MRI-radiofrequency tissue tagging in patients with aortic insufficiency before and after operation

We examined the relation between language dominance and regional cerebral blood flow (rCBF) during the intracarotid amobarbital procedure (IAP). A previous report limited to three patients suggested that dominant rather than nondominant hemisphere IAP may have a differential effect on rCBF. Behavioral assessment during the IAP also suggests that dominant hemisphere injection results in a differential effect on memory and affective symptoms rather than nondominant injection. Thirteen patients were assessed using single-photon emission CT (SPECT) brain imaging during both left and right IAP. The SPECTs were coregistered with the individual's MRI. Changes in rCBF during each IAP were compared with the patient's baseline SPECT. Nine patients had left hemisphere dominance, two were right dominant, and two had bilateral speech representation. In the left dominant subjects, left-hemisphere injection had a consistently greater effect on rCBF than right-hemisphere injection in the anterior (p < 0.005) and posterior (p < 0.01) temporal neocortex. There was also a trend for greater hypoperfusion in the frontal lobe of the left hemisphere. rCBF in the ipsilateral hippocampus was not significantly different after each injection (p > 0.05). In the two patients with right hemisphere speech, the reverse pattern was seen, with greater hypoperfusion after right (dominant) hemisphere injection. There was no consistent asymmetry in the two patients with bilateral speech. Dominant hemisphere IAP results in significantly greater hypoperfusion than does nondominant injection. These data provide a physiologic basis for behavioral differences noted after dominant versus nondominant IAP.     

The adolescent outcome of hyperactive children diagnosed by research criteria: II. Academic, attentional, and neuropsychological status.

One hundred hyperactive children meeting research diagnostic criteria and 60 community control children were followed prospectively over an 8-year period into adolescence. Younger (12–24 years) and older (15–20 years) groups were tested on measures of academic skills, attention and impulse control, and select frontal lobe functions. At follow-up, hyperactive Ss demonstrated impaired academic achievement, impaired attention and impulse control, and greater off-task, restless, and vocal behavior during an academic task, compared with control Ss. The limited set of frontal lobe measures did not differentiate groups. Age did not interact with group membership. However, several measures did not differentiate groups. Age did not interact with group membership. However, several measures showed age-related declines in both groups. It is concluded that hyperactive children may remain chronically impaired in academic achievement, inattention, and behavioral disinhibition well into their late adolescent years. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of Parkinson's disease and related syndromes using 123I-IMP-SPECT with the ARG method

We studied regional cerebral blood flow (rCBF) in 8 patients with non-demented Parkinson's disease (PD). 1 patient with progressive supranuclear palsy (PSP), 1 patient with multiple system atrophy (MSA), and 7 normal control subjects using single photon emission computed tomography (SPECT) with the IMP-ARG method. Regions of interest were studied in the cerebral cortex (upper frontal, lower frontal, temporal, occipital, parietal), thalamus, basal ganglia, and cerebellum. In patients with PD, rCBF was normal in 4/8, and decreased in occipital lobe in 4/8. In patient with PSP, rCBF was decreased in the upper and lower frontal lobes, and in the cerebellum. In patient with MSA, rCBF was diminished in the cerebellum. The results of our study were almost compatible with the conventional rCBF study by positron emission tomography (PET), however, the decrease of rCBF in occipital lobe had rarely been reported, suggesting that might be related to visuospatial dysfunction in Parkinson's disease.     

Bilateral frontal lobe disease and selective delayed response deficits in humans.

Compared the performance of 6 male patients (aged 24–65 yrs) with frontal lobe disease; 17 amnesic male patients (12 with etiology of alcoholic Korsakoff's disease [mean age 53.6 yrs] and 5 with surgically treated ruptured anterior communicating artery aneurysm [mean age 45.6 yrs]), and 12 male alcoholic controls (mean age 39.7 yrs) with no memory impairment on delayed alternation (DA) and delayed response (DR) tasks, known to be sensitive to frontal lobe damage in nonhuman primates. Ss (except the Korsakoff and alcoholic Ss) completed the Wechsler Memory Scale, and all Ss completed the Wechsler Adult Intelligence Scale (WAIS) and the Wisconsin Card Sorting Test. Results show that bilateral frontal lobe damage was associated with impairment on both tasks. There was no relation between performances on DA and DR and performance on the Wechsler Memory Scale, strengthening the suggestion that the former tasks are not sensitive to anterograde amnesia in humans. (41 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regional cerebral blood flow in pediatric moyamoya disease: age-dependent decline in specific regions

Thirteen pediatric patients (ages 4-13 years) who underwent surgical treatment were examined regarding their rCBF in the preoperative periods. The postoperative rCBF was measured 39 times in these 13 patients. Thirteen healthy normal subjects (ages from 6 to 21 years) were also examined. The rCBF in the operculum and in the frontal, parietal, and occipital lobes was measured with 133Xe inhalation method and single photon emission computed tomography. In the parietal and occipital lobes, the preoperative rCBF had a negative and significant correlation with their ages, but not in the operculum or frontal lobe. However, subsequent to the surgical treatment, the rCBF increased significantly in the patients 5 years old or less, and then post-operative rCBF values had significant negative correlations with age in each region.     

Cognitive impairment following frontal lobe damage and its relevance to human amnesia.

Whether frontal lobe pathology can account for some of the cognitive impairment oberved in amnesic patients with Korsakoff's syndrome was investigated. Various cognitive and memory tests were given to patients with circumscribed frontal lobe lesions, patients with Korsakoff's syndrome, non-Korsakoff amnesic patients, and control Ss. Patients with frontal lobe lesions were not amnesic. Nevertheless, they exhibited 2 deficits that were also exhibited by patients with Korsakoff's syndrome but not by other amnesic patients: (a) impairment on the Wisconsin Card Sorting Test and (b) impairment on the Initiation and Perseveration subscale of the Dementia Rating Scale. Thus, frontal lobe pathology can explain some of the cognitive deficits observed in patients with Korsakoff's syndrome. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Improvement in word-fluency performance in patients with multiple sclerosis by electromagnetic fields

Impairment of cognitive functions is well recognized in patients diagnosed with multiple sclerosis (MS), especially those with a chronic progressive course. In fact, MS has been considered a type of "subcortical dementia" in which cognitive and behavioral abnormalities resemble those observed in patients with frontal lobe syndrome. Patients with frontal lobe syndrome are known to exhibit diverse cognitive and behavioral abnormalities which include, among others, diminished spontaneity of speech with difficulties producing appropriate words and phrases. It has been reported recently that extracranial application of extremely weak electromagnetic fields (EMF) in the picotesla range produced improvement in motor and cognitive functions in patients with MS. The present report concerns three women with MS (mean age: 44.3 +/- 8.5 yrs; mean duration of illness: 18.3 +/- 3.5 yrs), two with chronic progressive course and the third with a relapsing-remitting course in whom the Thurstone Word-Fluency Test, a reputed test of frontal lobe function, was administered prior to and following a series of 4 to 5 treatment sessions with EMF. Prior to the initiation of treatment with EMF all patients demonstrated word fluency performance which was well below age and sex-matched normal controls of similar level of education (mean output of MS patients was 42.6 +/- 1.1 words vs. 79.0 +/- 6.2 words of the controls). A series of treatments with EMF produced a 100% increase in word output within a short period of time (mean: 83.3 +/- 14.0 words). These findings suggest that this treatment modality improves frontal lobe functions in patients with MS and corroborate previous reports indicating beneficial effects of EMF on cognitive functions in these patients.     

Semantic fluency in Alzheimer's, Parkinson's, and Huntington's disease: Dissociation of storage and retrieval failures.

Patients with Alzheimer's disease (AD), Huntington's disease (HD), and Parkinson's disease (PD), and normal controls were compared on 2 versions of a semantic fluency task: a standard, uncued version and a version in which Ss were cued with subordinate categories. All patients were impaired relative to controls on the standard version. On the cued version, PD and HD patients improved significantly, but AD patients did not. AD patients' fluency, but not PD or HD patients', correlated significantly with confrontation naming ability. Impairment exhibited by PD and HD patients on standard semantic fluency tasks may be due to a retrieval deficit, whereas that of AD patients may be due to degradation of semantic memory stores. In addition, the pattern of performance exhibited by a nonaphasic patient with bilateral frontal lobe lesions suggests that the retrieval functions involved may depend on integrity of the prefrontal cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Brain perfusion imaging predicts survival in Alzheimer's disease

BACKGROUND: The variability of disease course in patients diagnosed with AD makes prediction of survival difficult, despite the identification of numerous predictors to date. This study evaluated the predictive utility of measurements of regional cerebral blood flow (rCBF) obtained with SPECT in a group of AD patients. METHODS: Fifty AD patients were studied with SPECT and followed longitudinally. SPECT measures of relative rCBF were calculated by measuring radioactivity densities in dorsolateral frontal, orbitofrontal, temporal, and parietal cortex normalized to occipital cortical radioactivity density. Subjects were classified into three tertiles of rCBF ratios for each region. These rCBF ratios were used as predictors of survival in life-table and proportional hazard models to predict survival. RESULTS: Right parietal rCBF was a significant predictor of survival in the life-table analysis, with subjects in the lowest tertile having shortest survivals. No other brain region was a significant predictor of survival. In a proportional hazards model when a variety of other potential predictors were accounted for, right parietal rCBF ratio remained a significant predictor. CONCLUSIONS: These results demonstrate that brain perfusion in the right parietal lobe is a significant predictor of survival in patients with AD even when other predictors are taken into consideration. This suggests that SPECT perfusion imaging may provide additional useful information on disease prognosis in AD.     

The resting and activation issue of hypofrontality: a single photon emission computed tomography study in neuroleptic-naive and neuroleptic-free schizophrenic female patients

BACKGROUND: Functional neuroimaging findings of "hypofrontality" in schizophrenic patients is still controversial, due to the heterogeneity of methods and patient samples. This study tries to prevent some of these concerns by studying neuroleptic-naive (NN) and neuroleptic-free (NF) young female patients both in resting conditions and during a frontal cognitive activation task. METHODS: Regional cerebral blood flow (rCBF) was studied at rest and during the Wisconsin Card Sorting Test (WCST) in 25 young acute unmedicated schizophrenic female patients (14 NN and 11 NF) and 15 female controls, using single photon emission computed tomography. RESULTS: The schizophrenic and control groups did not differ in rCBF during the baseline condition, but the schizophrenic group failed to activate the frontal lobe during the WCST condition. In addition, the left anterior temporal rCBF at rest correlated with the Scale for the Assessment of Positive Symptoms total score. CONCLUSIONS: The results suggest that hypofrontality in young acute unmedicated schizophrenic patients is a result of an inability to activate frontal regions during cognition, rather than a baseline decrease in frontal activity. Furthermore, positive symptoms seem to be associated with left temporal cortex activity.     

Recollective experience, normal aging, and frontal dysfunction.

Examined the nature of verbal recognition memory in young and old Ss. Following presentation of a word list, Ss undertook a yes–no recognition test and indicated whether their decision was based on explicit recollection or assessment of familiarity. Explicit recollection declined with age, and familiarity-based recognition increased. Furthermore, the extent to which older Ss relied on familiarity-based recognition correlated with neuropsychological indices of frontal lobe dysfunction. A further experiment indicated that the change from explicit recollection to familiarity-based responding was unrelated to changes in older Ss' confidence about their memory. The data indicate the central role of frontal dysfunction in understanding age-related memory loss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive resources and dual-task interference effects at retrieval in normal people: The role of the frontal lobes and medial temporal cortex.

Conducted 3 experiments to examine the hypothesis that concurrent secondary tasks at retrieval will interfere more with long-term, episodic memory functions involving the frontal lobes than those involving the medial temporal lobes hippocampus (MTL/H). The rationale is that strategic retrieval processes mediated by the frontal lobes place greater demands on cognitive resources than do relatively automatic associative retrieval processes (ecphory) mediated by the temporal lobes. In Exps 1 and 2, sequential finger tapping was performed at encoding, at retrieval, at both, or at neither. Recall of a categorized list of 16 words from the California Verbal Learning Test in Exp 1, and release from proactive inhibition (PI) in Exp 2, both being tests that involve the frontal lobes, were impaired if normal Ss tapped at both encoding and retrieval. Concurrent tapping had little effect on rate of learning in Exp 1 and on total words recalled during the buildup of PI in Exp 2, both of which are indices that are affected more by MTL/H than by frontal lesions. In Exp 3, tapping by normal Ss affected letter fluency, a test more sensitive to frontal lobe than temporal lobe damage, but not category fluency, for which the reverse is true. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regional cerebral blood flow measured by 99mTc-HMPAO SPECT differs in subgroups of Alzheimer's disease

Alzheimer's disease (AD) is a heterogeneous entity. Identifying AD subtypes might have impact in patients' response to different treatment strategies. We designed a study to examine regional cerebral blood flow (rCBF) in AD subtypes. To identify AD subtypes, we performed a cluster analysis including performance on memory, language, visuospatial, praxic, and executive functions. The rCBF measured by 99mTc-HMPAO SPECT was referred to the cerebellum. We examined 35 patients fulfilling the NINCDS-ADRDA criteria of probable AD and 13 age and sex-matched healthy cognitively intact controls. AD patients were at the early stage of the disease, their mean Mini-Mental Status (MMS) score (S.D.) was 22.5 (3.6). The cluster analysis revealed two AD subgroups: AD1 (N = 12) and AD2 (N = 23). The subgroups did not differ in age, sex, or global clinical severity as assessed by MMS and Brief Cognitive Rating Scale (BCRS). Both subgroups had equally impaired memory. The AD2 group was inferior to the AD1 group on verbal, visuospatial, praxic, and executive functions. The AD1 group showed reduced rCBF ratios in the temporal and parietal cortices and the amygdala compared to controls. The AD2 group differed from controls in the rCBF ratios of frontal, temporal, parietal, occipital, basal ganglia, and amygdaloid regions bilateral and from AD1 in the rCBF ratios of frontal and temporal cortices. In AD patients, the rCBF ratios did not correlate with MMS or BCRS scores. In contrast, several significant correlations were found between decreases rCBF ratios and impairment of memory and other cognitive functions. In conclusion, a cluster analysis on neuropsychological test performance identified two AD subgroups that differed on the neuropsychological profile and on the rCBF in spite of similar global clinical severity.     

Auditory localization skills in mentally retarded children.

Measured the gross auditory and visual localization skills of 24 6–18 yr old mentally retarded Ss. Half of the Ss were selected randomly from a group of residents who had demonstrated visual discrimination skills and auditory speech discrimination skills. The other Ss were selected randomly from a group of residents who demonstrated visual discrimination skills but not auditory speech discrimination. Findings indicate that all Ss who previously demonstrated auditory speech discrimination passed the auditory localization task, and all Ss who previously failed to demonstrate auditory speech discrimination failed the auditory localization task. It is suggested that auditory localization skills may be used as an approximation to the development of auditory speech discrimination skills. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of cognitive function in community-dwelling and institutionalized old people of normal intelligence.

30 people (aged 70–88 yrs) living in the community and 44 institutionalized people (aged 71–89 yrs) were administered a neuropsychological cognitive test battery. Screening procedures ensured that Ss were equivalent in terms of health, age, education, and socioeconomic status (SES). A comparison of groups on a cognitive index derived from the test battery yielded a significant difference even when IQ as derived from the Wechsler Adult Intelligence Scale (WAIS) was factored out. Of the 15 cognitive tests, 8 contributed to the group differences. All 8 tests are sensitive to medial-temporal lobe or frontal lobe damage. Results confirm earlier findings (e.g., G. Winocur et al; see record 1988-20729-001) that people who are functioning well in institutions may have significant cognitive impairment. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Frontal lobe functions in psychopaths.

Hypothesized that psychopaths would exhibit deficits on tasks tapping the frontal lobe functions of cognitive flexibility and perseverance. 20 male psychopaths (mean age 26.5 yrs), 23 male psychiatric controls, and 18 normal male controls (18–20 yrs old) completed the Socialization scale of the California Psychological Inventory, a behavioral checklist, and a task battery. Relative to controls, psychopaths exhibited the performance pattern of frontal lesion patients on all measures empirically related to frontal dysfunction: perseverative errors on the Wisconsin Card Sorting Task, errors on a sequential matching memory task, and Necker Cube reversals. Results encourage the pursuit of a conceptualization of psychopathy based on deficits in cognitive functions previously associated with frontal lobe. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preictal SPECT in temporal lobe epilepsy: regional cerebral blood flow is increased prior to electroencephalography-seizure onset

Peri-ictal SPECT provides unique information on the dynamic changes in regional cerebral blood flow (rCBF) that occur during seizure evolution and, thus, could be useful in clarifying the poorly understood interplay of the interictal and ictal states in human focal epilepsy. The regional hyperperfusion observed on ictal SPECT is generally believed to be a consequence of electrical seizure activity. However, recent studies using invasive long-term cortical CBF monitoring have demonstrated that rCBF changes occur up to 20 min prior to ictal electroencephalography (EEG) onset. Because of apparent technical difficulties, no preictal SPECT studies have been reported so far. Therefore, we present our results on two patients with temporal lobe epilepsy in whom preictal SPECT scans were performed fortuitously under continuous video-EEG monitoring control. METHODS: Technetium-99m-hexamethyl propyleneamine oxime was injected 11 min (Patient 1) and 12 min (Patient 2) before clinical and EEG seizure onset, as documented from simultaneous video-EEG monitoring in two patients with temporal lobe epilepsy. We obtained accurate anatomical reference of CBF changes visible on SPECT by a special coregistration technique of MRI and SPECT. RESULTS: Whereas interictal SPECT showed a hypoperfusion of the temporal lobe ipsilateral to the seizure focus, on preictal SPECT, a significant increase in rCBF in the epileptic temporal lobe could be observed. These rCBF changes were not accompanied by any significant changes of the ongoing EEG. CONCLUSION: Our study provides evidence that rCBF is increased in the epileptic temporal lobe several minutes before EEG seizure onset. Thus, rCBF changes observed on peri-ictal SPECT scan cannot be considered a mere consequence of EEG seizure activity but may rather reflect a change in neuronal activity precipitating the transition from the interictal to the ictal state.     

Evidence for involvement of orbitofrontal cortex in memory functions: An interference effect.

Although it is frequently stated that the frontal lobes play a significant role in memory function, research proof has been ambiguous at best. The present study investigated this problem by administering a variety of memory tests (e.g., Wechsler Memory Scale, WAIS) to 16 schizophrenic patients who had undergone prefrontal leukotomy approximately 25 yrs earlier. Ss were divided into 3 groups on the basis of recovery after surgery. Two comparison groups (5 psychiatric and 5 normal controls) were established to control for psychiatric symptomatology, years of institutionalization, age, and years of education. Results indicate that large bilateral orbitofrontal lesions may not result in amnesia; in fact, the nonoperated schizophrenic control group performed the most poorly. Proactive interference was demonstrated, however, resulting in significant impairment for all Ss with prefrontal lobe damage despite normal scores on commonly used memory tests. Ability to maintain consistent and directed attention and to overcome interference is proposed as a role of the frontal lobes in memory function. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Parietal lobe syndrome and schizophrenia: Comparison of neuropsychological deficits.

Investigated reported communalities in the perceptual impairments and body image distortions found after parietal lobe lesions and in schizophrenia. To compare these 2 syndromes, 15 patients with lesions of the parietal lobe and 15 patients with schizophrenia were tested on a neuropsychological battery designed to assess deficits in proprioception, tactile functions, and body image experience. Control groups consisted of 15 normal persons and of a series of 15 brain-injured cases in which the parietal lobe had been spared. Results indicate that both schizophrenic and parietally damaged Ss showed significant impairments in weight-discrimination measures of proprioceptive acuity when compared to the control brain-injured and normal Ss. No significant differences among groups were found on a comparable tactile size-estimation task, but the group with parietal injury exhibited a significant deficit in tactile sensory perception on the Finger Agnosia Test. Only the schizophrenic group showed evidence of disturbed body image when reality factors of body dysfunction were taken into account in the brain-injured patients. It is concluded that persons with schizophrenia and parietal lobe damage share a deficit in proprioception that may be based on different neurological substrates leading to (a) tactile impairments in cases with parietal damage, and (b) body-image disturbance in schizophrenia. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of frontal brain impairment on fluency: Simple and complex paradigms.

Neuropsychological measures of fluency require productivity under timed conditions. The current study explored the parameters of fluency paradigms by extending the associated demands of the tasks. 17 Ss with frontal lobe tumors were compared with 17 normal Ss on simple and complex fluency tasks. Complex fluency tasks appeared to be more sensitive to tumor presence than simple tasks but were not more sensitive to absolute tumor volume. Results are discussed with regard to the potential role of the frontal lobes in associational memory search and creative thought. (PsycINFO Database Record (c) 2010 APA, all rights reserved)