How do I assess the best gaze component using the National Institutes of Health (NIH) stroke scale and what is the role of the oculocephalic reflex in evaluating a patient with a possible stroke?

From the Guidelines

To assess the best gaze component on the NIH stroke scale, observe the patient's eyes in primary position and test horizontal eye movements by asking them to follow your finger or a target object from side to side, scoring 0 if normal, 1 if partial gaze palsy, and 2 if forced deviation or total gaze paresis not overcome by the oculocephalic maneuver, as outlined in the NIHSS guidelines 1. The oculocephalic reflex, also known as the doll's eyes maneuver, is crucial when patients cannot follow commands, and it helps differentiate between supratentorial and brainstem lesions. To perform the oculocephalic reflex, hold the patient's head firmly and turn it quickly from side to side while keeping their eyelids open. In conscious patients with intact brainstem function, the eyes will move in the opposite direction of head rotation, as noted in the guidelines for the early management of patients with ischemic stroke 1. The NIHSS is an 11-part scale that measures the neurologic examination in a codified manner, with scores ranging from 0 to 42, and it provides important information about the severity of stroke and prognostic information, influencing decisions about acute treatment 1. Key points to consider when assessing the best gaze component include:

• Testing horizontal eye movements by asking the patient to follow a target object
• Scoring 0 for normal gaze, 1 for partial gaze palsy, and 2 for forced deviation or total gaze paresis
• Using the oculocephalic reflex to assess brainstem function when patients cannot follow commands
• Differentiating between supratentorial and brainstem lesions based on the presence or absence of the oculocephalic reflex, as recommended in the guidelines for the early management of adults with ischemic stroke 1.

From the Research

Assessing Best Gaze Component using the NIH Stroke Scale

• The best gaze component of the NIH stroke scale assesses the patient's ability to move their eyes in both directions, with a score ranging from 0 (normal) to 2 (patient looks in the direction of the lesion) 2.
• To test the best gaze component, the examiner should ask the patient to look to the left and right, and observe for any deviation or limitation of eye movement.
• The oculocephalic reflex, also known as the doll's eye reflex, can be used to assess the integrity of the brainstem and the cranial nerves that control eye movement 3.

Role of the Oculocephalic Reflex in Assessing a Patient with Possible Stroke

• The oculocephalic reflex is a reflexive movement of the eyes in response to head movement, and is typically assessed by gently rotating the patient's head from side to side while observing the eyes for movement 3.
• In patients with stroke, the oculocephalic reflex can be impaired, resulting in a decreased or absent reflexive movement of the eyes 4, 5.
• The presence or absence of the oculocephalic reflex can provide valuable information about the location and severity of the stroke, and can be used in conjunction with other clinical findings to guide diagnosis and treatment 2, 6.
• Studies have shown that gaze deviation, which can be assessed using the oculocephalic reflex, is associated with poor outcome and increased mortality in patients with acute ischemic stroke 5, 2.