Sulcal Lesions Research Articles

Intradural spinal cord arteriovenous shunts in a personal series of 210 patients: novel classification with emphasis on anatomical disposition and angioarchitectonic distribution, related to spinal cord histogenetic units.

Few classifications of intradural spinal arteriovenous shunts (ID-SAVSs) have considered their anatomical localization in relation to their phenotype and angioarchitectonics. The authors propose another vision of ID-SAVSs allowing a reappraised classification based on analysis of the anatomical disposition, angioarchitecture, and histogenetic location of these vascular malformations. The radiological and clinical records of 210 patients with ID-SAVSs were retrospectively reviewed, considering their localization, vascular architectonics, and correlation with the 5 histogenetic units of the spinal cord. Among these, 183 files with complete data allowed precise analysis of the ID-SAVSs. Among these 183 files (162 and 21 cases with single and multiple lesions, respectively), different entities were identified: 13 pial macro arteriovenous fistulas (MAVFs), 92 pial micro arteriovenous fistulas (mAVFs), 33 superficial pial niduses, and 69 intramedullary niduses. Thirteen sulcal shunts (either fistulas or niduses) were considered subtypes of pial lesions. Among the 21 multiple cases, 11 were monomyelomeric while 10 were multimyelomeric. Pial lesions, either fistulas or niduses, were dominantly vascularized by pial arteries (anterior or posterior depending on the localization of the shunt) and occasionally (except for MAVFs) by transmedullary arteries. Pial niduses occasionally extended into the funiculus by recruiting intrinsic veins or by extension of the nidus itself inside the white matter. Intramedullary niduses were always vascularized by both centrifugal and centripetal feeders, respectively, from sulcal arteries (SAs) and pial arteries. Sulcal lesions are pial lesions located within the ventral median sulcus and vascularized by SAs and veins. Single or multiple ID-SAVSs can be part of various syndromes such as hereditary hemorrhagic telangiectasia, Parkes-Weber, RASA1, CLOVES, and spinal arteriovenous metameric syndromes. Histogenetic analyses revealed a specific distribution of each ID-SAVS in the 5 histogenetic units of the spinal cord: intramedullary niduses were found almost equally from cervical to thoracic units, while MAVFs and mAVFs were mostly found from thoracic to postcrural ones. Pial niduses showed intermediate features between intramedullary and fistulous lesions and were mostly distributed from brachial to crural segments. Precise analysis of the anatomical disposition of ID-SAVSs in relation to functional histogenetic units allows a better understanding of these lesions and improved therapeutic management.

Abstract 162: Microhemorrhages in MRI Predict Infectious Intracranial Aneurysm in Infective Endocarditis

Background: MRI features such as cerebral microbleeds and sulcal susceptibility weighted imaging (SWI) or gradient-echo T2* (GRE-T2*) lesions have been reported to be associated with the presence of infectious intracranial aneurysm (IIA) in infective endocarditis (IE). We aimed to describe the MRI imaging features that predict the presence of IIA. Methods: The derivation cohort comprised 116 IE patients with neurological evaluation at a single tertiary referral center from January 2015 to July 2016. The MRI predictors associated with IIA was evaluated, and we developed the MRI imaging predictors and assessed sensitivity and specificity. External validation was performed in a cohort of 129 IE patients who underwent digital subtraction angiogram (DSA) at the same center from 2010-2014. We assessed the validity using a receiver operating characteristic curve (ROC). Results: Of 116 IE patients in the derivation cohort, 10 (9%) had IIAs. Of 129 in the validation cohort, 19 (15%) IIAs were identified. The MRI imaging predictors for IIA consist of 1) contrast enhancement with SWI lesions, 2) cerebral microbleeds > 5mm plus sulcal SWI lesions, and 3) any MRI hemorrhages. The sensitivity for the presence of IIA in each group of the derivation cohort was: 90%, 80%, and 100%, respectively. The sensitivity in the validation cohort was: 47%, 68%, and 94% respectively. The specificity in the derivation cohort was: 87%, 85%, and 18%. In the validation cohort, the specificity was similar (87%, 75%, and 27%). Conclusions: The suggested MRI imaging predictors can be used as a sensitive and specific tool to support clinical decision-making, especially when invasive DSA is considered for assessment for presence of IIA. The absence of MRI hemorrhages may not necessitate the need for DSA.

Magnetic Resonance Imaging Susceptibility-Weighted Imaging Lesion and Contrast Enhancement May Represent Infectious Intracranial Aneurysm in Infective Endocarditis

Background: Infectious intracranial aneurysm (IIA) can complicate infective endocarditis (IE). We aimed to describe the magnetic resonance imaging (MRI) characteristics of IIA. Methods: We reviewed IIAs among 116 consecutive patients with active IE by conducting a neurological evaluation at a single tertiary referral center from January 2015 to July 2016. MRIs and digital cerebral angiograms (DSA) were reviewed to identify MRI characteristics of IIAs. MRI susceptibility weighted imaging (SWI) was performed to collect data on cerebral microbleeds (CMBs) and sulcal SWI lesions. Results: Out of 116 persons, 74 (63.8%) underwent DSA. IIAs were identified in 13 (17.6% of DSA, 11.2% of entire cohort) and 10 patients with aneurysms underwent MRI with SWI sequence. Nine (90%) out of 10 persons with IIAs had CMB >5 mm or sulcal lesions in SWI (9 in sulci, 6 in parenchyma, and 5 in both). Five out of 8 persons who underwent MRI brain with contrast had enhancement within the SWI lesions. In a multivariate logistic regression analysis, both sulcal SWI lesions (p < 0.001, OR 69, 95% CI 7.8-610) and contrast enhancement (p = 0.007, OR 16.5, 95% CI 2.3-121) were found to be significant predictors of the presence of IIAs. Conclusions: In the individuals with IE who underwent DSA and MRI, we found that neuroimaging characteristics, such as sulcal SWI lesion with or without contrast enhancement, are associated with the presence of IIA

Coexisting cytotoxic and vasogenic edema in Wernicke encephalopathy

Wernicke encephalopathy (WE) is caused by a thiamine deficiency and typically results in symmetrical lesions in areas of the brain including the paraventricular regions of the thalamus and hypothalamus, the mammillary bodies, the periaqueductal region of the midbrain, the floor of the fourth ventricle and the superior cerebellar vermis. We observed a case of WE that exhibited simultaneous cytotoxic and vasogenic edema. Although cytotoxic edema and vasogenic edema are typical findings of Wernicke encephalopathy, it is very rare for both pathogenic findings to be observed together. A 52-year-old woman with a history of total colectomy was admitted for management of epigastric discomfort, nausea and vomiting 7 days in duration. The patient suffered from recurrent paralytic ileus due to systemic sclerosis. Three months prior to admission, the patient underwent a total colectomy due to colon obstruction. The patient had no prior history of hypertension, diabetes, or cerebrovascular diseases. She did not have a history of smoking or alcohol consumption (Fig. 1). Despite administration of antiemetics, vomiting persisted. The patient was treated with intravenous glucose and electrolyte solution without vitamin supplementation. After 15 days of hospitalization, the patient was referred to the Neurology Department for evaluation of convulsive movement, diplopia, and ataxia. On examination, the patient was alert, but disoriented. There was complete ophthalmoplegia with coarse spontaneous nystagmus. The upper and lower limbs were symmetrically hypotonic and weak. The patient was unable to maintain a sitting position or standing position without support due to truncal ataxia, and deep tendon reflexes were slightly depressed. Laboratory studies revealed anemia, leukocytosis and elevated liver enzymes. The serum thiamine level was below the normal range (14.5 lg/L, normal 28–85). Magnetic resonance imaging (MRI) performed on the referral day showed high signal intensity lesions in both medial thalami, the mammillary bodies, the periaqueductal region, the tectum of the midbrain and the medullary tegmentum in T2-weighted and fluid-attenuated inversion recovery (FLAIR) MR imaging. Diffusion-weighted images (DWI) showed more extensive symmetrical high signal intensities in the aforementioned areas, and also in both the central and precentral sulcus. Apparent diffusion coefficient (ADC) mapping showed low intensity areas in both cortical sulcal lesions, the most medial part of the thalami, the mammillary bodies, and the dorsal and upper part of the midbrain tectum, and simultaneous high or iso intensities in the rest of the medial thalamus, midbrain tectum and medullary tegmentum. The patient was given 100 mg of thiamine per day intravenously. Seven days after thiamine supplementation, her ocular motor function had improved, and 21 days after thiamine treatment began, the patient was able to walk without titubation. Many case investigations using DWI to examine patients with Wernicke encephalopathy have S. Kim S.-H. Kim J.-S. Kim (&) Department of Neurology, College of Medicine, Seoul St. Mary’s Hospital, The Catholic University of Korea, 505, Banpo-dong, Seocho-gu, Seoul 137-701, South Korea e-mail: neuronet@catholic.ac.kr

Effect of Apis mellifera Propolis from Two Brazilian Regions on Caries Development in Desalivated Rats

The purpose of the present study was to evaluate the effect of Apis mellifera propolis collected from two regions of Brazil on caries development in desalivated rats. Ethanolic extracts of propolis (EEP) were prepared from crude propolis samples collected in Minas Gerais state (MG), southeastern Brazil, and Rio Grande do Sul state (RS), southern Brazil. The flavonoid composition of EEP was analyzed by high–performance thin–layer chromatography (HPTLC) and reversed–phase high–performance liquid chromatography (HPLC). For the animal study, 30 specific pathogen–free Wistar rats were infected with Streptococcus sobrinus 6715 and surgically desalivated. The rats were randomly divided into three groups which were treated with 80% ethanol (control), EEP from MG and EEP from RS. The animals were placed in a König–Höfer programmed feeder and received 17 meals of diet 2000 daily at hourly intervals. The solutions were applied on the rat molars (25 μl on molars of each quadrant) twice a day, by using graduate syringes. After 3 weeks, the animals were killed by CO₂ asphyxiation. For microbial assessment, the left jaw was removed and sonicated in 154 mM NaCl solution. Dental caries was evaluated according to Larson’s modification of Keyes’ system. The HPTLC patterns and HPLC profiles demonstrated that both quality and quantity of flavonoid aglycones of EEP from MG were different compared to EEP from RS. In general, it is apparent that EEP from RS contained the highest concentrations of pinocembrin, chrysin, acacetin and galangin. The group of animals treated with EEP from RS showed the lowest smooth–surface and sulcal caries scores as well as less caries severity in smooth–surface and sulcal lesions, and these data were statistically different when compared with the control group. The group treated with EEP from MG only demonstrated a significant difference in the severity of sulcal lesions when compared to the control group. The percentage of S. sobrinus was lower in the groups treated with EEP, but did not differ statistically from the control group. The results showed that the cariostatic effect of propolis depends on its composition, and consequently the region of collection of propolis samples.

Demonstration of neurofibrillary tangles in the indusium griseum and of axonal disturbances in sagittal sulcal lesions of the corpus callosum: An immunohistochemical investigation

This is an immunohistochemical investigation of the indusium griseum (supracommissural hippocampus) of the brains of control subjects and patients with Alzheimer's disease (AD). Our assays revealed the presence of fine deposits of synaptophysin‐positive dots in the neuropil and around neurons in the indusium griseum of control subjects. By using an antibody to Alzheimer neurofibrillary tangles (NFT) we identified NFT and neuropil thread‐like structures in the indusium griseum of AD patients; no β‐amyloid protein‐containing senile plaques were seen. To our knowledge, this is the first documentation of the occurrence of NFT in the indusium griseum. We also performed immunohistochemical assays on anterior sagittal sulcal lesions of the corpus callosum (ASSLCC), also known as surface lesions of the corpus callosum. These studies revealed a uniformly increased expression of the 200 kDa phosphorylated neurofilament protein by the axons in the pale myelin areas around the zonal depressions caused by the mechanical pressure of the anterior pericallosal artery. By contrast, immunoreactivity with an antibody to glial fibrillary acidic protein was either unchanged or reduced in the ASSLCC.

Cariogenic Potential of Foods

A series of rat caries experiments was carried out to test the relative cariogenic potential and to identify the major carcinogenic elements of 22 popular snack foods. Parameters that were measured included rat caries, number of cariogenic bacteria in plaque, salivary parameters including flow rate, buffering capacity, total protein, lysozyme and amylase content, and composition of test foods including protein, fat, phosphorus, calcium, fluoride, galactose, glucose, total reducing sugar, sucrose, and starch. Many interesting relationships were observed between food components, numbers of plaque bacteria, salivary components, and specific types of carious lesions. Protein, fat, and phosphorus in foods were all associated with inhibition of both sulcal and buccolingual (smooth-surface) caries. Food fluoride was associated with inhibition of buccolingual caries, whereas calcium was related to inhibition of sulcal caries. Glucose, reducing sugar, and sucrose in foods were all related to promotion of both sulcal and smooth-surface caries. The numbers of Streptococcus sobrinus in plaque were associated with promotion of smooth-surface caries only, whereas lactobacilli, non-mutans bacteria, and total viable flora were related to promotion of both smooth-surface and sulcal caries. The salivary flow rate was associated with inhibition of both buccolingual and sulcal caries. Salivary buffering capacity (at pH 7) and salivary lysozyme delivery were associated with inhibition of number and severity of sulcal caries, while the salivary amylase content was related to the promotion of the number of sulcal lesions.

Visual impairments in macaques following inferior temporal lesions are exacerbated selectively by additional damage to superior temporal sulcus

The present study examined the behavioural effects of removing the inferior temporal cortex (area TE) either on its own or in combination with the adjacent fundus and upper bank of the superior temporal sulcus (area STP). Comparisons with preoperative behaviour showed that the addition of superior temporal sulcal damage led to an increase in visual components of the Klüver-Bucy syndrome, i.e. an increased tendency to touch and examine objects coupled with a decrease in emotional reactivity, but no excessive orality, changes in food preference, or coprophagia. No group differences were found in the learning of 3 pattern discriminations, but the animals with additional superior temporal sulcal lesions were more impaired than the others on 3 colour discriminations, successive reversals of an object discrimination, and a learning-set task. These findings indicate that STP provides an important route, independent of the route via TE, by which visual information can reach limbic structures to evoke affective responses and contribute to visual learning.

Inhibitory effect of barium on caries formation in rats.

The aim of this investigation was to study the effect of barium and fluoride in drinking water on caries formation in rats. Sprague-Dawley rats were fed a cariogenic diet (MIT-200) 17 times daily in a König-Hofer programmed feeding machine for 37 days. Drinking water containing barium (0, 50 or 100 ppm) and fluoride (0 or 10 ppm) was available ad libitum. Rats to whose water was added 50 ppm barium had significant reductions in the mean severity of both buccolingual lesions and sulcal lesions compared with those rats whose water contained no barium. As expected, F at 10 ppm in the drinking water significantly reduced caries severity but this F effect was independent of the barium effect. This suggests that the inhibitory effects of barium and fluoride at these levels are additive and operate by separate mechanisms.

ラット実験による飲用水フッ素のエナメル質フッ素濃度およびうしょく発生に及ぼす影響

The aim of the present study was to investigate the effect of fluoridated drinking water on the fluoride content of the enamel and on the development of dental caries in the rat. Twenty-one-dayold Sprague-Dawly rats were subjected to a 4-week pre-caries test period during which they were fed a non cariogenic diet and given distilled water containing 0 ppm, 10 ppm, or 50 ppm fluoride concentration as sodium fluoride. After this period, each group was fed a cariogenic diet and given distilled water for a further 4 weeks. The fluoride concentrations in enamel of the first or second mandibular molar after the fluoride treatment were determined weekly. The fluoride content in enamel of the molar was also determined after the end of the cariogenic period. The fissure and proximal surface carious lesions in the first and second mandibular molar were observed and scored for caries prevalence and severity following the method of Konig.The fluoride concentrations of the first molar treated with 10 ppm and with 50 ppm fluoride for 4 weeks were both significantly higher than those of the first molar treated for 1 week (P<0.05). Likewise, the fluoride contents of the second molar treated with both fluoride concentrations showed significantly higher values at 3 weeks than those at 1 week (P<0.05-0.01).The amount of fluoride uptake into the enamel of first and second molars was shown to be directly related to the level of fluoride in the drinking water with the latter being significantly higher than the former (P<0.05-0.01). The fluoride treated groups showed less caries than the control group on the sulcal surfaces of the first and second molar; especially, caries was significantly inhibited in the 50 ppm fluoride group (P<0.001). The groups receiving 10 ppm or 50 ppm fluoride developed significantly less caries than the control group on the proximal surfaces of the second molar (P<0.05). The fluoride incorporated into enamel by fluoride treatment seemed to be almost entirely retained even after the 4 week cariogenic period.The results of this study strongly suggest that enamel-bound fluorides provided prior to a cariogenic challenge conferred protection from caries, especially, from sulcal lesions.

Preliminary studies on calcium lactate as an anticaries food additive.

Enamel dissolution, Orofax and rat caries studies were carried out to assess the effects of calcium lactate in reducing the cariogenicity of four commercially used candies. When used at the 5% level, calcium lactate was effective in reducing enamel dissolution by as much as 43% in fermenting candy-saliva mixtures. In Orofax studies it reduced the amount of in vitro caries by as much as 87%. In a rat caries study, a test group fed a chocolate caramel candy containing 1.5% calcium lactate produced reductions of 38 and 17% in number and 47 and 31% in severity of smooth surface (buccolingual) and sulcal lesions, respectively, as compared to a control group fed the same candy without additive. These findings plus the fact that calcium lactate is a tasteless, nontoxic chemical compound, commonly used in a number of food products, all indicate that calcium lactate my be considered an effective anticaries food additive.

Pre- or Post-Eruptive Effects of Strontium Alone or in Combination with Fluoride on Dental Caries in the Rat

Doses of strontium were given pre-eruptively to rats at 0.0, 2.5, 5.0 and 10.0 μg Sr/10 g body weight, with or without fluoride at 1.0 μg/l0 g body weight by esophageal intubation. In a second experiment strontium at concentrations of 0, 50, 100 and 150 mg Sr/l, with and without fluoride at 10 mg/l, were given via the drinking water post-eruptively. Caries scores were made for buccolingual, morsal, sulcal und proximal lesions in all rats. Slight reductions in buccolingual caries scores were seen in rats given 5.0 μg Sr/10 g body weight pre-eruptively. Rats given post-eruptive doses of strontium only showed marked reductions in buccolingual scores with 50 mg Sr/l, and 10 mg F/l. No effect was seen on morsal, sulcal or proximal caries scores for any of the treatment regimens. The greatest reductions in buccolingual caries scores were found when a combination of 50 mg Sr/l and 10 mg F/l was given post-eruptively.

Antimicrobial Agents and Dental Caries in the Rat

Two rat plaque-caries studies indicated that a 0.2% chlorhexidine solution topically applied to rat teeth was effective in reducing dental plaque. This reduction in plaque was accompanied by marked reductions in smooth surface caries, but not in sulcal lesions.

Attenuation of self-stimulation from substantia nigra but not dorsal tegmental noradrenergic bundle by lesions of sulcal prefrontal cortex

Rats that self-stimulated from electrodes implanted in either the substantia nigra pars compacta (SNC) or the dorsal tegmental noradrenergic bundle (DTB) received bilateral electrolytic lesions of the prefrontal cortex dorsal to the rhinal sulcus. Immediately after the lesions, animals with SNC electrodes (n = 9) showed significant and permanent reductions in self-stimulation rates. The average reduction in the SNC group was 67% of prelesion bar-pressing scores. In contrast, rats with DTB electrodes (n = 11) were not significantly affected by similar sulcal lesions. Subsequent examination of the brains for prograde degeneration using procedure I of Fink and Heimer 11 revealed a descending system of sulcal efferents that was very dense in the region of the SNC but only scattered in the area of the DTB. The close relation between the effects of sulcal lesions on self-stimulation and the resultant density of degeneration as a function of stimulation site is discussed in terms of the contribution of prefrontal cortex to self-stimulation in general, and of the implications for the catecholamine hypothesis of self-stimulation in particular.

Pre-eruptive effects of Mo, B, Sr and F on dental caries in the rat

Pre-eruptive effects of trace elements on dental caries have not been extensively evaluated. To investigate the effect of Sr, Mo or B alone or in combinations with F, male rat pups were intubated oesophageally daily from 4 to 17 days of age. The rats were fed a high sucrose, caries-promoting diet from 18 to 35 days of age, killed and the first and second mandibular molars evaluated for carious lesions. Fluoride ( 100 μg 10 g body wt/day) reduced buccal enamel lesions by 50 per cent but did not reduce sulcal caries. Strontium and Mo at 500 and B at 150 μg 10 g body wt/day increased buccal dentine-enamel (Ds) lesions by 80, 85, and 43 per cent, respectively, and increased sulcal caries slightly. Strontium. Mo, or B, given in combination with F, increased buccal (Ds) caries by 63, 56 and 145 per cent, and increased sulcal (Ds) lesions by 27, 43 and 48 per cent, respectively, as compared to control values. The results demonstrate that administration of Sr, Mo or B, at these levels throughout the pre-eruptive period only, causes an increase in dental caries. Concomitant administration of F was ineffective in reversing the effect of Sr, Mo or B. In fact, sulcal lesions were augmented by each of the combinations and deep buccal caries was greatly enhanced when both B and F were given together. These data have important implications concerning pre-eruptive systemic exposure of teeth to F in the presence of other elements.

Reduction of rat caries by trimetaphosphate on different tooth surfaces: Variations produced by diet and oral flora

Osborne-Mendel rats fed coarse particle Diet 585 developed mostly sulcal lesions and showed no increase in caries as a result of being inoculated with exogenous mixed cariogenic flora including a strain of Streptococcus mutans. Uninoculated rats fed high sucrose Diet 2000 developed mostly sulcal lesions, while the inoculated animals showed some increase in the sulci and a very pronounced increase on the smooth surfaces. The addition of TMP to both of the diets was associated with a limited, but significant, reduction in sulcal caries and almost complete elimination of smooth surface lesions, which were already low on Diet 585 and a highly significant reduction on Diet 2000.

Development of caries in the Hung-Hoppert caries-susceptible and caries-resistant rats under different experimental conditions.

Rats of both Hunt-Hoppert lines, originally designated as caries-susceptible (Ca-S) and caries-resistant (Ca-R) lines, were highly susceptible to caries when subjected to a combination of diet and microflora that provided a challenge to the resistance of all surfaces of the teeth. Strain differences were indicated by the predominance of sulcal lesions in the Ca-S line and smooth-surface lesions in the Ca-R line.