NIHSS Item 6: Visual Field Testing & Scoring Guide

The neurological physical examination is a systematic assessment divided into two main parts: cranial nerve examination (12 pairs, numbered I-XII from cranial to caudal) and general neurological function evaluation. Cranial nerve examination includes testing the optic nerve (visual fields), oculomotor, trochlear, and abducens nerves (eye movements and pupillary reflexes), trigeminal nerve (facial sensation and mastication), facial nerve (muscle symmetry), vestibulocochlear nerve (hearing and balance via Romberg test), glossopharyngeal/vagus/accessory nerves (swallowing, speech, and head/shoulder movement), and hypoglossal nerve (tongue movement). General neurological assessment evaluates muscle strength (Minchin test, pronation, hand grip), tone, sensory function (light touch, proprioception, vibration), coordination (heel-to-shin, finger-to-nose), and reflexes (biceps, triceps, brachioradial, quadriceps, Achilles, Babinski sign). This comprehensive examination helps localize neurological lesions and diagnose conditions affecting the central or peripheral nervous system.

A neurological examination is a systematic assessment of the nervous system. Visual assessment includes visual acuity testing, visual field examination, and fundoscopic examination. Ocular motor function assessment evaluates the six extraocular muscles controlling eye movement. Cranial nerve assessment includes trigeminal nerve sensory testing (light touch, pain, temperature in three facial branches), facial nerve motor and sensory examination (forehead wrinkling, eye closure, nasolabial fold preservation, taste testing), and auditory examination (word recognition, Weber and Rinne tests). Vestibular function assessment evaluates balance and equilibrium by observing for nystagmus.

Neurological examination includes: (1) Level of consciousness assessment, (2) Cranial nerve evaluation (12 pairs), (3) Motor function testing (strength, tone), (4) Sensory examination, (5) Coordination testing, (6) Reflex assessment, (7) Gait and balance evaluation. Cranial nerve examination: (1) CN I (Olfactory) - smell testing, (2) CN II (Optic) - visual acuity and fundus examination, (3) CN III, IV, VI (Oculomotor, Trochlear, Abducens) - eye movement testing, (4) CN V (Trigeminal) - facial sensation and motor function, (5) CN VII (Facial) - facial expression testing, (6) CN VIII (Vestibulocochlear) - hearing and balance testing.

A cranial nerve examination systematically tests the nerves in the face, head, and neck. The examination begins with palpation of the face, temples, nose, cheeks, and jaw to assess for tenderness. The provider also listens to the heart and lungs using a stethoscope. Facial measurements are taken to document symmetry. Visual system testing includes pupillary light reflex testing, ocular motor function testing, visual acuity testing with Snellen chart, and color vision testing. This comprehensive assessment evaluates the optic nerve (CN II), oculomotor nerve (CN III), trochlear nerve (CN IV), and abducens nerve (CN VI).

A cranial nerve exam systematically tests the twelve cranial nerves that connect the brain to the head, neck, and body. The examination includes: (1) Visual testing (cranial nerve II) - assessing color, shape, and visual field recognition; (2) Olfactory testing (cranial nerve I) - evaluating smell identification; (3) Taste testing (cranial nerves VII and IX) - assessing taste sensation; (4) Tongue movement testing (cranial nerves VII and XII) - evaluating motor control. These basic tests form the foundation of neurological assessment, helping identify sensory and motor deficits that may indicate neurological conditions.

The NIH Stroke Scale is a 15-item standardized assessment tool used to quantify neurological deficits in stroke patients, ranging from 0 (no deficits) to 42 (severe deficits), with key components including level of consciousness assessment, lateral gaze testing, visual field evaluation, facial weakness examination, arm and leg strength testing, limb coordination assessment, sensation testing, language comprehension evaluation, and assessment for unilateral neglect; the scale helps identify patients eligible for emergent treatment, allows objective measurement of clinical status changes, and identifies those at higher risk for complications.

The NIH Stroke Scale (NIHSS) is a standardized neurological assessment tool developed in 1983 for acute stroke clinical trials. It serves four purposes: measuring neurological deficit, guiding treatment decisions, predicting outcomes, and monitoring progress. The scale consists of 11 items evaluating consciousness, gaze, visual fields, facial paralysis, motor strength, sensory function, ataxia, language, dysarthria, and neglect. Total scores range from 0-42, though the scale is non-linear beyond severe deficits. Four core principles govern testing: accept only the first response without coaching, score only observable actions, score only when impairment is definitely present, and include prior baseline deficits. These principles ensure consistency and reproducibility across examiners.

The NIHSS (National Institutes of Health Stroke Scale) is a standardized 11-item assessment tool with 13 sub-items evaluating neurological function in stroke patients. Scores range from 0-42, with higher scores indicating greater severity. NIHSS serves multiple clinical purposes: assessing neurological status, facilitating provider communication, rapidly evaluating stroke severity, and tracking disease progression. It does not support stroke diagnosis as it cannot determine lesion location. NIHSS thresholds guide treatment decisions, with scores above 22 points serving as relative contraindications for thrombolysis. Specific criteria identify patients at high risk of severe disability, including complete motor deficit, severe aphasia, or complete sensory loss.

The NIH Stroke Scale (National Institutes of Health Stroke Scale) is a more comprehensive assessment tool with 11 detailed parameters for stroke evaluation. While excellent for detailed assessment, it is impractical for routine emergency department use due to the significant time required to administer it. In acute stroke settings where time is critical ('time is brain'), the Cincinnati Scale provides a faster alternative that still effectively identifies patients needing urgent imaging and intervention.

The NIH Stroke Scale (NIHSS) is a standardized 15-item assessment tool used to quantify stroke severity. It evaluates: level of consciousness, gaze, visual fields, facial palsy, motor function (arms and legs), ataxia, sensory function, language, dysarthria, extinction/inattention, and best/gross motor function. Scores range from 0 (no stroke) to 42 (severe stroke). Scores of 0-4 indicate minor stroke, 5-15 indicate moderate stroke, and 16+ indicate severe stroke. NIHSS is used for: baseline assessment, monitoring recovery, determining thrombolytic eligibility, and predicting outcomes. It provides a common language for communication among healthcare providers.

Sensory extinction examines attention and sensory integration rather than basic sensation, particularly sensitive to parietal lobe dysfunction (most often non-dominant hemisphere). Patient closes eyes. Apply light stimulus to one side then the other to confirm each side perceived normally. Key step: apply stimulus to both sides simultaneously and ask patient to describe where they feel it (can use pin prick or visual stimuli). Normal response is perception of both stimuli simultaneously with symmetrical awareness. Sensory extinction is present when patient correctly detects unilateral stimulation but fails to report one side during bilateral stimulation. This finding points to contralateral parietal lobe lesion, classically involving right parietal cortex leading to left-sided extinction. Because extinction can be subtle, careful technique and repetition are important.

The extinction test assesses sensory integration by touching one side of the body, then the other side, then both sides simultaneously while the patient's eyes are closed. The patient indicates which side(s) they felt. In stroke patients with hemisensory loss, they may correctly identify single-sided touches but fail to recognize simultaneous bilateral stimulation on the affected side. This phenomenon demonstrates extinction of sensation on the lesioned side when both sides are stimulated together.

Extinction is tested using simultaneous bilateral stimulation (touching both sides simultaneously). The patient should report stimulation on both sides. If the patient only reports stimulation on the non-affected side, extinction is present. Scoring: 0 = no extinction, 1 = extinction in one sensory modality (visual, tactile, or auditory), 2 = extinction in multiple modalities or complete hemineglect. Hemineglect is dangerous because patients may not recognize injuries on the affected side.

Sensory inattention (perceptual rivalry) is tested by asking the patient to put out their hands while the examiner touches one or both hands. The patient identifies which hand(s) were touched with eyes closed. This tests cortical sensory processing.