Input-increase and input-decrease types of cortical reorganization after upper extremity amputation in humans

Elbert, Thomas; Sterr, Annette; Flor, Herta; Rockstroh, Brigitte; Knecht, Stefan; Pantev, Christo; Wienbruch, Christian; Taub, Edward

doi:10.1007/s002210050210

Cited by 128 publications

(64 citation statements)

References 14 publications

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“…An alternative explanation is that the slight hyperexcitability of the projections to the free arm may depend on 'use-dependent' plasticity, because patients were increasingly dependent on the free right arm in everyday life. It has been suggested that such 'use-dependent' plasticity takes place in upper limb amputees (Elbert et al, 1997), but its relevance has not been confirmed by other authors (Schwenkreis et al, 2001). …”

Section: Changes In the Representation Of Unconstricted Limbmentioning

confidence: 92%

Modulation of motor cortex excitability after upper limb immobilization

Zanette

Manganotti

Fiaschi

et al. 2004

Clinical Neurophysiology

102

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Objective: To examine the mechanisms of disuse-induced plasticity following long-term limb immobilization. Methods: We studied 9 subjects, who underwent left upper limb immobilization for unilateral wrist fractures. All subjects were examined immediately after splint removal. Cortical motor maps, resting motor threshold (RMT), motor evoked potential (MEP) latency and MEP recruitment curves were studied from abductor pollicis brevis (APB) and flexor carpi radialis (FCR) muscles with single pulse transcranial magnetic stimulation (TMS). Paired pulse TMS was used to study intracortical inhibition and facilitation. Compound muscle action potentials (CMAPs) and F waves were obtained after median nerve stimulation. In 4/9 subjects the recording was repeated after 35 -41 days.Results: CMAP amplitude and RMT were reduced in APB muscle on the immobilized sides in comparison to the non-immobilized sides and controls after splint removal. CMAP amplitude and RMT were unchanged in FCR muscle. MEP latency and F waves were unchanged. MEP recruitment was significantly greater on the immobilized side at rest, but the asymmetry disappeared during voluntary muscle contraction. Paired pulse TMS showed an imbalance between inhibitory and excitatory networks, with a prevalence of excitation on the immobilized sides. A slight, non-significant change in the strength of corticospinal projections to the non-immobilized sides was found. TMS parameters were not correlated with hand dexterity. These abnormalities were largely normalized at the time of retesting in the four patients who were followed-up.Conclusions: Hyperexcitability occurs within the representation of single muscles, associated with changes in RMT and with an imbalance between intracortical inhibition and facilitation. These findings may be related to changes in the sensory input from the immobilized upper limb and/or in the discharge properties of the motor units.Significance: Different mechanisms may contribute to the reversible neuroplastic changes, which occur in response to long-term immobilization of the upper-limbs.

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Section: Changes In the Representation Of Unconstricted Limbmentioning

confidence: 92%

Modulation of motor cortex excitability after upper limb immobilization

Zanette

Manganotti

Fiaschi

et al. 2004

Clinical Neurophysiology

102

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“…Multiple studies demonstrate that reorganization of higher level sensory systems occurs following either peripheral nerve damage (Elbert et al, 1997;Kaas, 1991a, 1991b;Merzenich and Jenkins, 1993;Jain et al, 2000;Borsook et al, 1998) or alteration in sensory inputs such as increased drive from pain fibers (Baumann et al, 1991;McMahon et al, 1993;Katz et al, 1999;Bruggemann et al, 2001). In animal models, plasticity has been observed following neural blockade or nerve damage and affects the sensory system almost immediately (see Pons et al, 1991;Florence and Kaas et al, 1995;Ergenzinger et al, 1998;Krupa et al, 1999;Jain et al, 2000;Kaas, 2002).…”

Section: Plasticity Of Somatosensory Systemsmentioning

confidence: 97%

Functional imaging of the human trigeminal system: Opportunities for new insights into pain processing in health and disease

2004

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Peripheral inflammation or nerve damage result in changes in nervous system function, and may be a source of chronic pain. A number of animal studies have indicated that central neural plasticity, including sensitization of neurons within the spinal cord and brain, is part of the response to nervous system insult, and can result in the appearance of altered sensation, including pain. It cannot be assumed, however, that data obtained from animal models unambiguously reflects CNS changes that occur in humans. Currently, the only noninvasive approach to determining objective changes in neural processing and responsiveness within the CNS in humans is the use of functional imaging techniques. It is now possible to use functional magnetic resonance imaging (fMRI) to measure CNS activation in the trigeminal ganglion, spinal trigeminal nucleus, the thalamus, and the somatosensory cortex in healthy volunteers, in a surrogate model of hyperalgesia, and in patients with trigeminal pain. By offering a window into the temporal and functional changes that occur in the damaged nervous system in humans, fMRI can provide both insight into the mechanisms of normal and pathological pain and, potentially, an objective method for measuring altered sensation. These advances are likely to contribute greatly to the diagnosis and treatment of clinical pain conditions affecting the trigeminal system (e.g., neuropathic pain, migraine).

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“…The Cretaceous fossil pollen genus Walkeripollis from the late Barremian -early Aptian of Gabon and the late Aptianearly Albian of Israel is winteraceous 2,3 . Winteraceae persisted in continental Africa until at least the lower Miocene in the southwestern Cape, represented there by two different pollen types associated with modern-day Bubbia and Tasmannia (sometimes considered Drimys section Tasmannia), both now restricted to Australo-malesia 4 .…”

mentioning

confidence: 99%

“…The somatosensory cortical representation of fingers expands when the amount of sensory input arriving in that part of the brain is increased [1][2][3][4][5][6] . Indeed, we have previously used magnetic source imaging to Nature 391 (1998), pp.…”

mentioning

confidence: 99%