Neurological Examination of an Unconscious Patient

Study Notes

The topic of an unconscious patient is crucial in the medical field, particularly in emergency rooms, intensive care units (ICUs), and critical care settings. Given the various causes of coma and the importance of early detection, it is essential to have a thorough understanding of the neurological exam of an unconscious patient. This article will provide a comprehensive guide to the essential practical steps and techniques used to assess and determine the nature of a patient's neurological status.

General Examination

The first step in the neurological exam of an unconscious patient is a systematic and thorough examination. The general examination should include observing the patient's stationary position on the bed and the attitude of their limbs. Document any spontaneous motor behavior or semi-purposive movements of all four extremities, breathing patterns, and oropharyngeal reflexes such as coughing, swallowing, hiccupping, or yawning.

Level of Consciousness

The level of consciousness is determined by assessing the patient's response to various stimuli, which can be either peripheral or central. The current recommendation by the European Academy of Neurology (EAN) is the Full Outline of UnResponsiveness (FOUR), a more comprehensive alternative to the Glasgow Coma Scale (GCS). This includes assessing eye response, motor response, brainstem reflexes, and respiration.

Eye Response

Eye response can be assessed using the following ratings:

4: Eyelids open or opened, tracking or blinking to command
3: Eyelids open but not tracking
2: Eyelids closed but open to loud voice
1: Eyelids closed but open to pain
0: Eyelids remain closed with pain

Motor Response

Motor response is evaluated using the following ratings:

4: Thumbs-up, fist, or peace sign
3: Localizing to pain
2: Flexion response to pain
1: Extension response to pain
0: No response to pain or generalized myoclonus status

Brainstem Reflexes

Brainstem reflexes are assessed as follows:

4: Pupil and corneal reflexes present
3: One pupil wide and fixed
2: Pupil or corneal reflexes absent
1: Pupil and corneal reflexes absent
0: Absent pupil, corneal, and cough reflex

Respiration

Respiration is assessed by examining the patient's breathing patterns:

4: Not intubated, regular breathing pattern
3: Not intubated, Cheyne–Stokes breathing pattern
2: Not intubated, irregular breathing
1: Breathes above ventilator rate
0: Breathes at ventilator rate or apnea

Cranial Nerves Assessment

Assessing the patient's cranial nerves is crucial in determining the location and nature of the neurological lesion responsible for the coma. This can be done by examining the following:

Olfactory nerve: Evaluate the patient's ability to identify and distinguish between different smells.
Optic nerve: Assess visual acuity, pupillary light reflex, and color vision.
Oculomotor nerve: Evaluate eye movement, convergence, and eye alignment.
Trochlear nerve: Assess eye movement in upward gaze.
Abducens nerve: Evaluate eye movement in lateral gaze.
Facial nerve: Assess facial symmetry, facial strength, and taste sensation.
Vestibulocochlear nerve: Evaluate hearing and balance.
Glossopharyngeal nerve: Evaluate taste sensation in the posterior third of the tongue.
Vagus nerve: Assess soft palate movement, vocal cord function, and gag reflex.
Accessory nerve: Evaluate neck muscle strength and trapezius muscle function.

Motor Assessment

Motor assessment is essential in determining the location and nature of the neurological lesion responsible for the coma. This can be done by:

Assessing muscle tone and strength
Evaluating deep tendon reflexes
Assessing the plantar reflex
Checking for abnormal movements, such as chorea or athetosis.

Conclusion

In conclusion, the neurological exam of an unconscious patient is a critical step in determining the location and nature of the neurological lesion responsible for the coma. It is essential to perform a systematic and thorough examination, starting with a history, physical examination, and laboratory evaluation. Recognizing the urgent steps needed to prevent further deterioration and ultimately determining the patient's neurological status are crucial in providing appropriate treatment and care.

Description

This article provides a comprehensive guide to the essential practical steps and techniques used to assess an unconscious patient's neurological status. It covers the general examination, level of consciousness assessment, cranial nerves examination, motor assessment, and emphasizes the importance of early detection for appropriate treatment.