Call
Chat for Appointment
Patient Reports / LoginInternuclear Ophthalmoplegia – Symptoms, Causes, and Treatment
Written by Medicover Team and Medically Reviewed by Dr Manaswini Priya Varanasi , Ophthalmologists
Table of Contents
Internuclear ophthalmoplegia (INO) is a neurological eye movement disorder caused by damage to the medial longitudinal fasciculus (MLF), the nerve pathway responsible for coordinating horizontal eye movements. When this pathway is affected, the eyes cannot move together normally, causing one eye to have difficulty turning inward while the other may show involuntary jerking movements (nystagmus).
This condition is commonly associated with neurological disorders such as stroke and multiple sclerosis. Early diagnosis and treatment of the underlying cause can help improve eye movement and reduce the risk of complications.
What Are the Symptoms of Internuclear Ophthalmoplegia?
The hallmark symptom of INO is horizontal gaze palsy, specifically:
- Inability to Adduct: The affected eye fails to move inward toward the nose.
- Nystagmus: The contralateral eye exhibits rapid, involuntary movements.
Other symptoms might include:
- Diplopia: Double vision due to misalignment of the eyes.
- Vertigo: A sensation of spinning or dizziness.
- Dysarthria: Slurred speech if the lesion impacts adjacent neural pathways.
What Causes Internuclear Ophthalmoplegia?
Internuclear ophthalmoplegia can be attributed to various etiologies. The causes can be broadly categorized into vascular, demyelinating, and neoplastic conditions.
Vascular Causes
Vascular causes are predominantly seen in older adults and include:
- Stroke: Hemorrhagic or ischemic stroke can lead to INO by damaging the blood vessels supplying the MLF.
- Atherosclerosis: Hardening and narrowing of the arteries can impede blood flow to the MLF.
Demyelinating Causes
The most common demyelinating cause of INO is multiple sclerosis (MS), particularly in younger adults. MS leads to the loss of myelin, the protective sheath around nerve fibers, disrupting the MLF's ability to transmit signals efficiently.
Neoplastic Causes
Tumors in the brainstem or adjacent areas can exert pressure on the MLF, leading to INO. These tumours might be primary brain tumours or metastases from other parts of the body.
Other Causes
Other potential causes include:
- Infections: Encephalitis or other infections that affect the brainstem.
- Trauma: Head injuries that damage the brainstem.
- Neurosurgical Complications: Post-surgical complications that impact the MLF.
When Should You See a Doctor for Internuclear Ophthalmoplegia?
Consult a ophthalmologist if you experience sudden double vision, difficulty moving your eyes, dizziness, or changes in vision. Immediate medical attention is essential if symptoms occur suddenly, as they may indicate a stroke or another serious neurological condition.
- Sudden double vision
- Difficulty moving one or both eyes
- Blurred vision with dizziness
- Slurred speech or weakness
- Loss of balance or coordination
- Symptoms after a head injury
Early diagnosis and treatment can help identify the underlying cause and reduce the risk of permanent neurological complications.
Find Ophthalmologists for Internuclear Ophthalmoplegia Treatment Near You
How Is Internuclear Ophthalmoplegia Diagnosed?
Diagnosing INO involves a combination of clinical examination and neuroimaging.
Clinical Examination
A neurologist will perform a thorough eye movement examination, often using tests such as the following:
- Cover-Uncover Test: To identify eye misalignment.
- Saccadic Eye Movement Test: To observe the speed and accuracy of eye movements.
Neuroimaging
Magnetic Resonance Imaging (MRI) is the gold standard for diagnosing INO. It provides detailed images of brain structures, allowing for the identification of lesions in the MLF.
What Are the Treatment Options for Internuclear Ophthalmoplegia?
The treatment of INO largely depends on addressing the underlying cause.
Medical Management
- Corticosteroids: Used in cases related to demyelinating diseases like MS to reduce inflammation.
- Antiplatelet Agents: Aspirin or other antiplatelet medications might be prescribed for vascular causes to prevent further strokes.
- Antibiotics/Antivirals: If an infection is the cause, appropriate antimicrobial therapy is necessary.
Rehabilitation Therapies
Rehabilitation plays a crucial role in managing INO symptoms:
- Vision Therapy: Exercises to improve eye coordination and reduce diplopia.
- Physical Therapy: To manage balance issues and vertigo.
- Speech Therapy: If dysarthria is present.
Surgical Interventions
In cases where a tumour is a cause, surgical resection might be necessary. Additionally, in severe cases of chronic INO, strabismus surgery might be considered to realign the eyes.
Your health is everything - prioritize your well-being today.
Consult Internuclear Ophthalmoplegia Doctors Today
What Are the Risk Factors for Internuclear Ophthalmoplegia?
Several risk factors increase the likelihood of developing INO:
- Age: Older adults are more prone to vascular causes, while younger adults are more susceptible to demyelinating causes like MS.
- Preexisting Conditions: Conditions such as hypertension, diabetes, and atherosclerosis increase the risk of stroke-related INO.
- Family History: A family history of MS or other demyelinating diseases.
What Complications Can Internuclear Ophthalmoplegia Cause?
If left untreated, INO can lead to several complications:
- Chronic Diplopia: Persistent double vision can affect daily activities.
- Reduced Mobility: Vertigo and balance issues can limit mobility and increase the risk of falls.
- Speech Difficulties: Dysarthria can affect communication.
Frequently Asked Questions
1. What causes internuclear ophthalmoplegia?
Internuclear ophthalmoplegia is caused by damage to the nerve pathways controlling eye movement, often due to multiple sclerosis or stroke.
2. What are the symptoms of internuclear ophthalmoplegia?
Symptoms include double vision and difficulty moving the eyes horizontally.
3. How is internuclear ophthalmoplegia diagnosed?
Diagnosis involves MRI or CT scans to detect nerve damage.
4. How is internuclear ophthalmoplegia treated?
Treatment depends on the underlying cause and may include medications for MS or stroke rehabilitation.
5. What are the complications of internuclear ophthalmoplegia?
Complications include persistent double vision and difficulty with eye coordination.
