The brain stem, the bottommost section of the brain, connects the rest of the brain with the spinal cord. This means that all nerve transmissions must travel through the brain stem. The brain stem consists of specialized areas known as the midbrain, the medulla oblongata and the pons. The brain stem controls vital functions such as the heart beat, blood pressure, breathing, vision, hearing and voluntary movements. Atrophy, or decrease in the mass of brain tissue in the brain stem can be caused by several different diseases.
Parkinson's Disease
Parkinson's disease is a degenerative neurological disorder in which dopamine-producing nerve cells in the substantia nigra, located in the midbrain, are lost. Parkinson's disease exhibits the characteristic symptoms of tremor, rigidity, slowness of movement and balance instability. A study published by Jubault and associates in the journal PLoS One suggests that the disease process resulting in the destruction of dopamine-producing cells may begin as atrophy in other areas of the brain stem, such as the medulla oblongata. Because of the limited size of this study, however, additional research and data must be collected to substantiate this theory.
Multiple Sclerosis
Multiple sclerosis, a disease that affects 2.1 million people worldwide, occurs when certain immune cells in the body attack and destroy myelin, the fatty substance protecting nerve cells, according to the National Multiple Sclerosis Society. Although classified as an autoimmune disease, information provided by the Montreal Neurological Institute suggests that atrophy of the brain stem or upper spinal cord may contribute to the symptoms of the disease. Symptoms of multiple sclerosis vary depending on the nerves affected, but commonly include numbness, dizziness, vertigo, vision impairments, emotional changes, cognitive impairments, depression and spasticity.
Aicardi-Goutières Syndrome
Aicardi-Goutières syndrome, classified as a type of leukodystrophy, is a progressive neurological disease that causes death before the age of 17 in 25 percent of patients, according to the United Leukodystrophy Foundation. Symptoms of Aicardi-Goutières syndrome, which include vomiting, feeding difficulties, irritability, spasticity and a lack of or loss of motor and social development, typically begin in the first six months of life. Doctors diagnose Aicardi-Goutières syndrome by using neuroimaging to visualize the calcification and hypodensity of the white matter and progressive atrophy of the cerebellum and brain stem, as described by GENEReviews.
Brainstem Stroke
A stroke occurs when brain tissue becomes deprived of blood and oxygen. This can happen when arteries leading to the brain become blocked or when a blood vessel bursts, leaking blood into the brain. Because the brain stem controls vital life functions, a stroke that affects the brain stem, causing death of tissue and atrophy in this region, can be life-threatening. Symptoms include paralysis, changes in breathing, changes in movement and sensation impairments.
