The Phases of Stroke & The Unique Importance of the Subacute Phase

By: BrainQ Team

Stroke Recovery


The subacute phase of stroke recovery plays a crucial role in determining the long-term outcomes for individuals who have experienced a stroke. During this critical period, which typically spans several weeks to months following the initial stroke event, the brain undergoes complex physiological and functional changes that significantly influence the overall recovery process. Understanding the importance of the subacute phase is essential for healthcare professionals and patients alike, as it enables tailored interventions, timely rehabilitation, and optimized strategies to maximize the potential for neurological healing and functional restoration. In this discussion, we will explore the reasons why the subacute phase matters in stroke recovery and delve into the key factors that contribute to its significance.

The 3 Phases of Stroke

Stroke management is typically categorized into three primary phases (See Figure 1 Below). This classification provides a fundamental framework to comprehend the various stages of stroke, helping to tailor medical interventions and rehabilitation strategies appropriately at each stage. Below we will discuss these 3 phases. 

Acute Phase

The first is the acute phase which refers to the initial period immediately after a stroke occurs. It typically lasts for the first few hours or days. During this phase, the focus is on urgent medical intervention to minimize brain damage and restore blood flow to the affected area.

Subacute Phase

The subacute phase is the period that follows the acute phase, typically starting a few days after the stroke and lasting up to several weeks or months. It is believed that this is a time when the brain is most primed for recovery, where the brain restructures its functions, adjusting to the damage from the stroke.

Chronic Phase

The chronic phase begins after the subacute phase and represents the long-term phase of stroke recovery. It encompasses the period of months to years after the stroke. In the chronic phase, the focus is on continued rehabilitation, management of residual symptoms, and long-term support for the individual's physical, cognitive, and emotional well-being.

Why the Subacute Phase Is So Important in Stroke Recovery

Typically beginning within a week and lasting up to six months after the stroke the subacute phase is characterized by the brain's remarkable adaptability and its ability to restore some functions spontaneously. With its heightened state of plasticity, the subacute phase forms the cornerstone of functional recovery, offering significant opportunities for rehabilitation. 

To support this notion, here are three activities that occur in this unique time frame:

  1. The Brain Is Primed For Plasticity and Adaptation: After a stroke, the brain undergoes a process known as plasticity - the brain's ability to adapt and change. During the subacute phase, the brain is at its highest level of plasticity, meaning it's more capable of reorganizing and forming new connections. For this reason, it's super important to focus on rehabilitation and really take advantage of this increased plasticity to promote recovery.
  2. The Brain Heals On Its Own: This self-healing is referred to as spontaneous recovery and during the subacute phase, it is common for stroke survivors to experience it. This spontaneous recovery can be attributed to various factors, including the resolution of edema, reperfusion of damaged but viable brain tissue, and the brain's inherent ability to compensate for lost functions. Whatever the reason it makes rehabilitation all the more important as it can be used to support and enhance the recovery the body is already engaged in.
  3. Subacute Rehabilitation Can Help Prevent Secondary Complications: Stroke survivors are at risk of developing secondary complications such as muscle weakness, contractures, spasticity, pressure ulcers, and respiratory problems. Early initiation of rehabilitation interventions in the subacute phase can help prevent or minimize these complications. Physical therapy and other rehabilitation modalities focus on preventing muscle deterioration, maintaining joint range of motion, promoting mobility, and addressing other functional limitations.

How BrainQ Is Addressing Subacute Recovery

In the past, stroke treatment innovations have primarily focused on the acute phase, often leaving patients in the subacute phase to grapple with outdated neurorehabilitation techniques, chiefly physical therapy. However, BrainQ is challenging this approach with the development of an innovative home recovery solution.

This innovative approach is specifically designed to aid patients in the subacute phase of a stroke, bringing relief and support to those grappling with post-stroke impairments. It involves a novel method of delivering targeted stimulation to neural networks, combined with customized physiotherapy, all conducted within the comfort of the patient's home. This targeted solution represents a significant step forward, designed to more effectively meet the needs of these patients during this crucial stage of recovery.

 Figure 1 - Timeline of stroke recovery:

Agreed definitions and a shared vision for new standards in stroke recovery research: The Stroke Recovery and Rehabilitation Roundtable taskforce, Sage Journal (July 2017). Link