Small vessel disease---SVD---of the brain occurs when the small arteries and arterioles in the brain become damaged and deteriorate due to the buildup of plaque, the formation of small tears, or the arteries becoming hard and inflexible. This inhibits the blood flow in the brain, leading to the death of brain cells and the formation of lesions, or infarctions. Infarctions interfere with normal brain functions and result in neurological symptoms. The risk of developing SVD increases with age. The American Stroke Association reports that 23 percent of patients over 65 and 43 percent over age 80 exhibit characteristics of SVD.
Memory Impairment
Patients suffering from SVD often suffer from memory impairment. Although SVD does not cause complete memory loss, patients may have trouble recalling memories and may need prompting, according to the University of Tasmania Department of Rural Health.
Thinking Difficulties
Severe SVD can also interfere with cognitive tasks. Thinking processes become slow, and although patients can usually provide an accurate answer, it takes longer. More advanced cognitive tasks, such as dealing with finances, performing mathematics or organizing tasks become difficult to perform.
Patients often fail to grasp their current health situation and fail to recognize that they need extra help. This can become dangerous as impaired motor coordination and balance problems worsen.
Gait Disturbances
Patients suffering from SVD often exhibit gait disturbances. This occurs because the areas of the brain most affected by SVD, including the pons and the basal ganglia, coordinate balance and movements. The basal ganglia contain a cluster of nerve cells deep inside the cortex of the brain. The basal ganglia receive information, process it and send it back through the thalamus to the motor cortex. When lesions form, the basal ganglia fail to send correct signals to the motor cortex resulting in uncoordinated movements.
Normally walking is an automatic process and does not require conscious thought. The lesions on the brain caused by SVD interrupt this process, and patients must concentrate in order to walk. Patients begin to dread walking for fear of falling. Their gait usually becomes slower as they begin to shuffle to avoid falls.
Balance Problems
In addition to affecting gait, SVD disrupts the patient's sense of balance. This problem can become so severe the patient finds it difficult to remain upright. Normally, when a person loses balance, the reflexes take over, moving the arms and legs to regain stability. The brain lesions caused by SVD interfere with these reflexes, which leaves the patient vulnerable to frequent falls.
References
- "Stroke" A Journal of the American Stroke Association: Small Vessel Disease of the Brain
- University of Tasmania Department of Rural Health: Small Vessel Disease of the Subcortical White Matter of the Brain
- "ACTA Neuropathologica": Vascular Pathology in the Aged Human Brain; Grinberg and Thal; March 2010
