Levels of brain wave activity (8–13 Hz) in persons with spinal cord injury

Abstract

Study design: Brain wave activity in people with spinal cord injury (SCI) was compared to brain wave activity in able-bodied controls. Objectives: To investigate whether a spinal injury results in changes in levels of brain wave activity in the 8-13 Hz spectrum of the electroencephalography (EEG). Setting: Sydney, Australia. Methods: Monopolar, multichannel EEG assessment was completed for 20 persons with SCI and 20 able-bodied, sex-and age-matched controls. A total of 14 channels of EEG were measured across the entire scalp for all participants. Comparisons between the able-bodied and SCI participants were made across the frontal, central, parietal, occipital and temporal regions. Comparisons were also made for impairment level, that is, between participants with tetraplegia and paraplegia. Results: Compared to the able-bodied controls, consistently reduced brain wave activity (measured by magnitude and peak amplitude) in the 8-13 Hz component of the EEG occurred in persons with SCI across all regions and sites, and differences were larger in the central, parietal and occipital sites. The SCI group also had consistently lower frequencies than the ablebodied controls. Furthermore, the subgroup of SCI participants with tetraplegia generally had significantly reduced brain activity (magnitude and peak amplitude) compared with the paraplegic subgroup and able-bodied controls. Conclusions: The findings of this research enhance our understanding of changes in brain wave activity that could be associated with deafferentation that occurs following SCI, as well as provide essential data on the potential of SCI persons to use a 'hands free' environmental control system that is based upon 8-13 Hz brain activity.

Spinal Cord Injury Immediately Changes the State of the Brain

“…Besides deafferentation of somatosensory structures, it is possible that spinal transection also directly affected the activity of brainstem structures and thalamic nuclei regulating cortical synchrony and arousal, contributing to the observed changes in cortical spontaneous activity (Moruzzi and Magoun, 1949;Lindvall et al, 1974;Hobson et al, 1975;Foote et al, 1980;Aston-Jones and Bloom, 1981a,b;Fox and Armstrong-James, 1986;Satoh and Fibiger, 1986;Hallanger et al, 1987;Steriade et al, 1990;Aguilar and Castro-Alamancos, 2005;Ren et al, 2009). Importantly, slower cortical activity after spinal cord injury has been previously observed with EEG recordings in patients (Tran et al, 2004;Boord et al, 2008), and both slower cortical activity (Wydenkeller et al, 2009) and long-term cortical reorganization (Wrigley et al, 2009) correlate with the emergence of neuropathic pain. From a translational perspective, it is thus tempting to suggest-with all the necessary caveats of comparing data from awake patients and anesthetized rats-that the immediate slowing of cortical spontaneous activity after spinal cord injury described here might have a pathophysiological role for long-term cortical reorganization and neuropathic pain.…”

Electroencephalographic slowing and reduced reactivity in neuropathic pain following spinal cord injury

“…Sign tests were used to indicate the consistency of the direction of difference over all channels between groups rather than basing a decision only on the size of the difference. 11 In this test, the binomial distribution was used to calculate the probability that a given measure would produce the same direction of difference indicated by the results.…”

“…Data collection and processing EEG data were recorded at 14 channels (Fp1, Fp2, F3, F4, Fz, C3, C4, P3, P4, T5, T6, Pz, O1 and O2), 12 referenced to Cz, 11,13 filtered to a bandwidth of DC-500 Hz and sampled at 2048 Hz. Electroopthalmogram (EOG) data were recorded from electrodes placed above and below the right eye and at the left and right outer canthi.…”

“…10 We recently published experimental evidence indicating a slowing of the human EEG in response to SCI. 11 In a comparison of 20 people with SCI and 20 controls matched for age and sex, the SCI group had consistently lower peak frequencies in the a frequency band (8-13 Hz) at 13 out of 14 sites recorded across the head, with six posterior sites showing a significant reduction (Po0.05). Owing to the prevalence of neuropathic pain in SCI being as high as 50%, 1 we hypothesized that the observed slowing of EEG frequency in SCI may be associated with neuropathic pain.…”

Estratégia terapêutica após contusão da medula espinhal: recuperação funcional e estabilidade cortical sensório-motora

“…Embora a lesão medular não afete diretamente os neurônios corticais, já foi demonstrado que ela afeta áreas sensório-motoras conectadas à área lesada e pode resultar em uma reorganização destas regiões com o objetivo de compensar a perda sensório-motora (Tran et al, 2004;Maier e Schwab, 2006). A reorganização do córtex pode ocorrer por mudanças tanto estruturais como funcionais.…”