Your Guide to Posterior Circulation Stroke Symptoms

Article by Moody Neuro

These strokes occur when the blood supply to these areas is compromised due to blockages (ischemia) or bleeding (hemorrhage) in the vertebrobasilar arterial system, which includes the vertebral and basilar arteries.

How Common is a Posterior Circulation Stroke?

Although PCS is less common than Anterior Circulation Stroke (ACS), which impacts the front part of the brain, it still represents a significant portion of stroke cases, accounting for approximately 20% of all strokes. In the United States alone, 70,000 to 100,000 people experience PCS annually.

The implications of a PCS can be profound, affecting various functions controlled by the posterior part of the brain, such as balance, coordination, vision, and consciousness. The severity of symptoms and the prognosis for individuals with PCS can vary widely.

Some patients may experience relatively mild effects and have a good chance of recovery, while others, particularly those with basilar artery occlusion (BAO), may face severe deficits or even death.

Mortality rates can be as high as 80% in severe cases, primarily when the occlusion affects the proximal or middle portions of the basilar artery, underscoring the critical nature of timely diagnosis and treatment.

Types and Locations of Posterior Circulation Stroke

PCS can manifest within the posterior part of the brain’s circulation system, primarily impacting the vertebral, cerebellar, and basilar arteries.

The diversity in the location of these strokes contributes to a broad spectrum of neurological symptoms, reflecting the complexity and critical functions of the affected areas.

Here’s a closer look at how strokes in these locations can influence brain function and patient symptoms:

Vertebral Arteries

The vertebral arteries are pivotal as they ascend through the neck and join at the base of the brain to form the single basilar artery. PCA strokes occurring in the vertebral arteries can lead to issues such as:

Lateral Medullary Syndrome (Wallenberg’s Syndrome): Symptoms might include difficulty swallowing (dysphagia), hoarseness, dizziness, nausea, and a unique pattern of sensory loss – loss of pain and temperature sensation on the opposite side of the body and the same side of the face.
Loss of Coordination: Affecting the cerebellum can lead to ataxia or a lack of muscle coordination, affecting the ability to perform voluntary movements like walking or picking up objects.

Cerebellar Arteries

The cerebellum, supplied by the cerebellar arteries, plays a crucial role in motor control and balance. Strokes in this region can cause:

Ataxia: As mentioned, this is a lack of voluntary coordination of muscle movements that can include gait abnormality, speech changes, and movements that are not smooth or precise.
Nausea and Vomiting: The cerebellum’s role in balance can also influence the vestibular system, leading to vertigo, dizziness, and associated symptoms.

Basilar Artery

The basilar artery supplies blood to the brainstem and parts of the cerebellum, making strokes in this area particularly severe. Potential posterior stroke symptoms include:

Quadriplegia: Loss of movement in all four limbs due to brainstem involvement.
Locked-In Syndrome: A condition where the patient is awake and mentally aware but cannot move or communicate verbally due to paralysis of nearly all voluntary muscles in the body except for eye movement.
Cranial Nerve Deficits: This leads to facial weakness, difficulty speaking (dysarthria), and swallowing problems.

How is a Posterior Circulation Stroke Diagnosed?

Diagnosing PCS is a multifaceted process that requires a combination of clinical acumen and advanced imaging techniques to identify and evaluate the extent of the stroke accurately.

The process typically unfolds in several key steps:

Initial Clinical Assessment

The first step in diagnosing PCS involves a comprehensive clinical evaluation beginning with a detailed patient history to gather information on symptom onset, duration, progression, and any potential risk factors like hypertension, atrial fibrillation, diabetes, smoking, or a history of previous strokes. This history helps assess the likelihood of a stroke and its possible type.

Neurological Examination

A more focused neurological examination assesses motor and sensory function, cranial nerve integrity, coordination, reflexes, and cognitive function. Specialized tests may also be conducted to evaluate balance, vision, speech, and swallowing. This comprehensive neurological evaluation helps localize the lesion within the central nervous system and supports the suspicion of PCS.

Imaging Tests

After the initial assessment suggests a PCS, imaging studies are pivotal in confirming the diagnosis and delineating the stroke’s location and extent.

Magnetic Resonance Imaging (MRI): Highly sensitive for detecting ischemic strokes, including those in the posterior circulation. DWI can reveal ischemic changes within minutes to hours after symptom onset, making it a crucial tool in PCS diagnosis. MRI can also provide detailed information about the brainstem, cerebellum, and other PCS-affected structures.
Computed Tomography (CT) Scan: Often the first imaging modality used in acute stroke settings due to their wide availability and speed. They can quickly rule out hemorrhagic strokes and other causes of similar symptoms.
Magnetic Resonance Angiography (MRA) and CT Angiography (CTA): Used to visualize the blood vessels and can identify occlusions or stenoses in the vertebral and basilar arteries, confirming the presence of a posterior circulation blockage.
Digital Subtraction Angiography (DSA): Considered the gold standard for detailed vascular imaging. It is instrumental when other imaging studies are inconclusive or when endovascular treatment options are being considered.

Understanding Crossed Symptoms

Crossed symptoms are common in PCS cases. These posterior circulation stroke symptoms manifest as a combination of cranial nerve dysfunctions on one side of the body (ipsilateral) and sensory or motor deficits on the opposite side (contralateral). This occurrence is directly linked to the brainstem’s unique anatomical structure and the crossing (decussation) of various neural pathways within the central nervous system.

The brainstem, a critical structure affected in PCS, houses the origins of most cranial nerves and is a conduit for long nerve tracts that relay motor and sensory information between the brain and the rest of the body.

Because some of these pathways cross to the opposite side before entering or after exiting the brainstem, a lesion in this area can impact the cranial nerves (affecting functions like facial movement or swallowing) and the long tracts (affecting sensation and movement in the limbs).

Crossed symptoms in PCS cases pose a significant diagnostic challenge for healthcare professionals. Unlike more straightforward instances in which deficits are localized to one side of the body, the dual nature of crossed symptoms can obscure the clinical picture, leading to potential misdiagnosis or delays in identifying the underlying stroke.

The Causes of Misdiagnosis

Regrettably, cases of PCS are frequently misdiagnosed, with substantial clinical studies indicating that a significant proportion of PCS cases are initially missed or incorrectly identified as other conditions.

In fact, between 28% and 59% of cerebellar strokes, a specific type of PCS, are initially misdiagnosed. According to a recent study involving 465 stroke patients, the misdiagnosis rate for those with PCS was 38%, which is 2.5 times more likely than those with ACS, who had a rate of 16%.

Causes of Misdiagnosis in PCS

Nonspecific and Overlapping Symptoms: Patients with PCS may experience symptoms similar to those of ACS and other non-stroke conditions. These symptoms are common and may not necessarily indicate a stroke, making it challenging for clinicians to diagnose PCS accurately.
Lack of Lateralizing Symptoms: One of the difficulties in diagnosing PCS is the absence of clear lateralizing signs, especially in younger patients. The sudden onset of neurological symptoms without clear lateralization can mislead clinicians to overlook stroke as a potential diagnosis.
Commonality of Presenting Symptoms: The PCA symptoms, such as dizziness and sensory disturbances, are commonly observed in emergency department patients, most of whom are not experiencing a stroke. Consequently, it can be hard to identify PCS, as these symptoms are prevalent and may not necessarily indicate a stroke.
Younger Age and Unusual Causes: A higher risk of misdiagnosis is associated with younger patients and those with vertebral artery dissection as the cause, mainly presenting with dizziness. This could be because stroke is believed to be less likely in younger individuals and the unique presentation of VAD-related strokes.
Transient Symptoms: Diagnostic errors may result from misconceptions about transient ischemic attacks (TIAs), especially isolated transient dizziness. A considerable proportion of patients experiencing posterior circulation TIAs present with isolated vertigo or non-focal symptoms, which may not meet traditional criteria for TIA but still indicate a significant risk for subsequent stroke.
Imaging Limitations: Although advanced imaging techniques such as diffusion-weighted imaging (DWI) MRI are essential for diagnosing PCS, there are limitations. In some cases, early imaging may fail to capture the stroke, contributing to a misdiagnosis.

Entrust Your Stroke Recovery Journey to Trusted Experts

Navigating the aftermath of a stroke can feel overwhelming, but you don’t have to face it alone. At Moody Neurorehabilitation, we specialize in providing compassionate and comprehensive post-stroke care, understanding the unique challenges of recovery, and recognizing and managing Posterior Circulation Stroke symptoms.

Our dedicated team of experts employs a patient-centered approach, crafting personalized treatment plans that address the physical and emotional aspects of recovery. We believe in empowering our patients and their families with knowledge, support, and the latest rehabilitative therapies.

Embark on your journey to recovery with Moody Neurorehabilitation. Let us guide you through each step with expertise and empathy, ensuring you feel supported in your rehabilitation journey.

Contact us today to schedule a consultation and discover how our specialized care can make a difference in your life or that of a loved one.

Sources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6170115/

https://www.rcpjournals.org/content/clinmedicine/23/3/219

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4530423/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3985033/

https://www.researchgate.net/publication/282344143_Missed_Stroke_in_Acute_Vertigo_and_Dizziness_It_is_Time_for_Action_not_Debate

https://www.researchgate.net/publication/262026405_Stroke_Risk_After_Non-Stroke_ED_Dizziness_Presentations_A_Population-Based_Cohort_Study

https://onlinelibrary.wiley.com/doi/full/10.1111/acem.13830

Strokes are medical conditions that affect millions globally. In the United States, more than 795,000 people have a stroke each year, with about 610,000 cases being first or new strokes.

These can lead to a wide range of physical and cognitive impairments. Speech and language disorders are among the most common and most challenging consequences of strokes, occurring in about a third of stroke survivors.

Understanding Stroke-Induced Speech & Language Disorders

Stroke-induced speech and language disorders significantly impact communication abilities. Among these, aphasia, dysarthria, and apraxia of speech are prevalent. Understanding how they are diagnosed and their specific symptoms can aid in prompt and effective management.

Aphasia

Aphasia is a common outcome of stroke, manifesting as difficulty in speaking, understanding, reading, and writing. There are many different types of aphasia, depending on the affected brain area, and are categorized based on the symptoms present:

Expressive Aphasia (Broca’s Aphasia): Characterized by broken speech, limited vocabulary, and difficulty forming complete sentences. Patients often understand what is being said to them but struggle to verbalize responses.
Receptive Aphasia (Wernicke’s Aphasia): Patients can produce fluent speech but may lack meaning or include nonsensical words. They often have significant difficulty understanding spoken language.
Global Aphasia: A severe form of aphasia where individuals have extensive difficulties with both speech production and comprehension.
Anomic Aphasia: Individuals have difficulty finding words, particularly nouns and verbs, making their speech sound vague.

Dysarthria

Dysarthria is a speech disorder that affects 20-30% of stroke survivors. It occurs when stroke impacts the muscles responsible for speech, leading to slurred or slow speech that can be hard to understand. It is typically diagnosed through a physical examination and a series of speech evaluations conducted by a speech-language pathologist (SLP).

It is characterized by the following symptoms:

Slurred or slow speech that can be difficult to understand
Monotone or robotic-sounding speech
Difficulty controlling the volume of speech, which may be too loud or too soft
Challenges with the rhythm and flow of speech, including rapid speech that’s hard to interrupt or slow, drawn-out speech
Respiratory issues affecting the ability to speak loudly or for extended periods

Apraxia of Speech (AOS)

Apraxia of speech is a neurological disorder characterized by difficulty sequencing the movements needed for speech. This is caused by the impact of the stroke on the brain’s pathways involved in producing speech.

Patients with AOS know what they want to say but struggle to coordinate the muscle movements to articulate words correctly. This results in distorted speech, difficulty initiating speech, or the inability to accurately produce speech sounds or sequences of sounds.

How Long Is the Stroke Speech & Language Recovery Time?

According to one study on post-stroke speech and language therapy, approximately one-third of stroke patients experience speech problems after a stroke. Many of these individuals begin to recover within a few months, with significant progress typically observed within three to six months.

In another study, 62% of subjects had speech challenges after suffering from a stroke. By six months post-stroke, 74% were able to completely recover their communication abilities.

However, the figures above provide a general timeline for post-stroke speech and language recovery. Stroke speech recovery time is highly individualized and can vary depending on several factors. These can include the following:

Severity of the Stroke: More severe strokes often lead to extensive brain damage, resulting in longer and more challenging recovery periods for speech.
Location of the Brain Injury: The brain’s specific regions control different speech and language functions; damage to these areas directly impacts recovery complexity and duration.
Age and Overall Health of the Patient: Generally, younger patients with better overall health before the stroke tend to experience faster and more complete recoveries.
Pre-existing Conditions and Comorbidities: Conditions such as diabetes or hypertension can slow down recovery by complicating the overall health scenario and rehabilitation process.
Individual Variability and Resilience: Personal resilience, the support system’s strength, and the individual’s motivation significantly influence the pace and success of speech recovery efforts.

The first three months after a stroke is a crucial period for recovery, as a majority of stroke patients see the most significant improvement during this period. However, it’s also important to note that, although at a slower pace, recovery can continue well past the 6-month mark with continued therapy and practice.

This underpins the importance of early intervention and ongoing rehabilitation efforts, including speech therapy, to maximize each patient’s recovery potential.

What Does the Stroke Speech & Language Recovery Process Look Like?

The journey to regain speech and language after a stroke is multifaceted and varies significantly from one individual to another. Understanding the structured phases of recovery can provide insight into what patients and their families can expect during this challenging time.

Here’s a closer examination of each phase in the stroke speech recovery process.

Initial Assessment and Diagnosis

Before recovery can begin, a thorough evaluation is conducted by a team of healthcare professionals led by an SLP. This assessment aims to identify the type and severity of the speech and language disorder, be it aphasia, dysarthria, or AOS. The evaluation may include cognitive-linguistic assessments, comprehension tests, speech production analysis, and functional communication measures.

Based on this assessment, a personalized therapy plan is crafted to address the patient’s specific needs.

Acute Phase

The acute phase typically occurs within the first days to weeks following a stroke. During this period, medical stabilization is the primary focus, with healthcare teams working to manage the immediate effects of the stroke.

Speech therapy may begin with simple exercises or assessments to gauge the patient’s abilities. However, intensive therapy usually does not start until the patient is medically stable. During the acute phase, the goal is to support overall recovery and prevent complications immediately after the stroke.

Subacute Phase

The subacute phase generally spans from two weeks to three months post-stroke and is characterized by more intensive speech therapy interventions. As the patient’s medical condition stabilizes, the focus shifts to active rehabilitation. Therapy during this phase is tailored to the individual’s specific speech and language deficits and may include:

Exercises to improve articulation, fluency, and voice control for those with dysarthria.
Language therapy to enhance understanding, speaking, reading, and writing skills in patients with aphasia.
Motor speech exercises and strategies to improve speech planning and production in apraxia of speech.

The subacute phase is crucial for taking advantage of the brain’s natural recovery processes and neuroplasticity, where the brain begins reorganizing and adapting to the loss of function.

Chronic Phase

The chronic phase of recovery extends from several months to years after the stroke. It focuses on long-term rehabilitation and adjustment to any residual speech deficits. During this time, patients may continue to see gradual improvements in their speech and language abilities, although the rate of recovery may slow. Therapy in the chronic phase often includes:

Advanced communication strategies to cope with ongoing challenges in daily life.
Maintenance exercises to preserve and enhance speech gains achieved in earlier phases.
Supportive technologies and aids, such as communication devices, to assist in effective communication.
Community reintegration activities to help patients return to as normal a life as possible, engaging in social, vocational, or recreational activities.

What Is the Role of Neuroplasticity in Speech & Language Recovery?

Neuroplasticity refers to the brain’s fundamental property to change and adapt its responses to new experiences, learning, and environmental changes. This adaptive capacity enables the brain to reorganize itself by forming new neural connections.

When the brain, or a part of the brain, is damaged after a stroke, neuroplasticity is what allows the other parts of the brain to take over the functions of the damaged area. Through targeted rehabilitation and therapy, such as speech therapy for stroke survivors, patients can retrain other brain areas to perform the lost functions and facilitate recovery.

Enhancing Stroke Speech & Language Recovery Time

Adopting a comprehensive approach involving several key strategies is vital to enhance the stroke speech and language recovery time. This multifaceted approach can maximize the chances of regaining speech and communication abilities.

This comprehensive approach must incorporate the following strategies:

Early intervention to leverage the brain’s highest potential for neuroplasticity in the initial period following a stroke, significantly improving the chances for recovery.
Alternative communication strategies, such as gestures, writing, and visual aids, to help maintain communication during the recovery process.
Adopting technology, including speech-generating devices and software applications designed for speech rehabilitation, for personalized exercises and continuous practice, which is vital for progress.
Providing continuous support from psychologists, support groups, and therapy to help manage feelings of frustration, depression, and anxiety, fostering a positive mindset essential for rehabilitation.
A healthy diet and lifestyle to supply essential nutrients that support brain function, along with regular physical activity, adequate sleep, and management of medical conditions.

Begin Your Post-Stroke Recovery Journey With Moody Neurorehabilitation

Moody Neurorehabilitation understands the complexities and challenges that come with post-stroke rehabilitation. We are dedicated to supporting patients and their families through this critical time with specialized care and personalized treatment plans.

Since our inception in 1982, Moody Neurorehabilitation has been a leader in brain injury rehabilitation. Our approach centers on providing comprehensive care tailored to each patient’s needs and goals. We believe in treating the whole person, not just the symptoms, to improve overall quality of life.

We invite you to start your recovery journey with us. Contact Moody Neurorehabilitation today to schedule a consultation with our experts. Let us help you navigate the path to recovery with care, compassion, and expertise.