Optic pathway glioma

What it is

From: Orphanet

Optic pathway glioma (OPG) is a benign tumor that develop along the optic nerve (chiasm, tracts, and radiations) characterized by impairment or loss of vision and may be accompanied by diencephalic symptoms such as reduced growth and alteration in sleeping patterns. OPG are often linked to neurofibromatosis type 1 (NF1).

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Neurofibromas · Frequent (79-30%)

A benign peripheral nerve sheath tumor that generally appears as a soft, skin-colored papule or small subcutaneous nodule. Individuals with neurofibromatosis can have numerous neurofibromas.

Nystagmus · Frequent (79-30%)

Rhythmic, involuntary oscillations of one or both eyes related to abnormality in fixation, conjugate gaze, or vestibular mechanisms.

Optic atrophy · Frequent (79-30%)

Atrophy of the optic nerve. Optic atrophy results from the death of the retinal ganglion cell axons that comprise the optic nerve and manifesting as a pale optic nerve on fundoscopy.

Visual loss · Frequent (79-30%)

Loss of visual acuity (implying that vision was better at a certain time point in life). Otherwise the term reduced visual acuity should be used (or a subclass of that).

Reduced visual acuity · Frequent (79-30%)

Abnormality of the nervous system · Occasional (29-5%)

An abnormality of the nervous system.

Blindness · Occasional (29-5%)

Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation.

Developmental regression · Occasional (29-5%)

Loss of developmental skills, as manifested by loss of developmental milestones.

Fatigable weakness · Occasional (29-5%)

A type of weakness that occurs after a muscle group is used and lessens if the muscle group has some rest. That is, there is diminution of strength with repetitive muscle actions.

Global developmental delay · Occasional (29-5%)

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

Growth delay · Occasional (29-5%)

A deficiency or slowing down of growth pre- and postnatally.

Headache · Occasional (29-5%)

Cephalgia, or pain sensed in various parts of the head, not confined to the area of distribution of any nerve.

Hydrocephalus · Occasional (29-5%)

Hydrocephalus is an active distension of the ventricular system of the brain resulting from inadequate passage of CSF from its point of production within the cerebral ventricles to its point of absorption into the systemic circulation.

Nausea · Occasional (29-5%)

A sensation of unease in the stomach together with an urge to vomit.

Other findings in the same source

From: Orphanet

Additional reported features include Ophthalmoplegia (Occasional (29-5%)); Papilledema (Occasional (29-5%)); Precocious puberty (Occasional (29-5%)); Proptosis (Occasional (29-5%)); Seizure (Occasional (29-5%)); Strabismus (Occasional (29-5%)); Vertigo (Occasional (29-5%)); Vomiting (Occasional (29-5%)); Visual field defect (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Not applicable

Which doctor should you see?

The suggested department for discussing Optic pathway glioma is Oncology, with a oncologist and relevant organ specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

Additional services that may be relevant, depending on the findings, include: Relevant organ specialist / Surgical Oncology as indicated.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Has the exact tumour type been confirmed, and is staging relevant?
• What is the goal of each proposed treatment option?
• How will side effects, daily function and supportive care be addressed?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Optic pathway glioma. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.