Neurological or ENT Examination - Nystagmus
Related Subjects:
|Cortical functions
|Motor System
|Sensory System
|Mental state Examination
|Speech and Language Exam
|Cranial nerves and examination
|Assessing Cognition
ℹ️ About
- Nystagmus: Abnormal involuntary, rapid, and repetitive movements of the eye.
- Nystagmus is named according to the direction of its fast phase if it is jerky.
- It may not have a faster phase and be equal in both directions, known as "pendular" nystagmus.
- Typically originates from retinal disease, labyrinthine (inner ear) disorders, or brainstem/cerebellar abnormalities.
Examination
- Nystagmus can be observed in normal individuals at the extremes of gaze.
- 1st Degree: Present only when the patient looks in the direction of the fast phase.
- 2nd Degree: Present when the patient looks in the direction of the fast phase and at the midline.
- 3rd Degree: Present in all directions of gaze.
- During examination, classify the nystagmus based on the direction of its fast phase if it is jerky.
- Pendular nystagmus has no faster phase and moves equally in both directions.
Peripheral Nystagmus (e.g., Damage to the Right Labyrinth/Vestibular Nerve)
- Direction: Slow phase moves toward the side of the lesion (e.g., right), and fast phase moves away (e.g., left).
- Associated Symptoms: May include tinnitus and hearing loss.
- Vertigo and nystagmus typically resolve together as the underlying condition improves.
- Examples: Meniere's disease, vestibular neuronitis, vascular disorders affecting the inner ear.
Central (CNS) Nystagmus
- Vertigo is uncommon with central nystagmus.
- Direction: If there is damage to the right cerebellum or brainstem connections, the fast phase will move toward the right and the slow phase toward the left.
- Possible Causes: Multiple sclerosis (MS), stroke, tumours, Wernicke's encephalopathy, alcohol, and certain drugs.
Other Forms of Nystagmus
- Downbeat Nystagmus: Suggests a lesion at the foramen magnum or the cervicomedullary junction. The fast phase of the movement is downward.
