Prevalence of cocaine and derivatives in blood and urine samples of trauma patients and correlation with injury severity: a prospective observational study.

PURPOSE: The abuse of cocaine and its derivatives presents a likely risk factor for injury. Trauma incurred by cocaine and derivative abusers may be more severe than that incurred by non-users. OBJECTIVES: To ascertain the presence of cocaine and its derivatives in trauma patients and to correlate RTS (Revised Trauma Score) and ISS (Injury Severity Score) with the presence of cocaine and its derivatives in blood and urine samples. METHODS: All trauma victims treated in an emergency unit between November 11, 2012 and September 15, 2013 were included in the study. Blood and urine samples were collected on admission to hospital. RTS and ISS scores were then compared with the presence or absence of cocaine and its derivatives in the samples. The associations between RTS < 7.84 and ISS > 16 and the independent variables were evaluated by the gross odds ratio values, determined by univariate logistic regression. Multivariate analysis was performed using multivariate logistic regression. RESULTS: Of 453 patients (83.7% male) included in the study, 28.6% presented ISS > 16 and 33.6% presented RTS < 7.84. A total of 435 samples were collected, and 86 (19.8%) provided positive samples for cocaine, 48 (11%) for crack and 69 (15.9%) for cocaethylene. Compared to other patients, drug users showed a greater probability of RTS < 7.84 (2.18 times greater) and a greater probability of ISS > 16 (1.76 times greater). CONCLUSION: For the trauma patients included in our study, the use of cocaine and its derivatives was shown to be associated with more severe traumas, as demonstrated by their RTS and ISS scores.

Patterns of anti-tuberculosis drug resistance among HIV-infected patients in Maputo, Mozambique, 2002-2003.

SETTING: Two tuberculosis (TB) reference hospitals in Maputo, Mozambique. OBJECTIVES: To assess the pattern of TB drug resistance and its risk factors in human immunodeficiency virus (HIV) patients. DESIGN: Adult HIV-positive patients with TB diagnosed by culture of sputum or bronchial washing were enrolled during 2002-2003. Cultures of 111 patients were tested for rifampicin, isoniazid, streptomycin and ethambutol sensitivity. Chest X-ray, haemoglobin (Hb), total lymphocyte and CD4 counts were also performed. RESULTS: Overall resistance to any drugs was found in 18% and multidrug-resistant TB (MDR-TB) in 9%. New cases of TB accounted for 62% of the studied group. Drug resistance in this subgroup was 13% compared with 26.3% in the previously treated subgroup, and MDR-TB was 5.8% vs. 15.8%. All patients presented Hb levels < 9 g/dl and total lymphocyte counts < 1200/microl. CD4 counts were significantly low in the drug resistance subgroup, with levels mostly < 100/microl. Cavities on X-ray were seen only in drug-sensitive patients. No risk factors for drug resistance were detected. CONCLUSIONS: Overall observed drug resistance was 18%, and MDR-TB 9%. Previously treated patients had high drug resistance (26.3%) and MDR-TB (15.8%).

Influence of rehabilitation on language skills in aphasic patients. A controlled study.

The influence of language rehabilitation on specific language skills (speaking, understanding, writing, and reading) was investigated in 281 aphasic patients (162 reeducated and 119 controls) who were subjected to a second examination no less than six months after the first. The relationship of the following factors to improvement was studied: (a) time between onset of aphasia and first examination; (b) type of aphasia; (c) overall severity of aphasia on first examination; (d) presence or absence of rehabilitation between first and subsequent examination. It was found that rehabilitation has a significant positive effect on improvement in all language skills. Time between onset and first examination and overall severity of aphasia were negatively related to improvement. The relationship of type of asphasia to improvement was not significant. Additional evidence of the efficacy of rehabilitation is provided by experience with patients who began language therapy several months or years after the onset of their language disorder.

Slowly progressive aphasia: a four-year follow-up study.

This paper reports the long-term follow-up of GC, a patient with primary progressive aphasia of the fluent type. GC presented at onset with an anomia characterized by sparing of first letter knowledge, that applied mainly to proper names and living categories. No semantic deficits were observed in the first stage of the disease, and MRI showed a left temporal lobe atrophy with a gradient from the pole to the posterior regions, the latter being less involved. We now report the clinical evolution of GC from the 2nd to the 4th year of disease. As the disease progressed, the anomia became more severe and the phenomenon of first letter sparing was no longer detectable. Also semantic knowledge was gradually affected and, eventually, was dramatically lost. However, no other cognitive deficits were seen at the last examination. By that time, the temporal atrophy shown by MRI was bilateral, although still more evident on the left side.

Proper name anomia: a case with sparing of the first-letter knowledge.

In this article we describe the case of GC, a woman affected by severe proper name anomia due to progressive brain atrophy that mainly affected the left temporal pole. Proper name comprehension and semantic knowledge about the people she was unable to name were normal. GC showed a sparing of initial letter knowledge of proper names, while other phonological characteristics were not equally available. At a later stage of her illness, the naming impairment began to affect common names as well as proper names, though at a lesser extent. Whereas there was no category effect between names of animate and inanimate stimuli, we observed a relative sparing of first letter knowledge selectively for animate categories, although less marked than with proper names. This case is discussed within the theoretical framework of two-stage models of name production. Knowledge of the initial letter of proper names supports the psychological reality of the "phonological address" as a preliminary stage of the production of this class of names. Moreover, the qualitative similarity between errors observed with proper names and with names of animate objects suggests that the production of names belonging to these classes may conform, at least in part, to analogous algorithms.

Living musical instruments and inanimate body parts?

In the literature about category effects in semantic memory, body parts and musical instruments are often considered atypical, because in cases with a disproportionate impairment of living categories body parts are relatively spared, while musical instruments are often severely defective. In this study the performance of 57 subjects affected by diseases generally associated with lexical-semantic impairment, for the most part Alzheimer's disease and other forms of cortical degeneration, but also herpetic encephalitis and traumatic brain damage are analyzed. The subjects were given a picture naming task tapping eight categories: three living categories (animals, fruits and vegetables) and three non-living categories (tools, furniture and vehicles), plus body parts and musical instruments. On a preliminary analysis at the group level, body parts were the least impaired category and musical instruments the most severely impaired, the six living and non-living categories being intermediate. However, these differences disappeared after covariance for lexical frequency, name agreement and age of acquisition. The relationship between living categories, non-living categories, musical instruments and body parts was investigated by means of a Lisrel model of Confirmatory Factor Analysis. Two latent variables related to living and non-living categories respectively were defined, and it was found that both body parts and musical instruments were significantly related only with non-living categories. The results showed that the definition of the latent variable expressing the substrate of non-living categories was less satisfactory than that expressing the living categories. On this basis, the conclusions of this study appear statistically definite but their psychological interpretation is less straightforward.

Semantic category dissociations in naming: is there a gender effect in Alzheimer's disease?

Several studies on picture naming in Alzheimer's disease have reported inconsistent findings regarding semantic category dissociation. To clarify this point, 26 patients suffering from dementia of the Alzheimer's type (DAT) were given a naming task, based on 60 black and white drawings, which allowed us to take into account several variables that might influence performance, notably word frequency, stimulus familiarity and prototypicality, name and image agreement and visual complexity. On a raw analysis, DAT patients as a group gave a lower performance with stimuli of Living Categories (LC) than with stimuli of Non-Living Categories (NLC), but when all the confounding factors were taken into account the category effect disappeared. Nevertheless, with a multiple single case approach, some patients presented a true dissociation: 11 were significantly better with Non-Living stimuli, and 3 with Living stimuli. In order to find what factors were involved in determining this distribution, we took the distribution of asymmetry indices of each patient, and plotted the individual category effect against the level of the general performance. In our sample, the distribution of asymmetry indices was skewed, and included a definite cluster of male subjects who were better at performing with Non-Living stimuli. Multivariate analysis suggested that the greater discrepancy shown by male patients was due to a protection acting on Non-Living stimuli rather than to a selective hampering of Living stimuli. The greater personal experience of males with Non-Living things could explain the relative preservation of these in male DAT subjects.

Living and non-living categories. Is there a "normal" asymmetry?

A picture naming task and a semantic memory verbal questionnaire were given to normal subjects to assess the possible asymmetry between knowledge for non-living and living things. We first examined 60 elderly subjects with low education. Asymmetry between non-living and living things was found in the semantic knowledge questionnaire and living things fared worse. This difference was not explained by discrepancy in item frequency, familiarity or prototypicality. Using the same questionnaire, we analysed difficulty judgements given by younger, better-educated subjects: questions about living things were slightly, but significantly more difficult than questions regarding non-living things. In order to check for a possible sample bias, we submitted another verbal questionnaire with an analogous structure to different judges and replicated the previous results. These findings are discussed with regard to the selective semantic memory deficit for living things observed in patients. We suggest that the cognitive pattern presented by these cases may be linked to, but not fully explained by the greater difficulty living things present for normal subjects.

Different basic components in the performance of Broca's and Wernicke's aphasics on the Colour-Figure Matching Test.

It is known that focal damage of the left hemisphere causes poor performances in a number of tasks devoid of overt verbal connotation, often referred to as "non-verbal intelligence", "association" or "abstract attitude" tasks. However, it is not clear whether the existence of a unitary basic functional defect to account for the faulty performances outlined above can be supposed. In this investigation we have compared the behaviour of left-hemisphere damaged patients grouped according to aphasia type and have studied the extent to which two different, widely used tests of this supposed "non-verbal basic ability" (i.e. the Weigl Sorting Test and the Raven Progressive Matrices) overlap in their predictive power of the performance of a non-verbal association task, i.e. the Colour-Figure Matching Test. Notwithstanding the identical level of performance in the three tests between groups having different aphasia types, a clear-cut dissociation was found between Broca's and Wernicke's aphasics; in the former group the Colour-Figure Matching Test was highly correlated only with Weigl Sorting Test and in the latter only with Progressive Matrices. The conclusions are that in this case the breakdown of non-verbal basic resources does not coincide in patients with different types of aphasia, and the hypothesis of the existence of a unitary basic defect caused by left hemisphere damage is not in line with our findings.

Picture naming and progression of Alzheimer's disease: an analysis of error types.

Seven patients affected by Dementia of the Alzheimer Type (DAT) took part in a longitudinal study aimed at assessing the qualitative and quantitative evolution of picture naming impairment. The follow-up lasted 6-36 months and the patients were examined at intervals of 6 months or longer. We found that the absolute number of lexical-semantic errors tended to be constant or to rise slightly until an advanced stage of DAT severity was reached. However, the proportion of errors of the lexical-semantic type in relation to the overall number of errors showed a decline as the disease progressed, with empty and unrelated responses being increasingly observed. Visual errors were generally a minority; they were produced in different proportions for each patient but did not vary greatly over time. For the observed patients, the proportion of lexical and semantic errors was inversely related to the overall naming performance, following a negative logarithmic function. This finding was replicated analysing cross-sectional data from another 24 DAT patients who were given the same naming task.

Interaction between lateralization of memory and probe stimulus in the recognition of verbal and spatial visual stimuli.

The aim of the study was to sort out whether in normal subjects hemispheric asymmetries in memory encoding arise at the input or at the recognition stage of verbal (diagrams of letters) and spatial patterns (diagrams of stars) in a 3 X 3 virtual matrix. Target and probe stimuli were tachistoscopically presented to the same or the opposite hemisphere. Letters, but not stars, were better recognized in a crossed condition in which targets were flashed to the right and probes to the left hemisphere. The finding suggests that the right hemisphere (but not the left) is capable of adding specific, possibly mnestic, resources to the first stage of letter processing.

Pattern of recovery of oral and written expression and comprehension in aphasic patients.

Three hundred and eighty-eight aphasic patients (250 rehabilitated and 138 non-rehabilitated) were subjected to a study whose aim was to analyze the relationship between recovery in 4 specific language skills: oral and written expression and comprehension. By means of Cohen's K coefficient of agreement we sought to ascertain whether recovery of one out of these language skills significantly affected recovery of the remaining 3 language modalities. In rehabilitated patients recovery of oral ad written comprehension and expression always turned out to be linked; in non-rehabilitated patients oral comprehension recovery was not associated with recovery of oral expression, reading and writing. Regarding the evolution of aphasia type, none of the experimental subjects changed from a fluent to a non-fluent form of aphasia.

Guillain-Barré syndrome associated with high titers of anti-GM1 antibodies.

We found high titers of anti-GM1 antibodies (1/1280 or more) in 3 of 14 consecutive patients (21%) with Guillain-Barré syndrome (GBS) and in 2 additional patients who developed GBS, 10-11 days after starting parenteral treatment with gangliosides. Antibodies were IgG in 4 patients and IgM in one, and they all bound to asialo-GM1, and, in 3, to GD1b as well. Although the clinical features in all the patients with high anti-GM1 titers fulfilled the criteria for the diagnosis of GBS and in 4 of them, proteins but not cells were elevated in cerebrospinal fluid, electrodiagnostic studies in 3 patients showed prominent signs of axonal degeneration, that in one case were confirmed by morphological studies on sural nerve biopsy. No recent antecedent infection was reported by these patients, but in 3, including patients treated with gangliosides, anti-Campylobacter jejuni antibodies were elevated. In 3 patients a consistent decrease in anti-GM1 levels was observed after the acute phase of the disease suggesting that the frequent occurrence of these antibodies in patients with GBS and their frequent association with a prominent axonal impairment may have pathogenetic relevance.

Cerebral dominance and visual similarity judgements.

Visual similarity judgements among rectangles varying in form and area were investigated in control subjects and in patients with lesions confined to either cerebral hemisphere. While an overweighing of form with respect to area was found in both control subjects and right brain-damaged, left brain-damaged patients equally weighted the two relevant dimensions. Beyond revealing differential processing rules related to the side of the injury in the brain, the findings lend themselves to some speculation about cerebral dominance.

Perceptual and associative knowledge in category specific impairment of semantic memory: a study of two cases.

We report two head-injured patients whose knowledge of living things was selectively disrupted. Their semantic knowledge was tested with naming and verbal comprehension tasks and a verbal questionnaire. In all of them there was consistent evidence that knowledge of living things was impaired and that of non-living things was relatively preserved. The living things deficit emerged irrespective of whether the question tapped associative or perceptual knowledge or required visual or non visual information. In all tasks the category effect was still significant after the influence on the performance of the following variables was partialled out: word frequency, concept familiarity, prototypicality, name agreement, image agreement and visual complexity. In the verbal questionnaire dissociations were still significant even after adjustment for the difficulty of questions for normals, that had proven greater for living things. Besides diffuse brain damage, both patients presented with a left posterior temporo-parietal lesion.

Sex differences in recovery from aphasia.

The influence of sex on recovery from aphasia was investigated for oral expression and auditory verbal comprehension separately in 264 males and 121 females subdivided according to presence/absence of rehabilitation. The conclusions were that females recover significantly better than males in oral expression, but not in auditory verbal comprehension. These results are discussed with regard to the possible existence of a different cerebral organization in males and females.

Phonetically cued word-fluency, gender differences and aging: a reappraisal.

Five-hundred and three normal subjects were given a phonetically cued word-fluency task in order to investigate the controversial issue of the influence of gender and aging on this task. Subjects were requested to say in one minute all the words that occurred to them, beginning with a given letter (F, P and L). Besides the expected significance of education, we observed a female advantage, but not a significant decline in the performance with aging. However, the slope of the line expressing word fluency as a function of age was different between females and males, indicating a greater sensitivity to aging for males. We provide inner and outer tolerance limits for this test in the normal population and give a formula useful for adjusting the raw scores on the basis of gender and education. The results are discussed with reference to previous findings and some hypotheses about the origins of the female advantage in PWF.

Gender affects word retrieval of certain categories in semantic fluency tasks.

Recent studies suggest that gender influences phonetically-cued fluency and some semantic memory tasks. In this study we analysed the effect of demographic variables on semantic fluency tasks. The semantic categories considered were: animals, fruits, tools and vehicles. The influence of age and education was common to all the categories considered and seems a general characteristic of the semantic fluency task. Gender had a significant effect only with fruits and tools, but a diverging role: females fared better with fruits and males with tools. We discuss whether the source of the gender effect should be located at the level of the semantic representation of each category or at the level of item recall in the short time (one minute) granted for the task.

Decision in ambiguity: hemispheric dominance or interaction?

Fifty-eight subjects were shown tachistoscopically grey rectangles, at the centre of the field of vision. The rectangles extended equally to the left and right of the visual fixation point, and were presented under four background conditions: all white, all black, white in the left half of the field and black in the right half, black in the left and white in the right half. "Chimerical" backgrounds were assumed to create an interhemispheric ambiguity in the perception of the greyness of the stimuli as a consequence of opposed brightness contrasts. The reported birghtness was therefore expected to reflect a hemispheric dominance or an interhemispheric averaging of information. The results of the experiment supported the second hypothesis.

Semantic category dissociations: a longitudinal study of two cases.

We report the neuropsychological findings of two patients (LF and EA) with herpes simplex encephalitis. Both patients presented a greater deficit for living than non-living categories in a number of tasks, although EA was much more impaired than LF. We controlled the several stimulus variables that might affect the performance and could demonstrate that the dissociation was not artifactual. Neither LF nor EA revealed a selective or preferential involvement of perceptual semantic knowledge, and both showed a homogeneous impairment of perceptual and associative encyclopaedic notions. At a second examination, carried out from 1 to 2 years later, LF showed a good recovery, whereas EA's improvement was confined to the non-living categories. The lesion of both patients affected the left temporal pole and the basal neocortical regions of the left temporal lobe. The involvement of limbic areas was more marked in LF, while the Wernicke area and the posterior parts of the middle and inferior temporal gyri were only involved in EA. Besides the basal temporal areas, also the posterior temporal regions are likely to play a role in determining the clinical picture of such patients, and their prospect of recovery.