More than half of dizzy strokes presented with imbalance and no spontaneous nystagmus

Design

Prospective single-centre emergency department cohort with lesion-symptom mapping

Population

75 patients with MRI-proven stroke presenting with vertigo, dizziness or imbalance

Primary outcome

Clinical phenotype (imbalance vs vestibular syndrome) and lesion location

Effect

Acute imbalance syndrome 58.7%, acute vestibular syndrome 38.7%, central positional vertigo 2.7%

In this prospective emergency department cohort from Munich, 75 patients with MRI-proven stroke causing vertigo, dizziness or imbalance were examined with video-oculography and posturography. Mean age was 66.

58.7% had no spontaneous nystagmus and presented mainly with postural or gait imbalance — termed acute imbalance syndrome. 38.7% had the classic acute vestibular syndrome with nystagmus, and 2.7% central positional vertigo. Imbalance-type strokes involved the anterior cerebellar lobe and deep cerebellar nuclei, linking to brainstem posture and gait networks. Nystagmus-type strokes sat in the posterior cerebellum and flocculonodular lobe, linking to vestibular nuclei.

The bedside tools most clinicians learn for dizzy stroke — head impulse, nystagmus, skew — are designed for patients with nystagmus. This cohort suggests the larger share of dizzy strokes would never trigger them. It is a single-centre study of patients already known to have stroke, so it cannot give the proportion of all dizzy patients who have a stroke, or the accuracy of a gait test. But it is a strong reason to examine posture and gait in every acutely dizzy patient.

• Check for spontaneous nystagmus first; its absence does not make a stroke less likely.
• Examine sitting balance, standing and gait in every patient with acute dizziness or imbalance.
• Consider MRI with diffusion when there is new marked imbalance, even with a normal head impulse test.
• Anterior cerebellar strokes may produce imbalance without vertigo; ask about unsteadiness as well as spinning.
• Document gait findings at triage so later reviewers can see the presenting deficit.

Why it matters

It suggests the most taught bedside test for dizzy stroke would not apply to most of the strokes in this cohort.

Don't overread it

All patients here had confirmed stroke, so the study cannot say how accurate a gait test is across all dizzy patients.

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