[Chronology of Justo Gonzalo's research on brain dynamics]

INTRODUCTION

The Spanish neuroscientist Justo Gonzalo y Rodriguez-Leal (1910-1986) investigated the functional organisation of the cerebral cortex over more than four decades. His findings led him to formulate a neurophysiological theory based on the laws of nervous excitability, which he called brain dynamics. This paper presents in chronological order how the main ideas on which it is based arose.

DEVELOPMENT

In 1939, Gonzalo observed the phenomena of dynamic action: asynchrony or disaggregation, facilitation and cerebral repercussion. This was followed by two principles: the cerebral effect of lesions according to their magnitude and position (1941), and spiral development of the sensory field (1947). At the same time, he characterised what he called the central syndrome of the cerebral cortex. In the 1950s he developed the concepts of the cortical gradient, similarity and allometry. In contrast to modular conceptions of the cerebral cortex, in which one region is responsible for one function, Gonzalo argued that 'cortical gradients provide the location of systems, while similarity and allometry reveal their functional mechanism.'

CONCLUSIONS

The theory of brain dynamics was established in two stages. The first (between 1938 and 1950) had an important clinical foundation, involving the observation of new phenomena and the formulation of new concepts. The second (between 1950 and 1960) included the introduction of more far-reaching concepts, such as the functional cortical gradient, and allometry laws based on a change of scale. Today, various authors believe that the concept of the gradient is crucial for understanding how the brain is organised.

[Predictors of the duration of post-traumatic amnesia following traumatic brain injury]

INTRODUCTION

The duration of post-traumatic amnesia (PTA) helps estimate the level of recovery following traumatic brain injury (TBI). Yet, little information is available about which sociodemographic and clinical variables influence its duration. This study aims to identify them and create a predictive model that makes it possible to estimate the time it takes for a patient to emerge from PTA.

PATIENTS AND METHODS

The sample consisted of 40 adult patients with PTA admitted to a neurorehabilitation centre. A total of 89.7% had suffered a severe TBI, whereas the remaining 10.3% had had a moderate TBI. Cognitive status was assessed using the Galveston Orientation and Amnesia Test (GOAT) - a scale for determining at what point a patient can be considered to be emerging from PTA.

RESULTS

A regression equation was found (F = 8.511; p < 0.001; R2 = 0.415), in which the following variables (ranked in order of importance) explained 41.5% of the variability observed in the duration of PTA: a) GOAT administered on arrival at the neurorehabilitation centre; b) years of formal education of the patient; and c) days with PTA prior to admission to the neurorehabilitation centre. The equation derived was as follows: 104.284 + (-0.708 x GOAT-initial) + (-4.124 x years formal education) + (0.219 x hospital acute-APT).

CONCLUSIONS

The time it takes for a patient to emerge from PTA is conditioned by the score obtained in the first GOAT administered on admission to the neurorehabilitation centre, their level of education, and the number of days elapsed with PTA between occurrence of the TBI and admission to the neurorehabilitation centre.

Neuropsychological rehabilitation for post-COVID-19 syndrome: results of a clinical programme and six-month follow up

INTRODUCTION

Patients with post-COVID-19 syndrome may present cognitive and emotional symptomatology. This study aims to analyse the results of an outpatient neuropsychological intervention programme for post-COVID-19 syndrome.

METHOD

In June 2020 Institut Guttmann started an outpatient post-COVID-19 neurorehabilitation programme, including respiratory therapy, physiotherapy, and neuropsychological rehabilitation. Before and after the programme, the cognitive-emotional state of all participants is assessed. Six months after treatment, a follow-up assessment is administered (which includes a collection of information on various aspects of daily life).

RESULTS

The sample analysed consisted of 123 patients (mean age: 51 years, SD: 12.41). Seventy-four per cent (n = 91) had cognitive impairment and underwent cognitive treatment (experimental group); the remaining 26% (n = 32) constituted the control group. After the intervention, the experimental group improved in working memory, verbal memory (learning, recall and recognition), verbal fluency and anxious-depressive symptomatology. The control group showed changes in immediate memory, verbal memory (learning and recognition) and depressive symptomatology, although the effect size in the latter two was smaller than in the experimental group. Six months after treatment, 44.9% of the patients were unable to perform their pre-COVID-19 work activity, and 81.2% reported difficulties in their activities of daily living.

CONCLUSIONS

Neuropsychological rehabilitation is an effective tool to treat the cognitive-emotional deficits present in post-COVID-19 syndrome. However, months after the end of treatment, not all patients recover their pre-COVID-19 functional level.

Social and nonsocial cognition: Are they linked? A study on patients with moderate-to-severe traumatic brain injury

OBJECTIVES

The first aim was to study the relationship between Social Cognition (SC) and nonsocial Cognition (n-SC) measures in a group of patients with moderate or severe traumatic brain injury (TBI) to assess the dependence or independence of both types of cognition. The second aim was to explore the relationships between SC measures and generate a model based on the results of these relationships.

METHODS AND PROCEDURES

Forty-three subacute patients with TBI were included in the study. They were administered a SC battery and n-SC battery. SC battery included the following measures: International Affective Picture System (IAPS); Facial Expressions of Emotion-Stimuli Test (FEEST); Moving Shapes Paradigm (MSP); Reading the Mind in the Eyes Test- Revised Version (RMET); Social Decision Making Task (SDMT). n-SC battery included Digit Span Forwards and Backwards; Trail Making Test (Part A); Rey's Auditory Verbal Learning Test; Letter-Number Sequencing; and verbal fluency test (PMR).

RESULTS

FEEST, MSP and RMET were related to n-SC measures. The exploratory factor analysis shows a two-factor SC structure: Factor 1: Emotional recognition and mentalization (FEEST, MSP and RMET) and Factor 2: Acquisition and contextualization (IAPS and SDMT).

CONCLUSION

The performance of subjects with moderate-to-severe TBI in the SC measures is related, at least partially, by the performance in the n-SC measures. Our SC model shows a two-factor structure characterized by a first factor that brings together SC measures that are highly related to n-SC domains and a second factor that brings together measures whose performance is not influenced by n-SC domains.

[Use of immersive virtual reality for cognitive rehabilitation of patients with brain injury]

INTRODUCTION

Virtual reality (VR) is a therapeutic tool that is widely used in the cognitive rehabilitation of brain-damaged patients. Depending on the degree of immersiveness, a distinction can be made between non-immersive, semi-immersive and immersive VR. Studies assessing the utility of VR have focused on the non-immersive and semi-immersive modes. Little evidence is available on the effectiveness of immersive VR.

AIM

To describe the characteristics, methodological quality and main results of studies that have applied immersive VR programmes in the cognitive rehabilitation of brain-damaged patients.

MATERIALS AND METHODS

Following the PRISMA guidelines, a bibliographic search was conducted for studies published in the PubMed and PsycINFO databases. The methodological quality of the articles that met the selection criteria was assessed using the PEDro scale.

RESULTS

After applying the inclusion and exclusion criteria, of the 369 articles of potential interest, five met the eligibility criteria. One of them was a randomised clinical trial (with acceptable/good methodological quality). Three were studies with pre- and post-treatment measures and one was a single case study, all four of them displaying poor methodological quality.

CONCLUSIONS

According to the results obtained, there is no evidence of the effectiveness or utility of immersive VR in cognitive rehabilitation in brain-damaged patients. This finding is explained by the lack of studies with a methodological design that allows for the generation of quality evidence rather than because the results obtained in the articles analysed are negative or inconclusive.

Computerized social cognitive training in the subacute phase after traumatic brain injury: A quasi-randomized controlled trial

OBJECTIVES

To assess the usefulness of a computerized tasks module designed for the rehabilitation of social cognition (SC) in acquired brain injury.

METHODS

Quasi-randomized controlled trial (ClinicalTrials.gov:NCT03479970) involving 45 patients with moderate-severe traumatic brain injury (TBI) in a subacute inpatient rehabilitation hospital. The experimental group (n = 28) received treatment with a computerized SC module in combination with a non-SC module. The control group (n = 26) only received a treatment with non-SC module.

RESULTS

Intragroup comparisons showed that the experimental group had better results for all SC measures, except for International Affective Picture System (IAPS). The control group improved for Facial Expressions of cEmotion-Stimuli and Tests (FEEST) and Moving Shapes Paradigm (MSP), showing no changes with respect to pretreatment in IAPS, MSP and Reading the Mind in the Eyes Test (RMET). Intergroup comparisons did not present differences between the two groups for pretreatment measures. Post-treatment comparison showed that the experimental group obtained better results for RMET than the control group.

CONCLUSION

The computerized SC module was useful for the rehabilitation of SC in patients with moderate-severe TBI in the subacute phase. The group that received combined rehabilitative treatment (SC + non-SC) obtained better results for SC than the group that received treatment intended only for non-SC.

[Non-pharmacological intervention in post-traumatic amnesia, a systematic review]

INTRODUCTION

Survivors of traumatic brain injury may experience a transient state of confusion and global disturbance of cognitive-behavioural functioning called post-traumatic amnesia.

AIM

To describe the characteristics, methodological quality and main results of studies that have analysed the impact of non-pharmacological interventions in the treatment of symptoms associated with post-traumatic amnesia.

PATIENTS AND METHODS

Following the PRISMA guidelines, a literature search was carried out on papers published in the PubMed and PsycInfo databases over the last 20 years (2000-2020). The methodological quality of the articles was assessed using the PEDro scale.

RESULTS

After applying the inclusion and exclusion criteria, of the 1,036 potentially interesting articles, eight met the eligibility criteria, four of which were randomised clinical trials. The interventions applied were grouped as follows: structured retraining of activities of daily living (four studies), reality orientation programme (two studies), Perceive, Recall, Plan and Perform system (one study) and therapeutic application of music (one study). Seven of the eight articles reviewed showed positive or partially positive results.

CONCLUSIONS

According to the results obtained, there is evidence that non-pharmacological interventions have positive effects on reducing the cognitive-behavioural signs and symptoms associated with post-traumatic amnesia.

[Topographical origins of the term «prefrontal»]

INTRODUCTION

Today, there is a broad consensus on the boundaries of what we call the prefrontal cortex, but this has not always been the case. The purpose of this historical review is to examine in greater depth the topographical origins of the term «prefrontal» and analyse its conceptual evolution.

DEVELOPMENT

The article is structured according to the main criteria that have been proposed successively over time in order to define the limits of the prefrontal cortex, namely, morphological, cytoarchitectural and hodological. During the second half of the 19th century, the criteria were essentially of a morphological nature. David Ferrier popularised the term «prefrontal» in this period. In the early years of the 20th century, criteria based on the architectural organisation of the cerebral cortex (or cytoarchitecture) predominated, and their main representative was Korbinian Brodmann. At the end of the 1940s, Jerzy E. Rose and Clinton N. Woolsey considered that the study of brain connections (hodology) was the way to define the boundaries of the prefrontal cortex and proposed that this frontal region was the main area of projection of the dorsomedial nucleus of the thalamus.

CONCLUSIONS

Historically, the limits of the so-called «prefrontal» region of the brain has been blurred and changing, as a result of the different criteria used at different times.

Rehabilitation of social cognition impairment after traumatic brain injury: A systematic review

INTRODUCTION

Many studies have described the presence of difficulty processing and generating social behaviour in patients who have suffered a traumatic brain injury (TBI). These difficulties in social cognition (SC) deteriorate personal relationships in the family, at work, or in the community. However, therapeutic programmes aiming to improve SC continue to be an outstanding issue in clinical practice. We performed a systematic review of the existing literature on the recovery of SC in patients with TBI, assessing the methodological quality of the included studies and the therapeutic effectiveness of the rehabilitation strategies used.

DEVELOPMENT

We performed a bibliographic search of papers published before June 2018 in the Medline/PubMed, Google Scholar, PsycINFO, and ClinicalTrials.gov databases. Of the 198 potentially relevant articles, 10 met our eligibility criteria. Two of the authors independently and blindly assessed the methodological quality of these studies using the PEDro scale.

CONCLUSIONS

The articles included in this systematic review essentially studied the effect of different interventions aimed at the rehabilitation of SC in patients with chronic TBIs. The analysis showed adequate methodological quality and an acceptable level of evidence. Future research should analyse the effect of these interventions in patients with TBIs in the sub- and post-acute phases.

Do traditional executive measures tell us anything about daily-life functioning after traumatic brain injury in Spanish-speaking individuals?

PRIMARY OBJECTIVE

To examine the relationship between traditional executive function measures and everyday competence in Spanish-speaking individuals with moderate-to-severe traumatic brain injury (TBI).

METHODS AND PROCEDURES

Thirty-two TBI patients (24 men, eight women) with an age range of 17-59 years (mean age = 30.73 years; SD = 13.34) were administered a battery of performance-based executive function measures. Such measures included the Trail Making Test part B, Wisconsin Card Sorting Test, Stroop Colour Word Interference Test, Controlled Oral Word Association Test and Letter-Number Sequencing. Behavioural manifestations of executive deficits were assessed by the Behaviour Rating Inventory of Executive Function-Adult version (BRIEF-A). Patient's everyday functioning was examined with the Patient Competency Rating Scale (PCRS).

MAIN OUTCOMES AND RESULTS

Traditional performance-based executive measures correlated significantly, although moderately, with the PCRS; this relationship was more significant in the Controlled Oral Word Association Test and Trail Making Test part B. A significant correlation was obtained between the BRIEF-A clinical scales and patient's everyday competence as measured by the PCRS.

CONCLUSIONS

The current findings suggest that traditional performance-based executive measures reveal some degree of ecological validity or real-world relevance, providing relevant information for predicting everyday competence after moderate-to-severe TBI.

[Phineas Gage and the enigma of the prefrontal cortex]

Perhaps the most famous brain injury in history was a penetrating wound suffered by a rail road worker named Phineas Gage on September 13, 1848. Twelve years after his injury, on the 21st of May, 1860 Phineas Gage died of an epileptic seizure. In 1868 Dr. Harlow gave an outline of Gage's case history and first disclosed his remarkable personality change. One might think this report would assure Gage a permanent place in the annals of neurology, but this was not the case. There was a good reason for this neglect: hardly anyone knew about Harlow's 1868 report. Dr. David Ferrier, an early proponent of the localisation of cerebral function, rescued Gage from obscurity and used the case as the highlight of his famous 1878 Goulstonian lectures. Gage had, through a tragic natural experiment, provided proof of what Ferrier's studies showed: the pre-frontal cortex was not a "non-functional" brain area. A rod going through the prefrontal cortex of Phineas Gage signalled the beginning of the quest to understand the enigmas of this fascinating region of the brain.

[Maturation of the prefrontal cortex and development of the executive functions during the first five years of life]

INTRODUCTION

The first five years of life are critical in the development of the executive functions. The changes that are seen to take place in executive competence and capacity are closely related to the maturational processes of the prefrontal cortex.

DEVELOPMENT

Evidence gathered over the past three decades indicates that executive functioning begins to develop earlier than was previously believed. At early ages it is possible to observe the appearance of different cognitive capacities that will later make up what we call the executive functions. The purpose of this article is to describe how the executive functions develop over the first five years of life and their relationship with the maturation of the prefrontal cortex.

CONCLUSIONS

The development of the executive functions involves the development of a series of cognitive capacities that have to enable the child to retain and manipulate information and to act accordingly; to self-regulate their behaviour so that they can act in a reflexive rather than impulsive manner; and to adapt their behaviour to fit the changes that can occur in the surroundings. Early upsets in executive development have a drastic restricting effect on the child's capacity to cope with novel situations, as well as to have the flexibility required to adapt to changes with ease.

[Assessment of decision-making capacity in primary and secondary progressive multiple sclerosis]

INTRODUCTION

Patients with multiple sclerosis (MS) may have an impairment in their decision-making. Altered decision making is a known cause of functional impairment in daily living activities and in the patient's autonomy, negatively contributing to their quality of life.

OBJECTIVE

The current study assessed the decision-making capacity of patients with primary progressive multiple sclerosis (PPMS) and secondary progressive multiple sclerosis (SPMS) compared to healthy control subjects.

PATIENTS AND METHODS

Nineteen patients with multiple sclerosis (9 PPMS and 10 SPMS) and 18 healthy controls participated in the study. Decision-making was evaluated using a computerized version of the Iowa Gambling Task (IGT), a test created to simulate punishment-reward contingencies in a real-life manner.

RESULTS

Overall, the PPMS group performed more poorly than the control and SPMS groups on the IGT. The SPMS group was not significantly impaired compared to control group on the task, but showed abnormalities of IGT performance similar to the PPMS group.

CONCLUSIONS

The authors suggest that the existence of decision- making impairments in patients with multiple sclerosis can be explained by a difficulty in the acquisition of stimulus-reward contingencies.

[Models of executive control and functions. II]

INTRODUCTION

Current models of the executive functions enable us to state that this construct embraces a large number of processes and sub processes that are in turn linked to different regions of the brain, and more specifically to the prefrontal cortex. Recent data suggest that different areas of the prefrontal cortex may be involved in a number of aspects related to executive functioning.

DEVELOPMENT

The aim of this article is to review the most important models of executive functioning in order to shed light on this controversial construct. The models put forward to date approach the same reality from a number of different perspectives, although in some cases they neglect certain parts of that reality. In this second part of our paper, we review the dynamic filter theory, the differential axes model, the theory of cognitive complexity and control, the theory of hierarchical representation, the attentional control model, the supervisory attentional system and the input hypothesis.

CONCLUSIONS

From the results obtained in the studies that were reviewed we can state that it is possible to divide the 'executive functions' construct into sub processes in order to make understanding, assessment and intervention easier. Each of these sub processes seems to be related to a specific area in the prefrontal cortex, although a particular region can be involved in different aspects of executive functioning at different moments in time.

[Models of executive control and functions (I)]

INTRODUCTION

As human beings we are capable of coping with novel situations and adapting to changes in a flexible manner. The cognitive skills that allow individuals to control and regulate their behaviour are called executive functions. Anatomically, the executive functions depend on a distributed neural system, in which the prefrontal cortex plays an essential role. Recent data suggest that different regions of the prefrontal cortex may be involved in a number of aspects of executive functioning.

DEVELOPMENT

The purpose of this article is to carry out a review of the main models of executive functioning in order to shed light on this controversial construct. The models put forward to date approach the same reality from a number of different perspectives, in some case avoiding certain parts of that reality. In this first part, we review the models and theories of contextual information, structured complex events, working memory, adaptive encoding, Miller and Cohen's integrating theory, and the factorial models of executive control.

CONCLUSIONS

There is no single model that allows us to explain how specific cognitive processes are controlled and coordinated while complex cognitive activities are being performed. Nevertheless, some agreement has been reached on accepting the idea that the executive functions construct does not consist of a single concept, but instead a combination of several cognitive processes that combine in a number of ways in order to operate in different situations.

[A historical view of behavioural alterations due to lesions in the prefrontal cortex: from Phineas Gage to Luria]

INTRODUCTION

Over the last 200 years, a number of authors have considered the prefrontal cortex to be the 'organ of civilisation', that is, the most characteristically human part of the brain, while others have seen this region of the brain as playing a far less important role in behaviour.

AIM

To examine the study of behavioural alterations caused by lesions in the prefrontal cortex from a historical perspective.

DEVELOPMENT

Since the middle of the 19th century, reports have appeared in the scientific literature of patients with behavioural alterations caused by traumatic injuries to the prefrontal region or brain tumours located in this area of the brain. From the beginning of the 20th century onwards, most of the information for this field of study has been obtained from the results of treating brain tumours and psychiatric disorders by means of brain surgery. The observations that have been gathered over these two centuries have sparked a heated debate about the connection between behaviour and the prefrontal cortex.

CONCLUSIONS

The fact that behavioural disorders and prefrontal lesions are constantly associated to each other seems to confirm the existence of a relation between the two. In recent decades, several theoretical approaches have appeared that continue to see the prefrontal cortex as playing an important role in performing the mental processes involved in human behaviour, but also offer new points of view about the relation between behaviour and the brain. These new perspectives are based on the connections between the prefrontal cortex and other cortical and subcortical regions.

[Examination of decision-making processes in patients with traumatic brain injury]

INTRODUCTION

Patients with moderate or severe traumatic brain injury (TBI) may show impairment in decision- making processes. The Iowa Gambling Task (IGT) has become a widely used neuropsychological research tool to investigate decision-making by simulating real-life decision-making in terms of uncertainty, reward, and punishment.

OBJECTIVE

Investigate decision-making in patients with moderate or severe TBI during performance of the IGT, and study patient's conscious knowledge of the task's reinforcement contingencies (reward/punishment schedule).

PATIENTS AND METHODS

Forty patients with moderate or severe TBI and 30 healthy volunteers participated in the study. Decision-making was evaluated using a computerized version of the IGT. After completing the task, the participants' knowledge of the task was tested.

RESULTS

The TBI group had worse performance on the IGT than the control group. They chose more unfavorable cards of the deck than the favorable ones. IGT score differences were observed among TBI patients in relation to level of knowledge of the task. The patients with knowledge of the task's reinforcement contingencies showed better performance, while the patients with scarce knowledge presented worse performance.

CONCLUSIONS

These results suggest that there is a direct relationship between the knowledge that patients with moderate and serious TBI have regarding the TBI reinforcement contingencies and their performance in the task.