What is the localization and level of a stroke if facial nerve (cranial nerve VII) paresis is present?

From the Guidelines

Facial nerve paresis from a stroke is typically localized to the facial nerve nucleus in the pons or its supranuclear pathways, with the level of the lesion determined by examining the pattern of facial weakness, as outlined in the National Institutes of Health Stroke Scale (NIHSS) 1. The NIHSS is a widely used scale that measures the neurologic examination in a codified manner, ranging from 0 to 42, with a score of less than 5 indicating a small stroke and greater than 20 indicating a large stroke 1. In a central (supranuclear) lesion, which is common in strokes, the lower face is predominantly affected while the forehead is relatively spared, due to the upper face receiving bilateral cortical innervation, while the lower face receives contralateral innervation 1. Some key points to consider when localizing and determining the level of stroke in patients with facial nerve paresis include:

• The pattern of facial weakness, with central lesions affecting the lower face and peripheral lesions affecting both upper and lower facial muscles equally 1
• Associated symptoms, such as hemiparesis on the same side as facial weakness, which suggests a cortical or subcortical lesion, while ipsilateral sixth nerve palsy or contralateral hemiparesis suggests a pontine lesion 1
• The use of the NIHSS to assess stroke severity and guide management decisions, with careful neurological examination focusing on these patterns essential for accurate localization and appropriate management of the underlying stroke 1. It is also important to note that the most recent and highest quality study on this topic is from 2018, which provides updated guidelines for the management of acute stroke, including the use of the NIHSS and other assessment tools 1. Some other key considerations when managing patients with facial nerve paresis due to stroke include:
• Rapid initial evaluation for airway, breathing, and circulation, as well as assessment of stroke severity using a standardized stroke scale such as the NIHSS 1
• Acute blood work, including electrolytes, random glucose, complete blood count, coagulation status, and creatinine, to guide management decisions 1
• Seizure assessment and management, with new-onset seizures at the time of an acute stroke treated using appropriate short-acting medications, and monitoring for recurrent seizure activity during routine monitoring of vital signs and neurological status 1.

From the Research

Localizing and Level of Stroke if Facial Nerve Paresis

• The level and localization of a stroke can be determined by assessing the severity and type of facial nerve paresis, among other symptoms 2.
• Central facial paresis (CFP) is a major symptom of stroke, and its impact on motor and non-motor disabilities in patients has been studied 2.
• A prospective cohort study of 112 patients with CFP found that the median interval from stroke to rehabilitation was 21 days, and rehabilitation lasted 20 days 2.
• The study also found that facial grading and Facial Disability Index (FDI)/Facial Clinimetric Evaluation (FaCE) scores improved during inpatient rehabilitation 2.

Factors Affecting Outcome

• The outcome of patients with acute ischemic stroke can be affected by various factors, including the time window for intravenous tissue-type plasminogen activator treatment 3.
• A study of 581 consecutive patients treated with alteplase found that the impact of time-to-treatment on favorable outcome varies widely depending on baseline stroke severity 3.
• In patients with mild stroke, younger age, no previous history of stroke, and no proximal occlusion were independent predictors of favorable outcome 3.
• In patients with moderate stroke, age, no proximal occlusion, and time-to-treatment before 120 minutes emerged as independent predictors of favorable outcome 3.

Treatment and Rehabilitation

• Orofacial therapy has been shown to have a significant effect on facial movement and mental state in patients with stroke 4.
• A prospective blind randomized study of 50 cases treated with regulation orofacial therapy found that facial movement was significantly better in the experimental group after orofacial therapy compared with the control group 4.
• Changes in mental status, as measured by the Beck Depression Inventory (BDI-II), were also significantly greater in the experimental group 4.
• The study suggests that orofacial therapy can be an effective treatment for patients with stroke and facial paresis 4.