Understanding dementia

Dr Meesha Haorongbam
“In a way, dementia is like going through the torture of drowning- again and again. Just when the victim has lapsed into unconsciousness, he suddenly succeeds in finding his way above water to snatch a breath of reality. This is simply another reminder that he is not dying….yet. Paradoxically for the sufferer, it is more painful at the beginning when his periods of lucidity are longer. In the end those around him become the victims. For they know that though he is not lost to the world, he is lost to them.”- Erich Segal in Prizes
Nicholas Sparks published his first book, “The Notebook”, in 1996. Eight years later it was adapted into a critically acclaimed movie of the same name. We watched/read Noah’s despair as Allie’s memory slowly faded and all she was left with was just a shadow of her former self. Many who closed the book or walked out of the movie halls with tears in their eyes wondered if such a disease that strips one of all their memories and their very identity really exists. The unfortunate answer is that dementia is very real.
Dementia, derived from the Latin word for “out of one’s mind”, refers to a disease process marked by progressive cognitive impairment (i.e the inability to process thoughts) in clear consciousness. Dementia is a disorder of the brain. This is an important assertion to make from the outset, because many members of the general public and even some health professionals still attribute the cognitive and behavioural changes to senility. Others claim that the impaired memory is due to past psychic traumas which can be cured by talking through. But the behavioural changes in dementia are not under conscious control nor are they due to “letting go”. Dementia must have been affecting people ever since humans began to survive in appreciable numbers into old age. But it is a condition that has come into prominence only during the late 20th century because of the unprecedented increase in the numbers of people all over the world who survive to become elderly.
The World Health Organisation (WHO) recognises dementia as a global health priority. According to their latest report, at present 50 million people around the world are living with dementia. Every year, 10 million new cases are diagnosed. It is estimated that 5-8% of the population aged 60 years and above have dementia. The total number of people with dementia is estimated to reach 82 million in 2030 and 152 in 2050.
The scenario isn’t so different in India. There are an estimated 4.1 million people with dementia in India and this is expected to double by 2030 and tripple by 2050. While the current scenario might have changed, a 2001 survey showed Manipur with the second highest prevalence of dementia among the North-eastern states. This increasing number of prevalence can be attributed to increased awareness, increased detection and increased geriatric population.
What causes dementia? It occurs due to damage to or changes in the brain. Some of the common causes of dementia are- Alzheimer’s disease, vascular dementia, Parkinson’s disease, dementia with lewy bodies, frontotemporal dementia, and severe head injury.
While most dementia has a progressive course, some can be reversed. Some common causes of reversible dementia are:
1.    Intoxicants/Drugs- Alcohol, beta blockers, antihistamines, lead, arsenic
2.    Infections- Meningitis, neurosyphilis,  herpes encephalitis, AIDS dementia complex
3.    Metabolic- Vitamin B1/B12/folate deficiency, hypo/hyperthyroidism
4.    Structural- Intracranial tumors, subdural haematomas
5.    Psychiatric- sleep apnoea syndrome, pseudodementia
6.    Cancer treatment- Chemotherapy, radiotherapy
An important thing worth noting is that there is no evidence for a discrete break between persons with dementia and the normal elderly. Still, it is often implied that elderly people fall into two groups- those with and those without dementia. Dementia can be considered to represent an exaggeration of certain cognitive and behavioural changes that commonly occur with ageing. Meaning, there is a continuum from normal functioning through to severe dementia. The majority of elderly persons have some changes in memory and thinking with very mild changes in behaviour and personality too. Nearly everyone undergoes some kind of deterioration in memory and a slowing of mental processes in very late life, while some, for reasons that are not yet well understood, undergo these changes quite early. Such states have been described by various terms- benign senescent forgetfulness, age-associated memory impairment, and mild cognitive impairment, to name a few.
While forgetfulness isn’t enough to diagnose one with dementia, memory decline has long been considered to be the hallmark of dementia- as various movies and books can attest to. We, with intact memory and cognitive abilities, rarely think about and give much importance to memory. But memory is the very foundation of our identity.  Luis Bunuel, in his biography was quoted saying “You have to begin to lose your memory, if only in bits and pieces, to realise that memory is what makes our lives. Life without memory is no life at all…Our memory is our coherence, our reason, our feeling, even our action…Without it, we are nothing.”
We often never give a second thought to the many memories we’ve subconsciously collected over the past many years until, suddenly, one day, we can’t remember the name of a good friend or a relative. In the initial stage of dementia, the person is aware of his/her declining memory. So they take tiny measures to keep track of things- like keeping a checklist of things to be done, making sure they place their belongings in the same spot always and keeping a fixed routine. This early stage is associated with a lot of frustrations and irritability as they are aware of their failing memory and declining overall health. Denial is also strongly at play at this stage; until one day, the person is taxed beyond restricted abilities leading to a catastrophic reaction, characterized by sudden explosion of anger or other emotions. Gradually as dementia progresses there are marked defects in their activities of daily living (ADL), mainly- maintaining personal hygiene, dressing, eating, maintaining continence, and mobility. Marked decline can also be seen in their Instrumental Activities of Daily Living (IADL) such as basic communication skills, transportation, meal preparation, shopping, housework, managing medications, and managing personal finances. As dementia is a process which cannot be halted but slowed, it is imperative that family members are aware of the initial subtle changes like repeating the same story or task over and over, difficulty in following storylines while conversing, taking longer time to recognize a known person, struggling to communicate thoughts, subtle personality changes, difficulty doing common tasks, a failing sense of direction etc.
The risk factors, presenting features, rate of decline, and prognosis varies depending on the type of dementia. Some of the common types of dementia are:
1.    Alzheimer’s dementia- This accounts for around 70% of all dementias. Its prevalence increases exponentially with age, doubling every five years, beginning at 1% at age 60 years and peaking at over 30% by age 85 years. It is strongly associated with age, family history and a particular type of protein known as Apolipoprotein E. The defining features of Alzheimer disease are progressive deficits in memory and other aspects of cognition. Family members usually report impaired memory, disorientation, word-finding difficulty, poor speech content, poor object or person recognition, impaired attention, disinhibition, poor planning, poor judgment etc. Behavioural problems such as apathy, hallucinations, delusions, wandering, pacing, and verbal and physical aggression are also reported. Alzheimer’s is usually preceded by a prodormal stage called Mild Cognitive Impairment where there are subjective memory and cognitive impairments but there are no remarkable social and functional impairments. The usually survival period after a diagnosis of Alzheimer Disease is 5-6 years.
2.    Vascular Dementia- It is characterized by abrupt cognitive decline with step wise deterioration, presence of dementia, and evidence of a cerebrovascular disease. While it is the second most common type of dementia in the western world, it is the highest contributor in some Asian countries. While the data for vascular dementia in India is a bit sketchy, we do have a very high prevalence for the risk factors of vascular dementia; namely- hypertension, diabetes mellitus, high cholesterol levels, smoking, obesity and cardiovascular and cerebrovascular disease. While the symptoms of vascular dementia are almost similar with Alzheimer’s, the former is preceded by a vascular event. It is also seen more commonly in males as opposed to Alzheimer’s which is predominant among women. It also shows a stuttering or episodic course of deficits with step-wise deterioration along with patchy cognitive deficits.
3.    Dementia with Lewy bodies (LBD)- It is a commonly misdiagnosed type of dementia which accounts for 10-15% dementias in autopsy. It has a prevalence of around 0.7% in population.  A very simplified description of LBD is that it looks like a combination of Parkinson’s disease (stiffness or rigidity, postural instability, gait difficulty) and Alzheimer’s (cognitive decline). LBD usually presents with attention deficits, the inability to judge spatial orientation of objects and lines in space (e.g. difficulty navigating in their homes or even moving out of a bed or chair), visual hallucinations (which are usually not upsetting to the person), anxiety and sleep disturbances. The differences in cognitive profile between LBD and Alzheimer’s are partially quantitative, and overlap increases with disease progression. It, therefore, comes as no surprise that many with LBD are misdiagnosed with Alzheimer. Compared to other forms of dementia, memory and verbal skills are better preserved and serious deterioration occurs only in the later stage. Cognitive fluctuation is the hallmark of this disease. They are often described as episodes of behavioural confusion, inattention, excessive sleep, and incoherent speech alternating with episodes of lucidity and capable task performance.
4.    Frontotemporal Dementia (FTD)- This is a less common type of dementia. It occurs due to loss of nerve cells in the frontal and temporal lobes of the brain i.e., the area behind your forehead and the regions behind your ears on either side, respectively. These are the areas responsible for behaviour, personality, and production and comprehension of speech. So defects in these areas will lead to defects in the above mentioned actions. There are three main types of FTD and therefore variations in presenting symptoms, but some of the common symptoms are-
a.    Decreased motor skills
b.    Increased sleepiness
c.    Excessive craving for alcohol and food especially sweet foods
d.    Decreased empathy
e.    Rigid and inflexible thinking and impaired judgment
f.    Bizarre somatic complaints
g.    Repetitive or compulsive behaviour
h.    Loss of insight into personal and social conducts
i.    Change in personal and social conducts. Person may lack initiative, seem unconcerned, and neglect domestic, financial and occupational responsibilities.
j.    Individual may show lack of emotional response or he/she may be inappropriately jovial. (To be contd)