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The Hunt and Hess Scale is a clinical grading system used to classify the severity of subarachnoid hemorrhage (SAH) based on the patient's neurological condition at presentation. Introduced by William E. Hunt and Robert M. Hess in 1968, it remains one of the two most commonly used SAH grading scales worldwide (alongside the World Federation of Neurological Surgeons, or WFNS, scale). The Hunt and Hess Scale categorizes patients into five grades based on clinical symptoms and signs, with each ascending grade representing more severe neurological compromise and poorer prognosis.
Subarachnoid hemorrhage, most commonly caused by rupture of an intracranial aneurysm, is a neurosurgical emergency with overall mortality rates of 30–50% and significant morbidity among survivors. Rapid, accurate grading is essential because it directly influences clinical management decisions: the timing and approach to aneurysm repair (surgical clipping versus endovascular coiling), the intensity of ICU monitoring, and the aggressiveness of vasospasm prevention protocols all depend on the patient's Hunt and Hess grade at admission.
Grade 1 patients are asymptomatic or have only minimal headache and slight nuchal rigidity, carrying surgical mortality of approximately 1%. Grade 2 patients have moderate-to-severe headache and nuchal rigidity but no neurological deficit other than cranial nerve palsy. Grade 3 patients show drowsiness, confusion, or mild focal neurological deficit. Grade 4 patients are stuporous with moderate-to-severe hemiparesis. Grade 5 patients are in deep coma with decerebrate rigidity and have a moribund appearance with surgical mortality approaching 77%.
This calculator enables rapid Hunt and Hess grading to facilitate communication among emergency physicians, neurologists, neurosurgeons, and intensivists in the time-critical management of subarachnoid hemorrhage.
The Hunt and Hess Scale assigns a grade (1–5) based on the patient's neurological examination at presentation:
Surgical mortality by grade: Grade 1 ≈ 1%, Grade 2 ≈ 5%, Grade 3 ≈ 19%, Grade 4 ≈ 42%, Grade 5 ≈ 77%. Grades 1–3 are generally considered favorable for early surgical intervention, while grades 4–5 may require stabilization before definitive treatment.
Grade 1–2 patients have good prognosis and are typically managed with early aneurysm repair (within 24–72 hours), vasospasm prophylaxis, and standard ICU monitoring. Grade 3 patients have intermediate prognosis and are managed similarly but with closer monitoring and more aggressive medical optimization. Grade 4 patients have poor prognosis; surgical timing is debated, and aggressive ICP management is often needed. Grade 5 patients have very poor prognosis; treatment is often supportive, though some centers pursue intervention in select cases, particularly younger patients.
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Results
Hunt and Hess Grade 2 — moderate headache with nuchal rigidity, no focal deficit. Early aneurysm repair indicated.
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Results
Hunt and Hess Grade 4 — stuporous with hemiparesis. 42% surgical mortality, requires stabilization.
The Hunt and Hess Scale is a 5-grade clinical classification system for subarachnoid hemorrhage severity, based on the patient's neurological status at presentation, ranging from asymptomatic (Grade 1) to deep coma (Grade 5).
The scale was introduced in 1968 by William E. Hunt and Robert M. Hess as a way to standardize the clinical grading of subarachnoid hemorrhage and predict surgical risk.
The WFNS (World Federation of Neurological Surgeons) scale uses the GCS and focal deficit to grade SAH. Hunt and Hess is more subjective but remains widely used. Both are recommended by international guidelines.
Hunt and Hess Grade 5 carries approximately 77% surgical mortality. These patients are in deep coma with decerebrate rigidity and have a grave prognosis regardless of treatment approach.
This is debated. Some neurosurgeons advocate for early intervention in Grade 4 patients and selected Grade 5 patients (especially younger ones), while others prefer medical stabilization first or supportive care only.
Approximately 80% of non-traumatic subarachnoid hemorrhage is caused by rupture of an intracranial aneurysm. Other causes include arteriovenous malformations, perimesencephalic hemorrhage, and vasculitis.
Yes. Patients can improve or deteriorate, and re-grading should occur after resuscitation and stabilization. Vasospasm, rebleeding, or hydrocephalus can cause clinical deterioration and grade escalation.
Nuchal rigidity refers to neck stiffness due to meningeal irritation from blood in the subarachnoid space. It is a hallmark sign of SAH and is assessed by attempting passive neck flexion.
Lower grades (1–3) generally favor early intervention (within 24–72 hours) to prevent rebleeding. Higher grades (4–5) may require medical stabilization, ICP management, and optimization before intervention.
Yes. With aggressive ICU management, some Grade 4 patients achieve meaningful recovery. Grade 5 outcomes are generally poor, but occasional good outcomes have been reported, particularly in younger patients.
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