Glucose, Vitals, NIHSS, and Neurologic Change

Glucose comes early

Stroke pathways begin with a fingerstick glucose because abnormal glucose can confuse the clinical picture and worsen brain injury. Severe hypoglycemia (often <50-60 mg/dL) can produce focal weakness, dysarthria, altered mental status, or seizure-like activity that perfectly mimics stroke. Treat hypoglycemia promptly and reassess the deficit before the team commits to thrombolysis — if the deficit clears with glucose correction, the patient is not having a stroke.

Hyperglycemia also matters, but lower is not always better. Admission and early hyperglycemia are associated with worse outcomes and higher hemorrhagic-transformation risk, yet the 2026 AHA/ASA acute ischemic stroke update advises maintaining glucose in the 140-180 mg/dL range and cautions against intensive control to 80-130 mg/dL, which increases severe hypoglycemia without improving outcome. Follow protocol, report critical values, and never let a correctable mimic go untreated.

Vitals are treatment data

Vital signs are not background information in hyperacute stroke. Oxygen saturation, respiratory pattern, temperature, blood pressure, cardiac rhythm, and level of consciousness all affect safety. Treat hypoxemia to keep SpO2 above 94%, but do not give supplemental oxygen to non-hypoxic patients. Fever worsens neurologic injury, so target normothermia and treat temperature above 38°C per protocol while investigating a source. Cardiac monitoring may reveal atrial fibrillation, the leading cardioembolic cause, which shapes both acute care and secondary prevention.

Blood-pressure interpretation depends entirely on the treatment pathway. Before IV thrombolysis, BP must be lowered to below 185/110 mm Hg. After thrombolysis, maintain BP below 180/105 mm Hg for 24 hours. In an ischemic patient who is not a thrombolytic candidate, permissive hypertension is allowed and antihypertensives are generally withheld unless BP exceeds 220/120 mm Hg. The 2026 update also stresses that intensive systolic lowering below 140 mm Hg after IV thrombolysis or endovascular therapy is not beneficial and may be harmful after thrombectomy.

The NIHSS: 11 items, 0 to 42

The National Institutes of Health Stroke Scale (NIHSS) is a standardized 11-item exam that quantifies severity from a total of 0 (normal) to a maximum of 42 (most severe). Each item scores impairment, and the items are summed. Severity bands are: 0 no symptoms, 1-4 minor, 5-15 moderate, 16-20 moderate-to-severe, and 21-42 severe. The number communicates severity quickly and supports treatment decisions, but the nurse must also describe the actual deficit in words.

NIHSS limitations and trending

A low NIHSS does not mean low risk. The scale is weighted toward dominant-hemisphere (left, anterior) function, so it systematically underscores posterior-circulation strokes. A basilar or cerebellar stroke causing disabling vertigo, diplopia, dysphagia, or impending coma may score only 2-4 yet be life-threatening. Likewise, isolated disabling aphasia, hemianopia, or severe neglect may carry a modest score while still warranting urgent reperfusion. Conversely, a high or rising NIHSS may signal an LVO, malignant edema, hemorrhagic transformation, recurrent embolization, or seizure.

Use the NIHSS as both a baseline and a trend. Perform it the same way each time, ideally by the same trained certified assessor, comparing speech, gaze, drift, sensation, neglect, and consciousness against the documented baseline. Ask whether any change is new, reproducible, and clinically meaningful. A two-point or greater rise is a common threshold that prompts re-evaluation and often repeat imaging, because it can be the earliest objective signal of hemorrhagic transformation, propagating thrombus, or evolving edema. Document the time, the items that changed, and who was notified, so the trend is unambiguous to the next provider.

Remember the scoring conventions that trip up exam takers: an intubated or aphasic patient is still scored (you score what you can observe, and untestable items have defined rules), a comatose patient with no response scores the maximum on most items, and you score the first effort, not the best effort after coaching. The scale measures impairment, not etiology — it cannot distinguish ischemia from hemorrhage, which is exactly why imaging, not the score, decides the bleeding question.

Neurologic change is never routine

Escalate sudden severe headache, vomiting, acute hypertension, decreased level of consciousness, new pupillary asymmetry, tongue swelling during thrombolysis, fresh bleeding, seizure, or a worsening NIHSS. In SCRN questions, any answer that continues routine checks after clear deterioration is unsafe. The correct nursing response is to stop a harmful exposure (such as an infusing thrombolytic) if applicable, call the stroke or rapid-response team, protect airway and hemodynamics, and prepare for emergent repeat imaging or intervention.