Ten Questions Answered on Dementia

  1. What is dementia?
    Dementia is not a specific disease. It is a descriptive term for a collection of symptoms that can be caused by a number of disorders that affect the brain. People with dementia have significantly impaired intellectual functioning that interferes with normal activities and relationships. They also loose their ability to solve problems and maintain emotional control. They may experience personality changes and behavioral problems such as agitation, delusions and hallucinations. Doctors diagnose dementia only if two or more brain functions such as memory, language skills, perception or cognitive skills including reasoning and judgment are significantly impaired with out loss of consciousness. The disease process cause many nerve cells to stop functioning, loose connections with other neurons and die. In contrast, normal aging does not result in loss of large number of neurons.
  2. What are the symptoms of dementia?
    At least two of the following core mental functions must be significantly impaired to be considered as dementia: memory, communication and language, ability to focus and pay attention, reasoning and judgment, visual perception. People with dementia may have problems with short term memory, keeping track of a purse or wallet, paying bills, planning and preparing meals, remembering appointments or travelling out of the neighbor hood.
  3. What are the causes of dementia?
    Dementia is caused by damage to brain cells. This damage interferes with the ability of the brain cells to communicate with each other. The brain has many distinct regions, each of which is responsible for different functions. When cells in a particular region are damaged, that region cannot carry out its functions normally. In Alzheimers disease high levels of certain proteins inside and outside brain cells make it hard for brain cells to stay healthy. Brain cells in the region of hippocampus are often the first to be damaged and hence memory loss is one of the earliest symptoms.
  4. What other conditions mimick dementia?
    Depression and other psychiatric disorders may mimick dementia. Metabolic conditions like deficiency of B12, folate and thyroid can mimick dementia. Herpes simplex encephalitis may lead to memory impairment. Primary HIV infection or syphilis may cause cognitive impairment. Mass lesions involving temporal lobes can cause progressive memory impairments. Normal pressure hydrocephalus is classically associated with the triad of cognitive impairment, urinary incontinence and gait disturbance. There are a wide variety of auto immune cognitive syndromes which mimick dementia. Another important entity is vascular cognitive impairment. Medial temporal lobe seizures can lead to significant memory impairment called transient epileptiform amnesia. Drugs and alcohol can both cause significant cognitive decline. Other conditions to be thought are sleep apnea and frontotemporal lobar degeneration.
  5. Can dementia be cured surgically?
    There is a condition called normal pressure hydrocephalus which manifests as dementia. This condition can be treated surgically if diagnosed correctly.
  6. How is normal pressure hydrocephalus diagnosed?
    Normal pressure hydrocephalus occurs when excess cerebrospinal fluid accumulates in the brain ventricles which are hallow fluid filled chambers. NPH is called normal pressure because despite the excess fluid, cerebro spinal fluid pressure as measured during a spinal tap is often normal. As brain ventricles enlarge with the excess cerebrospinal fluid, they can disrupt and damage nearby brain tissue, causing symptoms of NPH. The following symptoms are considered hallmarks of normal pressure hydrocephalus.

    • difficulty in walking thats sometimes compared to the way a person walks on a boat, with the body bent forward, legs held wide apart and feet moving as if they are glued to the deck.
    • Decline in thinking skills that include overall slowing of thought processes, apathy, impaired planning and decision making, reduced concentration and changes in personality and behavior.
    • Loss of bladder control, which tends to appear somewhat later in the disease than difficulty walking and cognitive decline.
  7. What are the treatment options in normal pressure hydrocephalus?
    There is no single test to determine if someone has normal pressure hydrocephalus. And even though the three hallmark symptoms listed above are considered the classic signs of this disorder, not everyone with NPH has all these symptoms. MRI plays a key role in diagnosing NPH. A person with suspected NPH should undergo a detailed examination by a neurologist. If symptoms and an MRI strongly suggest NPH, a large volume spinal tap may be used to identify those who may benefit from a shunt. In this procedure, doctors remove a large than usual amount of spinal fluid, and then observe the person for 30 to 60 minutes to note any improvements in walking or thinking and reasoning.
  8. What are the modes of treatment of NPH and their outcomes?
    Researchers have not found effective nonsurgical treatments for normal pressure hydrocephalus. Drugs that remove excess fluid throughout the body, such as diuretics, haven’t been shown to help. NPH can sometimes be treated with surgical insertion of a shunt, a long, thin tube that drains excess CSF from the brain to the abdomen. Difficulty walking is the symptom most likely to improve after surgery. Thinking changes and bladder control are less likely to get better. Shunting doesn’t help everyone with NPH, and there’s uncertainty about how best to identify those most likely to benefit. More research is needed to understand the prevalence of NPH, show how the excess CSF involved in NPH causes symptoms affecting movement, thinking and bodily functions and clarify the possible benefits of shunt insertion and who is most likely to benefit. The effectiveness of shunting in NPH has never been demonstrated in a randomized clinical trial. Most of these studies were small and followed people for a limited time. Available data suggest that difficulty walking is the symptom most likely to improve. Several studies found a significant rate of postsurgical complications. Findings also showed that short-term benefits of shunt insertion tended to decline over time.
  9. Has technology made any change in the treatment of NPH?
    Yes. Technology has made significant changes in the surgical treatment of normal pressure hydrocephalus. The most important is advances in MR imaging. One can read the CSF dynamics better now with newer soft wears being introduced. The introduction of programmable shunts has made pressure control possible. This prevents redo surgeries to a large extent. Another thing is antibiotic impregnated shunts. These prevent shunt related infection to a large extent.
  10. Can dementia be prevented?
    No unfortunately dementia cannot be prevented. But with regular clinical monitoring dementia related problems can be kept under control.