Clinical application of functional magnetic resonance imaging in presurgical identification of the central sulcus

OBJECT

The authors sought to evaluate the advantages and limitations of functional magnetic resonance (fMR) imaging when it was used regularly in the clinical context to identify the central sulcus.

METHODS

A 1.5-tesla MR system comprising a spoiled gradient recalled acquisition in the steady-state functional sequence and a cross-hand cancellation analysis method were used to evaluate 50 surgical candidates with centrally located space-occupying lesions in the brain. Three-dimensional (3-D) models of the patient's head and brain showing the relative position of the tumor and the eloquent cortex were obtained in each case. A selective and reproducible focal activation was found, indicating the probable central sulcus position in 41 patients (82%). Direct cortical stimulation confirmed the fMR findings in 100% of 22 intraoperatively assessed patients. Failure to identify the central sulcus occurred in 18% of cases and was mainly a consequence of intrinsic damage in the primary sensorimotor region that resulted in severe hand paresis.

CONCLUSIONS

Although specific factors were identified that contributed to reduced sensitivity of fMR imaging in the clinical context, the present study supports functional assessment and 3-D representation of specific surgical situations as generally feasible in common practice.

Periventricular white matter lucencies in patients with lacunar stroke. A marker of too high or too low blood pressure?

BACKGROUND

Periventricular white matter lucencies (PWML) have been described in stroke patients with arterial hypertension, hypotensive episodes, or increased nocturnal fall of blood pressure (BP). As a result of these mixed factors, the relationship between PWML and BP remains unsettled and the appropriate management of arterial BP in stroke patients with PWML is unknown.

OBJECTIVE

To clarify the relationship between PWML, arterial BP, and cerebral hemodynamics.

DESIGN

Cohort study followed up 6 months after index stroke.

SETTING

Referral center.

PATIENTS

In 41 consecutive patients with first-ever lacunar infarction, the extent of PWML detected on brain magnetic resonance images was measured. Six months after stroke, BP values were monitored during a 24-hour period and transcranial Doppler examinations were performed at rest and following the administration of acetazolamide.

MAIN OUTCOME MEASURES

Correlation of cerebral hemodynamics and BP values with the extent of PWML.

RESULTS

The severity of PWML varied substantially among patients, suggesting that PWML and lacunar infarctions could be due to several different mechanisms. Older age, elevated awake systolic BP, increased cerebrovascular tone, and the interaction between history of heart disease and the lowest heart rate were the strongest independent predictors of the severity of PWML. Diastolic BP and the vasodilatory capacity of the resistance vessels did not predict the severity of PWML.

CONCLUSIONS

Overall, PWML are markers of systolic damage in older lacunar stroke patients with stiffer arteries. In addition, hemodynamic failure may be relevant in patients with concomitant heart disease.

Lesions in the left arcuate fasciculus region and depressive symptoms in multiple sclerosis

Depression is a common mood disturbance in multiple sclerosis (MS) patients. Epidemiologic data suggest a causative relationship between depressive symptoms and cerebral demyelination, although a specific lesion site responsible for depressed mood has not been identified. Given that depression in neurologic disease is closely related to frontal and temporal lobe damage, we focused our study on investigating the extent to which lesions in the white matter connecting both cerebral lobes may account for depressive symptoms in MS. Forty-five patients were assessed using the Beck Depression Inventory and an MRI protocol conceived to quantify lesions separately in the basal, medial, and lateral frontotemporal white matter. The presence of lesions in the left suprainsular white matter, the region that mainly includes the arcuate fasciculus, was specifically associated with depressive symptoms, accounting for a significant 17% of the depression score variance. Although a multifactorial origin is suspected for depression in MS, this finding gives support to the existence of a direct negative effect of demyelination on mood.

Magnetic resonance imaging measurement of the caudate nucleus in adolescents with attention-deficit hyperactivity disorder and its relationship with neuropsychological and behavioral measures

OBJECTIVE

To investigate structural basal ganglia abnormalities in attention-deficit hyperactivity disorder (ADHD) and their relationship with the neuropsychological deficits and behavioral problems found in ADHD.

DESIGN

Case-control study.

SETTING

Adolescents were recruited from a local polytechnic institute of secondary education.

SUBJECTS

Eleven adolescents with ADHD and 19 healthy control subjects. Subjects with ADHD were diagnosed by the school psychologist from a total population of 450 students according to the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised. Diagnosis was confirmed by the Conners Teachers Rating Scale and a structured family interview.

MAIN OUTCOME MEASURES

Magnetic resonance imaging single-slice transversal measurements of the head of the caudate nucleus and a comprehensive neuropsychological evaluation, which was specially designed to assess frontal-striatal functioning.

RESULTS

The ADHD group had a larger right caudate nucleus area than the control group. In control adolescents, larger caudate nucleus areas were associated with poorer performance on tests of attention and higher ratings on the Conners Teachers Rating Scale.

CONCLUSIONS

These findings provide further evidence of the involvement of the caudate nucleus in the neuropsychological deficits and behavioral problems found in ADHD. The larger caudate nucleus found in the ADHD group could be related to a failure of the maturational processes that normally result in volume reduction.

[Neuropsychological deterioration in Huntington's disease]

INTRODUCTION

Huntington's disease (HD) is a neurodegenerative illness, autosomal dominantly inherited, that produces characteristic involuntary muscle movements (chorea) with cognitive abnormalities and personality.

DEVELOPMENT

Neuropathological studies report premature cell death principally affecting the basal ganglia. The disease most commonly begins in the fourth or fifth decade of life, although in some cases, abnormalities have been documented in early childhood and as late as 50 years of age. Early cognitive deterioration in HD is not uniform, and patients with recently diagnosed HD may evidence selective deficits in learning and visuospatial/visuomotor ability, along with a relatively consistent pattern of impairment on subtests of the Wechsler Adult Intelligence Scale (WAIS). Neuroimaging reports of basal ganglia function have described striatal abnormality in HD and related with neuropsychological impairment.

CONCLUSIONS

This paper provides the clinical-phenomenologic definition of the neuropsychological impairment and its associated features related with its neuropathological significance and to review the subject in the light of present day reports.

A Study of the Abney Effect in Some Colour Atlases: Designing Opponent Variables and Hue Functions

The Abney effect in colour-appearance systems (Munsell, NCS) means that the lines for identical apparent hue (at constant lightness) do not coincide with the straight lines for constant dominant wavelength. The curvature of constant-hue lines in chromaticity diagrams reflects the fact that cone signals are nonlinear functions of the rate of photon absorption. The most widely used nonlinear intensity-response function in vision is the Naka - Rushton function, which in an intermediate range can be approximated by a square-root function. Our purpose has been to study the Abney effect in the Munsell and NCS colour atlases in order to develop a mathematical-physiological description on this basis, designing the redness - greenness and yellowness - blueness perceptual variables and the perceptual hue function in each colour system. The description is applicable to both biological and machine-vision systems.

Influence of Progressive Lenses in the Retinal Image Quality

Progressive lenses (PL) are widely used to correct presbyopia, a visual dysfunction that affects most of the population aged over 40 years. The methods used to evaluate the optical quality of these lenses are mainly based on ray-tracing and optical bench testing. Psychophysical studies based on measurements of the contrast sensitivity function of human subjects also exist. However, all these methods exhibit important limitations because, in general, they do not take into account the optics of the eye. One of the objective techniques that permits evaluation of the retinal image in-vivo is the double pass method (Santamaria et al, 1987 Journal of the Optical Society of America A4 1109 – 1114). It has been possible to study the retinal image quality for different correcting optical systems, such as contact lenses, with this technique (Torrents et al, 1996 Perception25 Supplement, 112 – 113).

We studied the retinal image quality of the optical system formed by the eye and a progressive lens. The retinal image quality, characterised by the modulation transfer function (MTF), was measured for different observers as a variety of lines of sight that covered a lens diameter of 50 mm. We show the MTF variation as a function of the lens region and the capacity of this technique to characterise these optical systems.

Double-pass measurements of retinal image quality in monofocal contact lens wearers

The double-pass method is applied to determine the optical image quality in monofocal contact lens (CL) wearers. This is an objective non-invasive technique that permits in vivo testing of the optical performance of CL wearers' eyes. Retinal image quality was measured for three subjects wearing two types of monofocal CLs: a rigid gas permeable (RGP) CL and a soft contact lens (SL), for pupil diameters of 3 mm and 5 mm. Results show the importance of ocular astigmatism regarding retinal image quality. In eyes presenting corneal astigmatism, the best results are obtained when wearing RGP CLs, because the lens compensates the corneal astigmatism. The modulation transfer function (MTF) is considerably smaller when no lens or soft lenses are worn, even for small amounts of astigmatism (0.5 D). When the astigmatism is corrected, the retinal image quality obtained with both types of CLs and with no lens is similar.

Impaired estimation of word occurrence frequency in frontal lobe patients

Neuroanatomical correlates of the estimation of occurrence frequency have received little attention. This study investigates the possible role of the frontal lobe in estimating word occurrence frequency. A sample of 27 patients with frontal lesions were matched with normal controls by sex, age and years of education. Significant differences between patients and controls were found for frequency estimation, but not for item recognition. Studying accuracy of estimation as a function of actual frequency, the frontal group performed worse, especially at high frequencies of occurrence. As far as lesion lateralization is concerned, the right frontal subgroup performed worse than the control group in the estimation of frequency. Our results suggest that the prefrontal cortex plays a role in estimating word occurrence and that there is a dissociation between frequency memory and recognition memory, pointing to the involvement of two different cerebral systems.

Neuropsychological and neuroimaging findings of developmental dysphasia: A longitudinal case study

This article presents an unusual and interesting neuropsychological and neuroimaging longitudinal study of a child who showed a relatively specific developmental language disorder in the absence of any other significant cognitive, emotional or neurological disturbance. The neuropsychological assessment included tests of intelligence, memory, language and frontal lobe functions. Our patient had a marked developmental language disorder characterized by severe impairment of oral and written language and a restricted vocabulary, even though the comprehension of both spoken and written language was relatively preserved. Moreover, his non-verbal intellectual ability was normal and he showed superior visuoconstructive and visuospatial abilities which suggested good development of right temporoparietal functions. On computerized tomography and magnetic resonance imaging there were no structural abnormalities in those cerebral areas concerned with language, although both neuroimaging studies did show a feasible reversed asymmetry or further atrophy on the left sylvian. It is noticeable that at age 17 a severe deficit in the expressive aspects of language remains. In contrast, visuo-constructive functions have improved. These results suggest a functional reorganization of the brain by increasing non-verbal capabilities. The prognosis in dysphasic syndromes is worse than in acquired aphasia in children, since despite speech therapy, an important language impairment persists during adulthood.

Neurospectroscopic alterations and globus pallidus hyperintensity as related magnetic resonance markers of reversible hepatic encephalopathy

In patients with chronic hepatic encephalopathy, proton magnetic resonance spectroscopy can be used to detect specific metabolic abnormalities in the brain; MRI shows a hyperintense globus pallidus on T1-weighted sequences. We investigated the relationship between these two MR findings in a series of 25 patients with the use of quantitative data and a multiple regression analysis model. The cerebral increase in glutamine compounds and the decrease in myoinositol and choline correlated separately with globus pallidus hyperintensity, and each was complementary in accounting for this imaging finding. Such as association suggests that spectroscopic and imaging alterations are two different expressions of the reversible events that occur in the brain of patients with hepatic encephalopathy in that both disappear after liver transplantation. Globus pallidus hyperintensity seems to be a global indicator of the cerebral metabolic disorder, and the spectroscopic pattern denotes the specific metabolic alterations.

Frontal lobe activation during word generation studied by functional MRI

AIMS

To further delimit the specific verbal operations occurring in the dorsolateral frontal cortex during the generation of words.

METHODS

Different verbal fluency tasks guided by distinct specifications (phonological, semantic, or automatic production of words) were used in a functional magnetic resonance study. The study group comprised 10 right-handed normal subjects ranging in age from 23 to 27 years. Functional magnetic resonance images were obtained in a 1.5-Tesla magnet using a spoiled GRASS sequence.

RESULTS

Noticeable activation was found during the word generation tasks in the dorsolateral frontal cortex. The region showing the most prominent activation was the posterior part of the left middle frontal gyrus. Nevertheless, the different tasks each had a different activation effect. The phonologically guided generation of words produced the most consistent activation of the middle frontal gyrus, which mainly involved the premotor cortex.

CONCLUSION

The results suggest that operations concerned with the generation of sound sequences, rather than the amount of produced words or their semantics, are responsible for sustained focal activity observed in the frontal lobes during verbal fluency tasks.

Neuropsychological alterations in patients with computed tomography-detected basal ganglia calcification

OBJECTIVE

To investigate the cognitive and mental status of patients with basal ganglia calcification on a computed tomographic scan.

DESIGN

Eighteen ambulatory patients with basal ganglia calcification and without other radiological findings who were identified from the computed tomography records of a general hospital in a 2-year period and 16 control subjects who were matched for age, education, sex, and premorbid IQ estimation consented to participate. All subjects underwent a neurological evaluation, a comprehensive neuropsychological battery, and tests with psychiatric rating scales.

RESULTS

Significant differences for the control group were found in tests that evaluated motor speed and executive, visuospatial, and some memory functions. Four patients (22%) met criteria for organic mood disorder (minor depression, three patients; bipolar depression, one patient) according to the Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition, whereas six other patients (33%) met diagnostic criteria for obsessive-compulsive disorder.

CONCLUSIONS

These results indicate that patients with basal ganglia calcifications frequently have a subcortical pattern of neuropsychological dysfunction and behavioral changes that are known to be associated with alterations of the frontal-limbic-basal ganglia circuits. The pattern of neuropsychological impairment is consistent with basal ganglia damage. However, poor performance in other neuropsychological tests suggest additional involvement of other connected networks.

Contribution of arterial blood pressure to the clinical expression of lacunar infarction

BACKGROUND AND PURPOSE

The relation between symptomatic lacunar infarction, silent stroke, and arterial hypertension is controversial.

METHODS

From 500 patients with ischemic or hemorrhagic stroke admitted to the Downtown Barcelona Stroke Registry between July 1992 and December 1994, we evaluated prospectively the prevalence of silent infarction in 249 patients who had a brain MRI. The association of risk factors with silent infarction was investigated with the use of logistic regression analysis. In a selected group of 43 patients with symptomatic lacunes, we performed at stroke follow-up transcranial Doppler sonography and 24-hour continuous blood pressure monitoring to evaluate whether blood pressure, cerebrovascular tone, and cerebral blood flow at rest and after the administration of 1 g acetazolamide correlated with silent infarction.

RESULTS

A total of 147 silent infarctions were observed in 83 patients (33%). Most silent infarctions corresponded to small deep lesions in the territory of the lenticulostriate arteries. Patients with silent infarctions had higher systolic and diastolic blood pressure at stroke onset. However, on multivariate analysis, age greater than 60 years was the only risk factor associated with silent infarction. In a subgroup of 43 patients with symptomatic lacunes and patent extracranial vessels, systolic and diastolic pressure at stroke onset and diastolic pressure and vascular resistance at stroke follow-up were higher when silent infarctions co-existed. However, cerebral blood flow at rest and after acetazolamide injection were unrelated to silent infarction.

CONCLUSIONS

Silent ischemia in patients with symptomatic lacunar and nonlacunar stroke was only associated with aging. However, a history of arterial hypertension was perhaps unrecognized, since hemodynamic testing and continuous blood pressure monitoring in patients with lacunar stroke suggested that the coexistence of silent lesions indicated a more generalized cerebral arteriolosclerosis.

Presurgical identification of the primary sensorimotor cortex by functional magnetic resonance imaging

The ability of functional magnetic resonance (MR) imaging to detect a selective sensorimotor cortex activation in healthy subjects and the feasibility of motor activation in patients with lesions around the central sulcus were investigated. Twenty-five healthy volunteers performed 100 motor activation trials, using a variety of motor tasks, which were monitored by several image analysis methods. The functional images were obtained using a 1.5-tesla standard MR imaging system magnet with blood oxygenation level-dependent contrast. Four patients were assessed using functional MR imaging and invasive cortical mapping. Rolandic cortex activation was observed in 98% of the trials performed on healthy subjects in which no head motion occurred. Nevertheless, the cortical response was not selective in a task-rest analysis due to concurrent activation of neighboring regions. Across-task comparison analyses were useful in cancelling nonrelevant activity in most cases (86%). In the patient group, the region identified as the sensorimotor cortex by invasive means corresponded accurately to the area that was activated in functional MR imaging. Present data support the feasibility of detecting selective activation of the rolandic cortex, even in the clinical setting, leading the authors to suggest the usefulness of this widely available technique in surgical planning.

Are Himalayan Sherpas better protected against brain damage associated with extreme altitude climbs?

1. The potential risk of brain damage when low-landers attempt to climb the highest summits is a well-known fact. However, very little is known about what occurs to Himalayan natives, perfectly adapted to high altitude, when performing the same type of activity. 2. Taking into account their long-life climbing experience at extreme altitudes, we examined seven of the most recognized Sherpas with the aim of performing a comprehensive neurological evaluation based on medical history, physical examination and magnetic resonance brain imaging. We compared them with one group of 21 lowland elite climbers who had ascended to altitudes of over 8000 m, and another control group of 21 healthy individuals who had never been exposed to high altitude. 3. While all of the lowland climbers presented psychoneurological symptoms during or after the expeditions, and 13 of them (61%) showed magnetic resonance abnormalities (signs of mild cortical atrophy and/or periventricular high-intensity signal areas in the white matter), only one Sherpa (14%) showed similar changes in the scans, presenting neurological symptoms at extreme altitude. The neurological examination was normal in all three groups, and no neuroimaging abnormalities were detected in the control group. 4. The significant differences, in both clinical and neuroimaging terms, suggest that Sherpa highlanders have better brain protection when exposed to extreme altitude. Although the key to protection against cerebral hypoxia cannot be established, it is possible that an increase in the usually short period of acclimatization could minimize brain damage in those low-landers who attempt the highest summits without supplementary oxygen.

Multiple familial pilomatricomas: a cutaneous marker for Gardner syndrome?

A 40-year-old man and his 6-year-old only son had numerous, firm papulonodular lesions on their faces. Their medical histories were unremarkable and no family consanguinity was recorded. Surgical excision of several lesions was performed on each patient. All the lesions were solid tumors with the characteristic histopathologic features of pilomatricoma. A gastrointestinal radiologic and fibroscopic survey disclosed numerous adenomatous colonic polyps in the father. Additional studies revealed that he also had minor dental abnormalities, a small osteoma on the right mandible, and unilateral, ocular, pigmented retinal macules. The diagnosis of multiple adenomatous colonic polyposis was established only after the well-known association of pilomatricoma-like changes in epidermal cysts in patients with Gardner syndrome was considered. Possibly, multiple familial pilomatricomas could be considered a cutaneous marker of Gardner syndrome.

Motion of the cerebellar tonsils in Chiari type I malformation studied by cine phase-contrast MRI

We studied the effects on CSF dynamics at the foramen magnum and the clinical significance of the abnormal tonsillar motion in 14 patients with Chiari type I malformation and 14 control subjects using cine phase-contrast MRI. Dynamic MRI consisted of axial and sagittal cine phase-contrast sequences. CSF and tonsillar motion were qualitatively and quantitatively evaluated, and the subarachnoid space at the foramen magnum measured. In Chiari patients, cine phase-contrast MRI detected the abnormal pulsatile motion of the cerebellar tonsils, which produced a selective obstruction of CSF flow from the cranial cavity to the spine. The amplitude of the tonsillar pulsation and the severity of the arachnoid space reduction were associated with the symptom of cough-strain headache, but not with the presence of syringomyelia. The finding of abnormal valve dynamics of the cerebellar hernia revealed by cine phase-contrast MRI conforms to the pathophysiologic mechanisms suggested in pressure register studies and opens a new possibility in the presurgical assessment of Chiari patients with exertional symptoms.

Prothrombotic state and signs of endothelial lesion in plasma of patients with inflammatory bowel disease

Recent investigations suggest that microthrombi formation in bowel capillaries could be a determinant factor in inflammatory bowel disease (IBD) pathogenesis. To evaluate the implication of the hemostatic system during these thrombotic events, we analyzed plasmatic values of prothrombotic state markers, physiologic inhibitors of coagulation, and endothelial lesion markers in 112 IBD patients. We found an increase in thrombin-antithrombin complexes and a decrease in antithrombin III, probably due to consumption, demonstrating an increase in thrombin generation. High levels of D-dimer reflect increased fibrin formation, but there is no correlation between thrombin generation markers and D-dimer, possibly suggesting the presence of inadequate fibrinolysis. Levels of tissue factor pathway inhibitor were higher in patients than in controls. Nine patients with Crohn's disease (35% of our sample) had levels of this marker under 70% (range 37-69%). Von Willebrand factor values were increased and those of thrombomodulin only in active patients. Most of the changes were detected in patients with inflammatory activity, and there were no differences between ulcerative colitis and Crohn's disease. In conclusion, these results support the hypothesis that there is an endothelial lesion with sustained coagulation activation in IBD patients.

Abnormalities of the Bereitschaftspotential and MRI pallidal signal in non-encephalopathic cirrhotic patients

In cirrhotic patients, even in the non-encephalopathic state, MRI may show an increased signal in globus pallidus in T1-weighted sequences, the clinical significance of which is still poorly characterized. A dysfunction of the motor circuit of the basal ganglia might be predicted if the increased MRI signal expressed alterations in the globus pallidus activity. We compared the Bereitschaftspotential (BP) in 15 non-encephalopathic cirrhotic patients and 15 age-matched controls and found that the amplitude of the early component and the peak negativity of the BP before the electromyogram onset were significantly reduced in the patient group. The intensity of the pallidal signal was related to the plasma ammonia level but the amplitudes of the BP were not related to the pallidal signal or to ammonia. These findings indicate that a defective activity of the cortical areas implicated in the preparation of movement, not specifically related to the pallidal signal, can be present in cirrhotic patients, even in the non-encephalopathic state.

Persistence of MRI hyperintensity of the globus pallidus in cirrhotic patients: a 2-year follow-up study

We investigated the long-term persistence and short-term stability of globus pallidus (GP) hyperintensity on T1-weighted MRI in 19 cirrhotic patients. After a mean interval of 25.8 months, the hyperintensity of the GP persisted in 17 patients. Hyperintensity disappeared in two patients with hepatocarcinoma, indicating that hyperintensity can revert to normal in circumstances other than liver transplants. Ten patients participated in a 6-month study with repeated evaluations of GP signal intensity, plasma ammonia levels, and selected neuropsychological tests. The GP signal was fairly stable during the follow-up, and the variables considered maintained significant relationships. GP hyperintensity appears as a stable indicator of the functional status of cirrhotic patients.

A randomized study of bolus fluorouracil plus folinic acid versus 21-day fluorouracil infusion alone or in association with cyclophosphamide and mitomycin C in advanced colorectal carcinoma

From May 1988 to June 1992, 129 eligible patients suffering from measurable advanced colorectal cancer were enrolled in a randomized study comparing bolus fluorouracil plus leucovorin (FU-FA); continuous fluorouracil infusion (FU-cont); FUcont plus cyclophosphamide and mitomycin C (FUMIC). FU-FA consisted of weekly fluorouracil (FUra) bolus (600 mg/m2) 1 hour after the initiation of a 2-hour infusion of 500 mg/m2 of leucovorin, for 6 weeks every 8 weeks. FUcont patients were planned to receive 400 mg/m2/day FUra infusion, for 21 days every 28 days. In FUMIC patients, FUcont was associated with weekly cyclophosphamide bolus (300 mg/m2) and monthly mitomycin C bolus (10 mg/m2). Quality of life was evaluated using six linear analogue scales, completed by the patient. Accrual in the FUMIC arm was stopped after the 25th patient because of toxicity. The response rates were 22 of 48 (45.8%) with FUcont and 13 of 52 (25%) with FU-FA (P = .048). Progression-free survival (median: 8 v 4.4 months; P = .0026) and overall survival (median: 12.9 v 9.6 months; P = .028) were significantly greater for the FUcont arm compared with the FU-FA arm. Toxicity was observed in 62% of the FUcont patients (grade 3-4: 10%), mainly hand-foot syndrome, diarrhea, mucositis, and mainly gastrointestinal in 69% of the FU-FA patients (grade 3-4: 11.6%). Linear analogue scales exploring quality of life, available for the first 6 months, gave similar scores in FU-FA and FUcont patients. We conclude that this FUcont schedule, achieving high FUra dose-intensity, offers significant advantages, in terms of response and survival, over weekly FUra plus leucovorin.

[Delirium in an elderly population admitted at a general hospital]

BACKGROUND

Delirium is an organic mental disorder frequently seen in elderly patients admitted to hospital for medical or surgical diseases. The prevalence, triggering factors, the relationship with prior existence of dementia and the evolution of delirium were studied.

METHODS

One hundred eight elderly patients admitted to the Internal Medicine, General Surgery and Traumatology Departments of the Hospital Clínic i Provincial in Barcelona, Spain were randomly selected with clinical evaluation being performed following the DSM-III-R diagnostic criteria. Likewise a structured clinical interview (CAMDEX) was carried out, and the establishment of delirium, the possible causes and its evolution were evaluated.

RESULTS

Eighteen of the elderly patients studied presented delirium at some time during hospital stay. Of these patients 15 had previously been clinically diagnosed with dementia. These patients did not require longer hospital stay than those not presenting dementia. The most frequent etiology was surgery and fever due to an infectious process. In addition to etiologic treatment, 12 of the patients also received symptomatic treatment with a neuroleptic drug (haloperidol).

CONCLUSIONS

Most of the elderly who have presented delirium admitted in a general hospital had been diagnosed with dementia during hospital stay thus indicating the high comorbidity of the two entities. In many cases it is important to carry out symptomatic in addition to etiologic treatment to achieve rapid reversibility of the disorder.

The role of prefrontal regions in the Stroop task

The Stroop is a classical paradigm that presumably involves the inhibition of automatic responses and is frequently used to assess the frontal lobe functions. We investigated the effect of discrete prefrontal lesions in a Stroop task. A sample of 32 patients with frontal lesions were matched with normal controls by sex, age and years of education. Significant differences between patients and controls were found for errors but not for reaction time. Regression analysis showed that the region most related to errors was the right prefrontal lateral cortex. Left lobectomies did not impair the Stroop performance. Our results favour the role of the right prefrontal cortex in sustained attention, and disagree with the conception of the left prefrontal cortex having a role in the inhibition of verbal automatic responses.

[Study of cerebral activity with functional magnetic resonance]

BACKGROUND

Functional magnetic resonance is a new imaging method which allows the incruent observation of human cerebral activity. The authors describe their method of functional magnetic resonance and the results of cerebral activation.

METHODS

A total of 364 functional sequences were performed in 52 volunteers with a magnetic resonance system of 1.5 Tesla. A gradient echo sequence with a long echo time sensitive to the changes in oxygenation of venous blood was used. Different cortical areas were stimulated by visual, motor and language maneuvers and by complex mental operations.

RESULTS

Different cerebral areas representative of different levels of cerebral functional complexity were consistently activated and reproduced. Experiments of activation of primary cerebral cortex (visual and motor), premotor regions, specific area of language and areas of cortical association for cognitive operations are described.

CONCLUSIONS

Functional magnetic resonance imaging is a sensitive method for the observation of cerebral activity and provides functional images with great spatial and temporal resolution. This may be useful in both clinical and basic investigation.

Schnitzler's syndrome: report of a case with bone osteolysis

A case of chronic urticaria with macroglobulinemia (Schnitzler's syndrome) is described. To our knowledge, this is only the second case reported in the literature with osteolysis and the presence of cryoglobulins in sera. The characteristics of the previous 21 cases of this syndrome are reviewed. The pathogenesis of this peculiar entity is discussed.

MRI pallidal hyperintensity and brain atrophy in cirrhotic patients: two different MRI patterns of clinical deterioration?

In cirrhotic patients, even in a stable nonencephalopathic state, MRI may show cerebral atrophy and increased signal in globus pallidus on T1-weighted sequences. We investigated the relationship between cerebral atrophy and increased pallidal signal and the clinical status of 30 cirrhotic patients. We found a weak association between the two MRI findings. There were different patterns of clinical variables related to the imaging findings. Performance on motor tasks involving speed correlated with the pallidal signal and plasma ammonia levels but not with atrophy. Test results for memory and frontal-premotor function were associated with brain atrophy but not with the pallidal signal or with ammonia.

When does human brain development end? Evidence of corpus callosum growth up to adulthood

To locate structural changes in the brain accounting for the increasing effectiveness in cognition and skills that occurs at the final stage of behavioral development, we attempted to determine the age at which the corpus callosum completes its active growth period. We assessed the growth rate of the corpus callosum by measuring its area twice on midsagittal magnetic resonance imaging scans separated by a 2-year interval, in a series of 90 subjects with a wide range of ages. We observed an increase in the size of the corpus callosum as long as human mentation expands, up to the middle 20s. Clinical and experimental data about the corpus callosum, together with the present findings, suggest that the corpus callosum is part of the highest order-latest maturing neural network of the brain.

Hemiballismus and secondary mania following a right thalamic infarction

An 81-year-old woman had the sudden onset of left-sided ballismus and an accompanying behavioral change characterized by elation, distractibility, inflated self-esteem, and insomnia, suggesting secondary mania. An MRI revealed a small ischemic infarction of the right thalamus.

Hyperintense globus pallidus on T1-weighted MRI in cirrhotic patients is associated with severity of liver failure

Hyperintense globus pallidus on T1-weighted MRI is present in most patients with advanced liver disease. We evaluated the relationship between the signal intensity of the globus pallidus and clinical or laboratory data of 77 patients eligible for liver transplantation. There was a significant correlation between the intensity of the signal and the Child-Pugh score (as indication of severity of liver disease), presence of postural tremor, previous episodes of variceal bleeding or hepatic encephalopathy, prothrombin activity, serum aspartate and alanine aminotransferase, bilirubin, and the indocyanine green (ICG) hepatic clearance, a very sensitive marker of liver function. The multivariate analysis disclosed that the ICG hepatic clearance and previous episodes of variceal bleeding were independently associated with the signal intensity in the globus pallidus. MRI repeated in 21 patients 10 to 20 months after transplant showed a disappearance of the lesion in all cases. We conclude that the hyperintense globus pallidus is secondary to the severity of the liver disease, and is reversible when liver function returns to normal.

[Histological typing of the breast by multifocal biopsies]

The current concept of high risk mastopathy was revolutionised by the work of Dupont and Page (1985), who demonstrated the importance of proliferative mastopathies in the assessment of the risk, particularly when they are associated with epidemiological factors. Based on these data, the Montpellier breast pathology study and research group (GERPAMM) developed on original method designed to define the precise histological profile of women considered to be at risk of breast cancer, despite the absence of any focal mammographic signs. This typing, consisting of a rigorous surgical protocol strictly complying with Page's histological definitions, was performed in women presenting a certain risk defined by clinical, cytological and radiological criteria (density and disseminated microcalcifications). This paper presents a preliminary review of 6 years' experience in 162 cases. The preliminary results confirm than many cases of atypical hyperplasia are not associated with a focal mammographic abnormality. However, in the absence of focal signs, certain types of disseminated microcalcifications with a morphological appearance suggestive of an intraductal origin, are significantly associated with high-risk histological signs. Histological typing is therefore useful to predict the cancer risk, to dedramatise cases without significant hyperplasia and to propose an adapted and justified approach to cases with a high histological risk.

Pallidal hyperintensity on magnetic resonance imaging in cirrhotic patients: clinical correlations

Patients with cirrhosis show increased signal intensity in the globus pallidus on T1-weighted magnetic resonance imaging of the brain. This abnormal appearance of the basal ganglia has been related to the severity of liver failure and to the presence of portal-systemic shunting, although its cause and clinical significance remain unknown. We prospectively assessed the metabolic, neurological and neuropsychological statuses of 30 stable cirrhotic patients and correlated these clinical variables with computed measurements of globus pallidus signals. Some metabolic variables denoting disease severity appeared to be significantly related to image changes, although the strongest association was found with plasma ammonia levels. After adjustment for ammonia level, on multiple regression analysis, the other variables were not significant. Furthermore, pallidal changes were associated with specific neurological symptoms and neurological functions, symptoms and functions that also had a significant correlation with ammonia levels. Our findings suggest that globus pallidus signal abnormality could arise as a marker of brain impairment related to hyperammonemia.

Portacaval graft patency demonstrated by scintigraphic calculation of portal contribution to hepatic blood flow

The case presented refers to a cirrhotic patient with portal hypertension in whom a portacaval graft bypass was surgically implanted. The calculation of the portal contribution to hepatic blood flow helped to demonstrate the patency of the graft.

Reduction of the substantia nigra width and motor decline in aging and Parkinson's disease

We studied the functional significance of the involutional and degenerative changes in the substantia nigra as seen on magnetic resonance imaging. The width of the pars compacta correlated with motor performance in both healthy elderly subjects and idiopathic Parkinson's disease groups. Patients exhibited significant reduction of the width of the pars compacta and the level of this reduction correlated strongly with the clinical status evaluated by the Unified Parkinson's Disease Rating Scale. These results suggest that pars compacta shrinkage may account for a substantial part of the structural substratum of motor decline in the elderly. Moreover, an analysis of the relationship of the midbrain damage with specific symptoms in Parkinson's disease could contribute to a better understanding of the pathogenesis of this degenerative process.

Biological significance of iron-related magnetic resonance imaging changes in the brain

Iron, an essential element for basic cellular metabolism, regularly accumulates in certain brain areas in normal subjects and in patients with certain diseases. Magnetic resonance imaging can depict iron deposition, offering a singular opportunity to correlate the regional iron content with the functional status of the human brain in vivo. We studied the relationship between age and the iron-related signal loss on T2-weighted images in basal ganglia, and observed a strongly significant signal decrease in the globus pallidus at the age of brain development (first two decades of life), but we found no such decrease in later years. Moreover, in healthy adults, subject-to-subject variability was relevant in changes due to iron deposition in magnetic resonance imaging. We found increased signal loss to be associated with poor performance on motor and specific cognitive tasks, suggesting that these image changes can provide functional information with respect to the brain in normal subjects.