What Causes Cerebellar Infarction?

The cause of cerebellar infarction is an occlusion of the cerebellar arteries. Depending on the severity of the occlusion and size of the occluded vessel, the symptoms and the effect on the patient can vary. If the blood supply to the posterior circulatory system fails, the cerebellum and brain stem are not sufficiently supplied with blood, which can result in the necrosis of brain tissue.

A particular syndrome, known as Wallenberg’s syndrome, is caused by PICA occlusion. In addition to the typical symptoms listed below, it can also cause deafness, paralysis of the eye muscles, and nystagmus, as these areas are supplied by the posterior inferior cerebellar artery (PICA).This vessel is an important branch of the vertebral artery. The vertebral artery should also be examined in patients involved in an accident, especially in those suffering from high-velocity trauma. In cases of high-velocity trauma, dissection of the vertebral artery can occur, which can be ruled out with CT-based imaging.

Other important vessels branching off from the basilar artery are the anterior inferior cerebellar artery (AICA) and the superior cerebellar artery (SCA), which supplies the cerebellar vermis.

The symptoms of an infarction occur in the areas supplied by these vessels.

For an overview of the functional anatomy of the cerebellum, please refer to medical textbooks (e.g. neurology: anatomy and function of the cerebellum) or illustrative drawings and videos.

Typical Symptoms of Cerebellar Infarction

Typical symptoms of cerebellar infarction include nausea, vomiting and dizziness, caused by insufficient blood flow to the cerebellum. Impaired balance and coordination along with a tendency to fall or fine motor skill disorders can also occur.

In the context of cerebellar infarction, the reduced blood flow can lead to increased swelling of the brain, also known as edema. This leads to increased compression of the fourth ventricle, preventing the drainage of cerebrospinal fluid. A build-up of fluid, known as hydrocephalus, occurs and the brainstem can become compressed.Affected patients can become unconscious and die.

To prevent this, decompressive craniotomy of the posterior fossa, involving the opening of the dura and removal of the cerebellar tissue affected by the infarction, is indicated. During this surgical procedure, the patient is placed on their stomach and the head is secured inside a metal clamp at an angle. In doing so, it must be ensured that the head is securely fixed in a specific position and can no longer move. The correct position is essential to ensure that surgical decompression can be safely performed. One such device to ensure the precise and secure clamping of the skull is the evoBase from Evonos. The positions of the fixing pins are variable, ensuring greatest possible adaptability to the shape, size, and position of the individual patient’s skull.

If surgery is needed to relieve the swelling of the cerebellum, both the damaged cerebellar tissue and the bone will be removed. The skull is opened using a craniotome such as the Evonos evoDrill. It is available in different diameters and for two different skull thicknesses. The unique cutting geometry allows precise and effortless trepanation with minimal force.

Alternatively, the skull can be perforated using a diamond knife like Evonos evoCarat.

What Are the Risk Factors for Stroke?

Among the risk factors for stroke, atherosclerotic changes in the vessel wall are the most noteworthy ones. Plaque deposits in the vessel wall cause a narrowing, a so-called stenosis in the artery, which can lead to short-term circulatory dysfunctions, but also to an irreversible stroke.

Prevention and minimization of risk factors is therefore of great importance. It is important to treat and manage blood pressure, diabetes mellitus, and cholesterol. Smoking and obesity also increase the risk of stroke.While patients at risk are usually well aware of the recommendations of treating physicians regarding a healthy lifestyle that lowers the risk of stroke, these recommendations are often not followed consistently.

Another significant risk factor is absolute arrhythmia (atrial fibrillation). This condition occurs more frequently in elderly patients and is often associated with embolic stroke.Cardioversion and/or anticoagulant medication is indicated here. In addition, there are rare vascular diseases, such as Moya-Moya disease, in which a congenital narrowing of the vessels can lead to circulatory disorders.

To confirm the diagnosis of stroke, a CT scan with additional imaging of the vessels should be performed as soon as possible after the onset of symptoms. If the CT scan shows vascular occlusion, mechanical recanalization or systemic thrombolysis can be performed, depending on how much time has passed since the onset of symptoms. The aim of this therapy is to save brain tissue by maintaining the blood flow and preventing a stroke. One of the risks associated with lysis is the onset of hemorrhage.

As these procedures are no longer likely to be successful three hours after the onset of symptoms, fast presentation of the affected patients at a hospital is essential for treatment success. Unprecedented visual or speech disorders, or even minor numbness and paralysis, should be investigated and examined immediately through neurological imaging. Frequent precursors include minor circulatory dysfunction associated with often very mild and reversible symptoms. Headaches and problems with fine motor control can also be signs of infarction.

If this diagnosis is confirmed, the patient should be transferred to a stroke unit specializing in stroke patients to ensure proper treatment.

What Are the Long-Term Effects of Cerebellar Infarction?

Depending on the severity and location of the affected brain area, cerebellar infarction can cause both immediate and long-term effects:

In cases of extensive infarction, the swelling may become so pronounced that it causes compression of the brain, which can be fatal for the patient.Smaller lesions can cause milder symptoms such as fine motor skill dysfunction. The infarcted tissue will not regenerate, but other, undamaged areas can take over its functions and compensate its failure. The long-term effects are therefore largely dependent on the extent of the damage, but also on the patient’s ability to recover. Age and other pre-existing conditions or limitations play a role here. In addition, the loss of independence often causes additional psychological stress.

After emergency treatment at the hospital, most patients require rehabilitation. The aim is to regain as many functions as possible in order to lead as independent a life as possible.

Patients recovering from cerebellar infarction often experience mobilization as a major challenge. Persistent vertigo and impaired target motor skills often cause great insecurity when getting out of bed. Nursing staff and physiotherapists work to prevent this by practicing getting out of bed with patients at an early stage and using aids such as high walkers. Occupational therapy also plays an important role, particularly in practicing fine motor skills. The prognosis after cerebellar infarction is generally good.Depending on the extent of the brain damage and the patient’s age, functional loss can often be compensated, albeit with some lasting insecurity.

Brainstem infarction can result in a high and very complex degree of severe handicap, since this area of the brain not only contains the vital respiratory and circulatory center, but also many cranial nerve functions that can be damaged and cause difficulty seeing, swallowing, and breathing. Furthermore, infractions in this area can lead to permanent lightheadedness. The care and further rehabilitation of these patients should take place in specialized medical centers offering neurological early rehabilitation, where they can regain as many of their lost faculties as possible and avoid complications.

Is Vertigo a Sign of Cerebellar Damage?

Vertigo is one of the classic symptoms of cerebellar damage. It is often accompanied by nausea and vomiting. However, vertigo can also have other causes than cerebellar infarction and stroke. The underlying causes are manifold and often difficult to determine.

• The most common form is benign positional vertigo, in which rotatory vertigo attacks are caused by mechanical disturbances in the equilibrium organ that are provoked by certain changes in position.
• If the cause is a lesion of the vestibular nerve, the vertigo will last for several days.
• Furthermore, the cause can be vertigo migraine or even inner ear damage—known as Meniere’s disease—which causes sudden vertigo and hearing loss for a few hours.
• Sometimes, the cause is low blood pressure associated with orthostatic dysregulation. Psychological factors should not be underestimated either.

It is important to consult a medical specialist to rule out cerebellar causes and to document the findings.If a patient experiences an unprecedented neurological event or if existing symptoms worsen significantly, immediate investigation is always required. This is because early action is required in the event of a circulatory disorder in order to save brain tissue that may be critically affected by poor circulation. Brain tissue can get damaged and cerebral infarctions can occur after just a few minutes of interrupted oxygen supply. If eloquent areas such as the brainstem are affected, this can severely impair the patient’s ability to speak

and lead to the loss of vital functions.

Parenthesis: Which Other Diseases Can Occur in the Cerebellum?

Symptoms such as vertigo, balance disorders and impaired fine motor skills, as seen in cerebellar infarction, can also be caused by other cerebellar disorders.

Tumors that develop in this area are particularly worthy of mention in this respect. In adults, these are usually metastases, i.e. secondary tumors that have spread from another tumor in the body, often in the lungs, breast, or skin. For a more precise diagnosis, an MRI scan using a contrast medium is indicated if a tumor is suspected. This can help distinguish the tumor and the swelling of the brain caused by it from the surrounding tissue.

Depending on the extent and number of tumors, as well as the overall situation of the patient, treatment options include surgical removal and/or radiation.

A special type of tumor is the vestibular schwannoma (also known by its former name, acoustic neuroma). This is a benign tumor that grows in the cerebellopontine angle. It originates from the vestibular nerve and grows from the inner auditory canal towards the brainstem, leading to the displacement and functional impairment of the adjacent cranial nerves. In patients with smaller tumors, this causes unilateral hearing loss, high-frequency, unilateral tinnitus, as well as balance disorders and vertigo. These symptoms usually develop progressively over several months or years as the tumor grows slowly.

With larger tumors which oppress other cranial nerves such as the trigeminal nerve, the glossopharyngeal nerve, or the facial nerve, further symptoms can occur. This can cause sensory disturbances on one side of the face, unilateral facial paralysis, and difficulty swallowing.

Very large tumors can cause additional compression of the brainstem, resulting in ataxia, hemiplegia, headaches, and nausea.

Vestibular schwannomas can be diagnosed in an MRI scan using contrast agents, in addition to a clinical neurological examination and a pure tone audiometry.

Depending on the size and extent of the tumor, and the patient’s hearing and general health, different treatment options can be offered.

In addition to monitoring very small and clinically irrelevant tumors, surgery and/or stereotactic radiosurgery are available.

During surgery, particular attention should be paid to the neighboring cranial nerves to avoid injury. This requires continuous intra-operative monitoring of the cranial nerves and auditory function by measuring the AEP. The aim of this procedure is the complete removal of the tumor while avoiding new neurological symptoms. Especially facial nerve paralysis causing facial paralysis should be avoided.

An alternative to surgical treatment is stereotactic radiosurgery for smaller, localized tumors. This involves necrotizing and inactivating the tissue by means of dose-dependent radiation instead of removing it. Like surgery, this also leads to the functional deactivation of the tumor.