Posterior Circ. Strokes

IMPORTANT: For use by qualified healthcare professionals only.

Posterior Circulation Stroke is an 8-step clinical pathway covering the most frequently missed stroke subtype. Built for neurologists, stroke physicians, ED doctors, and neurosurgeons. Purple accent on dark navy design. Interactive HINTS examination, pc-ASPECTS calculator, and full references throughout.

OVERVIEW AND RED FLAGS
Missed or misdiagnosed in up to 35% of initial presentations. CT has only 40-50% sensitivity for posterior fossa ischaemia. Nine red flags: acute vestibular syndrome, inability to walk, diplopia, occipital headache, crossed deficits, Horner syndrome, dysphagia, reduced consciousness with brainstem signs, hyperdense basilar sign. Normal CT does NOT exclude posterior stroke.

HINTS EXAMINATION -- INTERACTIVE TOOL
Only valid in AVS: continuous dizziness plus nystagmus. Sensitivity 100% for central cause (Kattah 2009) -- superior to early MRI DWI. Interactive 3-component tool: HIT (normal = central, no saccade; abnormal = peripheral), Nystagmus (direction-changing/vertical = central; unidirectional = peripheral), Test of Skew (vertical refixation = central). One central feature = stroke until proven otherwise. Instant verdict displayed. Additional high-risk signs checklist: gait inability, truncal ataxia, hearing loss (AICA), Horner, dysphagia, crossed deficit.

NEUROIMAGING PROTOCOL
MRI DWI: 17-20% false-negative for brainstem infarcts in first 24h -- repeat at 48-72h if negative. Sequences: DWI, ADC, FLAIR, T2*GRE, T1 fat-sat neck (VAD crescent sign), MRA intracranial. CTA: explicitly request V1-V4 plus basilar plus PCA origins. Hyperdense basilar sign = BAO -- immediate EVT activation.

POSTERIOR CIRCULATION SYNDROMES
Six accordion-expandable cards: Wallenberg (crossed deficits, Horner, dysphagia -- highest aspiration risk); Cerebellar (PICA/AICA/SCA); BAO (locked-in, quadriplegia, prodrome); Top-of-Basilar (bilateral visual fields, vertical gaze palsy); Lacunar (alternating syndromes -- Weber, Millard-Gubler); PCA (hemianopia, Dejerine-Roussy pain, DVLA notification required).

BASILAR ARTERY OCCLUSION AND pc-ASPECTS
Up to 80% mortality without recanalisation. BASICS 2021, ATTENTION 2022 (NNT 5), BAOCHE 2022 -- EVT up to 24h. Interactive pc-ASPECTS: tap 6 regions (midbrain -2, pons -2, cerebellum and PCA -1 each), score updates live. pc-ASPECTS 7 or above: EVT suppo