A cerebral blood flow evaluation during cognitive tasks following a cervical spinal cord injury: a case study using transcranial Doppler recordings

Abstract

A spinal cord injury (SCI) is one of the most common neurological disorders. In this paper, we examined the consequences of upper SCI in a male participant on the cerebral blood flow velocity. In particular, transcranial Doppler was used to study these effects through middle cerebral arteries (MCA) during resting-state periods and during cognitive challenges (non-verbal word-generation tasks and geometric-rotation tasks). Signal characteristics were analyzed from raw signals and envelope signals (maximum velocity) in the time domain, the frequency domain and the time-frequency domain. The frequency features highlighted an increase of the peak frequency in L-MCA and R-MCA raw signals, which revealed stronger cerebral blood flow during geometric/verbal processes respectively. This underlined a slight dominance of the right hemisphere during word-generation periods and a slight dominance of the left hemisphere during geometric processes. This finding was confirmed by cross-correlation in the time domain and by the entropy rate in informationtheoretic domain. A comparison of our results to other neurological disorders (Alzheimer's disease, Parkinson's disease, autism, epilepsy, traumatic brain injury) showed that the SCI had similar effects such as general decreased cerebral blood flow and similar regular hemispheric dominance in a few cases.

Hemispheric asymmetry non-linear analysis of EEG during emotional responses from idiopathic Parkinson’s disease patients

“…There has been growing evidence that non-linear research studies have been devoted to analysis of EEG signals recorded from participants with pathological conditions such as Alzheimer's, dementia, depression, disturbed cognition, epilepsy, schizophrenia and sleep disorders as well as the brain function related to emotional states (Bleton and Sejdic 2015;Liu et al 2015;Poppy and Speckens 2015;Stam 2005). These studies shows that non-linear analyses are more in tune with nature of EEG signals and systems, thus, they are widely used in biological and medical applications.…”

Cerebral Autoregulation during Postural Change in Patients with Cervical Spinal Cord Injury—A Carotid Duplex Ultrasonography Study

“…In 1991, a study using TCD suggested that the difference in CA, which regulates CBF, rather than changes in BP, would be involved in symptomatic improvement in patients with sympathetic nervous system abnormalities due to an SCI [6]. Since then, several studies have investigated CBF control in patients with a high-level SCI using TCD [18,19]. CA involves myogenic, metabolic, and neurogenic control mechanisms, as well as systemic factors [20,21], and while static CA is well preserved in patients with a high-level SCI, dynamic CA is severely altered [22,23].…”