Supranuclear ophthalmoplegia


Supranuclear ophthalmoplegia

Description, Causes and Risk Factors:

This disorder occurs because the brain is sending and receiving faulty information through the nerves that control eye movement. The nerves themselves are healthy. People who have this problem may have progressive supranuclear palsy, a disorder that affects the way the brain controls movement. A brain injury (such as stroke) also can cause supranuclear ophthalmoplegia.

Eye movements bring visual stimuli to the fovea and also maintain foveal fixation on a moving target and during head movements. These movements are performed by the ocular motor system that consists of ocular motor nerves and nuclei in the brainstem originating in the cerebral cortex, cerebellum, vestibular structures, and the extraocular muscles. The ocular motor system is divided according to anatomic location into infranuclear, nuclear, internuclear, and supranuclear components. It is important to distinguish supranuclear and internuclear from nuclear and infranuclear disturbances affecting cranial nerves III, IV, and VI, because the disturbances are of highly varied causes and present different clinical pictures. Internuclear ophthalmoplegia is due to a lesion of the medial longitudinal fasciculus, caused by multiple sclerosis in younger patients, particularly when the ophthalmoplegia is bilateral, and usually of vascular origin in the elderly. Eye movement abnormalities of supranuclear origin are characterized by gaze palsies, tonic gaze deviation, saccadic and smooth pursuit disorders, vergence abnormalities, nystagmus, and ocular oscillations. Supranuclear disorders result from lesions above the level of the ocular motor nerve nuclei. If oculocephalic maneuvers move the eyes appropriately, the lesion causing the gaze palsy is supranuclear. Supranuclear disorders account for almost 10% of all patients with disorders of eye movements.

Risk Factors:

    Trauma.

  • Diabetes mellitus.

  • Demyelinating disease (multiple sclerosis).

  • Autoimmune disorders such as myasthenia gravis.

  • Increased intracranial pressure.

  • Post operatively as a complication of neurosurgery.

The syndrome of supranuclear ophthalmoplegia and its relation to other syndromes are discussed on the basis of a number of case histories and a survey of the pertinent literature. The validity of vertical ophthalmoplegia as a pathognomonic symptom is questioned. The main symptoms are as follows: the heightened tone of the neck muscles, as a rule combined with other indications of Parkinsonism and an inclination to fall down. To varying degree there are also bulbar signs and subcortical dementia. Neuropathologically the syndrome can be classed with the "multiple system degeneration" group, on which little enough is known. It remains an open question whether the syndrome is of its own or whether it is just a variety of Parkinsonism.

Symptoms:

Supranuclear ophthalmoplegia may result in compression of the parasympathetic fibers before any disruption of the motor fibers occurs, since the parasympathetic fibers run on the outside of the nerve. Therefore, one could have lid ptosis and mydriasis (a "blown" pupil) as a result of parasympathetic fiber compression before the "down and out" position is seen.

Diagnosis:

Neurological examination may show:

    Limited eye movements, especially vertical movements.

  • Mild dementia.

  • Normal vision, hearing, sensation, and voluntary control of movement.

  • Stiff and uncoordinated movements like those of Parkinson's disease.

Other Tests:

    The healthcare provider may do tests to rule out other diseases. Magnetic resonance imaging (MRI) might show shrinking of the brainstem.Positron-emission tomography (PET) or single-photon emission computed tomography (SPECT) scan sometimes is helpful in diagnosis other conditions.

Treatment:

Treatment and prognosis depend on the underlying causes. Treatment during the symptomatic interval is directed at alleviating symptoms. For more appropriate treatment options consult your ophthalmologist.

NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.

DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.

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