Neurological Causes of Dementia
Some of the most well-known medical conditions affecting the brain and nerves have symptoms that can mimic dementia features alongside their own, more specific features. So doctors may want to rule out some of these diseases before coming to a final diagnosis:
- Parkinson’s disease: This condition has a genuine overlap with dementia, because people with Parkinson’s disease have a higher-than-average risk of also developing dementia. In fact, Parkinson’s disease-related dementia accounts for 2 percent of all cases.
The symptoms of Parkinson’s disease-related dementia are very similar to those of Lewy body disease, and researchers think a link may exist between the two. Thus, alongside problems with cognitive function and movement, people also experience significant visual hallucinations, mood swings, and irritability. Unfortunately, medication to help treat the movement difficulties found in Parkinson’s disease, such as tremor and stiffness of muscles, may make the symptoms of this dementia worse.
- Subdural hematomas: A subdural hematoma (SDH) is a large blood collection that occurs underneath the dura mater, or the tough, fibrous, protective covering of the brain, but is external to the brain itself. Because your skull doesn’t have a square centimeter of extra space inside it, the pressure of an SDH can cause brain swelling, which produces a variety of symptoms including abnormal neurologic findings, intense headaches, nausea, vomiting for the acute variety, and confusion and combativeness for the chronic variety. The symptoms get worse as the clot grows larger. An acute subdural hematoma is a life-threatening condition. The chronic variety is the type that produces symptoms that can be confused with AD.
SDH can be the result of traumatic injury or blunt-force trauma to the head. People who are on aspirin therapy or taking a blood-thinning medication such as Coumadin have a higher risk. Alcoholism also increases the risk.
- Brain tumors: Depending on their size and location within the brain, brain tumors may cause a variety of symptoms, some of which may mimic AD. Although most significantly large brain tumors cause intense headaches, nausea, and vomiting, tumors located in the frontal lobe of the brain cause the type of symptoms that mimic AD, including memory loss, personality changes, and impaired judgment. Whether the tumor is benign or malignant doesn’t really alter the symptoms it causes. Its position within the skull is more predictive of symptoms produced and the outcome of potential surgical removal.
- Multiple sclerosis: In this disease, the insulating outer coating of nerve cells, called myelin, is deficient in some parts of the nervous system, which means messages carried by the nerves aren’t transmitted as well as they should be and may not get through at all. If the nerves affected are in the cortex of the brain, which is where most of the clever functions people perform are carried out, patients can develop cognitive symptoms including forgetfulness and difficulty with problem solving.
- Normal pressure hydrocephalus: The brain and spinal cord are surrounded by cerebrospinal fluid, which supplies nutrients and acts as a shock absorber to protect the nervous system from damage during trauma. People with hydrocephalus have too much of this fluid, which accumulates and begins to damage brain cells because of the increased pressure. Normal pressure hydrocephalus usually begins to develop in people aged 55 to 60.
The damage that normal pressure hydrocephalus causes in the brain produces symptoms similar to those of dementia, accompanied by difficulties with walking and urinary incontinence. Treatment involves placing a shunt in the brain to allow the fluid to drain. If the treatment is carried out early in the disease process, the success rate for resolving symptoms is at least 80 percent.
- Huntington’s disease: Huntington’s disease is hereditary and is caused by a defect on chromosome 4. If one parent has the disease, a couple’s children have a 50-50 chance of inheriting the condition because it’s a dominant trait. Symptoms don’t develop until middle age, but once they do, the disease progresses relentlessly until death. Alongside dementia, sufferers develop jerking movements of their limbs and changes in mood and personality.