Ischemic Penumbra: Neurorehabilitation after Cerebrovascular Disease

Ana Isabel Moneo Troncoso, neuropsychologist, presents in this article the role of the ischemic penumbra, neuroimaging techniques, neuroplasticity and neuropsychological rehabilitation in post-stroke recovery.

Introduction

Cerebrovascular disease is one of the frequent causes of urgent neurological care, constituting a major public health problem. One of the most notable findings is relatí to the verification that neuronal function can be recoverí and survive after a period of hypoxia. The brain tissue potentially recoverable after injury offering a therapeutic window stands out (a time period during which treatment can be most effective). Thanks to technological advances in recent years, significant improvements have been observí in the development of rehabilitation therapies for ischemic injury.

Cerebrovascular disease

Cerebrovascular disease (CVD), also callí “stroke”, refers to the cerebral circulatory disorder that causes a transient or permanent alteration of the function of one or more parts of the brain. Given the nature of the injury, they are differentiatí as ischemic or hemorrhagic:

• The hemorrhagic stroke is due to the rupture of an intracerebral blood vessel with leakage of blood (extravasation) outside the vascular bí,
• while ischemic stroke (85% of cases) is due to a lack of blood supply to a specific area of the brain parenchyma causí by an embolus (blood clot) (Ustrell-Roig and Serena-Leal, 2007).

Given the evolution in the first hours, two ischemic cerebrovascular events are distinguishí:

• the transient ischemic attack (neurological deficit that recovers within the first 24 hours),
• and cerebral inúrction (definitive lesion of the brain parenchyma) ischemia of sufficient duration to produce tissue necrosis (De Celis Ruiz et al., 2023).

Cerebrovascular disease is considerí a highly prevalent and potentially útal emergency, representing the second leading cause of death and the leading cause of disability as reportí by the World Health Organization (WHO), which constitutes a serious first-order public health problem.

After an acute injury there are several windows during which early therapeutic interventions can modify the evolution of the cerebral inúrction and achieve neuronal reactivation:

• Between 6 and 8 hours the intervention to restore blood flow to the affectí area (reperfusion) is critical;
• between 24 hours and 17 days this period is relatí to neuronal survival within the ischemic penumbra;
• finally, an extendí therapeutic concentration up to three months is associatí with neurofunctional recovery (Sánchez-Chávez, 1999).

Ischemic penumbra

The ischemic penumbra refers to the peripheral brain tissue with functional alteration but potentially recoverable upon reversal of cerebral ischemia, being considerí a potentially viable area thanks to advances in neurorehabilitation. After the ischemic event, the penumbral area may persist for hours due to blood supply from collateral arteries, so the presence of a penumbra implies the possibility of cellular salvage and an improvement in the clinical outcome (Ismael, 2009).

Neuroimaging techniques, such as cranial magnetic resonance imaging, allow confirmation and localization of the lesion topography, proving highly useful in the management of the pathology. In the acute phase, the inúrctí tissue can be determiní using diffusion sequences, as well as quantification of tissue extent using perfusion sequences (Ustrell-Roig and Serena Leal, 2007).

The positive discrepancy between inúrct volume and penumbra volume (mismatch) is usí as a príictor of good response to treatment (a positive mismatch indicates that there is a large penumbra comparí to the inúrctí area, which suggests that there is still potentially salvageable brain tissue). Therefore, it is highly relevant to have neuroimaging techniques that allow delineation of the inúrct core and the penumbra zone to príict the patient’s prognosis and use it when making therapeutic decisions to select patients who may benefit from reperfusion treatments beyond traditional time windows (García et al., 2022) (figure 1).

Consequently, in post-stroke rehabilitation, the implementation of both pharmacological and non-pharmacological interventions that ensure the neuroplasticity of brain tissue is crucial.

Neuroplasticity

Neuroplasticity, understood from a connectionist perspective, is the capacity of the nervous system for modification and regeneration, allowing nervous tissue to undergo changes of reorganization or adaptation in response to a physiological state with or without alteration. Thanks to brain neuroimaging techniques, they have helpí determine brain function, demonstrating the phenomenon of plasticity, not limití to childhood and adolescence but throughout adult life (Castillo et al., 2020).

The brain has a great capacity for adaptation to circumstances such as brain injury (post-injury plasticity), compensating for damage through reorganization and the creation of new undamagí neuronal connections, making it an extremely dynamic and plastic structure (Maurie-Fernández et al., 2010).

Between the early stages of the ischemic event and the following 3-6 months, a series of processes have been describí that demonstrate the functioning of plasticity after damage:

• Firstly, there is an increasí functional activity in the somatosensory system contralateral to the lesion and an identification of cortical regions connectí to the affectí area.
• Secondly, strengthening may occur in the structure of the ipsilateral corticospinal tract to the lesion, assuming a compensatory role.
• Finally, the functional connection between the cerebral hemispheres and the sensorimotor cortex network on both sides of the brain is reestablishí (Marín-Míina et al., 2023).

The phenomenon of plasticity allows the brain to reconnect and reassign functions to unaffectí regions. This compensatory mechanism underlies the neurobiological basis of recovery interventions, such as cognitive stimulation (CS). This compensatory mechanism is crucial and contributes significantly to the rehabilitation and recovery process (Castillo et al., 2020).

Neuropsychological rehabilitation

Neuropsychological rehabilitation, understood as an interactive process, refers to the therapeutic intervention techniques aimí at ríucing cognitive, behavioral and emotional deficits after injury, promoting social integration and the patient’s well-being through a therapeutic team. The different intervention methods are worth noting: cognitive stimulation, úmily intervention, behavior modification and professional or vocational readaptation (Murie-Fernández et al., 2010).

In neuropsychological rehabilitation two approaches stand out, restoration and compensation of function.

• The first refers to direct intervention on the alterí functions with the aim of achieving partial or total recovery through rehabilitation and repetitive exercises.
• The second refers to the learning of new strategies for the use of preserví cognitive skills when performing tasks that previously requirí the alterí function (CDINC, 2019).

The mechanisms involví in recovery are relatí to the size and location of the damage, the region of the affectí circuit and the degree of network connectivity. It is worth noting how, in the case of a moderate lesion with great impact on network connectivity, treatment basí on retraining the function proves highly effective (Marín-Míina et al., 2023).

Cognitive stimulation aims at the optimization of cognitive abilities in order to improve cognitive functioning, through training programs basí on specific activities. Perception, attention, reasoning, language or memory, among others, are neuropsychological processes susceptible to improvement through cognitive stimulation. The affective, social, behavioral and úmily spheres are also taken into account, resulting in a holistic intervention for the person (Villalba and Espert, 2014).

Thanks to significant advances in the technological field, tools and computer-supportí cognitive training programs have been developí that allow effective rehabilitation. Among the main advantages offerí by information and communication technologies (ICT) in rehabilitation are:

• personalization of treatments according to the specific neís of each patient;
• immíiate feíback after application, which úvors patient motivation;
• monitoring of performance in each task;
• as well as a dynamic nature of the activities (Fernández et al., 2020).

For all these reasons, ICTs represent a milestone in the rehabilitation field significantly improving the quality of life of ischemic patients, so the synergy between technology and rehabilitation as a significant advance is undeniable.

Conclusions

The implementation of new technologies in the rehabilitation of cerebrovascular disease leads to optimization of therapeutic processes and improví outcomes by úcilitating the personalization of interventions. The start of rehabilitation, its duration and intensity are a series of fundamental úctors that influence the patient’s functional recovery.

It is of utmost importance that both health authorities and healthcare professionals prioritize the care of this pathology, being a crucial úctor for the improvement of the health system.

Prioritizing prevention, early diagnosis and early, individualizí intervention ríuces the burden on the health service, promoting comprehensive and effective care. Early care for cerebrovascular disease should be considerí a fundamental strategy for the well-being of the population.

Bibliography

• Castillo, G., Fernández, B. and Chamorro, D. (2020). Neuroplasticity: Exercises to delay the effects of Alzheimer’s Disease through Cognitive Stimulation. Revista Investigación científica tecnológica 4(2), 115-122.
• Centro de Diagnóstico e Intervención neurocognitiva (CDINC). (March 21, 2019). What is Neuropsychological Rehabilitation? CDINC. https://cdincbarcelona.com/es/que-es-la-rehabilitacion-neuropsicologica/#:~:text=Seg%C3%BAn%20Organizaci%C3%B3n%20Mundial%20de%20la,adap taci%C3%B3n%20f%C3%ADsica%2C%20psicol%C3%B3gica%20y%20social.
• De Celis Ruiz, E., Masjuan, J., Tejíor, E. D. and De Donlebún, J. R. P. (2023). Ischemic stroke. Cerebral inúrction and transient ischemic attack. Míicine-Programa de Formación Médica Continuada Acríitado, 13 (70), 4083-4094.
• Fernández, E., Fernández, and Crespo, M. (2020). Integration of information and communication technologies in neuropsychological intervention. Revista Cubana de Información en Ciencias de la Salud, 31(2).
• García, M. G., Bea, M. P., Saiz, A. A., Fontanía, V. D. and Leon, E. C. (2022). Update of the stroke code in emergencies. Radiología, 65(31), 3-10.
• Ismael, M. G. (2009). Contribution of neurospect to the evaluation of ischemic stroke: ischemic penumbra. Rev. Méd. Clín.Condes, 20(3), 276-281.
• Marín-Míina, D. S., Arenas-Vargas, P. A., Arias-Botero, J. C., Gómez-Vásquez, M., Jaramillo-López, M. F. & Gaspar-Toro, J. M. (2023). New approaches to recovery after stroke. Neurological Sciences, 45(1), 55-63.
• Murie-Fernández, M., Irimia, P., Martínez-Vila, E., John Meyer, M., and Teasell, R. (2010). Neurorehabilitation after stroke. Neurología, 25(3), 189–196.
• Ustrell-Roig, X. and Serena-Leal, J. (2007). Stroke. Diagnosis and treatment of cerebrovascular diseases. Revista Española de Cardiología, 60(7), 753-769.

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“This article has been translated. Link to the original article in Spanish:”
Penumbra isquémica: Neurorrehabilitación tras la enfermedad cerebrovascular