Effect of house dust mite avoidance measures in children with atopic dermatitis

BACKGROUND

House dust mite allergens are associated with atopic dermatitis (AD).

OBJECTIVES

The aim of our study was to verify if house dust mite allergen avoidance measures can improve the clinical manifestations of AD in children.

METHODS

Forty-one children (mean age 3.9 years) affected by AD associated with high total and/or specific IgE serum levels ('extrinsic' AD) were recruited. Clinical evaluation was performed utilizing the Severity Scoring of AD (SCORAD) index; dust was sampled from the children's beds and tested using an enzyme-linked immunosorbent assay. The study was planned in two parts. In the first part, a placebo-controlled trial of 2 months duration, mite allergen avoidance measures (encasing mattresses and pillows; a weekly hot wash of bedding; frequent vacuum cleaning of living room and bedroom; soft toys and carpets regularly cleaned or removed; no pets allowed) were recommended to group A patients, but not to group B. In the second part of the study, environmental avoidance measures were recommended to initial control group B patients also. One year after the start of the study the amounts of mite allergen in the home and clinical score of AD were measured in both groups.

RESULTS

At the end of the first part of the study, significant decreases in major allergens of Dermatophagoides pteronyssinus (Der p1) and D. farinae (Der f1) load (from 393 to 94 ng m-2) and concentration (from 1.84 to 0.73 microg g-1 of dust) in children's beds were observed in treatment group A. At the same time, in this group the mean SCORAD index improved significantly (from 33 to 26; P = 0.022). After 12 months, when all patients had used allergen avoidance measures, Der p1 + Der f1 load, concentration and clinical score had improved, reaching similar values in both groups.

CONCLUSIONS

Simple mite allergen avoidance measures should be recommended to families with children affected by extrinsic AD in order to control the clinical manifestations and prevent mite sensitization.

Treatment of symptomatic intracranial arachnoid cysts by stereotactic cyst-ventricular shunting

BACKGROUND

The optimal treatment of symptomatic intracranial arachnoid cysts is controversial and different surgical approaches have been described. The aim of the treatment is to reduce the intracystic pressure. To accomplish this goal, many techniques have been proposed, each with specific limitations or failures.

METHODS

Nine patients with symptomatic arachnoid cysts were treated by stereotactic cyst-ventricular shunting. One patient with suprasellar arachnoid cyst showed signs related to intracranial pressure, the remaining 8 patients complained of headache and/or drug-resistant epilepsy. All the intracranial cysts were supratentorial. The surgical procedure was performed under general anesthesia in 6 cases and local anesthesia in 3 cases. The CRW Stereotactic System (Radionics) was used. The acquisition of both target points (cyst and ventricle) was always realized by means of CT scan slices. A right precoronal burr hole was made and a silicon catheter was stereotactically inserted into the lateral ventricle. Another burr hole was subsequently performed close to the cyst; a silicon catheter was placed in the middle of the cavity in the shortest intracerebral crossing. Then both catheters were connected to a subcutaneous burr hole Ommaya reservoir.

RESULTS

All patients tolerated the procedure well and the preoperative clinical signs progressively disappeared or improved. The CT scan at 1, 3, 6 and over 12 months showed progressive reduction in size of the cysts. No clinical recurrence was found at the follow-up (14-73 months).

CONCLUSIONS

The successful outcome of the above cases suggests that, in carefully selected symptomatic intracranial arachnoid cysts, stereotactic cyst-ventricular shunting is likely to prove an effective operative method.

Antimicrobial activity of Mitracarpus scaber extract and isolated constituents

The antimicrobial activity of a methanol extract and isolated constituents of Mitracarpus scaber, a species used in folk medicine by West African native people, was evaluated against Staphylococcus aureus and Candida albicans strains. The mitracarpus methanol extract possesses both antibacterial and antimycotic activities (minimum inhibitory concentration-MIC 31.25 and 62.50 microg ml-, respectively). This extract was subsequently fractioned and monitored by bioassays leading to the isolation of seven compounds screened for antibacterial and antimycotic activities. Among these compounds, gallic acid and 3,4,5-trimethoxybenzoic acid inhibited the growth of Staph. aureus (MIC 3.90 and 0.97 microg ml-). 4-Methoxyacetophenone and 3,4,5-trimethoxyacetophenone effectively inhibited C. albicans (MIC 1.95 microg ml-). The other compounds (kaempferol-3-O-rutinoside, rutin and psoralen) which were also isolated showed low antibacterial and antimycotic activities (125-500 microg ml-).

Hemobilia, intrahepatic hematoma and acute thrombosis with cavernomatous transformation of the portal vein after percutaneous thermoablation of a liver metastasis

A 53-year-old-man underwent US-guided percutaneous thermal ablation with a cooled-tip needle of three liver metastases from gastric cancer. Six days later, the patient was re-admitted for melena, scleral jaundice, and anemia. Abdominal US disclosed echogenic material in the gallbladder lumen (hemobilia) and a focal lesion with mixed echotexture in segment III (hepatic hematoma). On day 5 portal cavernomatosis was diagnosed at US and confirmed by color Doppler and a helical CT exam. The case described emphasizes that radio-frequency interstitial hyperthermia may cause not only traumatic injury of the liver parenchyma but also thermally mediated damage of vascular structures.

Effects of some Malian medicinal plants on the respiratory tract of guinea-pigs

Crossopteryx febrifuga, Pteleopsis suberosa and Entada africana are used in Mali traditional medicine for fever and various respiratory diseases. We have investigated the effects of these three drugs in the form of a decoction on the respiratory tract using different experimental models. On citric acid-induced cough in guinea-pigs, the three drugs significantly decreased the number of coughs at the doses of 250 (P < 0.01), 500 (P < 0.05; P < 0.01) and 1000 (P < 0.01) mg kg(-1). The percent inhibition was respectively 62.86, 69.03 and 77.44% for C. febrifuga, 57.80, 53.90 and 61.40% for E. africana, and 37.13, 42.44 and 73.72% for P. suberosa. Codeine phosphate (10 mg kg(-1)) used as reference drug showed an inhibition of 76.32%. E. africana (1000 mg kg(-1)) reduced (65% inhibition) significantly (P < 0.05) bronchoconstriction induced by histamine (99.25% and 34.00% for control and extract, respectively). Furthermore, E. africana (1000 mg kg(-1)) provoked a bronchodilatation response when administered under basal conditions. On antigen-induced bronchospasm, C. febrifuga protected (54% inhibition) sensitized guinea-pigs with a pulmonary ventilation pressure (PVP) of 24.87% (control value < 55.00%). P. suberosa was inactive in both experimental models. The reference drug, disodium cromoglycate (10 mg kg(-1), i.v.) protected significantly (P < 0.05) with a PVP of 12.00% (78% of inhibition). This study confirmed the traditional use of these plants in the treatment of cough and other respiratory disorders.

Osteochondroma of the L-5 vertebra: a rare cause of sciatic pain. Case report

Solitary or multiple osteochondromas, which are benign bone tumors that usually occur in the long bones, are rarely found in the vertebral column. When present in the spine, however, they have a predilection for the cervical or upper thoracic regions. The authors present the case of a solitary osteochondroma arising from the left L-5 articular process that contributed to sciatica; complete cure was achieved following its removal. It is possible to speculate that the cartilage of secondary ossification centers can be the origin of aberrant islands of cartilaginous tissue that cause the osteochondroma to form. The more rapid the ossification process of these centers, the greater the probability that aberrant cartilage will form. Therefore, the fact that osteochondromas are more frequently located in the higher segments of the vertebral column could be explained by the different durations of the ossification processes in these centers, which increase gradually below the cervical segments.

Hepatoprotective properties in the rat of Mitracarpus scaber (Rubiaceae)

The effect of Mitracarpus scaber on carbon tetrachloride-induced acute liver damage in the rat has been evaluated. Results showed that treatment with Mitracarpus scaber decoction resulted in significant hepatoprotection against CCl4-induced liver injury both in-vivo and in-vitro. In-vivo, Mitracarpus scaber pretreatment reduced levels of serum glutamate-oxalate-transaminase (P < 0.01 for 250, 500 and 1000 mg kg(-1)) and serum glutamate-pyruvate-transaminase (P < 0.05 for 250 mg kg(-1) and P < 0.01 for 1000 mg kg(-1)) previously increased by administration of CCl4. In-vitro results indicated that addition to the culture medium of Mitracarpus scaber extracts significantly reduced glutamate-oxalate-transaminase (P < 0.05 for 100 microg mL(-1) and P < 0.01 for 10 and 1000 microg mL(-1)) and lactate dehydrogenase activity (P < 0.05 for 10 microg mL(-1)). Mitracarpus treatment also resulted in a good ( > 93%) survival rate for the CCl4-intoxicated hepatocytes as demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Moreover, as in the in-vitro assay, Mitracarpus scaber had radical-scavenging properties, shown by its reaction with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical (EC50, the extract concentration resulting in a 50% reduction in the absorbance of DPPH blank solution, = 41.64+/-1.5 microg mL(-1)). The results of this study showed that Mitracarpus scaber had antihepatotoxic potential, a finding which supports the validity of traditional usage of this drug in Mali for the treatment of liver diseases.

Losses of hemifield contrast sensitivity in patients with pituitary adenoma and normal visual acuity and visual field

OBJECTIVE

To detect early losses of contrast sensitivity (CS) in patients with pituitary adenomas, before the occurrence of visual acuity and visual field defects.

METHODS

CS has been evaluated in both hemifields of 28 patients with different kinds of pituitary adenoma (mainly intrasellar) and normal visual acuity and visual field, as well as in 15 age-matched controls. Two different stimuli were used: a coarse (0.3 c/deg) dynamic (10 Hz) grating and a finer (2 c/deg) static grating.

RESULTS

On average, CS and/or hemifield asymmetry were reduced in patients, whereas perimetric sensitivity was normal. CS losses were more frequent for 2 c/deg static-, as compared with 0.3 c/deg, 10 Hz stimuli. However selective losses for either stimuli were also found. CS losses did not correlate with anatomical measurements (size, chiasm involvement) of tumors as established by MRI scans.

CONCLUSIONS

CS evaluation may provide a simple and effective tool for early detection and monitoring of visual dysfunction in patients with pituitary adenoma. The lack of correlation between CS losses and chiasm involvement suggests causes different from chiasmal compression for visual dysfunction.

Mite allergen (Der p 1) levels in houses of children with atopic dermatitis: the relationship with allergometric tests

Several studies, in particular in adult groups, have evaluated the involvement of mites in the pathogenesis of atopic dermatitis (AD). This still remains controversial. The objective of this study was to determine the level of house dust mites (HDMs) in the beds of a group of children with AD and correlate these levels with their allergometric assessment. Forty-one children with AD underwent allergometric tests (prick test, patch test and radioallergosorbent test, RAST) and the concentration levels of HDMs in their homes were evaluated. Our data show that about half of the children (51%) with AD presented Dermatophagoides pteronyssinus positivity (prick test and/or RAST and/or patch test). Dust was collected in the period October-November from the children's beds, by the same two operators, using a dust-collection device. The dust mite level was tested by an enzyme-linked immunosorbent assay with antibody against Der p 1 allergen. Ten children (24%) presented a Der p 1 concentration > 2 microgram/g of dust (the value assumed to be a risk level for sensitization), 20 (49%) between 0.1 and 2 microgram/g and 11 (27%) < 0.1 microgram/g of dust. In the group with the highest Der p 1 concentration (> 2 microgram/g dust) nine children (90%) presented an allergometric D. pteronyssinus sensitivity, the difference with the other two groups being statistically significant at P < 0.018. The results of the present study show that the highest HDM concentrations were observed in the group with an allergometric D. pteronyssinus positivity (prick test and/or RAST and/or patch test). It is hypothesized that a higher HDM concentration may elicit D. pteronyssinus IgE sensitization and delayed hypersensitivity in children with AD.

Cerebrovascular reactivity before and after carotid endarterectomy

BACKGROUND

The hemodynamic relevance of internal carotid artery (ICA) stenosis often does not correlate with anatomic features, as angiographically defined. The cerebrovascular reactivity (CVR) has been advocated as a means of defining the cerebral hemodynamic impairment.

METHODS

We assessed the results of pre- and postoperative CVR evaluation, using the CO2 transcranial doppler method, in 25 patients with high-grade ICA stenosis. The patients with history of stroke, evidence of cerebral CT infarction or symptoms from the contralateral circulation or the brain stem were excluded to avoid the effects of cerebral infarction on the hemodynamic studies. Statistical analysis was used to evaluate the CVR changes after carotid endarterectomy.

RESULTS

Preoperative evaluation showed that CVR was generally well correlated with the degree of ICA stenosis and concomitant contralateral carotid steno-occlusion. Before endarterectomy the mean CVR value was 66.5% (moderately reduced). After surgery the overall mean value of CVR was 84.1% (normal), with a statistically significant improvement.

CONCLUSION

The results of this study suggest that the CVR evaluation allows one to obtain hemodynamic information of clinical interest in the patients with ICA stenosis and that carotid endarterectomy is effective to restore the CVR in patients with cerebral hemodynamic impairment.

Congenital absence of the internal carotid artery

We report three cases of congenital absence of an internal carotid artery (ICA), diagnosed incidentally by digital subtraction angiography. The analysis of the cases is based on the classification of segmental ICA agenesis proposed by Lasjaunias and Berenstein. Usually the patients with this rare vascular anomaly are asymptomatic; some may have symptoms related to cerebrovascular insufficiency, compression by enlarged intracranial collateral vessels, or complications associated with cerebral aneurysms. Diagnosis of congenital absence of ICA is made by skull base computed tomography (CT) scan, CT and magnetic resonance angiography, and conventional or digital subtraction angiography.

Morphological and functional study of dwarf neurons in the rat striatum

Combination of morphological and electrophysiological techniques provided data, suggesting existence in the young rat striatum of a peculiar class of neurons, the neurogliaform or dwarf neurons. Striatal neurons (n = 92), intracellularly recorded from rat brain slices, were filled (one in each slice) with the intracellular marker biocytin, to compare physiological and morphological properties in the same cell. Moreover, some neurons (n = 7) were filled with biocytin plus the fluorescent calcium indicator fura-2, identifying cells during electrophysiological recording. Electrophysiological recording showed that striatal neurons had different firing patterns, suggestive in most cases (n = 80) of spiny neuron class and in others (n = 12) of interneuron class. Fura-2 injection clearly identified the body of six medium-sized cells and of one distinctive tiny cell. This small cell, however, showed a resting membrane potential and spontaneous and evoked firing pattern characteristic of striatal interneurons. Moreover, the fura-2 injected in such small neuron also completely filled the cell body of a near large neuron; the fura-2 fluorescence changed synchronously in the two paired neurons after electrical stimulation of the impaled small one. Accordingly, the biocytin staining identified the morphology of the small recorded neuron as a neurogliaform-like cell apposed to a dendrite of an aspiny neuron, suggesting that the dye injected in one neuron had diffused to the other of a different type. Furthermore, such heterologous dye coupling unexpectedly involved seven pairs of cells detected with biocytin staining (7.6% of the recorded neurons), invariably represented by a medium or large neuron on one side, and on the other side by a small (5.44 +/- 0.15 x 9.14 +/- 0.7 microns, mean +/- SD; n = 7) neurogliaform cell, roundish in shape with few slender and short processes, usually apposed to a dendrite of the companion neurons (six out of seven). In the other cases, the biocytin staining revealed in each slice either the morphology of single spiny or aspiny neurons (80.4% of recorded neurons), or of two-three medium-sized spiny neurons detected near to each other, suggesting that dye coupling had occurred typically between similar neurons (11.9% of the recorded neurons). These data suggest that some neurogliaform cells in the striatum of young rat can be identified as dwarf interneurons, that may be dye-coupled with neurons of different classes.

[Echo-guided radiofrequency percutaneous ablation of hepatocellular carcinoma in cirrhosis using a cooled needle]

INTRODUCTION

Radiofrequency hyperthermia using the newly-developed "cooled-tip" needle is one of the latest US-guided percutaneous treatments of hepatocellular carcinoma arising in cirrhosis. The continuous cooling of the needle tip allows tissue heating and necrosis far from the electrode without tissue charring, which was the major drawback of the old monopolar technique. Herein we report our preliminary results on feasibility and effectiveness of the thermoablation of mono- or paucifocal hepatocellular carcinoma with the cooled-tip needle.

MATERIAL AND METHODS

November, 1996, to January, 1998, we treated thirteen cirrhotic patients (mean age 69.5 yrs, 10 men, 12 HCV-positive; 11 in Child's Class A and 2 in Class B) with 19 hepatocellular carcinoma nodules (mean diameter: 27 mm; range: 10-41 mm; 6 with diameter > 3 cm). None of the patients had portal thrombosis and/or extrahepatic spread. We used a radiofrequency generator (100 W power) connected to an 18 G perfusion electrode needle with an exposed tip of 2-3 cm. The circuit is closed through a dispersive electrode positioned under the patient's thighs. A peristaltic pump infuses a chilled (2-5 degrees C) saline solution to guarantee the continuous cooling of the needle tip. The needle was placed into target lesions under US guidance. The interventional procedure was carried out under general anesthesia using Propofol without intubation. Dynamic CT (more recently with the helical technique) was carried out 15-20 days after thermoablation to assess treatment efficacy.

RESULTS

In all, 31 thermal injuries (at 1000-1200 mA for 10-15 minutes) were caused in 21 sessions in the 19 hepatocellular carcinoma nodules (mean: 1.5 lesions per nodule and 1.6 sessions per patient). Complete necrosis as assessed at dynamic CT (no enhancement during the arteriographic phase) was achieved in 16 of 19 nodules (84%). No side-effects occurred. During the follow-up (median: 11 months) no death occurred and five patients had recurrent hepatocellular carcinoma appearing either as single nodule or as multinodular liver involvement.

CONCLUSIONS

In our experience radiofrequency hyperthermia with the cooled-tip needle permits effective and safe percutaneous ablation of HCC in cirrhosis. In addition, treatment time is short and lesions > 3 cm can be treated. Further experience is needed to better define the role of percutaneous thermoablation in the treatment strategy of hepatocellular carcinoma.

Problems with post-clipping aneurysmal rests

The postclipping aneurysmal rest is a uncommon but sometimes dangerous event, that is generally underestimated. We distinguish the aneurysmal rest on the basis of its morphology in: 1) partial neck, 2) whole neck, 3) partial neck + partial sac, 4) whole neck + partial sac; on the basis of the relationship with the clip in: 1) proximal, 2) distal, 3) proximal + distal; on the basis of its size in: 1) small (< 2 mm), 2) medium (2-4 mm), 3) large (> 4 mm). From the surgical point of view the aneurysmal rests in our opinion can be classified as unavoidable, avoidable and intentional. Then we analyze the literature data in regard to the possible evolution and the risk of the rest and emphasize the importance of intraoperative angiography which has shown itself to be useful in avoiding aneurysmal rests. There is no consensus of opinion with regard to the type of treatment of the aneurysmal rest. In our opinion the factors which must be considered when deciding on the surgical treatment of a rest are: the age of the patient, mode of presentation of the previous aneurysm, the expertise of the surgeon and the approaches and the techniques used in the first operation, clinical presentation of the rest and its evolution, the surgeon's experience and the possibility of endovascular therapy. Finally we analyze some of the technical aspects of re-operation in relation to the anatomical relationship among the parent artery, the rest and the old clip.

L-type Ca2+ channel blockers attenuate electrical changes and Ca2+ rise induced by oxygen/glucose deprivation in cortical neurons

BACKGROUND AND PURPOSE

Experimental evidence supports a major role of increased intracellular calcium [Ca2+]i levels in the induction of neuronal damage during cerebral ischemia. However, the source of Ca2+ rise has not been fully elucidated. To clarify further the role and the origin of Ca2+ in cerebral ischemia, we have studied the effects of various pharmacological agents in an in vitro model of oxygen (O2)/glucose deprivation.

METHODS

Pyramidal cortical neurons were intracellularly recorded from a slice preparation. Electrophysiological recordings and microfluorometric measurements of [Ca2+]i were performed simultaneously in slices perfused with a glucose-free physiological medium equilibrated with a 95% N2/5% CO2 gas mixture.

RESULTS

Eight to twelve minutes of O2/glucose deprivation induced an initial membrane hyperpolarization, followed by a delayed, large but reversible membrane depolarization. The depolarization phase was accompanied by a transient increase in [Ca2+]i levels. When O2/glucose deprivation exceeded 13 to 15 minutes, both membrane depolarization and [Ca2+]i rise became irreversible. The dihydropyridines nifedipine and nimodipine significantly reduced either the membrane depolarization or the [Ca2+]i elevation. In contrast, tetrodotoxin had no effect on either of these parameters. Likewise, antagonists of ionotropic and group I and II metabotropic glutamate receptors failed to reduce the depolarization of the cell membrane and the [Ca2+]i accumulation. Finally, dantrolene, blocker of intracellular Ca2+ release, did not reduce both electrical and [Ca2+]i changes caused by O2/glucose depletion.

CONCLUSIONS

This work supports a role of L-type Ca2+ channels both in the electrical and ionic changes occurring during the early phases of O2/glucose deprivation.

Relapsing neoplastic seeding after percutaneous ethanol injection for hepatocellular carcinoma. Clinical and ultrasonographic findings in a cirrhotic patient

A case of neoplastic implant after percutaneous ethanol injection (PEI) therapy for hepatocellular carcinoma (HCC) occurring in two steps is described. A 74-year-old male cirrhotic patient underwent PEI for a 5-cm HCC nodule. To obtain complete tumoral necrosis, 80 ml were injected under sonographic guidance in four sessions. Ten months after the completion of PEI a subcutaneous nodule was palpated in the abdominal wall within the area of needle punctures. Histologic examination of the excised nodule confirmed the sonographic and Power Doppler diagnosis of metastatic HCC. At the US exam scheduled three months later a non-palpable subcutaneous nodule of 16 mm was appreciated near the surgical wound. Once again metastatic HCC was demonstrated at pathological examination. Copyright 1997 Elsevier Science Ireland Ltd.

Opposite membrane potential changes induced by glucose deprivation in striatal spiny neurons and in large aspiny interneurons

We have studied the electrophysiological effects of glucose deprivation on morphologically identified striatal neurons recorded from a corticostriatal slice preparation. The large majority of the recorded cells were spiny neurons and responded to aglycemia with a slow membrane depolarization coupled with a reduction of the input resistance. In voltage-clamp experiments aglycemia caused an inward current. This current was associated with a conductance increase and reversed at -40 mV. The aglycemia-induced membrane depolarization was not affected by tetrodotoxin (TTX) or 6-cyano-7-nitroquinoxaline-2,3-dione plus aminophosphonovalerate, antagonists acting respectively on AMPA and NMDA glutamate receptors. Also, the intracellular injection of bis(2-aminophenoxy)ethane-N,N, N',N'-tetra-acetic acid, a calcium (Ca2+) chelator, and low Ca2+/high Mg2+-containing solutions failed to reduce this phenomenon. Conversely, it was reduced by lowering external sodium (Na+) concentration. A minority of the recorded cells had the morphological characteristics of large aspiny interneurons and the electrophysiological properties of "long-lasting afterhyperpolarization (LA) cells." These cells responded to aglycemia with a membrane hyperpolarization/outward current that was coupled with an increased conductance. This current was not altered by TTX, blockers of ATP-dependent potassium (K+) channels, and adenosine A1 receptor antagonists, whereas it was reduced by solutions containing low Ca2+/high Mg2+. This current reversed at -105 mV and was blocked by barium, suggesting the involvement of a K+ conductance. We suggest that the opposite membrane responses of striatal neuronal subtypes to glucose deprivation might account for their differential neuronal vulnerability to aglycemia and ischemia.

[Magnetic resonance angiography in stenosing-occlusive diseases of the carotid arteries: 3D with time of flight versus 3D with phase contrast]

We assessed the comparative sensitivity, specificity and diagnostic accuracy of 3D time of flight (TOF) versus 3D phase contrast (PC) MRA in the study of stenoses/occlusions of the extracranial carotid artery. Fifty-four patients were submitted to MRA because of their symptoms or of signs of cerebrovascular insufficiency. 3D TOF and 3D PC axial slices were acquired with a high field magnet; digital angiography was the gold standard. The parameters of 3D TOF acquisitions were: TR/TE/FA 50/8/20, 1 NEX, 512 x 256 matrix, 16 x 12 FOV, 1 axial slab of 60 slices, 1 mm slice thickness, superior presaturation band, ramp pulse, TA 10-18 minutes. 3D PC parameters were: TR/TE/ FA 25/9/20, 1 NEX, 256 x 128 matrix, 18 x 13 FOV, 1 axial slab of 60 slices, 1 mm slice thickness, VENC 35 cm/s, TA 10-15 minutes. 3D TOF MRA was in agreement with digital angiography in 95.6% of cases (22/23), overestimating a grade 3 stenosis as grade 4 (one case, 4.3%) and underestimating no stenoses. 3D PC MRA was in agreement with digital angiography in 78.2% of cases (18/23), overestimating three stenoses (13%); one grade 1 as grade 2 and two grade 4 as grade 5; two stenoses were underestimated (8.6%); one grade 4 as grade 3 and one grade 4 as grade 2. Sensitivity, specificity and diagnostic accuracy were 91.4%, 98.9% and 95.7% for 3D TOF, versus 83.2%, 97.2% and 92.3% for 3D PC, respectively. The two MRA techniques had different semiology. In spite of outstanding background noise suppression, 3D PC poorly depicted the turbulent flow at the carotid bifurcation in carotid stenoses. Therefore, 3D TOF appears a better technique to study stenoses/occlusions of the extracranial carotid arteries.

Surgical treatment of anterior callosal tumors

OBJECTIVE

Thirteen patients with neoplasm of anterior corpus callosum have undergone our observation during the last two years.

METHODS

For the diagnosis, all the patients underwent TC, NMR and stereotactic biopsy. In 6 cases with glioblastomas, a radiation treatment was adopted. The other 7 patients underwent total surgical treatment in 5 cases, and partial in 2 cases, as documented by postoperative contrast-enhanced CT scanning. Histologically, there were: 3 glioblastomas, 1 grade III astrocytoma, 1 neuroblastoma (PNET), 2 pilocytic astrocytomas.

RESULTS

Neuropsychological tests carried out on the 5 patients still living showed persistent disturbances of verbal memory in all five and disturbances of verbal phonological fluency in 3 cases. No patient presented apraxia, dysgraphia and dyslexia.

CONCLUSIONS

Thus, no severe neuropsychological deficits developed after surgical treatment of anterior callosal tumors.

[Imaging with magnetic resonance imaging of the operated cervical spine]

The Authors report their personal experience with postoperative neuroradiologic studies in surgical patients with a herniated disk and/or degenerative cervical spondylosis. Twenty-six patients were enrolled: 16 of them underwent anterior diskectomy, 7 posterior decompressive laminectomy and 3 vertebral body removal. The patients were submitted to pre- and postoperative MRI with high field equipment (Signa 1.5 T, General Electrics), using sagittal SE T1- (TR/TE 360/15), PD and T2-weighted (TR/TE/FA 2000/40/120) sequences and T2-weighted GE axial sequences (TR/TE/FA 400/34/30). FSE sequences (TR/TE/ETL 4000/95/8) were used in 15 cases instead of the above T2-weighted SE sequences. The main postoperative MR findings were analyzed. In particular, the morphological and signal features of bone grafts, of vertebral end-plates, of the subchondral bone and of the surgical site were studied. After anterior diskectomy, the most frequent MR features were massive signal changes in the bone graft and lower vertebral plates, which were hypointense in T1 and hyperintense in T2; the adjacent subchondral bone also exhibited signal changes. Other postoperative MR findings accounted for early postoperative mobility (4 cases of persistent myelomalacia and 3 of bone graft fracture with consequent spinal instability) and late mobility (2 cases of herniated disk, 5 of spinal stenosis and one pseudomeningocele). The main limitation of MRI in postoperative cervical spine studies was the presence of ferromagnetic artifacts during SE, and even more GE, sequences; these artifacts were the main cause of misdiagnoses. In our experience, this troublesome limitation was overcome with FSE sequences but diagnostic accuracy remained poor in 4 patients. MRI, thanks to its multiparametric and multiplanar yield, is the gold standard for the examination of several early and late postoperative features and of postoperative mobility in the cervical spine. Moreover, T2-weighted FSE acquisitions are better than conventional SE to this purpose, because examination time is shorter, myelographic effect is improved and the sensitivity to ferromagnetic artifacts reduced.

Preoperative embolization in surgical treatment of spinal thoracic dumbbell schwannoma. A case report

Schwannoma is the most common intraspinal tumor, which at times goes out of spinal canal and spreads into the paraspinal tissue to produce a dumbbell configuration. A 58-year-old woman is reported, in whom a plain thorax X-rays accidentally disclosed a mass located in the posterior mediastinum. Computerized tomography (CT) revealed a dumbbell lesion, 4.5 cm in diameter, in the right rib-vertebral groove at the T9 level. Spinal angiography showed localization of Adamkievicz artery at the T10 level on the left side. The lesion appeared hypervascular and was embolized by particulate agents (Contour Emboli 150-250 mu) with reduction of its blush. A combined two-team (thoracic and neurosurgeon) approach permitted an uneventful removal of a schwannoma.

NADPH-diaphorase neurons contacting the cerebrospinal fluid in the ventricles of rat brain

Two populations of scattered neurons containing nitric oxide synthase activity were detected in the wall of the third and lateral cerebral ventricles of rat brain, using histochemistry for NADPH-diaphorase activity. One type was multipolar and lay supraependymally, with dendrites oriented in the plane of the ependymal layer. The second type was bipolar and was situated subependymally, with dendrites extending in opposite directions, either into the surrounding brain tissue or to the ventricular surface. Moreover, multipolar neurons, situated in the corpus callosum and in the subcortical white matter, had long varicose dendrites extending toward the roof of the lateral ventricles. As a result, numerous NADPH-diaphorase neurites spread out on the free surface of the ependymal layer in contact with the CSF. These observations raise the possibility that periventricular nitrergic neurons play an essential role in registering the composition of the CSF and in modulating subcortical cerebral blood flow. A further possibility is that supraependymal nitrergic neuronal processes are effectors regulating activity of ependymal cells.

[Interhemispheric epidermoid cyst. A clinical case]

The authors report a rare case of epidermoid cyst with interhemispheric growth closely connected to the anterior portion of the corpus callosum. Although extremely sensitive in determining the site, dimensions and relations of the lesion, NMR does not allow the nature of this pathology to be diagnosed owing to the lack of signal specificity. CT, using the measurement of Hounsfield units, allows a differential diagnosis of epidermoid cysts and arachnoid cysts and lipomas to be made in almost all cases. Treatment is surgical and the complete excision of the capsule avoids recidivation.

Surgical treatment of a cerebral mycotic aneurysm using the stereo-angiographic localizer

The authors report a case of mycotic aneurysm surgically treated by means of the Suetens-Gybels-Vandermeulen angiographic localizer system. The major advantages of this technique are reported.