When looking at the brain, you will see the two main lobes, the occipital and the temporal. The spinal cord terminates at the brainstem, which is attached to the Cerebellum. The Cerebellum is tucked underneath these two lobes a the back of the skull on top of the brainstem. The cerebellar Vermis is located at the center of the Cerebellum’s two lobes, in the Cerebellum’s coriconuclear region.
The Vermis relates to body posture and mobility and divides the two cerebellar hemispheres. Therefore, the anatomy of the Vermis resembles that of the cerebellar hemispheres in most respects. Disorders commonly associated with the Vermis are Dandy-Walker, Joubert syndrome, Medulloblastoma, and more.
The Vermis sits at the heart of the Cerebellum, and many disorders and malformations affect patients. In addition, the Cerebellum regulates movement and posture automatically, and new motor patterns are learned in this region.
The Anatomical Structure Of The Vermis
The Cerebellum’s medial or central corticonuclear zone consists of the cerebellar Vermis and the fastigial nucleus. This functional zone is related to the posture and motility of the entire body. Traditionally, the Vermis is believed to be part of the spinocerebellum and to receive somatic sensory information from ascending spinal pathways.
The spinocerebellum comprises the Vermis and intermediate zones of the cerebellar cortex, in addition to the fastigial and interposed nuclei. It receives large inputs from the spinocerebellar tract. In addition, it sends signals to the rubrospinal, vestibulospinal, and reticulospinal tracts.
In contrast, the lateral zone of the Cerebellum is classified as Cerebral-cerebellum due to its intense connectivity with the cerebral cortex. The Cerebro-cerebellum, the Cerebellum’s most recent enlargement, receives convergent inputs from cortical, subcortical, and spinal sources and is believed to do the predictive computation for motor control and motor learning, and cognitive tasks.
The region of the Vermis is said to get extensive cerebral cortex input. The Vermis can further be divided into two distinct lobes. The central or primary fissure divides the Vermis into a tiny anterior lobe and a considerably larger posterior lobe. It can be broken further into nine lobules created by clusters of folia that correspond to paired cerebellar hemisphere lobules. The size, shape, and quantity of folia that are usually between 1–4 are prone to variation.
The Anterior Lobe
- Lingula
- Central Lobule
- Culmen
The Primary (Tentorial) Fissure
- Posterior Lobe
- Declive
- Folium
The Horizontal (Petrosal) Fissure
- Tuber
The Prebiventral/Prepyramidal (Suboccipital) Fissure
- Pyramid
- Uvula
The Flocculonodular Lobe
- Nodulus
We found a study that contradicts the long-held beliefs on the functional arrangement of the Cerebellum. For example, the Cerebellum has traditionally been divided into three cortico-nuclear zones:
- Firstly, a medial zone consisting of the cerebellar Vermis and the fastigial nucleus
- Secondly, an intermediate region comprised of the paravermal cortex and the interposed nuclei
- Thirdly, a lateral area consists of the most lateral cerebellar cortex and the dentate nucleus
Current literature considers the Vermis part of the spino-cerebellum and stresses that ascending spinal pathways furnish the Vermis with head and proximal body somatic sensory input. As stated previously, the lateral zone gets categorized as Cerebro-cerebellum due to its dense connection with the cerebral cortex. The study’s findings indicated that a part of the Vermis receives intense output from the cerebral cortex.
The findings imply that the Vermis should no longer be considered wholly separated from the cerebral cortex. Instead, at least some lobules provide specific locations where the cortical motor regions can impact descending control systems involved in regulating whole-body posture and movement. The cortical connection to the Vermis may be as crucial for movement control as the hemisphere cortical link.
Furthermore, it is still unknown if additional parts of the cerebral cortex, such as nonmotor portions of the frontal lobe, impact the operation of other sections of the Vermis. Therefore, researchers should conduct further experiments and studies in this field.
What Is The Primary Function Of The Vermis
From a functional standpoint, the Vermis sits at the center of the Cerebellum’s two lobes and is partially responsible for connecting the brain to the body’s posture and movement. The Cerebellum is responsible mainly for adjusting the body’s posture, and it helps maintain balance, eye movements, coordination, and speech.
Disorders Associated With The Vermis
By the second trimester, the Cerebellum develops embryologically over a period, making it susceptible to a broad spectrum of abnormalities and disorders. Therefore, knowledge of the principal stages of fetal posterior fossa development is vital to spot abnormalities or malformations.
Standard imaging patterns at various stages of embryogenesis can clearly show the vast range of cerebellar abnormalities. Therefore, early detection and diagnosis of disorders associated with the Vermis and Cerebellum will help in counseling parents.
Sonography is the most effective imaging technique for detecting cerebellar abnormalities since it is non-invasive, readily accessible, and safe for both mother and child. Fetal MRI offers an excellent contrast resolution than prenatal sonography and may aid in better tissue classification. Both prenatal neurosonography and fetal MRI provide a reliable prenatal diagnosis of most posterior fossa abnormalities.
Dandy Walker Syndrome
Dandy-Walker syndrome or Dandy-Walker malformation is a disorder of prenatal brain development. Dandy-Walker concerns the Cerebellum and surrounding areas. As a result, the Dandy-Walker Syndrome is characterized by sluggish motor development and big head size. Dandy-Walker deformity affects around 1 in 25,000 to 35,000 newborns in the United States. It affects more newborn females than newborn males.
In children, hydrocephalus occurs when the brain’s fluid cannot drain adequately. The hydrocephalus treatment comprises a VP (Ventriculoperitoneal) shunt to drain excess fluid. The extra brain fluid drainage helps children perform regular everyday duties.
Less than half of children born with Dandy-Walker will have intellectual impairment. Severe Intellectual impairment occurs when children with Dandy-Walker syndrome also have severe hydrocephalus, chromosomal, and other congenital disorders.
There is no known way to circumvent or prevent Dandy-Walker syndrome. Patients with this disease have a wide range of standard and aberrant experiences. Some people have experienced minor symptoms, while others have significant impairment and mobility concerns.
Are Dandy-Walker syndrome and Dandy-Walker complex the same?
Dandy-Walker complex refers to a cluster of illnesses having comparable characteristics. Dandy-Walker syndrome is included in the Dandy-Walker complex disorders list. There are a few disorders within Dandy-Walker Complex:
Posterior fossa arachnoid cyst: The most frequent form of brain cyst is the arachnoid cyst. Often congenital (from birth), these cysts can also occur later in life due to a brain injury or trauma. The cysts are fluid-filled sacs and not malignancies. Males are 4-times more likely than females to have arachnoid cysts, which generally do not require treatment if they remain stable.
Blake’s pouch cyst: Although Blake’s pouch cyst (BPC) is commonly cited in the spectrum of posterior fossa cysts, cyst-like abnormalities it is relatively uncommon. As a result, BPC may continue to be underdiagnosed. BPC is a lesser-known but distinct condition within the radiological spectrum of posterior fossa cysts and cyst-like abnormalities; however, some writers still classify it as a DWC.
Mega cisterna magna: Normal mega cisterna magna is defined by a focused expansion of the CSF-filled subarachnoid space in the inferior and posterior regions of the posterior cerebral fossa. On mid-sagittal images, MCM refers to a retro- and infracerebellar CSF (Cerebrospinal fluid) space of more than 10 mm. It is an accidental discovery of neuroimaging. No particular symptoms are associated with this illness.
Isolated cerebellar vermis hypoplasia: is a rare, nonsyndromic (not part of a syndrome) cerebellar malformation characterized by an underdeveloped cerebellar vermis. Patients diagnosed with Isolated cerebellar vermis hypoplasia can develop normally.
Hypoplasia Of The Cerebellar Vermis
Hypoplasia is the deficiency of cells in tissues or organs, which impairs their function. Cerebellar Vermis Hypoplasia gets defined by the standard position of the Cerebellar Vermis relative to the brainstem, or there exists a slight upward rotation due to a minimally enlarged fourth ventricle without tentorial (primary fissure) elevation.
Typically, the retrocerebellar fluid collection in the Virmis’s fourth ventricle is small, making it very difficult to diagnose CVH accurately. As a result, CVH is the most challenging prenatal diagnosis since it gets frequently misdiagnosed as variations of Dandy–Walker Syndrome, mega cisterna magna, or Blake’s pouch cyst.
There is no established treatment protocol for cerebellar hypoplasia. The effectiveness of treatment relies on the underlying condition and the intensity of symptoms. Treatment is often symptomatic and supportive.
Other conditions related to an underdeveloped or missing Cerebellum include but are not limited to:
- Pontocerebellar hypoplasias (PCH)
- Unilateral cerebellar hypoplasia (UCH)
- Cerebellar hypoplasia
- Isolated cerebellar vermis hypoplasia
- Isolated inferior vermian hypoplasia (iiVH)
What Is The Treatment For Dandy Walker
The treatment for Dandy-Walker syndrome is based on the symptoms originating from the condition. Therefore, a thorough evaluation by a healthcare professional is necessary before beginning treatment. For instance, healthcare providers may suggest:
- VP (Ventriculoperitoneal) shunt: To drain excess fluid from the brain, surgeons insert a VP shunt, a tiny device. The shunt can alleviate cerebral pressure and ease symptoms
- Prescription Drugs: Your child’s doctor may prescribe anticonvulsant medications to control seizures
- Physical and occupational therapy: can assist youngsters in maintaining their muscle strength. Additionally, therapists can teach children new ways to perform their routine activities.
- Speech therapy: can aid in the development of language and speech
- Special education: The proper learning environment can assist students in achieving their educational and social objectives
Joubert Syndrome Associated With The Vermis
Joubert syndrome is an uncommon illness characterized by abnormal brain development in newborns and children. For example, the Cerebellar Vermis, which regulates balance and coordination, may be undeveloped, partially or entirely missing. Joubert syndrome can affect a variety of body components. It can result in many health issues, developmental delays, and intellectual impairment.
Ashkenazi Jews, French Canadians, and Hutterites are among the ethnic groups more likely to suffer from the illness. The condition known as Joubert syndrome is extremely rare. Only one in every 100,000 or so births is thought to be affected. However, people who have a family history of Joubert syndrome are more likely to pass it on to their children.
The “molar tooth sign” can be seen on MRI midbrain scans in people with Joubert syndrome. The section of the brain stem that didn’t develop correctly resembles a molar tooth in appearance.
What Is The Treatment For Joubert Syndrome
Joubert syndrome is incurable. However, your medical team may suggest therapies to alleviate the symptoms and enhance the patient’s well-being. Treatment for Joubert syndrome varies from person to person, depending on how the condition affects them.
- Infant body and brain stimulation can be used to correct developmental delays
- Therapy in the field of occupational medicine will also be beneficial
- Physical therapy is an option to help with motion control
- Speech treatment will help, especially for those patients with a cleft palate or lip
Medulloblstoma Embryonal Tumor
Medulloblastoma is a malignant (cancerous) brain tumor that begins in the Cerebellum, targeting fetal embryonic cells. In pediatric oncology, Medulloblastoma, a tiny blue cell tumor of the Cerebellum, is a leading source of morbidity and death. These tumors spread throughout the brain and spinal cord through the cerebrospinal fluid (CSF). It is unlikely to spread to other areas of the body.
Following are the four primary subgroups of Medulloblastoma, and each group has various subtypes:
- Wnt
- Wnt α
- Wnt β
- Shh
- Shh α
- Shh β
- Shh γ
- Group 3
- Group3 α
- Group3 β
- Group 4
- Group4 α
- Group4 β
The type and quantity of subsets for each subgroup are presently unclear. Therefore, until they are sufficiently described and named according to their molecular etiology, one should use the Greek letters (α,β,γ, etc.) to name them.
What Is The Treatment For Medulloblstoma
Imaging through Ct or MRI can aid in determining the location and size of a brain tumor. Surgery, followed by radiation treatment, chemotherapy, or sometimes both, is frequently used to treat patients diagnosed with Medulloblastoma.
Rhomboencephalosynapsis Associated With The Vermis
An uncommon congenital condition called Rhombencephalosynapsis (RES) is characterized by partial or complete agenesis of the cerebellar Vermis and midline fusion of the cerebellar hemispheres, dentate nuclei, and the superior cerebellar peduncles, giving the fourth ventricle its recognizable keyhole look.
Rhombencephalosynapsis patients may exhibit the following symptoms:
- Atypical eye movements
- Delayed motor function development
- Ataxia (Loss of body movement)
- Swallowing issues
- Muscular hypotonia (decreased muscle tone)
- Spastic quadriparesis (type of cerebral palsy)
- Odd eye movements
- The distinctive “figure-of-eight” head shaking
Patients diagnosed with Rhombencephalosynapsis can be divided into the following four categories:
- Rhombencephalosynapsis related to GLHS
- Rhombencephalosynapsis associated with VACTERL syndrome
- Rhomboencephalosynapsis associated with atypical holoprosencephaly
- Rhombencephalosynapsis that is separated from other conditions
What Is The Treatment For Rhomboencephalosynapsis
There is no cure for Rhomboencephalosynapsis since the whole or part of the Vermis is missing. Therefore, managing the symptoms through physical and social care according to the patient’s prognosis.
Dystonia Movement Disorders
Dystonia is an umbrella term for various movement disorders with differing symptoms, causes, development stages, and therapies. These neurological disorders get characterized by involuntary muscle contractions that drive the body into unnatural, often painful postures or movements.
Although Dystonia is generally believed to be caused by a dysfunction of the basal ganglia, there is growing evidence that the cortical motor areas and the Cerebellum Vermis contribute to some forms’ of genesis and maintenance. There is increasing evidence that the cortical motor areas and the Vermis of the Cerebellum contribute to the beginning and maintenance of some forms of Dystonia.
According to some test results, an abnormal signal from the cortical motor regions, an unusual Vermis reaction to this signal input, or a combination of the two might result in a sort of “action” dystonia characterized by excessive anticipatory postural responses.
What Is The Treatment For Dystonia
Dystonia may affect people of all ages, genders, races, and ethnicities. The diagnosis of Dystonia is based on recognizing distinctive symptoms, a comprehensive patient and family history, and a thorough clinical assessment.
Conclusion
Regarding how the brain controls posture and movement, the Vermis is an essential portion of the Cerebellum because it sits in the middle of the two lobes. Sluggish motor development and a large head are two of the symptoms of Dandy-Walker Syndrome. Children with Dandy-Walker syndrome who also have severe hydrocephalus, chromosomal, and other congenital problems have a severe intellectual disability.
Patients with Isolated Cerebellar Vermis Hypoplasia can go on to have an average life span despite their diagnosis. However, treatment for Dandy-Walker syndrome depends on the symptoms of the disorder. In neonates and children, Joubert syndrome is characterized by impaired brain development.
References
https://radiopaedia.org/articles/vermis
https://en.wikipedia.org/wiki/Cerebellar_vermis
https://www.sciencedirect.com/topics/neuroscience/cerebellar-vermis
https://www.sciencedirect.com/science/article/abs/pii/S1878875021019069
