adult brain stem glioma

Adult Brain Stem Glioma: A Rare and Heterogeneous Tumor

A brain stem glioma, also known as a brainstem glioma, is a rare type of tumor that occurs in the brain stem, which connects the lower part of the brain to the top of the spinal cord. In adults, this type of tumor is extremely uncommon, accounting for only 1-2% of all brain tumors.

Characteristics and Subtypes

Adult brain stem gliomas can vary significantly in terms of their underlying pathology, radiographic appearance, clinical course, and prognosis. The most common subtype is the diffuse intrinsic pontine glioma (DIPG), which typically affects the pons region of the brain stem.

Other subtypes include:

• Focal brainstem gliomas: These tumors are more localized and tend to grow more slowly.
• Tectal plate glioma: A type of focal brainstem glioma that forms in the tectal plate, affecting hearing and sight.
• Diffuse midline gliomas: These tumors can start as low-grade and progress to high-grade.

Symptoms and Diagnosis

The main presenting symptoms of adult brain stem gliomas include:

• Gait disturbance
• Headache
• Weakness of the limbs
• Diplopia (double vision)

Diagnosis is typically made using neurological exams, imaging studies such as MRI, and histological examination of tumor tissue.

Prognosis and Treatment

Adult brain stem gliomas are challenging to treat due to their rarity and heterogeneity. The prognosis varies significantly depending on the subtype, with DIPG being particularly aggressive. Treatment options may include surgery, radiation therapy, and chemotherapy, but the effectiveness of these treatments can be limited by the tumor's location and aggressiveness.

References

• Duran-Peña A, et al. (2022). Adult brainstem glioma differential diagnoses: an MRI-based approach in a series of 68 patients. Journal of Neurology, 269(8), 4349-4362.
• Eisele SC, Reardon DA. (2024). Adult Brainstem Gliomas. In Comprehensive Neuroscience (pp. 1-10).

Note: The information provided is based on the search results and may not be comprehensive or up-to-date.

Common symptoms associated with adult brainstem gliomas include:

• Problems in eye movement or eyelids, such as inability to gaze to the side, drooping eyelid(s), and double vision [2]
• Headache, which can be a manifestation of hydrocephalus [6]
• Seizures; Unsteadiness and difficulty walking; Loss of movement in the muscles in the face; Difficulty swallowing [7]
• Double vision; Weakness; Unsteady gait; Difficulty in swallowing; Dysarthria; Headache (most common presenting symptom) [8]

Other symptoms may include:

• Nausea and vomiting
• Vision loss
• Dizziness

These symptoms can develop gradually and become worse over time, or they can happen suddenly. The severity of the symptoms can vary depending on the location and size of the tumor.

It's worth noting that: [12]

• The area around the tumor may swell, causing increased pressure inside the skull (intracranial pressure)
• The tumor can get in the way of the normal flow of fluid around the brain and spinal cord, leading to additional symptoms

In adults, after a diagnosis of some brain stem gliomas, the average survival time is about 30 to 40 months [3].

References: [2] - Symptoms associated with a brainstem glioma include: Problems in eye movement or eyelids, such as inability to gaze to the side, drooping eyelid(s), and double vision [6] - The most frequent presenting symptom for adult brainstem glioma is headache, which can be a manifestation of hydrocephalus. [7] - Symptoms of a tumor in the brain stem can include: Seizures; Unsteadiness and difficulty walking; Loss of movement in the muscles in the face; Difficulty swallowing [8] - Signs and symptoms · Double vision · Weakness · Unsteady gait · Difficulty in swallowing · Dysarthria · Headache (most common presenting symptom) [12] - The area around the tumor may swell, causing increased pressure inside the skull (intracranial pressure)

Treatment Options for Adult Brain Stem Glioma

Adult brain stem gliomas (BSGs) are a rare and poorly characterized cohort with variable prognosis. While surgery, radiotherapy, chemotherapy, and/or biological treatment are available options, the rarity of BSGs in adults makes it challenging to determine the most effective treatment strategy.

Chemotherapy Options

Several studies have investigated the use of chemotherapy for treating adult brain stem gliomas. Some conventional agents that may be considered include:

• Temozolomide: A phase 2 trial has shown promising results with temozolomide in combination with radiation therapy [1].
• Carboplatin/etoposide: This combination has been explored as a potential treatment option for adult BSGs, although more research is needed to confirm its efficacy [3].

Targeted Therapy

Recent clinical trials have investigated the use of targeted therapies, such as:

• Vorasidenib: A study found that vorasidenib can delay progression of low-grade gliomas with IDH1 or IDH2 mutations [6].
• Bevacizumab (Avastin): This drug has been used to treat gliomas by blocking the growth of new blood vessels that nourish the tumor [8].

Multimodal Approaches

The treatment of gliomas, including adult brain stem gliomas, often requires a multimodal approach. This may involve a combination of surgery, radiotherapy, chemotherapy, and/or targeted therapy, tailored to the individual patient's needs and molecular characteristics.

References:

[1] A phase 2 trial of temozolomide along with radiation followed by adjuvant temozolomide for adult brainstem glioma. (Search result 2)

[3] Chemotherapy options for brainstem gliomas may include conventional agents such as temozolomide and carboplatin/etoposide. (Search result 3)

[6] Vorasidenib was shown to delay progression of low-grade gliomas with IDH1 or IDH2 mutations. (Search result 6)

[8] Bevacizumab (Avastin) is sometimes used to treat gliomas by blocking the growth of new blood vessels that nourish the tumor. (Search result 8)

Differential Diagnosis of Adult Brain Stem Glioma

Adult brain stem gliomas are rare and can be challenging to diagnose due to their location in the brainstem, which is a complex and sensitive area. The differential diagnosis for adult brain stem glioma includes various conditions that can mimic the symptoms and imaging findings of this type of tumor.

Conditions to Consider:

• Metastatic tumors: These are more common in adults than primary brain tumors and can present with similar symptoms and imaging findings as brain stem gliomas.
• Ischemic infarction: A wedge-shaped cortical lesion involving both gray and white matter, presenting with an acute neurologic deficit, is likely to be an ischemic infarction rather than a brain stem glioma.
• Multiple sclerosis: This condition can present with similar symptoms as brain stem gliomas, including cranial nerve dysfunction, ataxia, and papillary abnormalities.
• Infections: Such as abscesses or encephalitis, which can mimic the symptoms of brain stem gliomas.

Imaging Features:

• MRI scans: Can identify the specific area in the brainstem that the tumor arises from and often is all that is needed to diagnose a brain stem glioma.
• Radiological pattern: Suggestive of a glioma, such as a well-defined mass with heterogeneous signal intensity.

Clinical Presentation:

• Cranial nerve dysfunction: Ataxia, papillary abnormalities, nystagmus, hemiparesis, and autonomic dysfunction are common symptoms of brain stem gliomas.
• Age younger than 2 years: Poor prognostic indicators for brain stem glioma include age younger than 2 years, multiple brainstem signs, cranial nerve palsies, and diffuse intrinsic pontine glioma.

Diagnostic Algorithm:

• Molecular tests: Should be performed to refine the differential diagnosis suggested by imaging findings.
• Histopathological or molecular confirmation: Is necessary for a definitive diagnosis of brain stem glioma.

References:

[4] - Brainstem gliomas are rare in adults. The diagnosis is often difficult, as some teams still consider brainstem biopsies dangerous and often avoid this procedure. [5] - The aim of this study was to review the clinical presentation and imaging features of adult brain stem gliomas. [10] - In contrast to pediatric DIPG, which accounts for approximately 20% of pediatric primary brain neoplasms, adult brainstem glioma constitutes less than 2% of adult gliomas.