Before my mom's diagnosis, I had never heard of semantic dementia. I have found this to be the case for most people in my life. I hear the question over and over,
"What is Semantic Dementia?"
To answer that question, let's first talk about what dementia is. First and foremost, let me just say that I am not a medical expert. When my mom was diagnosed with this disease, I began extensive research to figure out exactly what it meant. What I am sharing is based on all the research that I have found, and sources that I have consulted with on the disease. If you believe your loved one has dementia, please consult a professional.
Moving right along....dementia is when the cognitive functioning in a person begins to diminish. There are many causes for and many types of dementia. The most common form of dementia is Alzheimer's, which accounts for 50-60% of all dementia cases. There are many common characteristics among the different forms of dementia, including problems with short-term memory, language, visuospatial processing...to name a few. Dementia can affect a person's language and speaking abilities. It alters the person's personality as they tend to become depressed, irritable and paranoid. Often times, a person with dementia loses their sense of what is socially appropriate and inappropriate; their filter disappears.
Different parts of the brain are affected by different types of dementia. Semantic dementia is a form of frontotemporal lobe dementia; it affects the frontal and temporal lobes of the brain. Only about 20% of FTD cases are diagnosed as semantic dementia. Another nickname for FTD is Pick's disease (named after the scientist Arnold Pick who discovered the disease). Even within FTD, there are a few variations: semantic dementia being one, primary progressive aphasia (PPA) being another one, and a few others. Pick's, or FTD, is the general term for each of these variant dementias.
In semantic dementia, the first noticeable change is in behavior. Some of these behaviors include: obsessive behaviors, repetitive behaviors, social withdraw, personal hygeine issues, inappropriate behaviors, inability to keep a job. People with dementia can become very inflexible, self-centered and selfish. They lose the ability to think of others and they place themselves and their needs/wants above all else.
Emotional changes also begin to emerge: depression, moodswings, inappropriate moods (for example they might laugh when a situation is serious or somber). They fail to recognize the changes in their behavior. They develop a lack of emotion (we noticed this when my mom's mom died), and they lose interest in daily activities that they were once involved in.
Language changes include: difficulty finding words, shrinking vocabulary, difficulty understanding and processing words spoken to them. They begin to lose the meanings of words, which makes conversation difficult. Their mind cannot process the words you speak to them. They also lose the words for certain objects and whatnot. Difficulties in reading and writing eventually become present.
Neurological changes will also occur: weakness, movement and coordination difficulties, increasing memory difficulties. Initially, only certain types of memory, which is called semantic memory, are affected. Semantic memory tells you who faces represent, what objects signify, what words mean. While there is a disconnect in this area of memory, other memories are well preserved, such a how to drive to familiar places, or recalling certain events from the past. Faces that they do not see on a regular basis become unrecognizable. They cannot recall names to go with faces either. Eventually, as the disease becomes severe, they forget everything and everyone around them.
Most of these sypmtoms come in stages (or become more advanced as the disease progresses). My mom has exhibited most of these behaviors. It started with the behavior and emotional changes and soon trickled into language and memory. With other forms of FTD, the language changes are seen first, followed by behavior. In Alzheimer's, the memory is affected first. Though each form of dementia starts off differently, they pretty much end up the same towards the end, with complete (or almost complete) memory loss, inability to speak, walk and sometimes unable to swallow or eat. Incontinence (the inability to control urination and defecation) is also prevalent in the severe stages of dementia.
Semantic dementia is not genetic. It usually occurs out of the blue, with no family history of dementia (which has been our case). There are cases, however, when there is a family history of dementia present.
There is no cure for this disease and the sufferer cannot control or change these behaviors. The average duration for FTD is 6-8 years. Semantic dementia tends to last a little longer, with an average of 12 years. However, each case is different and there is no definitive timeline for the disease.