[Asomatognosia and oral drive: a psychoanalytical perspective]. / Asomatognosie et troubles de l'oralité. Une lecture psychanalytique.

OBJECTIVE: The psychoanalytic concept of specular image refers to the complex construction that associates the body image with the language coordinates of the individual, thus making him/her a human subject. The acquisition of this specular image implies the loss of corporeal exchanges between mother and child, i.e., the "neutralization" of those body parts or extensions where these exchanges take place. These conceptions of body image and subjectivity lead to the hypothesis that neurological disturbances of body schema may alter the patients' subjectivity and their relation to the lost "object" insofar as they alter body image. MATERIAL: In the present paper, we present two patients aged under 50, with a unique first ever stroke due to ischemia in the right middle cerebral artery territory and asomatognosia. METHODS: On one hand, Bisiach's protocol was used to assess hemiplegia, sensory troubles, visual troubles, hemineglect and anosognosia, and adapted to assess asomatognosia. On the other hand, subjective data were gathered during a semistructured interview and a self-portrait test. RESULTS: This showed that asomatognosia was accompanied by a destructuration of body image and aberrant oral manifestations involving the paralyzed hand. DISCUSSION-CONCLUSION: The psychological positive phenomena accompanying asomatognosia might correspond to the intrusion of the lost object in the patients' psychic reality, due to the alteration of body schema and body image.

DWI prediction of symptomatic hemorrhagic transformation in acute MCA infarct.

PURPOSE: Symptomatic hemorrhagic transformation is a severe complication of acute ischemic stroke which occurs at a higher frequency after thrombolysis. The present study was designed to analyze whether early DWI can be used for predicting the risk of hemorrhagic transformation with clinical worsening in MCA stroke patients. MATERIALS AND METHODS: Of 28 patients with a middle cerebral artery (MCA) infarct and proven MCA or carotid T occlusion on DWI and MR angiography performed within 14 hours after onset (mean 6.5 +/- 3.5 hours, median 5.2 hours), 4 developed hemorrhagic transformation with clinical worsening, while 24 did not. For the 2 groups, we compared admission NIHSS score, site of arterial occlusion, volume of DWI abnormalities, and several apparent diffusion coefficient (ADC) measurements: ADC(infarct) (mean ADC value of the whole infarct), ADC(core) (peak ADC decrease as calculated in a 57 mm(2) circular ROI, manually centered on the ischemic area with the lowest ADC value on the ADC maps), ADC(superficial) and ADC(deep). Discriminant function analysis was used to determine the most accurate predictors of symptomatic hemorrhagic transformation. RESULTS: The best predictor was the ADC(core) (F=5.34, p=2.9%, cut-off value=300 x 10(-6) mm(2)/s). This monovariate model allowed to correctly classify all 4 patients (ADC(core) 300 x 10(-6) mm(2)/s) with subsequent symptomatic hemorrhage, and 17 of the 24 patients without symptomatic hemmorrhage (ADC(core)>300 x 10(-6) mm(2)/s) (100% sensitivity, 71% specificity). CONCLUSION: Although preliminary, these results suggest that a simple measurement of minimum ADC values within an acute MCA stroke could be useful in targeting those patients with a high risk of severe hemorrhagic transformation.

[Endoluminal dilatations and stenosis of symptomatic vertebral arteries]. / Dilatations endo-luminales des sténoses des artères vertébrales symptomatiques.

Surgical treatment of symptomatic atherosclerotic stenosis of vertebral arteries has been proposed for many years but this technique remains quite confidential due to technical difficulties and relatively high risks. Transluminal angioplasty has been proposed and we developed a simplified technique using coronary stent placement. The aim of this study was to evaluate the feasibility and efficacy of transluminal angiography with primary stenting for proximal stenosis for vertebral arteries. Eleven patients with symptomatic atherosclerotic stenosis of vertebral arteries were treated by trans luminal angioplasty with primary stent placement. Two patients, one with stenosis of the proximal vertebral artery and one with distal stenosis of the vertebral artery where only treated by transluminal angioplasty. In all cases transluminal angioplasty and stenting were feasible with restitution ad integrum of the diameter of the artery in 98 cases and with residual moderate stenose (<20%) in 5 cases. All patients were followed for more than one year, only one patient had recurrence of symptoms, but he stopped spontaneously the anti platteless drugs. Vertebro basilar symptoms disappeared completely in 12/13 cases and were improved in 1/13 cases. No restenose of the artery was observed on control (echodoppler) excepted in one case, where a tight stenose of pre vertebral sub clavian artery developed. Transluminal angioplasty for symptomatic stenosis of vertebral artery appears as a very successful technique with a low complication rate. It should be proposed in many cases of vertebrobasilar insufficiency related with tight vertebral artery stenosis.

Unusual origin of the artery of Adamkiewicz from the fourth lumbar artery.

The main arterial supply of the dorso-lumbar spinal cord is usually derived from a single anterior radiculo-medullary artery called the artery of Adamkiewicz and referred to as having a middle or low location. In some cases, the artery origin is higher, and a vessel which arises in the lower part of the region supplements the supply of the anterior spinal artery. In the literature, those arteries have been described as arising from L3 upwards, and have never been previously described angiographically, to our knowledge, below this level, although Suh and Alexander and Gililan have mentioned this eventuality. Of the 4,000 spinal cord angiographies performed in our institution, we report three cases in which the fourth lumbar artery flows into the anterior spinal artery of the conus medullaris. This anatomical variant may explain the sometimes devastating post-operative neurological complications from a spinal cord infarction on surgery of the lumbar spine or the abdominal aorta below L3.

Incidence and predictive factors of cerebrovascular events in 8,846 elderly treated hypertensive patients during a 3-year follow-up: the PRESAGE study.

This epidemiological study was carried out as a 3-year follow-up project to assess the incidence of transient ischemic attacks (TIAs) and strokes; 8,846 treated hypertensive patients (mean BP, 149/84 mm Hg) aged 65 years or over (mean age, 73.7 +/- 6.3 years), devoid of symptoms of dementia and with documented vascular risk factors were recruited from January 1994 to August 1995, by 1,598 general practitioners in connection with 36 referral university neurology units throughout metropolitan France. Among these patients, 506 (5.7%) had at least one cerebrovascular event during the follow-up period: 309 (3.5%) experienced one or more isolated TIAs, and 197 (2.2%) had a stroke with or without a preceding TIA. A total of 510 TIAs were reported. The stroke subtypes were ischemia, hemorrhage, and unclassified in 70, 16, and 15% of the cases, respectively. The estimated annual stroke incidence was 7.42 per thousand. Of the 197 patients who developed strokes, 51 (26%) died. This case-fatality rate should be compared with the 4.5% mortality rate observed in the whole population during the study period. The 3 subgroups (with isolated TIAs, strokes, or no events during the study) were found to differ regarding age, sedentary lifestyle, past history of cardiovascular events, duration of hypertension, and evidence of complicated hypertension (univariate analysis). The factors identified as predictive of a stroke (multivariate analysis) were: the patient's age; sedentary lifestyle; pulse pressure (SBP-DBP); identification of TIA at baseline, and presence of arrhythmias.

Diffusion-weighted imaging patterns of brain damage associated with cerebral venous thrombosis.

BACKGROUND AND PURPOSE: Apart from cases studies, little is known regarding diffusion-weighted imaging of brain lesions associated with human cerebral venous thrombosis (CVT). Our aim was to describe the initial diffusion-weighted imaging patterns observed in brain areas with MR signal changes associated with CVT and to compare them with those of follow-up imaging. METHODS: The cases of nine patients with brain lesions associated with CVT who underwent CT and diffusion-weighted imaging 3 hours to 4 days after sudden neurologic onset were retrospectively reviewed. The apparent diffusion coefficient (ADC) in abnormal brain was compared with that of contralateral normal regions using z score analysis. MR images obtained during 3 to 6 months of follow-up were available for seven patients. RESULTS: All patients had nonhemorrhagic T2-hyperintense brain regions. These were associated with partially hemorrhagic areas on the CT scans of four patients. In nonhemorrhagic edematous areas, ADC was heterogeneous (coexistence of increased, normal, or decreased ADC) in five patients and homogeneous in four. In the latter four patients, ADC values were within normal range in three, whereas a large homogeneous hyperintensity with decreased ADC values (0.3-0.4 10(-3)mm2/s, <-3 z scores) was observed in one. When available, follow-up images always showed hemorrhagic sequelae in initially hemorrhagic areas. Nonhemorrhagic edematous areas with initially increased ADC values returned to normal. Initially normal or decreased ADC values were predictive of reversibility, although imaging sequelae were rarely observed. CONCLUSION: The diffusion-weighted imaging/ADC pattern of venous stroke is more heterogeneous than previously thought. Large brain regions of reduced ADC values that are not predictive of ultimate infarction in cases of CVT can be observed.

Diagnosis of acute ischaemic stroke with fluid-attenuated inversion recovery and diffusion-weighted sequences.

We evaluated the feasibility and use of diffusion-weighted and fluid-attenuated inversion-recovery pulse sequences performed as an emergency for patients with acute ischaemic stroke. A 5-min MRI session was designed as an emergency diagnostic procedure for patients admitted with suspected acute ischaemic stroke. We reviewed routine clinical implementation of the procedure, and its sensitivity and specificity for acute ischaemic stroke over the first 8 months. We imaged 91 patients (80 min to 48 h following the onset of stroke). Clinical deficit had resolved in less than 3 h in 15 patients, and the remaining 76 were classified as stroke (59) or stroke-like (17) after hospital discharge. Sensitivity of MRI for acute ischaemic stroke was 98%, specificity 100%. MRI provided an immediate and accurate picture of the number, site, size and age of ischaemic lesions in stroke and simplified diagnosis in stroke-like episodes. The feasibility and high diagnostic accuracy of emergency MRI in acute stroke strongly support its routine use in a stroke centre.

False-negative diffusion-weighted MR findings in acute ischemic stroke.

BACKGROUND AND PURPOSE: Lesions associated with acute stroke are often missed by diffusion-weighted imaging (DWI), suggesting that the sensitivity of this technique for detecting acute ischemic stroke may not be as high as initially thought. Our aim was to estimate the rate of false-negative DWI studies in patients with persistent neurologic deficit due to an ischemic stroke and to identify which stroke lesions are most likely to be missed by DWI. METHODS: We reviewed MR images obtained within 48 hours after stroke onset in 139 patients admitted for symptoms consistent with ischemic stroke in whom the deficit lasted more than 24 hours. Cases of negative initial DWI findings with an ischemic lesion visible on follow-up MR studies and a final diagnosis of arterial ischemic stroke were analyzed in terms of delay between onset of symptoms and initial DWI (MR latency), size and vascular distribution of the lesions, and relationship to findings in patients with positive initial DWI results. RESULTS: We found eight cases (5.8%) of false-negative initial DWI studies, of which four were positive on initial fluid-attenuated inversion recovery (FLAIR) imaging. Follow-up FLAIR/DWI showed a hyperintensity matching clinical presentation in all eight patients. The mean size of the lesion was 0.19 +/- 0.16 cm3. False-negative studies occurred more often in cases of stroke in the posterior (19%) than in the anterior (2%) circulation or when DWI was obtained within 24 hours after symptom onset. Of the six false-negative vertebrobasilar stroke lesions, five were located in the brain stem. In all, 31% of patients with vertebrobasilar ischemic stroke had a false-negative initial DWI study during the first 24 hours. CONCLUSION: A false-negative DWI study is not uncommon during the first 24 hours of ischemic stroke. Vertebrobasilar stroke should therefore not be ruled out on the basis of early negative DWI, especially when symptoms persist and are suggestive of this diagnosis.

Prediction of malignant middle cerebral artery infarction by diffusion-weighted imaging.

BACKGROUND AND PURPOSE: This study was designed to analyze whether early diffusion-weighted imaging (DWI) provides reliable quantitative information for the prediction of stroke patients at risk of malignant brain infarct. METHODS: We selected 28 patients with a middle cerebral artery (MCA) infarct and proven MCA or carotid T occlusion on DWI and MRI angiography performed within 14 hours after onset (mean 6.5+/-3.5 hours, median 5.2 hours). Of these, 10 patients developed malignant MCA infarct, whereas 18 did not. For the 2 groups, we compared the National Institutes of Health Stroke Scale (NIHSS) score at admission, site of arterial occlusion, standardized visual analysis of DWI abnormalities, quantitative volume measurement of DWI abnormalities (volume(DWI)), and apparent diffusion coefficient values. Univariate and multivariate discriminant analysis was used to determine the most accurate predictors of malignant MCA infarct. RESULTS: Univariate analysis showed that an admission NIHSS score >20, total versus partial MCA infarct, and volume(DWI) >145 cm(3) were highly significant predictors of malignant infarct. The best predictor was volume(DWI) >145 cm(3), which achieved 100% sensitivity and 94% specificity. Prediction was further improved by bivariate models combining volume(DWI) and apparent diffusion coefficient measurements, which reached 100% sensitivity and specificity in this series of patients. CONCLUSIONS: Quantitative measurement of infarct volume on DWI is an accurate method for the prediction of malignant MCA infarct in patients with persistent arterial occlusion imaged within 14 hours of onset. This may be of importance for early management of severe stroke patients.

Percutaneous transluminal angioplasty and stenting of the proximal vertebral artery for symptomatic stenosis.

BACKGROUND AND PURPOSE: Percutaneous transluminal angioplasty (PTA) for significant stenosis involving the origin of the vertebral artery is now a well established treatment for selected patients when posterior cerebral arterial circulation is compromised. Arterial spasm, dissection, and restenosis may occur in some instances, with subsequent hemodynamic compromise. To prevent these potential complications, we combined PTA of the vertebral artery with primary stenting, using coronary stents, in seven patients. We herein present our short- and intermediate-term results. METHODS: A total of seven lesions affecting the origin of the vertebral artery were treated by primary trans-stenotic coronary stent placement. All patients were symptomatic, fulfilling the general criteria for vertebral artery angioplasty. Patients were followed for up to 36 months after treatment. RESULTS: All seven lesions were successfully dilated. Residual stenosis was never greater than 20% in diameter. No perioperative complications occurred. Clinical follow-up showed immediate resolution or improvement of symptoms in all patients. One patient's condition deteriorated 15 months after stent placement because of atheromatous stenosis of the prevertebral segment in the ipsilateral subclavian artery. CONCLUSION: Stent placement to treat significant stenosis involving the origin of the vertebral artery is safe and effective for alleviating symptoms and improving blood flow to the posterior cerebral circulation. Coronary stent design seems to be particularly well suited to cover atherosclerotic lesions of the origin of the vertebral artery. The stent mesh probably prevents elastic recoil and early restenosis after PTA, as it does in coronary arteries.

[Mechanisms of aphasia recovery and brain imaging]. / Mécanismes de la récupération de l'aphasie et imagerie cérébrale.

Aphasia recovery may depend on right hemisphere or non-lesioned left hemisphere structures, pre-morbid brain language organization, and de novo learning of language. Here we review the brain imaging evidence supporting these different hypotheses. CT-scan studies have investigated the prognosis value of size and site of left hemisphere lesions. The size of the lesion is a global but not an individual predictor of the initial severity and subsequent recovery of aphasia. Studies on the site of the lesion have given different results for verbal expression and comprehension. There is no consensus on a single critical site for recovery of verbal expression in non-fluent aphasia, which may depend on sub-cortical more than cortical extend of the lesion. Conversely the extend of the lesion in the superior temporal gyrus emerges as a critical negative factor for comprehension recovery. Rest measurements of brain metabolism have consistently shown that aphasia severity depends much more on the degree of dysfunction of language-related areas in the left hemisphere than on the site of the lesion it-self. This suggests that aphasia recovery may depend on metabolic dysfunction recovery in peri-lesional structures. More recently, activation studies have shown consistent right hemisphere activation during language tasks in aphasic subjects, but their role in recovery remains debated. It is likely limited, and may depend on atypical pre-morbid language lateralization. Left hemisphere activations are also found in aphasic patients. They are often relocalized in peri-lesional areas, and emerge in most studies as the main factor of aphasia recovery.

[Fronto-temporal degenerative dementia. A modern neuropathologic approach]. / Les démences dégénératives fronto-temporales. Une approche neuropathologique moderne.

The classification of degenerative dementias with fronto-temporal atrophy has been debated since the description of Pick's disease. The study of a clinico-pathological series of 10 cases using immunohistochemistry lead to the following conclusions: reserving the name of Pick's disease to those cases with argyrophilic inclusions, the most recognisable and characteristic marker at neuropathological examination, allows an easy and reliable diagnosis; keeping on with the splitting of these disorders into various clinico-pathologic entities seems today more useful than grouping them into a single syndrome until new data, based for example on genetic analysis, show that different phenotypes correspond to the same disease.

A 24-month, double-blind, placebo-controlled multicentre pilot study of the efficacy and safety of nicergoline 60 mg per day in elderly hypertensive patients with leukoaraiosis.

In this pilot study, 72 non-demented and non-depressive elderly hypertensive patients with evidence of leukoaraiosis on cerebral computed tomography scan (Rezek score: > 16) were randomly assigned to receive either nicergoline 30 mg b.i.d. (n = 36) or a placebo (n = 36) for 24 months. All patients received antihypertensives and their hypertension was controlled under treatment. They were evaluated by nine neuropsychological tests exploring memory, concentration, verbal and motor performances, administered at baseline and at every six-month interval during the study period. At baseline, the two groups were comparable for all demographic and clinical characteristics, including cognitive functions, except for the delayed recall of the Auditory Verbal Learning Test (AVLT), which was better in the placebo group (P = 0.04). Changes in scores over time were compared between the two groups. At the last visit, patients on nicergoline (n = 31) were found to have deteriorated less or to have improved more on test scores than the patients on placebo (n = 30). Significant differences were observed for memory function (AVLT short term recall, P = 0.026; AVLT delayed recall, P = 0.013; and, Benton Visual Retention Test, P = 0.002) and attention and concentration (Letter Cancellation Test, P = 0.043; and, WAIS-R Digit Symbol subtest, P = 0.006). The Rezek score remained unchanged in the two groups. Tolerance of nicergoline was similar to that of placebo. In conclusion, this study shows that nicergoline 30 mg b.i. d. administered over a 24-month period attenuates the deterioration in cognitive functions in elderly hypertensive patients with leukoaraiosis. Whether these effects were specific for this type of white matter changes could not be determined in the context of this pilot study.

Somatosensory cortical activations are suppressed in patients with tactile extinction: a PET study.

OBJECTIVE: To investigate whether tactile extinction alters the cortical somatosensory activations induced by hand vibration. BACKGROUND: Tactile extinction occurs mainly after right-brain lesions and consists of the inability to perceive a contralesional cutaneous stimulation when a similar stimulus is applied to the mirror region of the ipsilesional hemibody. The pathophysiology of tactile extinction is poorly understood, but it is considered to be a deficit of selective attention of somatosensory stimuli. Although other theories have been proposed, our understanding of the pathophysiology of tactile extinction may benefit from functional imaging studies. METHODS: We selected three patients with pure tactile extinction and a mainly subcortical right-brain lesion that spared the primary sensorimotor cortex (SM1). We used PET to investigate the responses to unilateral and bilateral hand vibration in SM1 and the secondary somatosensory cortical area (SII). RESULTS: During bilateral hand vibration, activation was normal in the left SM1, suppressed in the right SM1, and markedly decreased in both SII, which was consistent with the extinction of the left-hand stimulus. During unilateral left-hand vibration, the activation of the right SM1 was still markedly impaired, but the activation of both SII was normal. CONCLUSIONS: We found marked changes in the activation of cortical somatosensory areas induced by hand vibration in patients with tactile extinction. The role of selective attention in cortical activation is also examined.

Diffusion-weighted magnetic resonance imaging in a case of cerebral venous thrombosis.

BACKGROUND: Diffusion-weighted imaging (DWI) is the most sensitive MR sequence in acute arterial ischemic stroke but has not yet been evaluated in venous cerebral ischemia. We describe a patient with DWI performed at the acute phase of a venous ischemic stroke. CASE DESCRIPTION: A rapid cerebral MRI including DWI and fast fluid-attenuated inversion recovery (FLAIR) sequences was performed at the acute phase of a venous stroke confirmed by conventional angiography. DWI showed a slight decrease in apparent diffusion coefficient values 3 hours after onset (0.53+/-0.07x10(-3) mm2/s) and was normal 48 hours later (0.064+/-0.15x10(-3) mm2/s). Fast FLAIR sequences showed large left frontoparietal hyperintensities. The lack of a clear decrease in apparent diffusion coefficient values associated with marked FLAIR abnormalities may suggest prominent or early associated vasogenic edema. Physiopathological differences between arterial and venous ischemia may explain the different type of DWI FLAIR abnormalities during the acute phase as well as the better recovery of neurological deficit in venous stroke than in arterial ischemic stroke. CONCLUSIONS: In the context of an acute stroke, the contrast between marked FLAIR and subtle DWI abnormalities on MRI may reflect the venous mechanism of cerebral ischemia.

Frontal dysfunction in neurologically normal chronic alcoholic subjects: metabolic and neuropsychological findings.

BACKGROUND: Neuropsychological and imaging studies suggest that frontal dysfunction may occur in apparently normal chronic alcoholic subjects. METHODS: To investigate this issue further, we performed neuropsychological and fluorodeoxy-glucose-PET studies in 17 chronic alcoholics without patent neurological and psychiatric complications. RESULTS: Metabolic abnormalities were found in the mediofrontal and in the left dorsolateral prefrontal cortex, but not in the orbitofrontal cortex. Neuropsychological testing revealed significantly reduced verbal fluency and impaired performance on the Stroop test. The mediofrontal hypometabolism correlated with the reduction in verbal fluency and the time necessary to perform the interference condition of the Stroop test. The left dorsolateral prefrontal hypometabolism correlated with the number of errors on the Stroop test. CONCLUSION: These data indicate that circumscribed frontal dysfunctions may occur in chronic alcoholic subjects before clinically obvious neurological complications, and may account for some of the alcohol-related neuropsychological and behavioural impairments.

Clinicometabolic dissociation of cognitive functions and social behavior in frontal lobe lesions.

OBJECTIVE/BACKGROUND: Case studies suggest a dissociation between cognitive functions that have been impaired after damage to the dorsolateral prefrontal cortex and social skills disturbed when the ventromedial prefrontal areas are affected. Because this dissociation had not been confirmed in a clinical setting, clinicometabolic correlations were sought in 13 patients with various lesions of the prefrontal cortex. DESIGN/METHODS: The clinical assessment included extensive testing of executive functions and evaluation of behavioral abnormalities based on an informant questionnaire. Regional cerebral glucose metabolism (rCMRGlu) was measured with [l8F] fluorodeoxyglucose ([18F] FDG) and 31-slide high-resolution PET. RESULTS: Executive-function test performance was significantly correlated with rCMRGlu in the dorsolateral prefrontal cortex (Brodmann's areas 8, 9, 45, 46, and 47) and anterior cingulate cortex (Brodmann's areas 24 and 32). Behavioral scores were significantly correlated with rCMRGlu in the frontopolar (Brodmann's area 10) and orbitofrontal cortex (Brodmann's areas 11, 12, 13, and 14). CONCLUSION: These results show that impaired executive functions and serial skill deficits are associated with distinct metabolic patterns in patients with frontal lobe pathology. In agreement with activation studies in normal subjects, our data suggest the existence of a modular organization of the frontal cortex in humans, as previously reported in nonhuman primates.

Effects of anterior cingulate cortex lesions on ocular saccades in humans.

Cerebral blood flow studies in humans suggest that the anterior cingulate cortex (ACC) could be involved in eye movement control. In two patients with a small infarction affecting the posterior part of this area (on the right side) and in ten control subjects, we studied several paradigms of saccadic eye movements: gap task, overlap task, antisaccades (using either a 5 degrees or 25 degrees lateral target), memory-guided saccades with a short (1 s) or long (7 s) delay, and sequences of memory-guided saccades. Compared with controls, patients had normal latency in the gap task but increased latency in the other tasks. The gain of memory-guided saccades was markedly decreased, bilaterally, whatever the duration of the delay. Patients made more errors than controls in the antisaccade task when the 5 degrees lateral target was used, and a higher percentage of chronological errors in the sequences of saccades. These results show that the posterior part of the right ACC plays an important role in eye movement control and suggest that this area could correspond to a "cingulate eye field" (CEF). The role of this hypothetical CEF could be an early activation exerted on the frontal ocular motor areas involved in intentional saccades and also a direct action on brainstem ocular premotor structures.