Biomedical subjects

Paul Bach-Y-Rita

Publications and source records attributed to Paul Bach-Y-Rita.

4 recordsLinked to original sources

PubMed2005

Emerging concepts of brain function.

For over 40 years, since I first obtained evidence for nonsynaptic diffusion neurotransmission (most scientists call it Volume Transmission), I have been convinced that we scientists were ignoring organizational dynamics other than the mechanistic synaptic organization of the brain. For many years it was an uneasy feeling, since I was aware there are so many avenues to explore in brain function. I have wondered how much we scientists have ignored, in our quest to understand how the brain really works, due to our efforts to "be scientific". In addition to the difficulty of understanding how the brain functions, how could we even begin to explore the human experience? In this paper I will first discuss some emerging concepts of brain function. I will then comment on the development of concepts that have been a part of my own research experience.

Animals↗

PubMed2004

Reconsidering the motor recovery plateau in stroke rehabilitation.

Termination of motor rehabilitation is often recommended as patients with cerebrovascular accident (CVA) become more chronic and/or when they fail to respond positively to motor rehabilitation (commonly termed a "plateau"). Managed-care programs frequently reinforce this practice by restricting care to patients responding to therapy and/or to the most acute patients. When neuromuscular adaptation occurs in exercise, rather than terminating the current regimen, a variety of techniques (eg, modifying intensity, attempting different modalities) are used to facilitate neuromuscular adaptations. After presenting the concepts of the motor recovery plateau and adaptation, we similarly posit that patients with CVA adapt to therapeutic exercise but that this is not indicative of a diminished capacity for motor improvement. Instead, like traditional exercise circumstances, adaptive states can be overcome by modifying regimen aspects (eg, intensity, introducing new exercises). Findings suggesting that patients with chronic CVA can benefit from motor rehabilitation programs that apply novel or different parameters and modalities. The objectives of this commentary are to (1) to encourage practitioners to reconsider the notion of the motor recovery plateau, (2) to reconsider chronic CVA patients' ability to recover motor function, and (3) to use different modalities when accommodation is exhibited.

Activities of Daily Living↗

PubMed2004

Is it possible to restore function with two percent surviving neural tissue?

How much surviving normal neural tissue is required for functional reorganization after a lesion? Clinical and experimental studies suggest that at little as two percent remaining tissue may be sufficient, at least in some cases, for functional reorganization. Recent sensory substitution studies with persons who have been diagnosed with total vestibular loss (e.g., due to an ototoxic reaction to an antibiotic) suggest that the persisting function after removal of the substitution system may be related to the survival of a small amount of vestibular tissue.

Aged↗

PubMed2003

Closing an open-loop control system: vestibular substitution through the tongue.

The human postural coordination mechanism is an example of a complex closed-loop control system based on multisensory integration [9,10,13,14]. In models of this process, sensory data from vestibular, visual, tactile and proprioceptive systems are integrated as linearly additive inputs that drive multiple sensory-motor loops to provide effective coordination of body movement, posture and alignment [5-8, 10, 11]. In the absence of normal vestibular (such as from a toxic drug reaction) and other inputs, unstable posture occurs. This instability may be the result of noise in a functionally open-loop control system [9]. Nonetheless, after sensory loss the brain can utilize tactile information from a sensory substitution system for functional compensation [1-4, 12]. Here we have demonstrated that head-body postural coordination can be restored by means of vestibular substitution using a head-mounted accelerometer and a brain-machine interface that employs a unique pattern of electrotactile stimulation on the tongue. Moreover, postural stability persists for a period of time after removing the vestibular substitution, after which the open-loop instability reappears.

Acceleration↗