Sunday, September 26, 2010
Mastoiditis
(On the left is an MRI axial T1-weighted image with IV contrast which shows Acute Mastoiditis on the left mastoid process)
Mastoiditis is a bacterial infection of the mastoid air cells within the mastoid process which is the bump located behind each ear. In most occurrences, it happens when an ear infection extends to the mucus membrane encompassing the mastoid process and finally reaches the walls of the mastoid bone itself.
If mastoiditis continues and is not treated it can end in hearing loss and bone destruction in the skull. At the present time, the possibility is good for a full recovery if it is treated without any delay otherwise it could lead to worst problems such as facial paralysis, labyrinthitis, meningitis and brain abscess.
There are various bacteria that can cause mastoiditis such as beta-hemolytic streptococci, staphylococci, hemophilus influenzae, gram-negative organisms and pneumococcus (typically in children under the age of six). Mastoiditis is commonly a complication of Chronic and acute otitis media.
Indications of mastoiditis may consist of low-grade fever, edema of the tympanic membrane, dull ache and tenderness in the area of the mastoid process, thick purulent discharge that commonly becomes more prolific possible conductive hearing loss and postauricular erythema and edema. In order to treat mastoiditis, intense parenteral antibiotic therapy is used which can be done intravenous or intramuscular. If the bone has minimal damage, a myringotomy is done to drain the purulent fluid. A simple mastoidectomy would be required if the infection persists or recurs but if the mastoid is habitually inflamed a radial mastectomy would be necessary. With both the simply or radical mastectomy, the patient would still undergo oral antibiotic therapy.
Saturday, September 18, 2010
Medullablastoma (MRI)
Medullablastoma is a fast- growing tumor of the cerebellum. The cerebellum controls posture, balance and complex motor functions like speech and balance. Tumors found in the cerebellum are called infratentorial tumors. In adults this tumor can usually be found in the body of the cerebellum especially toward the edges. In children, medullablastomas arise most often near the vermis.
There are different types of medullablastomas: classical medullablastoma, large-cell or anaplastic medullablastoma, desmoplastic nodular medullablatoma, melanotic medulloblastoma, medulloblastoma with glial differentiation, medulloblastoma with neuroblastic or neuronal differentiation and medullomyoblastoma.
The first course of action a doctor needs to take in making a diagnosis is to get a symptom history of the patient and to run a neurological examination. MRI is the modality performed to identify the presence of a tumor in the brain and is done with and without contrast.
Once the tumor is established as being a medullablastoma, treatment currently consists of surgery to remove as much of the tumor as viable. The person’s doctor will recommend a treatment plan constructed of details that show the risk of the tumor returning. The doctor will also look at the patients age, how much of the tumor persists or spreads after surgery and amount of metastases to verify risk.
The most crucial measure in treating medullablastoma is to take out as much of the tumor as attainable to help ease the cerebrospinal fluid buildup from either swelling or tumor. After surgery, radiation therapy is typically used to treat medullablastoma because there may be some microscopic tumor cells that persist in the adjoining brain tissue. Chemotherapy can be used in children to decrease the risk of tumor cells extending through the spinal fluid. This treatment may not aid adults because their tumors tend to relapse in the cerebellum.
Prognosis of a patient depends upon how well they respond to treatment, which relies on their age, the size and magnitude of the tumor, the amount of the tumor that can be taken out safely and the stage of metastatic disease.