What are the key clinical features to differentiate between peripheral and central causes of dizziness?

Key clinical features to differentiate peripheral from central causes of dizziness include the nature of nystagmus, associated neurological signs, symptom onset, and response to specific bedside tests.

Peripheral dizziness typically presents with sudden-onset vertigo accompanied by nausea, vomiting, and gait unsteadiness but without focal neurological deficits. Nystagmus in peripheral causes is usually unidirectional, horizontal or torsional, and suppressible with visual fixation. The head impulse test is often abnormal, indicating a peripheral vestibular lesion. Positional maneuvers such as the Hallpike test may provoke vertigo and nystagmus in benign paroxysmal positional vertigo (BPPV), a common peripheral cause. Peripheral vertigo often improves with canalith repositioning maneuvers like the Epley maneuver ¹.

In contrast, central dizziness is more likely when there is sudden-onset dizziness with focal neurological signs such as vertical or direction-changing nystagmus, skew deviation, new-onset unsteadiness, or new deafness. The head impulse test is typically normal in central causes. Central vertigo may be associated with other neurological symptoms or signs, including limb ataxia, dysarthria, or weakness. The HINTS (Head-Impulse, Nystagmus, Test-of-Skew) examination is a critical bedside tool: a normal head impulse test, direction-changing nystagmus, or skew deviation strongly suggest a central cause such as stroke, warranting immediate neuroimaging and referral ¹.

Additional features favoring central causes include persistent vertigo without improvement, absence of auditory symptoms, and presence of other brainstem or cerebellar signs. Peripheral vertigo often has a history of positional triggers or recent ear infection or trauma, whereas central vertigo may be associated with vascular risk factors or migraine history (vestibular migraine) ¹.

Recent literature supports these distinctions, emphasizing the diagnostic value of the HINTS exam in acute vestibular syndrome to differentiate central from peripheral vertigo, with high sensitivity for stroke detection when performed by trained clinicians (Zwergal and Dieterich, 2020; Lee and Kim, 2020; Voetsch and Sehgal, 2021).