Question

Describe the differentiating points in history and clinical examination between central and peripheral vertigo.

Hint:

If vertigo is associated with neurological signs such as ataxia, dysarthria, or diplopia, it is more likely to be of central origin.

Answer 1

Step 1: Introduction to Central vs. Peripheral Vertigo.
Vertigo is a symptom of dizziness that can be caused by various underlying conditions. Vertigo is classified as either central or peripheral based on the origin of the problem. Central vertigo arises from lesions in the central nervous system (CNS), particularly the brainstem or cerebellum, while peripheral vertigo results from abnormalities in the vestibular apparatus (inner ear or vestibular nerve). Differentiating between the two is important for determining the appropriate treatment.

Step 2: Differentiating Points in History.
- Onset of Vertigo:
- Peripheral Vertigo: Often sudden onset of vertigo, typically triggered by head movements or changes in position (e.g., BPPV).
- Central Vertigo: The onset may be gradual and not necessarily related to head position.
- Duration of Symptoms:
- Peripheral Vertigo: Episodes are typically brief, lasting from seconds to minutes.
- Central Vertigo: The episodes may last longer and are often more persistent.
- Associated Symptoms:
- Peripheral Vertigo: Associated with nausea, vomiting, and hearing loss (in cases of vestibular neuritis or labyrinthitis).
- Central Vertigo: May be associated with other neurological symptoms, such as diplopia (double vision), ataxia (lack of coordination), or numbness. - Triggers:
- Peripheral Vertigo: Often triggered by changes in head position (e.g., BPPV).
- Central Vertigo: Not typically associated with positional triggers.

Step 3: Differentiating Points in Clinical Examination.
- Nystagmus:
- Peripheral Vertigo: Nystagmus is usually horizontal and may have a latent onset or fatigue after several beats. It often improves with gaze fixation. - Central Vertigo: Nystagmus is usually vertical or multidirectional and is persistent, even with gaze fixation.
- Neurological Signs:
- Peripheral Vertigo: Neurological exam is usually normal, with no focal deficits.
- Central Vertigo: There may be additional neurological deficits, such as weakness, sensory loss, or abnormal reflexes, indicating a central cause. - Head Impulse Test:
- Peripheral Vertigo: Abnormal head impulse test (HIT) on the side of the lesion, indicating vestibular dysfunction.
- Central Vertigo: HIT is usually normal, even if the vertigo is severe.

Step 4: Conclusion.
The key differentiating factors between central and peripheral vertigo lie in the onset, duration, and associated symptoms. Peripheral vertigo is typically related to positional changes and may be associated with nystagmus that fatigues, while central vertigo involves more gradual onset, persistent symptoms, and additional neurological signs. Proper clinical evaluation, including history, examination, and relevant tests, is crucial for accurate diagnosis and management.