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Trochlear Nerve Paralysis

Fourth [trochlear] Nerve Palsy


Presentation

  • Topics are presented logically and the text in an easy-to-read style. The accompanying line drawings emphasize important concepts in a clear and uncluttered manner.[books.google.com]
  • Congenital fourth nerve palsies may present with several unique findings, as follows: Patients with long-standing head tilt present during early childhood may develop facial asymmetry.[emedicine.medscape.com]
  • In the case presented here, the patient was educated about his new diagnosis.[reviewofoptometry.com]
  • When present at birth, it is known as congenital fourth nerve palsy. See also [ edit ] Trochlear nerve Harada-Ito procedure References [ edit ] External links [ edit ][en.wikipedia.org]
  • Fourth nerve palsy can be congenital or acquired, unilateral or bilateral, each of which presents with a distinct clinical picture.[patientslikeme.com]
Physician
  • However, the finding of one of these symptoms does not necessarily imply a specific facial nerve problem; the physician needs to make a careful investigation in order to make a precise diagnosis.[medicinenet.com]
  • Ophthalmological Society, Canadian Society of Oculoplastic Surgery, Chinese Canadian Medical Society, European Society of Ophthalmic Plastic and Reconstructive Surgery, North American Neuro-Ophthalmology Society, Ontario Medical Association, Royal College of Physicians[emedicine.medscape.com]
Asymptomatic
  • Patients are often asymptomatic until the fourth to sixth decades of life, when their vertical fusional amplitudes diminish and diplopia develops. Most patients maintain a chronic head tilt.[aao.org]
  • Patients with underlying, well-controlled, and asymptomatic fourth nerve palsy may decompensate gradually as they lose binocular function resulting from cataract. Following restoration of good vision, these patients become aware of diplopia.[emedicine.medscape.com]
Torticollis
  • Any condition that leads to torticollis in early life may result in similar facial asymmetry.[emedicine.medscape.com]
  • Residual torticollis in patients after strabismus surgery for congenital superior oblique palsy. Br J Ophthalmol 2009; 93(12):1616-1619. PMID: 19586931 Bale JF, Scott WE, Yuh W, Sato Y, Menezes A.[webeye.ophth.uiowa.edu]
  • For example, torticollis can produce a similar appearance. Causes [ edit ] The clinical syndromes can originate from both peripheral and central lesions.[en.wikipedia.org]
Strabismus
  • ICD-10-CM Codes › H00-H59 Diseases of the eye and adnexa › H49-H52 Disorders of ocular muscles, binocular movement, accommodation and refraction › H49- Paralytic strabismus › Fourth [trochlear] nerve palsy, left eye 2016 2017 2018 2019 Billable/Specific[icd10data.com]
  • ICD-10-CM Codes › H00-H59 Diseases of the eye and adnexa › H49-H52 Disorders of ocular muscles, binocular movement, accommodation and refraction › H49- Paralytic strabismus › Fourth [trochlear] nerve palsy, unspecified eye 2016 2017 2018 2019 Billable[icd10data.com]
  • Errors in the three-step test in the diagnosis of vertical strabismus. Ophthalmology. 1989 Jan. 96 (1):127-32. [Medline]. Kono R, Okanobu H, Ohtsuki H, Demer JL.[emedicine.medscape.com]
  • Practically speaking, the specific muscle(s) involved and the etiology of a vertical strabismus not due to a fourth nerve palsy is often not resolved by the 3-step plus fourth step test, because acquired vertical strabismus is often the result of the[aao.org]
  • To the Editor: Although the “three-step test” is regarded as the gold standard for diagnosing fourth nerve palsies, there are a number of instances in which its usefulness is diminished, including restrictive ocular myopathies, longstanding strabismus[neurology.org]
Esotropia
  • Loss of the tertiary abducting action causes a V-pattern esotropia (esotropia greater in downgaze) in half of patients (2). ( Video, “congenital IV palsy” ) Bilateral IV nerve palsies show a small hypertropia in primary position, which increases with[neuroophthalmology.ca]
  • Etiology Clinical features Extorsion of the eye : inability to depress and adduct the eyeball simultaneously (the pupil shoots upward during attempted adduction of the eyeball) Diplopia ( double vision ) Mild esotropia Trigeminal nerve lesion (V) Etiology[amboss.com]
  • Additionally, a small esotropia may be found on down gaze as the superior oblique is also a weak abductor.[webeye.ophth.uiowa.edu]
Myokymia
  • Superior oblique palsy and superior oblique myokymia. In: Clinical Strabismus Management: Principles and Surgical Techniques. 1999:219-229. Wang Q, Flanders M. Surgical Management of Unilateral Superior Oblique Palsy: Thirty Years of Experience.[emedicine.medscape.com]

Workup

  • A referral will then likely be made to a neurologist or neuro-ophthalmologist for evaluation and workup. Treatment Since most fourth nerve palsies are idiopathic, treatment is conservative given the high rate of spontaneous resolution.[encyclopedia.com]

Treatment

  • Experience of the optic neuritis treatment trial. Neurology 1997:49:1404-1413. ‏[books.google.com]
  • Treatment of the cause, if identified Eye exercises Prism glasses The disorder causing 4th cranial nerve palsy, if identified, is treated. Eye exercises may help, as may wearing prism glasses.[merckmanuals.com]
  • Treatment Since most fourth nerve palsies are idiopathic, treatment is conservative given the high rate of spontaneous resolution.[encyclopedia.com]
  • The prognosis of fourth nerve palsies due to a structural lesion depend on the treatment of the underlying lesion. Most patients with symptoms that do not recover spontaneously can improve with prism or surgery.[emedicine.medscape.com]

Prognosis

  • The prognosis of a fourth nerve palsy depends on the underlying etiology.[emedicine.medscape.com]
  • Prognosis The prognosis for trochlear nerve palsies is dependent upon the underlying cause. Most cases of idiopathic or microvascular nerve palsies resolve within a several weeks to six-month time period without treatment.[encyclopedia.com]
  • Causes and prognosis in 4,278 cases of paralysis of the oculomotor, trochlear, and abducens cranial nerves. Am J Ophthalmol. 1992 May;113(5):489-96. 16. Bagheri A, Eshaghi M.[reviewofoptometry.com]
  • Specific CN IV palsy treatments will depend on the prognosis for spontaneous recovery and the severity of symptoms.[metrowestdailynews.com]
  • What is the prognosis for other facial nerve problems? The prognosis for facial nerve damage depends on the underlying cause.[medicinenet.com]

Etiology

  • Incidence and Etiology of Presumed Fourth Cranial Nerve Palsy: A Population-based Study. Am J Ophthalmol. 2018 Jan. 185:110-114. [Medline]. Richards BW, Jones FR Jr, Younge BR.[emedicine.medscape.com]
  • Etiology Clinical features Extorsion of the eye : inability to depress and adduct the eyeball simultaneously (the pupil shoots upward during attempted adduction of the eyeball) Diplopia ( double vision ) Mild esotropia Trigeminal nerve lesion (V) Etiology[amboss.com]
  • However, the underlying etiologies remain unknown in most of the cases and are yet to be elucidated.[bmcophthalmol.biomedcentral.com]
  • If a presumed microvascular CN IV palsy does not spontaneously recover as expected, neuroimaging is warranted to investigate for an alternate etiology.[webeye.ophth.uiowa.edu]
  • Practically speaking, the specific muscle(s) involved and the etiology of a vertical strabismus not due to a fourth nerve palsy is often not resolved by the 3-step plus fourth step test, because acquired vertical strabismus is often the result of the[aao.org]

Epidemiology

  • Epidemiology Frequency Most cases of isolated fourth nerve palsy are believed to be congenital. [4] However, estimating the true frequency of congenital fourth nerve palsy is difficult.[emedicine.medscape.com]
Sex distribution
Age distribution

Pathophysiology

  • Pathophysiology Congenital Trochlear Nerve Palsy A series of high-definition MRI studies by Yang et al have identified two etiologies of congenital trochlear nerve palsies, with the most common being congenital cranial dysinnervation syndrome.[emedicine.medscape.com]
  • Pathophysiology and Etiology CN IV has the longest intracranial course of any of the cranial nerves and is the only nerve to exit the brainstem dorsally. Consequently, it is especially susceptible to damage in the setting of head trauma.[webeye.ophth.uiowa.edu]

Prevention

  • This condition often causes vertical or near vertical double vision as the weakened muscle prevents the eyes from moving in the same direction together.[en.wikipedia.org]
  • 完全静脈栄養 late-onset hypogonadism 加齢男性性腺機能低下 latent autoimmune diabetes mellitus in adults 緩徐発症成人自己免疫性糖尿病 limited joint mobility 関節運動制限 lipid peroxide 過酸化脂質 liver x receptor 肝臓X受容体 loss of sensation 感覚減退 loss of sensation 感覚鈍麻 lower extremity amputation prevention[jds.or.jp]

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