Neurology Book

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Nystagmus

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  1. Definitions
    1. Direction of nystagmus
      1. Named for quick component of nystagmus
    2. Speed
      1. Slow Nystagmus: <40 jerks per minute
      2. Fast Nystagmus: >100 jerks per minute
    3. Amplitude
      1. Fine Nystagmus: <1 mm
      2. Coarse Nystagmus: >3 mm
    4. Involvement
      1. Associated Involvement: Bilateral eyes
      2. Dissociated Involvement: Unilateral eye
  2. Indication: Vertigo Evaluation
    1. Absent nystagmus in acute severe Vertigo is unusual
      1. Casts doubt on the symptom
  3. Normal Findings: Lateral gaze nystagmus
    1. Associated with stretch receptor
    2. All patients have a few beats of end point nystagmus
  4. Abnormal Findings
    1. Spontaneous on Forward gaze or on moderate lateral gaze
    2. Direction
      1. Horizontal Nystagmus indicates peripheral disease
        1. Unilateral vestibular pathology
      2. Vertical Nystagmus indicates Central DIsease
        1. Brain stem lesion
  5. Causes of Nystagmus in Infants and Children
    1. Albinism (iris and retinal Hypopigmentation)
    2. Bilateral Optic Nerve hypoplasia
      1. Seen in de Morsier's Syndrome
    3. Bilateral media opacities
    4. Achromatopsia
    5. Usher's Syndrome (Retinitis Pigmentosa)

Nystagmus (C0028738)

Definition (CSP)involuntary, rapid, rhythmic movement of the eyeball.
Definition (MSH)Involuntary movements of the eye that are divided into two types, jerk and pendular. Jerk nystagmus has a slow phase in one direction followed by a corrective fast phase in the opposite direction, and is usually caused by central or peripheral vestibular dysfunction. Pendular nystagmus features oscillations that are of equal velocity in both directions and this condition is often associated with visual loss early in life. (Adams et al., Principles of Neurology, 6th ed, p272)
Definition (NCI)Involuntary movements of the eyeballs. The presence or absence of nystagmus is often used in the diagnosis of a variety of neurological and visual disorders.
ConceptsDisease or Syndrome (T047)
ICD9379.50
EnglishNystagmus, Pathologic Nystagmus, Unspecified nystagmus
Spanishnistagmo, nistagmo no especificado, nistagmus no especificado
CreditsDerived from the NIH UMLS (Unified Medical Language System)



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