Oculomotor apraxia, also known as Cogan II syndrome, is an extremely rare eye disease that makes it impossible for those affected to perform eye movements for fixation. The syndrome is mostly congenital, but acquired variants also occur. The movement disorder in this form is usually related to another disease, such as a stroke. Acquired oculomotor apraxias usually resolve by themselves by adulthood and are no longer a particular limitation for those affected from the age of about 20 years.
What is oculomotor apraxia?
Doctors understand oculomotor apraxia to be the inability to perform eye movements that serve to fixate an eye. These eye movements are also known as gaze target movements, whereby the entirety of all eye movements is to be understood synonymously with the medical term oculomotor function. See acronymmonster for Definition of HLP in English.
The expression oculomotor apraxia is a confusing term in this respect, because the movement disorder in this disease does not have to relate to the entire oculomotor function, but can actually remain limited to the fixation movements mentioned. The phenomenon is sometimes called Cogan II syndrome or COMA. The phenomenon was first documented in 1952 by the American ophthalmologist David G. Cogan.
Causes
Oculomotor apraxia can be congenital, but acquired forms are also conceivable, although they occur much more rarely. The cause of the congenital form is so far unclear, but the phenomenon usually manifests itself in imaging as a missing connection in the corresponding gaze movement centers of the brain or as a movement disorder of the third cranial nerves.
If acquired Cogan II syndrome is present, this phenomenon is probably due to neurological diseases or damage. For example, it can occur with supranuclear, mostly bilateral, lesions, that is, lesions of the supranuclear visual centers in the brain, which are sometimes accompanied by paralysis and are usually located in the frontoparietal cortex.
Symptoms, Ailments & Signs
Congenital Cogan II syndrome particularly affects horizontal gaze movements. In the case of acquired Cogan II syndrome, on the other hand, vertical gaze fixation movements are often affected by the disorder. The disorder often manifests itself at an early age in the form of a stare, although it is usually easier for those affected to move their eyes together with a head movement.
In adulthood, this often results in a horizontal and vertical tossing of the head, which suddenly and suddenly overturns the entire head in one direction. The so-called vestibulo-ocular reflex forces the eyes to come into contact with each other, so that they are mechanically carried along, so to speak, when the head is thrown.
Those affected by oculomotor apraxia usually move their head back a little after the slinging process, whereby their eyes remain fixed in the targeted direction. In young children, cerebellar ataxia and motor development delay are among the most common accompanying symptoms of oculomotor apraxia. Balance problems and difficulties with eye-hand coordination can also occur.
Diagnosis & course of disease
Because of the characteristic head movements that people with Cogan II syndrome need to control their gaze, the diagnosis can usually be made by pure observation. In the case of acquired oculomotor apraxia in particular, however, the doctor will initiate imaging that will help him with differential diagnosis and the localization of possible lesions and the assessment of their cause.
Cogan II syndrome usually resolves over the course of life. This means that those affected with a congenital variant in adulthood often only need a tiny and hardly noticeable head movement to carry out the fixation movements with their eyes. Especially up to the age of 20 there are often drastic improvements.
In acquired forms, spontaneous improvement is less likely to occur, since in this case the phenomenon is often associated with another disease. For example, a tumor can also cause such symptoms, which an experienced doctor can recognize from its typical shape in the imaging.
Complications
Oculomotor apraxias, which are very rare overall and are mostly congenital, involve a limitation or complete inability to follow a moving target with the eyes. Those affected tend to compensate for the oculomotor apraxia by appropriate head movements. If it is a congenital disease, there are usually no further complications to be feared because the inability to follow a moving object with the eyes usually improves in adolescents.
A causal treatment is not (yet) possible for genetic diseases. However, special exercises and physiotherapy can further reduce the effects of the disease, which is associated with a certain degree of rigidity. If the oculomotor apraxia is caused by an accident, a stroke or a tumor, serious complications can arise if the cause is not found or not treated.
For example, in the case of a stroke or CNS hemorrhage, the site of the clot or hemorrhage should be diagnosed using imaging techniques in order to initiate appropriate treatment that may prevent major complications. Similar approaches are indicated when the apraxia is caused by a tumor that is compressing certain oculomotor nerves by displacing space.
In this case, if left untreated, serious complications can be expected if it is a malignant tumor that can continue to grow or, depending on the tumor type, can also form metastases.
When should you go to the doctor?
Werden bei neugeborenen Kindern Unregelmäßigkeiten der Blickbewegungen festgestellt, besteht Handlungsbedarf. In den meisten Fällen übernehmen Geburtshelfer in einem routinierten Ablauf die Erstuntersuchungen des Säuglings und bemerken die Auffälligkeiten der Augen. Für die Eltern besteht daher keine Notwendigkeit, weitere Schritte in die Wege zu leiten. Die anwesenden Krankenschwestern, Hebammen oder Ärzte koordinieren die weiterführenden Untersuchungen, um eine Diagnosestellung zu ermöglichen. Anschließend wird ein Behandlungsplan erstellt, damit eine ausreichende medizinische Versorgung stattfinden kann.
If there are sudden abnormalities in eye positions and eye movements in adulthood, a doctor must be consulted. If the irregularities occur after a jerky head movement, a fall or an accident, a doctor must be consulted. Medical advice should be sought in the event of balance problems, headache pain or swelling. Visual impairments, sleep disorders or a decrease in physical and mental performance should be examined by a professional. If there are any peculiarities in behavior or if there are strong emotional stress conditions, a doctor is also needed.
Dizziness, unsteady gait and a general feeling of being unwell must be presented to a doctor. If there are changes in memory, impaired consciousness or attention deficits, a doctor’s visit is necessary. In the event of an acute health-threatening condition, an emergency service must be alerted. To ensure survival, first aid must be initiated in accordance with first aid guidelines.
Treatment & Therapy
Oculomotor apraxias cannot be treated causally as such. However, the side effects can be treated and compensatory mechanisms can be learned through physiotherapy, ergotherapy, remedial early support, optometry and orthopedics.
In addition, individual symptoms can possibly be alleviated with medication. As a rule, those affected visit a specialist once a year, who documents their current condition in a video log in order to keep an overview of the course of the disease.
For acquired oculomotor apraxia, the treatment method depends on the cause. If there is a tumor associated with the condition, the doctor will probably remove it surgically as much as possible. In the case of inflammation-related lesions of the gaze centers, the inflammation is likely to be counteracted by administering medication. In the case of brain infections, however, intensive care inpatient treatment may also be necessary.
Outlook & Forecast
The prognosis of oculomotor apraxia is unfavorable in most cases. A congenital disorder is a genetic defect. Since human genetics cannot be modified for legal reasons, the cause cannot be treated. Overall, early intervention programs bring about changes. However, freedom from complaints is not achieved.
The further course of acquired oculomotor apraxia is similarly unfavourable. Eye movement disorders are the result of a serious illness. Most patients have an emergency situation that led to the development of health problems. An accident, cancer or a stroke are the most common acquired reasons for apraxia. The general state of health is therefore already weakened. The focus of medical care is normally on alleviating the symptoms of the underlying disease. The overall quality of life should be improved and the remaining lifespan of the patient should be extended. Nevertheless, the prognosis can improve if the underlying disease is cured.
In addition, individual complaints can be alleviated or completely reversed by the administration of medicines. The person concerned must go into long-term therapy for this. In order to stabilize and improve his health, he needs regular check-ups from a doctor treating him.
Prevention
Since oculomotor apraxia is congenital and the cause of the defect has not yet been determined, the phenomenon cannot be prevented. However, the condition is extremely rare, so expectant parents should not live in fear of the disorder.
Phenomena such as strokes, which in the rarest of cases can be the cause of acquired Cogan II syndrome, can be prevented by taking various measures. For example, regular check-ups of the arteries and the use of special medication can count as part of prevention.
Aftercare
In the case of oculomotor apraxia, any overexertion of the affected eye must be avoided. Bright sunlight and bright lamp lights should be avoided, and those affected should adapt the lighting conditions to the disease. For example, if there is a desire to read a book, then those affected must ensure that they are provided with sufficient light.
If patients do not follow this, they accept an aggravation of the oculomotor apraxia and the symptoms. The disease usually also causes imbalances. In this case, those affected should ensure that they are sufficiently safe when moving. For example, help and support from family or relatives can be used for everyday tasks.
If this is not an option for those who are ill, there are special walking aids that allow those affected to move around safely and can provide sufficient support. The shoes of the patient should be tightly laced and as stable as possible in order to be able to offer enough support. No high-heeled shoes may be worn.
These do not provide enough security and can lead to a loss of balance. The loss of vision triggers a high emotional burden for many of those affected. Therefore, treatment by a psychologist should be considered.
You can do that yourself
In everyday life, the possibilities of self-help in the case of oculomotor apraxia are extremely small. In many cases, the movement disorder of the eye is only a complaint that the person concerned has.
In everyday life, excessive strain on the eyes should be avoided. Under no circumstances should you look into bright light sources. This includes sunlight as well as bright radiators built into lamps. Although there is no change in movement options, it is still important that the environment is provided with sufficient lighting conditions when reading or writing is desired. Otherwise, the eye will be subjected to further strain and existing complaints will increase in scope or intensity.
Since the disease is often associated with balance disorders, it is important to ensure adequate safety when moving. If necessary, walking aids are to be used, as they can provide necessary support in unsafe situations. The footwear worn should be closed and stable. High heels should be avoided as they promote unsteady gait.
Loss of vision causes anxiety in many sufferers. It should be checked whether psychotherapeutic support should be used. In order to avoid panic, the patient should inform himself in advance about the best behavioral guidelines in anxiety-provoking situations.
