Description, Causes and Risk Factors:
Midbrain tegmentum lesion characterized by ipsilateral oculomotor nerve paresis and contralateral paralysis of the extremities, face, and tongue.
It is caused by midbrain infarction as a result of occlusion of the paramedian branches of the posterior cerebral artery or of basilar bifurcation perforating arteries.
Weber syndrome is rare compared to acquired oculomotor nerve palsy. Ischemia is the most common cause of pupil sparing Weber syndrome. Intracranial aneurysms are the most common cause of isolated Weber syndrome involving the pupil.
The majority of Weber syndrome are caused by minor injury to vessels in subarachnoid space or in the cavernous sinus. Less common causes are compression (due to aneurysm or tumor) and inflammation (sarcoidosis and vasculitis). In cases of trauma-related third cranial nerve palsy, underlying lesions such as aneurysms and tumors should be considered and ruled out.
Cerebellar signs (eg, dysmetria, ataxia) are frequent.
Dysarthria and dysphagia typically are present.
As medial rectus is paralyzed and the lateral rectus is unopposed; Diplopia.
Double-vision as one of the eye deviates from the midline.
Inability to move the eye medially or vertically;
If the ipsilateral levator palpebrae superioris is paralysed; Mydriasis.
Unresponsiveness to light as the sphincter pupillae is non-functional and the dilator pupillae is unopposed; Inability for the affected eye to focus on near objects as the ciliary muscles have also been paralysed.
The diagnosis is based on results of a neurologic examination and computed tomography (CT) or magnetic resonance imaging (MRI). If the pupil is affected or if symptoms suggest a serious underlying disorder, CT is done immediately. If a ruptured aneurysm is suspected and CT does not detect blood, a spinal tap (lumbar puncture), magnetic resonance angiography, CT angiography, or cerebral angiography is done.
Treatment if often surgical.
The surgical treatment of third nerve palsies presents a formidable challenge to the ophthalmic surgeon. A complete third nerve paralysis with complete ptosis is best left untreated.
When the paralysis is partial, especially when some adduction is preserved, the patient may benefit from maximal recession of the lateral and resection of the medial rectus muscles. This may be combined with upward transposition of the muscle insertions to counteract the hypotropia. Transfer of the superior oblique muscle to the insertion of the medial rectus muscles with or without fracture of the trochlea has also been recommended.
Ptosis surgery is postponed until alignment of the eyes has been achieved by surgery. Caution with regard to ptosis surgery is advised if elevation is impaired because of exposure problems.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.
A new research from the University of Edinburgh, UK, suggests that cheap cilostazol tablets may reduce damage to arteries, which lead to blood clots, resulting in strokes and cognitive decline. The researchers plan to assess the medications’ ability to cut the risk of...
A new study from the US discovers that flavonoids, natural compounds found in fruits and vegetables, may help preserve the lung function, which tends to decline with age. For the study, a team of researchers looked at data from 463 adults from Norway and England whose...
Quiz about this article
0 of 2 questions completed
Please answer on few questions to make our service more useful
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading...
You must sign in or sign up to start the quiz.
You have to finish following quiz, to start this quiz:
0 of 2 questions answered correctly
Time has elapsed
You have reached 0 of 0 points, (0)
Question 1 of 2
Was this article useful for you?Correct
Thanks for your feedback!Incorrect
Thanks for your feedback!
Question 2 of 2
What else information about this disease you want to know ?Correct
Thanks for feedback!Incorrect
Thanks for feedback!
Good weather is the best reason to do outdoor sports, which will help not only lose weight, but also will strengthen health. Bicycle The sun dries out the local paths, so you can safely sit on your favorite bike and confidently twist the pedals, where the eyes look....read more
First aid for injuries consists of simple rules that need to be clearly implemented. If this is a closed injury, you need to immobilize the injured limb, otherwise the person may lose consciousness from a painful shock. If you need to get to the emergency room...read more
Many people spontaneously decide starting to do sport, while others weigh all the pros and cons for a log time. But almost all of them make the same mistakes, listening to the advice of non experts. There are 10 anti-tips for those who want to do plan to do some sport...read more