Introduction:
Horizontal gaze palsy is a rare recessive disorder. The neurological disorder affects the ability to move the eyes horizontally. The condition is due to the nerves related to eye movement. The particular nerves are the third and sixth cranial nerves. It may be due to the cerebral hemispheres' lesions that cause paresis from brain stem lesions and the side of the lesion. If the condition occurs from the frontal eye fields in the midbrain may cause weakness toward the side of the lesion. The situation will result in horizontal gaze palsy. The condition is present at birth or in the early childhood stage. horizontal gaze palsy is associated with neurological disorders like Moebius syndrome, pontine gliomas, and brainstem anomalies. It can interfere with other tasks such as driving, reading, and playing sports which require good eye coordination. There is no treatment for horizontal gaze palsy, but treatment manages the symptoms and improves the quality of life.
What Is Horizontal Gaze Palsy?
Horizontal gaze palsy is a rare neurological disorder that affects the movement of the eye horizontally. The condition may be caused due to neurological lesions and damage to the cranial nerves. It may lead the person inability to perform daily life activities which require eye movement.
What Are the Causes of Horizontal Gaze Palsy?
Horizontal gaze palsy is due to damage to the nerves that control eye movement. The cranial nerves associated with the condition are the third cranial nerve which is the oculomotor nerve and the sixth cranial nerve which is the abducens nerve. The underlying condition can lead to cranial nerve damage including:
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Congenital Abnormalities: Horizontal gaze palsy can be caused by genetic or developmental abnormalities affecting the nerves responsible for eye movement. The condition can be present at birth.
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Traumatic Brain Injury: Trauma to the brain or head can damage the nerves related to the control of eye movement leading to the condition.
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Infection: Certain infections can cause inflammation of the nerves that control eye movement. The infections such as encephalitis and meningitis can lead to horizontal gaze palsy.
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Tumors: Tumors can affect the brainstem and other structures in the brain and can damage the nerves responsible for the control of eye movement leading to the condition.
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Vascular Events: Vascular events and stroke can affect the blood flow to the brainstem and other structures in the head that are related to the control of eye movement.
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Neurodegenerative Diseases: Diseases like progressive supranuclear palsy and multiple system atrophy can lead to horizontal gaze palsy.
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Unknown Causes: In some cases, the cause of the condition can be unknown.
What Are the Signs and Symptoms of Horizontal Gaze Palsy?
Horizontal gaze palsy is characterized by a person being unable to move the eyes horizontally. The symptoms vary depending on the cause of the condition. Not all people experience symptoms. The signs and symptoms of the condition are as follows:
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Unable to Move the Eyes Horizontally: The person is unable to move their eyes from side to side. The patient may have to move their head to compensate for the lack of eye movement.
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Difficulty in Tracking Moving Objects: The person may feel difficulty in tracking objects. The person may need to turn their head to keep things in view.
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Nystagmus: It refers to repetitive and involuntary eye movements. The person may feel nystagmus when they move the eyes horizontally.
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Difficulty in Performing Daily Activities: People face difficulty in performing daily life activities. The activities include driving, reading, and playing sports.
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Head Tilting: People with the condition may turn or tilt their heads to one side when looking at objects.
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Double Vision: People may experience double vision as they are unable to coordinate with their eyes properly.
What Is the Difference Between Conjugate and Horizontal Gaze Palsy?
Conjugate horizontal gaze palsy is the condition in which both eyes are unable to move in any direction. Horizontal gaze palsy is the condition in which both eyes are unable to move in the horizontal direction. Both conditions can interfere with performing daily life activities.
How Can Horizontal Gaze Palsy Be Diagnosed?
The neurologist or ophthalmologist may diagnose the condition based on the medical history, physical examination, and diagnostic test. Various diagnostic tests are as follows:
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Physical Examination: The doctor may examine the patient's eye movement and check the symptoms of horizontal gaze palsy.
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Magnetic Resonance Testing (MRI) Or Computed Tomography (CT) Scan: The doctor may prescribe MRI or CT scan to look for any abnormalities in the brain and nerves related to eye movement.
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Electromyography (EMG): The doctor may use EMG to assess the function of the muscles related to eye movement.
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Blood Test: The doctor may prescribe a blood test to check for infections and underlying medical conditions.
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Genetic Testing: In the case of hereditary horizontal gaze palsy, the doctor may perform genetic testing to look for a gene mutation that causes the condition.
How Can Horizontal Gaze Palsy Be Treated?
Horizontal gaze palsy is a rare neurological disorder. It affects the movement of the eye. There is no cure for the condition, but the treatment may manage the symptoms related to the condition. The doctor may prescribe the treatment based on the cause of the disorder, and congenital anomalies related to the condition. In the case of congenital horizontal gaze palsy, the doctor may prescribe therapy, exercise, and visual aid to improve visual tracking.
In the case of a tumor or injury, treatment involves surgery to remove the tumor. Chemotherapy and radiation therapy may shrink the tumor. The doctor may prescribe medications like Botulinum toxin injections and Baclofen to control muscle spasms.
Conclusion:
Horizontal gaze palsy is a neurological disorder that affects eye movement. Currently, there is no cure for the condition. Treatment can improve the quality of life and helps in performing daily life activities. Treatment depends on the cause and severity of the condition. It includes visual aids, eye exercises, surgery, chemotherapy, radiation therapy, and medication that can manage the symptoms. Safety measures like wearing a helmet when engaging in sports activities can reduce head injury. Reducing alcohol and exposure to toxins can help with brainstem injuries.
