biology

Oculogyric crisis

Oculogyric crisis is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Oculogyric crisis rather than just read about it. In short: Oculogyric crisis (OGC) is a rare sudden, paroxysmal, dystonic reaction that may manifest in response to specific drugs, particularly neuroleptics, or medical conditions, such as movement disorders. This neurological phenomenon is characterized by a sustained dystonic, conjugate, involuntary upward deviation of both eyes lasting seconds to hours.

Key takeaways

Oculogyric crisis belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Oculogyric crisis to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Oculogyric crisis from memory before moving on to harder problems.

Reference excerpt

Oculogyric crisis (OGC) is a rare sudden, paroxysmal, dystonic reaction that may manifest in response to specific drugs, particularly neuroleptics, or medical conditions, such as movement disorders. This neurological phenomenon is characterized by a sustained dystonic, conjugate, involuntary upward deviation of both eyes lasting seconds to hours. The term oculogyric is applied in reference to the simultaneous upward movement of both eyes, although the reaction may encompass a variety of additional responses. The reaction is not life-threatening. For clarification, oculogyric seizures, also termed versive seizures, represent one of the manifestations of epilepsy. These seizures exhibit the same upward eye movement observed in OGC but are classified as a specific subtype of epilepsy.

Signs and symptoms Initial symptoms include restlessness, agitation, malaise, or a fixed stare. Then comes the more characteristically described extreme and sustained upward deviation of the eyes. In addition, the eyes may converge, deviate upward and laterally, or deviate downward. The most frequently reported associated findings are backwards and lateral flexion of the neck, widely opened mouth, tongue protrusion, and ocular pain. However, the condition may also be associated with intensely painful jaw spasms which may result in the breaking of a tooth. A wave of exhaustion may follow an episode. The abrupt termination of the psychiatric symptoms at the conclusion of the crisis is most striking. Other features that are noted during attacks include mutism, palilalia, eye blinking, lacrimation, pupil dilation, drooling, respiratory dyskinesia, increased blood pressure and heart rate, facial flushing, headache, vertigo, anxiety, agitation, compulsive thinking, paranoia, depression, recurrent fixed ideas, depersonalization, violence, and obscene language. In addition to the acute presentation, oculogyric crisis can develop as a recurrent syndrome, triggered by stress and by exposure to the drugs mentioned below.

Causes Drugs that can trigger an oculogyric crisis include neuroleptics (such as haloperidol, chlorpromazine, fluphenazine, olanzapine), carbamazepine, chloroquine, cisplatin, diazoxide, levodopa, lithium, metoclopramide, lurasidone, domperidone, nifedipine, pemoline, phencyclidine ("PCP"), reserpine, and cetirizine, an antihistamine. High-potency neuroleptics are the most common cause. Other causes can include aromatic L-amino acid decarboxylase deficiency, postencephalitic Parkinson's, Tourette's syndrome, multiple sclerosis, neurosyphilis, head trauma, bilateral thalamic infarction, lesions of the fourth ventricle, cystic glioma of the third ventricle, herpes encephalitis, kernicterus and juvenile Parkinson's disease.

Diagnosis The diagnosis of oculogyric crisis is largely clinical and involves taking a focused history and physical examination to identify possible triggers for the crisis and rule out other causes of abnormal ocular movements.

Treatment Immediate treatment of drug-induced OGC can be achieved with intravenous antimuscarinics, such as benzatropine or procyclidine. Any causative new medication should be discontinued. The condition may also be treated with the antihistamine diphenhydramine.

References

External links

Worked examples

Example 1 — a first encounter with Oculogyric crisis

Start with the simplest possible case. Write down what Oculogyric crisis claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Oculogyric crisis before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Oculogyric crisis ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Oculogyric crisis

In research: Oculogyric crisis appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Oculogyric crisis in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Oculogyric crisis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Neurological disorders, Symptoms and signs: Nervous and musculoskeletal systems, so understanding it makes those chapters shorter.
In everyday life: Look for Oculogyric crisis outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Oculogyric crisis in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Oculogyric crisis means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Oculogyric crisis out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Oculogyric crisis in simple terms?

Why does Oculogyric crisis matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Oculogyric crisis?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Oculogyric crisis.