MALIGNANT BRAINSTEM GLIOMAS--CHILDHOOD
Childhood Malignant Brainstem Glioma; Malignant Brainstem Glioma- Childhood Diffuse Intrinsic; Malignant Brainstem Glioma; Diffuse Intrinsic Pontine Gliomas; DIPG; Malignant Brain Tumor; Pediatric Malignant Brain Tumor; Malignant Brain Tumor – Children
Malignant Brain Stem Gliomas are a common type of brain tumor that occurs in the region of the brain referred to as the brainstem. Approximately 80 percent of malignant pediatric brainstem gliomas arise within the pons. The majority of pontine tumors, diffuse intrinsic pontine gliomas (DIPG), are usually high-grade, aggressive, locally infiltrative, and have a uniformly poor prognosis. Diffuse intrinsic pontine gliomas meet the listings upon confirmed diagnosis alone.
Brainstem gliomas are classified into four grades. Grades I and II are considered low grade; grades III and IV are considered high grade. Grade I and II are the slowest growing and least aggressive. In children, Grade II brainstem tumors medically equal 13.13A2 only if they are progressive or recurrent despite treatment. Grade I tumors are generally considered benign, and we evaluate them under the neurological listings (111.05). Grade III and Grade IV childhood brainstem tumors are the fastest growing and most aggressive. Common presenting symptoms include double vision, weakness, unsteady gait, difficulty swallowing, dysarthria, headache, drowsiness, nausea, and vomiting. Older children may have deterioration of handwriting and speech. DIPG results in partial paralysis, loss of voice and sight, and finally ending with an inability to eat and breathe.
DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM CODING
Diagnostic testing: MRI scans are the preferred tool to evaluate a brainstem tumor, although a CT scan may be performed in the rare circumstances where MRI is unavailable. A biopsy is seldom performed outside specialized biomedical research protocols for DIPG, unless the diagnosis of this tumor is in doubt. Tumors also are characterized on the basis of site of origin, direction and extent of tumor growth, degree of brainstem enlargement, presence or absence of cysts, necrosis, hemorrhage, and hydrocephalus.
Physical findings: Common clinical findings usually involve cranial nerve deficits, ataxia (inability to coordinate muscles) of trunk and limbs, papilledema (edema of the optic disc), facial sensory loss, and nystagmus (involuntary movement of the eyeballs).
ONSET AND PROGRESSION
The average age at diagnosis is 5 to 9 years of age. DIPG has a high rate of recurrence or progression. DIPG often follows an inexorable course of progression, despite therapy. A large majority of children die within a year of diagnosis.
Surgery is not usually performed because of the tumor’s infiltrating location in the brainstem; however, surgical procedure to reduce pressure inside the skull caused by hydrocephalus is common. Surgery may be performed if the tumor extends into the fourth ventricle.
Radiation is used to shrink the tumor, improve, stabilize or prolong life. New therapies have yielded little benefit over conventional treatment with radiotherapy alone. Unfortunately, recurrence usually occurs after 6 to 9 months of treatment.
Adjuvant chemotherapy is generally not used in children because efficacy has not been proven. Data suggest that pre-radiation chemotherapy may improve survival in diffuse intrinsic pontine gliomas. The effectiveness of chemotherapy at relapse is uncertain, but it may benefit some patients.
Individuals who have difficulty swallowing or diminished gag reflex may require gastrostomy tube placement. Individuals with frequent upper respiratory infections, pneumonia, or altered voice may require post-op ventilator assistance.
SUGGESTED PROGRAMMATIC ASSESSMENT*
Suggested MER for evaluation: The adjudicator needs medical evidence from treating sources and hospitals. It may include clinical history and examination that describe the diagnostic features of the impairment, imaging tests, pathology reports, surgical procedures, pertinent treatment records, or up-to-date progress notes.
Suggested Listings for Evaluation:
Malignant brainstem gliomas occurs more frequently in children. Grade III and Grade IV brainstem cancers in children, such as diffuse intrinsic pontine gliomas; meet the listing upon confirmed diagnosis alone.