteristic features in two patients with inclusion body myositis

According to recently published criteria a diagnosis of definite sporadic inclusion body myositis is made if the typical histopathological abnormalities (rimmed vacuoles and abnormal accumulations of proteins, in addition to mononuclear cell infiltrates) are present. The two women described here presented with myositis which was unresponsive to treatment. Patient 1 had features of non-progressive sporadic inclusion body myositis clinically, whereas patient 2 had a very slowly progressive limb girdle syndrome. The cryostat sections of the first biopsies did not show rimmed vacuoles, even in retrospect. Only a repeated biopsy, 12 years after presentation in one patient and 18 years after presentation in the other, disclosed the typical features of sporadic inclusion body myositis. The initial absence of abnormal fibres probably represents a real absence or scarcity rather then a sampling error due to a multifocal nature of the histological abnormalities. It is of importance for the clinician to realise that some patients with myositis unresponsive to treatment, even if both clinical and histological features do not suggest sporadic inclusion body myositis, may prove to have the disease on repeated histopathological examination.

Proteinuria precedes cerebral edema in stroke-prone rats: a magnetic resonance imaging study

BACKGROUND AND PURPOSE

Stroke-prone spontaneously hypertensive rats (SHRSP) subjected to high sodium intake develop severe hypertension, cerebral edema, and proteinuria, culminating in organ damage and early death. MRI, which can be applied serially, provides the unique opportunity to study temporal and quantitative relations between these changes and whether diminution of sodium intake can attenuate established cerebral edema.

METHODS

SHRSP were subjected to 1% NaCl in drinking water. Cerebral MRI, proteinuria and systolic blood pressure (SBP) were measured serially. After detection of cerebral edema (T2-weighted MRI), 6 rats were killed for histology, to confirm the diagnosis of cerebral edema. The others were followed up for 7 more days while salt loading was continued (n = 10, group 1) or after sodium intake was normalized (n = 7, group 2).

RESULTS

SHRSP invariably developed cerebral edema in 30 days (range, 8 to 54 days). At this point neurological signs were absent in 16 of 23 rats. SBP rose until 1 week before detection of cerebral edema, and then stabilized at approximately 265 mm Hg. Proteinuria invariably preceded cerebral edema, with a concentration exceeding 40 mg/d predicting development of cerebral edema in 9 days (range, 3 to 15 days). There was linear correlation (R=.62, P<.0001) between proteinuria and cerebral edema (pixels with an intensity above a defined threshold). Rats in group 1 showed an increase in cerebral edema (from 5.8+/-1.1% to 12.5+/-2.8%; P<.05), and proteinuria remained high (from 305+/-44 to 338+/-29 mg/d); and 2 died spontaneously. Rats in group 2 showed no significant change in edema (from 4.9+/-0.5% to 6.9+/-1.3%) but a marked fall in proteinuria (from 294+/-24 to 119+/-10 mg/d; P<.05), both significantly different from group 1 (P<.05); all survived. SBP remained unaltered in both groups.

CONCLUSIONS

Our data establish MRI as a sensitive method for detection of cerebral edema, often prior to neurological signs, in SHRSP. Proteinuria predicts cerebral edema, and these two variables, both obtained noninvasively, are quantitatively related. Moreover, in SHRSP normalizing sodium intake after salt loading attenuates development of cerebral edema and reduces proteinuria.

S-phase fraction, 5-bromo-2'-deoxy-uridine labelling index, duration of S-phase, potential doubling time, and DNA index in benign and malignant brain tumors

Seventy-one histologically malignant brain tumors, 52 histologically benign brain tumors, and 14 cerebral metastases were characterized according to DNA content and proliferative capacity. DNA ploidy, DNA index (DI), S-phase fraction (SPF), 5-bromo-2'-deoxy-uridine (BrdUrd) labelling index (LI), duration of S-phase (Ts), and potential doubling time (Tpot) were assessed by flow cytometry (FCM). In histologically benign tumors, a high percentage of DNA diploid tumors and a low proliferative capacity in DNA diploid tumors were found. Histologically malignant tumors and cerebral metastases were both found to be characterized by a low percentage of DNA diploid tumors and a high proliferative capacity in DNA diploid tumors. The proliferative capacity of DNA aneuploid benign tumors and that of DNA aneuploid malignant tumors, however, appeared not to differ significantly. The number of DNA aneuploid tumors was small. Duration of S-phase was short (range 3.9-4.7 hr) and appeared not to differ between the three groups. From this, the observed differences in Tpot values should be accredited mainly to differences in LI. High-grade as well as low-grade gliomas both appeared to be characterized by malignant (FCM) features, i.e., 1) a high percentage DNA aneuploidy, 2) a high mean DI (for DI > 1), and 3) a high proliferative capacity.

Antibodies against enteroviruses in intravenous Ig preparations: great variation in titres and poor correlation with the incidence of circulating serotypes

Antibody titres in immunoglobulin preparations for intravenous use were tested against 24 different enterovirus serotypes and varied between 1:100 and 1:10,000 within a single batch. Differences up to 8-fold were found for homologous titres between two different batches that were prepared 6 years apart. The lowest titre obtained was 1:40. The observed differences within and between the two batches could not be explained by different incidence of serotypes of enteroviruses circulating at the time blood was collected. Differences in titres of up to 18-fold were observed when several strains of the same serotype were tested suggesting that intratypic variation influences antibody titres. It is concluded that immunoglobulin preparations contain antibodies against many enteroviruses, but that titres can be low and cannot be predicted from the incidence of any particular serotype circulating in the community. Because of intratypic variation, selection of a batch for specific treatment should be based on results obtained with the patient's own isolate, and not with a reference strain.

Assessment of the preferred plane and sequence in the depiction of mesial temporal sclerosis using magnetic resonance imaging

RATIONALE AND OBJECTIVES

Definition of optimal magnetic resonance (MR) scanning plane and conventional MR sequence for the detection of mesial temporal sclerosis (MTS).

METHODS

Coronal and axial T2-weighted images and axial T2-weighted images parallel to the long axis of the hippocampus (APLAH) and coronal inversion recovery (IR) images were obtained in patients with medically intractable temporal lobe epilepsy in their phase 1 preoperative evaluation. Thirty-three consecutive MR scans were reviewed by a panel of three radiologists. Twenty-three patients had MR abnormalities consistent with MTS, and ten scans were normal. To assess the best single scanning technique, another group of three radiologists, who were masked to all patient data, individually assessed the different planes and sequences of the 33 studies presented separately in a random fashion. For each plane and sequence, the likelihood (L) ratio for the correct diagnosis was determined separately.

RESULTS

For all planes considered separately, a likelihood ratio of 4.4 was optimal for the coronal T2-weighted images. The likelihood ratio of APLAH T2 was 2.2; of axial T2, 3.9; of coronal IR, indefinite because of 100% specificity.

CONCLUSIONS

For the assessment of MTS, coronal T2-weighted images were considered the best single scanning technique.

[Microscopic tumor embolisms in metastasized breast carcinoma]

In two patients, women of 54 and 46 years old, with metastatic carcinoma of the breast, multiple microscopic tumour emboli in the lungs were found at autopsy. Ante mortem, unexplained respiratory distress in the former and an atypical thrombotic thrombocytopenic purpura-like syndrome in the latter were the most characteristic clinical features. Pulmonary microscopic tumour embolism is a rare diagnosis but it may occur in all types of cancer. Clinically, thrombotic pulmonary emboli are difficult to distinguish from microscopic tumour embolism. Special attention is to be paid to typical findings on radionuclide perfusion lung scanning (multiple subsegmental perfusion defects at the periphery of the bronchopulmonary segments with a normal ventilation named "segmental contour pattern'). Microangiopathic haemolytic anaemia and consumption coagulopathy are associated disorders. Tumour-directed therapy is the treatment of choice.