Causes of Dementia
There are different causes of dementia like biological and physical causes that may occur in the body. Biological causes include neurodegenerative, cerebrovascular, infection related and toxic and metabolic causes.
Neurodegenerative cause of dementia: Neurodegeneration is the most common cause of dementia that may later leads to Alzheimer disease. Amyloid plaques, neurofibrillary tangles and loss of connection between cells are the causes of Alzheimer’s disease. Firstly, in brain amyloid plaques are present between the nerve cells and they are insoluble deposits of toxic protein called beta- amyloid. Due to genetic mutations the production of beta-amyloid protein increases and leads to inherited AD or early onset AD. Secondly, neurofibrillary tangles that are formed from twisted protein threads found inside the nerve cells. Tau is the main component of tangles. Tau helps to stabilize the microtubules but the hyperphosphorylation of Tau results in separation of Tau from microtubules and attach to other Tau threads and form tangles within the cell. This causes disintegration of neuron and results in collapse of neuron and therefore, neuron lose the ability to communicate with each other. Thirdly, neurons communicate with each other through synapse. So, due to neurofibrillary tangles neurons can not communicate and results in improper functioning of neurons and then cells died that leads to brain atrophy (https://adrccares.org/wpcontent/uploads/2016/01/alzheimers_disease_unraveling_the_mystery_0.pdf).
Infection-related dementia: Various bacteria, viruses and parasites can cause severe infections and destroy brain cells that may results in dementia like dementia with HIV/ AIDS.
Toxic and metabolic cause of dementia: Due to various chemical changes that occur in our body can also cause dementia like toxic drugs, malnutrition or metabolic disorders. For instance, Wernicke- Korsakoff syndrome.
Physical causes: These include traumas like serious injuries to the brain may leads to dementia like traumatic brain injury.
All the above discussed factors mainly affect the hippocampus region of the brain that controls learning and long-term memories. The healthy neurons are affected and undergoes to damage due to which they lose the communication ability and finally the affected areas start shrinking and results in atrophy that leads to different types of dementia.
Diagnosis of Dementia
Diagnosis of dementia is based on number of medical tests and patient’s medical and family history. Not based on single test a physician can determine that whether you have dementia or not. Therefore, physicians go through various steps or tests to determine the dementia.
1) Patient and Patient’s family history: Physicians ask questions about how and when signs and symptoms develop first. Ask for the description of patient and his/ her family’s and medical history. Asses patients living environment and his/her emotional state.
2) Get information from patient’s close friends and family members who can tell about the changes in the patient’s behavior and personality.
3) Conduct Physical &Neurological examinations and Laboratory tests: In physical examination physicians check the blood pressure, pulse, body temperature, examine heart and lungs. Also collect the urine and blood sample for laboratory tests. Also review the current medication of patient, diet, nutrition and alcohol consumption. Whereas, in neurological examination physician will examine the patient closely for any brain disorder that may not related to Alzheimer. They check muscle coordination and tone, eye movement, reflexes, speech etc.
4) Conduct Neuropsychological examination: In this examination physicians ask few questions to patient that evaluate the patient’s language and thinking skills, memory, ability to solve the problems etc. this includes Mini- Mental State Exam (MMSE) and Mini-cog in which physician ask few designed questions that evaluate the daily mental skills.
5) Imaging and other investigating techniques: These days there are various imaging techniques are used to diagnose different types of dementia like computed tomography (CT) scan, magnetic resonance imaging (MRI), hexamethyl propylene amine oxime (HMPAO), single photon emission computed tomography (SPECT), fluoro-2-deoxy-D-glucose positron emission tomography(FDG-PET). Cerebrospinal fluid sampling test is also conducted in patients with rapid cognitive impairment of age less than 55 years (Robinson et al, 2015, p. 2-3)
Treatment of Dementia
Two classes of drugs that are available for the treatment of dementia. First class of drugs are cholinesterase inhibitors like donepezil, rivastigmine, galantamine and tacrine. These drugs inhibit an enzyme called cholinesterase which breakdown the neurotransmitter called acetylcholine and therefore, maintain the increased level of acetylcholine in the brain and these drugs can maintain the ability of person to carryout some daily activities. This class of drugs is used in person suffering from mild to moderate dementia. Second class of drugs include N-methyl-D-aspartic acid (NMDA) receptor antagonist named as memantine which regulates the level of other neurotransmitter called glutamate. This class of drugs is used for moderate to severe dementia (https://adrccares.org/wpcontent/uploads/2016/01/alzheimers_disease_unraveling_the_mystery_0.pdf).
Impact on family and friends
Family and friends can act as caregivers of a person suffering from dementia. It was found that dementia caregivers may also experience more anxiety, stress and other mental health problems which in turn may affect their personality and behaviour badly. As caregivers spend more time with such patients due to which they are prone to such changes. But chronic exposure to stress or anxiety cause bad effects on physical as well as on mental health. They feel more burdened, stressful life that may lead to serious consequences.