A high resolution assessment of the repeatability of relative location and intensity of transcranial magnetic stimulation-induced and volitionally induced blood oxygen level-dependent response in the motor cortex.

OBJECTIVE: Using functional magnetic resonance imaging, we assessed variation in location and intensity of blood oxygen level-dependent contrast associated with movements induced by transcranial magnetic stimulation or volition. BACKGROUND: Anatomic location and within-subject repeatability of blood oxygen level-dependent responses induced by transcranial magnetic stimulation comprise critical information to the use of interleaved transcranial magnetic stimulation/functional magnetic resonance imaging as a neuroscience tool. METHODS: Eleven healthy adults were scanned 3 times each at 1.5 T. Interleaved with functional magnetic resonance imaging, 1-Hz transcranial magnetic stimulation was applied over motor cortex. VOL was alternated with transcranial magnetic stimulation over the scans. RESULTS: Intra-subject standard deviations in blood oxygen level-dependent locations ranged between 3 and 6 millimeters, allowing localization to subregions of the motor strip. Coil placement relative to blood oxygen level-dependent location varied more than blood oxygen level-dependent location (sdx = 9.5mm, sdy = 8.7 mm, sdz = 9.0mm) with consistent anterior displacement (dy = 21.8 mm, P = <0.025). Analysis of variance did not detect significant differences between transcranial magnetic stimulation and VOL blood oxygen level-dependent locations or intensities, in contrast to significant intensity differences detected in auditory blood oxygen level dependence. CONCLUSION: The high repeatability of location of transcranial magnetic stimulation-induced blood oxygen level-dependent activation suggests that transcranial magnetic stimulation/functional magnetic resonance imaging stimulation can be used as a precise tool in investigation of cortical mechanisms. The similarity between VOL and transcranial magnetic stimulation suggests that transcranial magnetic stimulation may act through natural brain movement circuits.     

Neural correlates of refixation saccades and antisaccades in normal and schizophrenia subjects.

BACKGROUND: Schizophrenia subjects demonstrate difficulties on tasks requiring saccadic inhibition, despite normal refixation saccade performance. Saccadic inhibition is ostensibly mediated via prefrontal cortex and associated cortical/subcortical circuitry. The current study tests hypotheses about the neural substrates of normal and abnormal saccadic performance among subjects with schizophrenia. METHODS: Using functional magnetic resonance imaging, blood oxygenation level-dependent (BOLD) data were recorded while 13 normal and 14 schizophrenia subjects were engaged in refixation and antisaccade tasks. RESULTS: Schizophrenia subjects did not demonstrate the increased prefrontal cortex BOLD contrast during antisaccade performance that was apparent in the normal subjects. Schizophrenia subjects did, however, demonstrate normal BOLD contrast associated with refixation saccade performance in the frontal and supplementary eye fields, and posterior parietal cortex. CONCLUSIONS: Results from the current study support hypotheses of dysfunctional prefrontal cortex circuitry among schizophrenia subjects. Furthermore, this abnormality existed despite normal BOLD contrast observed during refixation saccade generation in the schizophrenia group.     

Increased temporal and prefrontal activity in response to semantic associations in schizophrenia

CONTEXT: Loosening of associations has long been considered a core feature of schizophrenia, but its neural correlate remains poorly understood. OBJECTIVE: To test the hypothesis that, in comparison with healthy control subjects, patients with schizophrenia show increased neural activity within inferior prefrontal and temporal cortices in response to directly and indirectly semantically related (relative to unrelated) words. DESIGN: A functional neuroimaging study using a semantic priming paradigm. SETTING: Lindemann Mental Health Center, Boston, Mass. PARTICIPANTS: Seventeen right-handed medicated outpatients with chronic schizophrenia and 15 healthy volunteers, matched for age and parental socioeconomic status. INTERVENTIONS: Functional magnetic resonance imaging as participants viewed directly related, indirectly related, and unrelated word pairs and performed a lexical decision task. MAIN OUTCOME MEASURES: Event-related functional magnetic resonance imaging measures of blood oxygenation level-dependent activity (1) within a priori temporal and prefrontal anatomic regions of interest and (2) at all voxels across the cortex. RESULTS: Patients and controls showed no behavioral differences in priming but opposite patterns of hemodynamic modulation in response to directly related (relative to unrelated) word pairs primarily within inferior prefrontal cortices, and to indirectly related (relative to unrelated) word pairs primarily within temporal cortices. Whereas controls showed the expected decreases in activity in response to semantic relationships (hemodynamic response suppression), patients showed inappropriate increases in response to semantic relationships (hemodynamic response enhancement) in many of the same regions. Moreover, hemodynamic response enhancement within the temporal fusiform cortices to indirectly related (relative to unrelated) word pairs predicted positive thought disorder. CONCLUSION: Medicated patients with chronic schizophrenia, particularly those with positive thought disorder, show inappropriate increases in activity within inferior prefrontal and temporal cortices in response to semantic associations.     

Abnormal object recall and anterior cingulate overactivation correlate with formal thought disorder in schizophrenia.

BACKGROUND: The neural basis of formal thought disorder (FTD) is unknown. An influential theory is that FTD results from impaired semantic memory processing. We explored the neural correlates of semantic memory retrieval in schizophrenia using an imaging task assessing semantic object recall. METHOD: Sixteen healthy control subjects and sixteen schizophrenia patients whose FTD symptoms were measured with the Thought Disorder Index completed a verbal object-recall task during functional magnetic resonance imaging. Participants viewed two words describing object features that either evoked (object recall) or did not evoke a semantic concept. RESULTS: Schizophrenia patients tended to overrecall objects for feature pairs that did not describe the same object. Functionally, rostral anterior cingulate cortex (ACC) activation in patients positively correlated with FTD severity during both correct recalled and overrecalled trials. Compared with control subjects, during object recalling, patients overactivated bilateral ACC, temporooccipital junctions, temporal poles and parahippocampi, right inferior frontal gyrus, and dorsolateral prefrontal cortex, but underactivated inferior parietal lobules. CONCLUSIONS: Our results support impaired semantic memory retrieval as underlying FTD pathophysiology. Schizophrenia patients showed abnormal activations of brain areas involved in semantic memory, verbal working memory, and initiation and suppression of conflicting responses, which were associated with semantic overrecall and FTD.     

Retinotopic mapping in the human visual cortex using vascular space occupancy-dependent functional magnetic resonance imaging

Recently, we introduced a new methodology, vascular space occupancy functional magnetic resonance imaging, which detects brain activation on the basis of blood volume changes in parenchymal microvasculature and may provide higher spatial specificity than the blood oxygenation level-dependent method. To study whether this technique can be used for advanced brain mapping applications, we performed retinotopic mapping using alternating horizontal and vertical wedges that stimulate different portions of the visual field. The results using vascular space occupancy functional magnetic resonance imaging showed clear boundaries for V1/V2/VP/V4v in the ventral areas and V1/V2/V3/V3A in the dorsal areas, similar to the maps obtained using blood oxygenation level-dependent functional magnetic resonance imaging. Vascular space occupancy functional magnetic resonance imaging is a useful addition to the other neuroimaging techniques. Disadvantages of vascular space occupancy functional magnetic resonance imaging include lower contrast-to-noise ratio (about 1/3 of that of blood oxygenation level-dependent method) and limited volume coverage (nine slices for TR=3 s).     

Functional and biochemical alterations of the medial frontal cortex in obsessive-compulsive disorder

CONTEXT: The medial frontal cortex (MFC), including the dorsal anterior cingulate and the supplementary motor area, is critical for adaptive and inhibitory control of behavior. Abnormally high MFC activity has been a consistent finding in functional neuroimaging studies of obsessive-compulsive disorder (OCD). However, the precise regions and the neural alterations associated with this abnormality remain unclear. OBJECTIVE: To examine the functional and biochemical properties of the MFC in patients with OCD. DESIGN: Cross-sectional study combining volume-localized proton magnetic resonance spectroscopy and functional magnetic resonance imaging with a task encompassing inhibitory control processes (the Multi-Source Interference Task) designed to activate the MFC. SETTING: Healthy control participants and OCD patients recruited from the general community. PARTICIPANTS: Nineteen OCD patients (10 males and 9 females) and 19 age-, sex-, education-, and intelligence-matched control participants recruited from the general community. MAIN OUTCOME MEASURES: Psychometric measures of symptom severity, Multi-Source Interference Task behavioral performance, blood oxygen level-dependent activation, and proton magnetic resonance spectroscopy brain metabolite concentrations. RESULTS: Multi-Source Interference Task behavioral performance did not differ between OCD patients and control subjects. Reaction time interference and response errors were correlated with blood oxygen level-dependent activation in the dorsal anterior cingulate region in both groups. Compared with controls, OCD patients had greater relative activation of the supplementary motor area and deactivation of the rostral anterior cingulate during high- vs low-conflict (incongruent > congruent) trials. Patients with OCD also showed reduced levels of neuronal N-acetylaspartate in the dorsal anterior cingulate region, which was negatively correlated with their blood oxygen level-dependent activation of the region. CONCLUSIONS: Hyperactivation of the MFC during high- vs low-conflict conditions in patients with OCD may be a compensatory response to a neuronal abnormality in the region. This relationship may partly explain the nature of inhibitory control deficits that are frequently seen in this group and may serve as a focus of future treatment studies.     

Differences in fMRI and MRS in a monozygotic twin pair discordant for schizophrenia (case report)

OBJECTIVE: This paper presents functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (MRS) findings in a monozygotic twin pair discordant for schizophrenia. METHOD: Functional magnetic resonance imaging was used to determine hemispheric lateralization for speech and proton MRS (1H-MRS) was employed to assess the extent of putative insult to anterior hippocampus. RESULTS: Despite concordant right handedness, subject with schizophrenia displayed bilateral activation in areas subserving speech with greater extent of the total activated area compared with the healthy twin. The affected twin displayed relative bilateral decrease in N-acetylaspartate/creatin concentration in the anterior hippocampus compared with the healthy one. CONCLUSION: This is an evidence for non-genetic impairment of cerebral lateralization in monozygotic twin with schizophrenia.     

A functional magnetic resonance imaging study of amygdala and medial prefrontal cortex responses to overtly presented fearful faces in posttraumatic stress disorder

BACKGROUND: Previous functional neuroimaging studies have demonstrated exaggerated amygdala responses and diminished medial prefrontal cortex responses during the symptomatic state in posttraumatic stress disorder (PTSD). OBJECTIVES: To determine whether these abnormalities also occur in response to overtly presented affective stimuli unrelated to trauma; to examine the functional relationship between the amygdala and medial prefrontal cortex and their relationship to PTSD symptom severity in response to these stimuli; and to determine whether responsivity of these regions habituates normally across repeated stimulus presentations in PTSD. DESIGN: Case-control study. SETTING: Academic medical center. PARTICIPANTS: Volunteer sample of 13 men with PTSD (PTSD group) and 13 trauma-exposed men without PTSD (control group). MAIN OUTCOME MEASURES: We used functional magnetic resonance imaging (fMRI) to study blood oxygenation level-dependent signal during the presentation of emotional facial expressions. RESULTS: The PTSD group exhibited exaggerated amygdala responses and diminished medial prefrontal cortex responses to fearful vs happy facial expressions. In addition, in the PTSD group, blood oxygenation level-dependent signal changes in the amygdala were negatively correlated with signal changes in the medial prefrontal cortex, and symptom severity was negatively related to blood oxygenation level-dependent signal changes in the medial prefrontal cortex. Finally, relative to the control group, the PTSD group tended to exhibit diminished habituation of fearful vs happy responses in the right amygdala across functional runs, although this effect did not exceed our a priori statistical threshold. CONCLUSIONS: These results provide evidence for exaggerated amygdala responsivity, diminished medial prefrontal cortex responsivity, and a reciprocal relationship between these 2 regions during passive viewing of overtly presented affective stimuli unrelated to trauma in PTSD.     

Emotion processing in Parkinson's disease: a blood oxygenation level-dependent functional magnetic resonance imaging study

Parkinson's disease is a neurodegenerative disorder caused by loss of dopamine neurons in the substantia nigra pars compacta. Tremor, rigidity, and bradykinesia are the major symptoms of the disease. These motor impairments are often accompanied by affective and emotional dysfunctions which have been largely studied over the last decade. The aim of this study was to investigate emotional processing organization in the brain of patients with Parkinson's disease and to explore whether there are differences between recognition of different types of emotions in Parkinson's disease. We examined 18 patients with Parkinson's disease(8 men, 10 women) with no history of neurological or psychiatric comorbidities. All these patients underwent identical brain blood oxygenation level-dependent functional magnetic resonance imaging for emotion evaluation. Blood oxygenation level-dependent functional magnetic resonance imaging results revealed that the occipito-temporal cortices, insula, orbitofrontal cortex, basal ganglia, and parietal cortex which are involved in emotion processing, were activated during the functional control. Additionally, positive emotions activate larger volumes of the same anatomical entities than neutral and negative emotions. Results also revealed that Parkinson's disease associated with emotional disorders are increasingly recognized as disabling as classic motor symptoms. These findings help clinical physicians to recognize the emotional dysfunction of patients with Parkinson's disease.     

Hippocampal dysfunction during free word association in male patients with schizophrenia

In schizophrenia, speech production deficits in patients with positive formal thought disorder (FTD e.g. loosening of associations and derailment) have been attributed to impairments in the semantic network. The brain area implicated in the retrieval of associated (i.e. relational) concepts is the hippocampus, a key region in the psychopathology of schizophrenia. However, its role in schizophrenic speech production and FTD in particular is yet little understood.

To investigate the neural correlates of associative verbal retrieval, twelve patients with schizophrenia with varying degrees of FTD and twelve matched healthy control subjects underwent a free verbal association (FVA), a semantic (SVF) and a phonological verbal fluency (PVF) task while brain activity was measured with fMRI. The tasks varied in the relational binding operations needed for linking the stimulus to the respective response.

Compared to control subjects, patients revealed attenuated left hippocampal activity during both semantic word generation tasks (FVA, SVF). Contrasting verbal fluency with FVA, a failure in recruiting the anterior cingulate gyrus emerged in the patient group. A negative correlation was found between right middle temporal activity and the severity of FTD during FVA.

The hippocampus seems to play a major role in word generation. In schizophrenia, attenuated hippocampal activity during semantic tasks strengthens the hypothesis of impaired relational memory processes, affecting thought and language.     

Identification of Alzheimer disease risk by functional magnetic resonance imaging

BACKGROUND: Functional magnetic resonance imaging plays a promising role in the preclinical characterization of Alzheimer disease (AD) for use in early diagnosis and in preventive drug trials. OBJECTIVE: To determine whether functional magnetic resonance imaging can reliably distinguish risk groups for AD among cognitively normal middle-aged adults. DESIGN: Cross-sectional case-control study. SETTING: University of California, San Diego, Alzheimer Disease Research Center participants and San Diego community volunteers. PARTICIPANTS: Twenty cognitively normal individuals (10 high risk and 10 low risk), aged 58 to 65 years, were divided into 2 groups based on the presence or absence of the apolipoprotein E epsilon4 allele and a positive family history of AD. MAIN OUTCOME MEASURES: Word pairs were presented in a blocked design alternating between conditions of novel pairs, repeated pairs, and fixation. Whole-brain differences in blood oxygenation level-dependent brain responses between conditions were compared across risk groups. RESULTS: Compared with the low-risk group, the high-risk group showed many areas of differential blood oxygenation level-dependent response in regions commonly associated with AD pathology (eg, the left medial temporal lobe). Furthermore, different patterns of association between left medial temporal lobe activity and memory performance were demonstrated. CONCLUSIONS: Results support a theory of up-regulation in neuronal memory systems in people at risk for AD many years before the typical age at disease onset. They further demonstrate that functional magnetic resonance imaging is a viable technique to identify persons at risk for AD.     

Altered lateralisation of emotional prosody processing in schizophrenia

Alterations of cerebral lateralisation in schizophrenia have been reported consistently, and a reduced left-lateralisation has been suggested for language functions. Speech contains non-verbal information, e.g. prosody, and on a behavioural level, the extraction of emotional information from prosody is often impaired in schizophrenia. A previous functional magnetic resonance imaging study suggests increased left-lateralisation in schizophrenia during prosody processing, but did not disentangle effects of speech processing as such and emotional prosody processing. Here, we used meaningless syllables spoken with neutral, angry or fearful speech melody and measured blood oxygen level-dependent (BOLD) responses in 15 in-patients with schizophrenia and 15 healthy control participants matched for age and gender. Lateralisation indices were calculated for responses to emotional versus neutral prosody, and for all types of prosody versus baseline. Compared to control participants, patients with schizophrenia showed an increased right-lateralisation of emotional and non-emotional prosody processing in the temporal and parietal cortex. This right-lateralisation was increased in patients with reduced right-handedness and decreased in patients with stronger negative symptoms, particularly affective blunting, and with longer hospitalisation. Although patients with schizophrenia performed worse in emotion identification, this deficit was not related to lateralisation indices. Enhanced right-lateralisation to prosody resembles previous findings on laterality changes in speech processing and might suggest a common underlying cause in the organization of language functions.     

Brain activation in patients with congenital bilateral hearing impairment

Twelve patients with idiopathic, congenital, symmetric, moderate-to-severe sensorineural hearing loss participated in this study. Functional magnetic resonance imaging was performed while speech sounds were presented to each patient monaurally. Notable blood oxygenation level-dependent responses were clustered mainly in the superior temporal gyrus and transverse temporal gyrus of both hemispheres during right and left ear stimulation. In addition, the middle temporal gyrus of the right hemisphere was activated during right ear stimulation. The activation pattern was very similar to that of participants with normal hearing. Thus, as long as peripheral acoustic stimulation has not been totally absent from childhood, the classical activation pattern can be elicited in patients with congenital bilateral hearing impairment.     

Medial frontal hyperactivity in reality distortion.

BACKGROUND: Schizophrenia/schizoaffective disorder involves reality distortion (RD), which impairs the ability to process socioemotional information. Because this psychological capacity maps to the medial prefrontal cortex (MPFC) and schizophrenia involves abnormal MPFC function, we tested the hypothesis that treated schizophrenic/schizoaffective patients with persistent RD (RD+) would exhibit greater MPFC dysfunction than patients without significant RD (RD-). The amygdala interacts with MPFC, also carries out socioemotional processing, and has been implicated in schizophrenia; thus, we also tested the hypothesis that patients would exhibit aberrant amygdala activity. METHODS: Eleven RD+ patients, 12 RD- patients, and 15 healthy control subjects (HC) viewed emotionally salient pictures with neutral, aversive, and positive content during the acquisition of blood oxygenation level-dependent (BOLD) sensitive functional magnetic resonance imaging. RESULTS: All groups had similar behavioral responses to the pictures. The RD+ subjects had greater BOLD responses (compared with the RD- and HC groups) to the aversive pictures in the anterior MPFC. Both patient groups showed reduced activation in MPFC and the left amygdala (compared with HC) for neutral pictures (compared with blank condition), although this effect could be explained by medication. CONCLUSIONS: Reality distortion is associated with hyperactivity of the MPFC in schizophrenic/schizoaffective patients whose symptoms persist in spite of antipsychotic treatment.     

Left-Dominant Temporal-Frontal Hypercoupling in Schizophrenia Patients With Hallucinations During Speech Perception

Background:

Task-based functional neuroimaging studies of schizophrenia have not yet replicated the increased coordinated hyperactivity in speech-related brain regions that is reported with symptom-capture and resting-state studies of hallucinations. This may be due to suboptimal selection of cognitive tasks.

Methods:

In the current study, we used a task that allowed experimental manipulation of control over verbal material and compared brain activity between 23 schizophrenia patients (10 hallucinators, 13 nonhallucinators), 22 psychiatric (bipolar), and 27 healthy controls. Two conditions were presented, one involving inner verbal thought (in which control over verbal material was required) and another involving speech perception (SP; in which control verbal material was not required).

Results:

A functional connectivity analysis resulted in a left-dominant temporal-frontal network that included speech-related auditory and motor regions and showed hypercoupling in past-week hallucinating schizophrenia patients (relative to nonhallucinating patients) during SP only.

Conclusions:

These findings replicate our previous work showing generalized speech-related functional network hypercoupling in schizophrenia during inner verbal thought and SP, but extend them by suggesting that hypercoupling is related to past-week hallucination severity scores during SP only, when control over verbal material is not required. This result opens the possibility that practicing control over inner verbal thought processes may decrease the likelihood or severity of hallucinations.Key words: schizophrenia, inner speech, speech perception, functional magnetic resonance imaging, functional connectivity     

Functional magnetic resonance imaging and magnetoencephalography differences associated with APOEepsilon4 in young healthy adults

Functional neural alterations are present in middle-aged to late-aged healthy individuals carrying the epsilon4 allele of the apolipoprotein E (APOEepsilon4) gene, a known risk factor for Alzheimer's disease. Neural activity was measured in young adults with and without the epsilon4 allele (APOEepsilon4+ and APOEepsilon4-) by functional magnetic resonance imaging and magnetoencephalography while performing a visual working memory task on two separate days. Greater activity was observed in frontal areas and cingulate gyri in APOEepsilon4+ participants by both functional magnetic resonance imaging and magnetoencephalography with regional blood oxygenation level-dependent responses correlating with increased theta band power. The findings suggest that the presence of the APOEepsilon4 allele has physiological consequences before aging that may contribute to risk for Alzheimer's disease.     

Basal ganglia-thalamocortical circuitry disruptions in schizophrenia during delayed response tasks.

BACKGROUND: Schizophrenia is characterized by executive functioning deficits, presumably mediated by prefrontal cortex dysfunction. For example, schizophrenia participants show performance deficits on ocular motor delayed response (ODR) tasks, which require both inhibition and spatial working memory for correct performance. METHODS: The present functional magnetic resonance imaging (fMRI) study compared neural activity of 14 schizophrenia and 14 normal participants while they performed ODR tasks. RESULTS: Schizophrenia participants generated: 1) more trials with anticipatory saccades (saccades made during the delay period), 2) memory saccades with longer latencies, and 3) memory saccades of decreased accuracy. Increased blood oxygenation level-dependent (BOLD) signal changes were observed in both groups in ocular motor circuitry (e.g., supplementary eye fields [SEF], lateral frontal eye fields [FEF], inferior parietal lobule [IPL], cuneus, and precuneus). The normal, but not the schizophrenia, group demonstrated BOLD signal changes in dorsolateral prefrontal regions (right Brodmann area [BA] 9 and bilateral BA 10), medial FEF, insula, thalamus, and basal ganglia. Correlations between percentage of anticipatory saccade trials and BOLD signal changes were more similar between groups for subcortical regions and less similar for cortical regions. CONCLUSIONS: These results suggest that executive functioning deficits in schizophrenia may be associated with dysfunction of the basal ganglia-thalamocortical circuitry, evidenced by decreased prefrontal cortex, basal ganglia, and thalamus activity in the schizophrenia group during ODR task performance.     

Functional anatomy of auditory verbal imagery in schizophrenic patients with auditory hallucinations

OBJECTIVE: This study investigated the functional neuroanatomy of inner speech and auditory verbal imagery in schizophrenic patients predisposed to auditory hallucinations. METHOD: Eight patients with schizophrenia with a history of prominent auditory hallucinations and six comparison subjects underwent functional magnetic resonance imaging while generating inner speech or imagining external speech. RESULTS: Patients showed no differences while generating inner speech but experienced a relatively attenuated response in the posterior cerebellar cortex, hippocampi, and lenticular nuclei bilaterally and the right thalamus, middle and superior temporal cortex, and left nucleus accumbens during auditory verbal imagery. CONCLUSIONS: Patients with schizophrenia who were prone to auditory hallucinations show attenuated activation when processing inner speech in areas implicated in verbal self-monitoring.     

Functional magnetic resonance imaging in the assessment of motor centers in patients with brain tumors in motor area]

Magnetic resonance imaging (MRI) is become recognised as the most sensitive and specific imaging modality for the examination of central nervous system pathology. Blood oxygen level-dependent (BOLD) contrast imaging is a non-invasive functional MRI technique for localising active neuronal brain centres. The aim of our study was to determine usefulness of fMRI in detecting hand movements cortical activity in hemisphere with brain tumour and comparison with corresponding one. Six right-handed patients with brain tumours of central sulcus area, aged 20-50 years were examined using a commercial 1.5 T scanner. All patients underwent both conventional and functional magnetic resonance imaging (MRI) examinations. Simple hand movements were examined separately for right and left hand at a self-paced rate. Significant increase of signal intensity was found in: a) contralateral primary motor cortex in all cases during both motor tasks, b) ipsilateral primary motor cortex, supplementary motor cortex and premotor cortex of both hemispheres in a part of the cases c) displacement of the activity in the affected hemisphere in comparison to the opposite one was noticeable depending on the localisation and size of the tumour and accompanied oedema. Usefulness of functional MRI in detecting primary motor area in patients with brain tumours was proved. There is a difference between activation in affected cortex and corresponding normal cortex in the opposite hemisphere.