Functional MRI in double cortex: Functionality of heterotopia

Pinard, Jean Marc; Feydy, A.; Carlier, Robert; Pérez, Netzahualcóyotl Mayek; Piérot, Laurent; Burnod, Yves

doi:10.1212/wnl.54.7.1531

Cited by 86 publications

(49 citation statements)

References 9 publications

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“…In agreement with previous studies of patients with DCS that used a motor paradigm comparable to ours, we found a contralateral M1 activation [Draganski et al, 2004;Iannetti et al, 2001;Pinard et al, 2000]. In addition, we found ipsilateral M1 activation, as well as a network including SMA, PMA, and SII as shown in the three examples in Figure 2.…”

Section: Activation In Normotopic Cortexsupporting

confidence: 92%

“…A study using magnetoencephalography showed that the heterotopic neurons participate in processing somatosensory and auditory stimuli [Toulouse et al, 2003]. Functional magnetic resonance imaging (fMRI) studies have shown motor activation of the heterotopic band underneath the primary motor cortex in a few DCS cases [Draganski et al, 2004;Iannetti et al, 2001;Pinard et al, 2000;Spreer et al, 2001]. On the other hand, a [ 15 O] H 2 O positron emission tomography (PET) study of complex cognitive and motor learning tasks [Richardson et al, 1998] in two DCS patients and a visual fMRI study [Spreer et al, 2001] failed to show significant activation of the heterotopic band.…”

Section: Introductionmentioning

confidence: 99%

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Sensorimotor organization in double cortex syndrome

Jirsch¹,

Bernasconi²,

Villani³

et al. 2005

Human Brain Mapping

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Subcortical band heterotopia is a diffuse malformation of cortical development related to pharmacologically intractable epilepsy. On magnetic resonance imaging (MRI), patients with "double cortex" syndrome (DCS) present with a band of heterotopic gray matter separated from the overlying cortex by a layer of white matter. The function and connectivity of the subcortical heterotopic band in humans is only partially understood. We studied six DCS patients with bilateral subcortical band heterotopias and six healthy controls using functional MRI (fMRI). In controls, simple motor task elicited contralateral activation of the primary motor cortex (M1) and ipsilateral activation of the cerebellum and left supplementary motor area (SMA). All DCS patients showed task-related contralateral activation of both M1 and the underlying heterotopic band. Ipsilateral motor activation was seen in 4/6 DCS patients. Furthermore, there were additional activations of nonprimary normotopic cortical areas. The sensory stimulus resulted in activation of the contralateral primary sensory cortex (SI) and the thalamus in all healthy subjects. The left sensory task also induced a contralateral activation of the insular cortex. Sensory activation of the contralateral SI was seen in all DCS patients and secondary somatosensory areas in 5/6. The heterotopic band beneath SI became activated in 3/6 DCS patients. Activations were also seen in subcortical structures for both paradigms. In DCS, motor and sensory tasks induce an activation of the subcortical heterotopic band. The recruitment of bilateral primary areas and higher-order association normotopic cortices indicates the need for a widespread network to perform simple tasks.

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Section: Activation In Normotopic Cortexsupporting

confidence: 92%

Section: Introductionmentioning

confidence: 99%

Sensorimotor organization in double cortex syndrome

Jirsch¹,

Bernasconi²,

Villani³

et al. 2005

Human Brain Mapping

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“…In classic or type 1 lissencephaly, the pyramids are hypoplastic or absent [48, 103,115].In subcortical band heterotopia (SBH) or 'double cortex', bilateral, extensive plates of heterotopic grey matter are found beneath the cortex. With functional MRI it was shown that, despite its epileptogenic activity, SBH seems to be responsible for part of the functional activity [111]. This suggests that the double cortex in SBH participates in the formation of the corticospinal tract.…”

Section: Malformations Of the Human Pyramidal Tractmentioning

confidence: 99%

Development and malformations of the human pyramidal tract

et al. 2004

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The corticospinal tract develops over a rather long period of time, during which malformations involving this main central motor pathway may occur. In rodents, the spinal outgrowth of the corticospinal tract occurs entirely postnatally, but in primates largely prenatally. In mice, an increasing number of genes have been found to play a role during the development of the pyramidal tract. In experimentally studied mammals, initially a much larger part of the cerebral cortex sends axons to the spinal cord, and the site of termination of corticospinal fibers in the spinal grey matter is much more extensive than in adult animals. Selective elimination of the transient corticospinal projections yields the mature projections functionally appropriate for the pyramidal tract. Direct corticomotoneuronal projections arise as the latest components of the corticospinal system. The subsequent myelination of the pyramidal tract is a slow process, taking place over a considerable period of time. Available data suggest that in man the pyramidal tract develops in a similar way. Several variations in the funicular trajectory of the human pyramidal tract have been described in otherwise normally developed cases, the most obvious being those with uncrossed pyramidal tracts. A survey of the neuropathological and clinical literature, illustrated with autopsy cases, reveals that the pyramidal tract may be involved in a large number of developmental disorders. Most of these malformations form part of a broad spectrum, ranging from disorders of patterning, neurogenesis and neuronal migration of the cerebral cortex to hypoxic-ischemic injury of the white matter. In some cases, pyramidal tract malformations may be due to abnormal axon guidance mechanisms. The molecular nature of such disorders is only beginning to be revealed.

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“…Over the last years, fMRI has shown its ability to demonstrate coactivation of malformations of cortical development during physiological activation tasks [18] . Two studies on patients with subcortical laminar heterotopia [19,20] showed fMRI activation both in the outer cortex and the subcortical band heterotopia during performance of a motor task. In another patient with epilepsy and a microgyric visual cortex, the dysplastic cortex was activated by visual stimulation [21] .…”

Section: Malformations Of Cortical Developmentmentioning

confidence: 99%

Imaging Epileptic Activity Using Functional MRI

Krakow

2008

Neurodegener Dis

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This review concentrates on functional MRI (fMRI) methods to identify the epileptic focus, i.e. ictal and interictal fMRI. First, established clinical applications of fMRI in the field of epilepsy are briefly introduced: fMRI of sensorimotor, language and memory function can already be considered as clinically relevant tools to identify the eloquent cortex and to predict postoperative functional deficits in patients considered for epilepsy surgery. fMRI offers a valid alternative to invasive methods like the Wada test for establishing language dominance, and it is likely that it will also replace the Wada test for assessing presurgical memory function in the nearer future. Ictal fMRI (fMRI studies of epileptic seizures) will remain confined to exceptional cases due to practical limitations. The generators of interictal epileptiform discharges (IED) can be studied with EEG-correlated fMRI. Despite its technical challenges, it has proved useful to provide insights into the generation of IED in patients with focal and generalized epilepsy. In selected patients with focal IED, EEG-correlated fMRI has the potential to reproducibly identify cortical areas involved in generating IED, i.e. the irritative zone. In patients with generalizes IED, suspension of functional networks due to the IED can be demonstrated. The utility of EEG-correlated fMRI in clinical epileptology cannot be definitely determined yet.

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Functional MRI in double cortex: Functionality of heterotopia

Cited by 86 publications

References 9 publications

Sensorimotor organization in double cortex syndrome

Sensorimotor organization in double cortex syndrome

Development and malformations of the human pyramidal tract

Imaging Epileptic Activity Using Functional MRI

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