What is Nystagmus?

Nystagmus is defined as any rhythmic, involuntary oscillation of the eyes. It can be physiological or pathological, generally maintaining a forward gaze due to balanced input from both left and right vestibular systems.

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Types of Nystagmus

• Peripheral Nystagmus: Often linked to inner ear issues such as vestibular neuritis or benign paroxysmal positional vertigo (BPPV).
• Central Nystagmus: Arises from brain or neural pathway issues, more complex in diagnosis and management.
• Positional Nystagmus: Triggered by head position changes, typically indicating BPPV.

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Common Causes

• Inner Ear Disorders: Primary culprits of peripheral nystagmus, including BPPV and labyrinthitis.
• Neurological Conditions: Leading to central nystagmus, such as multiple sclerosis or brainstem lesions.
• Medications: Can induce nystagmus as a side effect.

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Detailed Diagnosis

Our clinic uses a thorough approach, including:

• Detailed Patient History: Understanding onset, duration, and triggers.
• Physical and Neurological Examination: Identifying nystagmus type and underlying conditions.
• Specialized Tests: Videonystagmography (VNG) and MRI provide a comprehensive view of the vestibular and neurological status.

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Treatment Approaches

Treatment is highly individualized, from medications managing symptoms or underlying conditions to vestibular rehabilitation improving balance and surgical options for resistant cases.

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Comprehensive Nystagmus Patterns

• Jerk Nystagmus: Asymmetric oscillation with a slow pathological phase and a rapid corrective phase.
• Pendular Nystagmus: Oscillations of equal amplitude in any direction, typically due to a loss of inhibitory feedback or increased feedback delay, resulting in spontaneous oscillation.
• Gaze-Evoked Nystagmus: Occurs when the eyes move to an extreme position, often due to an abnormality in gaze-holding systems or muscle fatigue.
• Periodic Alternating Nystagmus (PAN): A horizontal jerk nystagmus that periodically changes direction, typically due to neurological issues or medications.
• Rebound Nystagmus: A type of gaze-paretic nystagmus where the jerk nystagmus gradually decreases in amplitude when the eyes are held in an eccentric position for long.

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Special Nystagmus Types

• Seesaw Nystagmus: Vertical disconjugate nystagmus with alternating elevation and depression of each eye.
• Convergence-Retraction Nystagmus: Occurs with attempted upgaze, causing the eyeball to retract and converge.
• Convergence Nystagmus: A pendular type induced by eye convergence, often accompanied by synchronous muscle contractions, characteristic of certain neurological conditions.

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Revolutionary Insights by Dr. Ian Purcell

Dr. Purcell has meticulously identified various nystagmus patterns related to dislodged otoliths in the inner ear, significantly advancing diagnosis and treatment of BPPV. The key to Dr. Purcell’s approach is precision in diagnostic techniques, crucial for accurate maneuvers like the Dix-Hallpike and Epley, using advanced tools like canalith repositioning chairs.

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