Genetic and Environmental Contributions to Dementia - Research Paper Example

? Neurofinal project of Learning: content Background 0 DSM ification 1 Genetic and environmental contributions to Dementia 1.2 Use of various brain scans 1.3 Legal, ethical and forensic issues 1.4 Tests and Assessments 2.0 Use of various tests and assessments 2.1 Recommendations 3.0 Prognosis 4.0 Conclusion 5.0 References 1.0 Background Dementia resulting directly from HIV disease can occur at any age and individual infected with the viral disease may be prone to dementia from various associated causes. HIV stands for Human Immunodeficiency virus infection while AIDS stands for Acquired Immunodeficiency Syndrome which is a progressive disease that affects the immune system of the human body. HIV is transmitted through contaminated blood transfusions, sharing needles or syringes with infected persons, having unprotected sex with infected partners and from mother to child during birth or breastfeeding. Early symptoms include an influenza-like illness with patients experiencing high body temperature and this is followed by a long period without symptoms. HIV causes AIDS and as the illness progresses it interferes with the immune system by attacking the CD4 T-cells leaving the body vulnerable to opportunistic infections and tumors. The presence of symptomatic cognitive disability foretells non-central nervous system morbidity and overall HIV mortality. Dementia may be caused by rapid evolution of HIV in certain brain regions causing a cycle of infections of macrophages and inflammation. HIV moves around the brain in distinct paths and evolves at different rates depending on where it is on the brain due to the different genetic sequences in the virus particles in the different areas of the brain. Patients in high risk environments are at a greater risk of cognitive complications related to immunosuppression. AIDS Dementia complex (ADC) is a type of dementia that occurs in advanced stages of AIDS and leads to the loss of noetic abilities such as memory, abstract thinking and judgment. It affects brain function in areas of thinking ability, behavior, mood, coordination and movement. Brain monitoring or neuroimaging involves the use of various techniques which can be either invasive or non-invasive to view the structure and function of the brain. The non-invasive techniques include PET, fMRI, SPECT, MEG among others. The Functional magnetic resonance imaging (fMRI) involves the use of magnetic properties of oxygenated and deoxygenated hemoglobin to observe the changing blood flow in the brain due to activity of the nervous system. The patient is presented with various touch, visual and sound stimuli and the scanners are used to show brain structures and processes associated with thought, perception and action. Positron emission tomography (PEF) involves measuring active chemical compounds emission from radioactively labeled metabolically active chemicals injected to the bloodstream of a patient. The labeled compound makes its way to the brain through the bloodstream and sensors detect the radioactivity as the compound accumulates in the different regions of the brain. The compounds show blood flow and the metabolism of oxygen and glucose in the tissues of the brain which reflects the amount of brain activity in those regions. It helps in the diagnosis of brain disease like brain tumors, stroke, and neuron-damaging diseases such as dementia (Alzheimer’s disease and Pick’s disease) all of which cause significant brain metabolism, which is easily detectable on PET scanners. Single-photon emission computed tomography (SPECT) uses radioisotopes that emit gamma rays and a manna camera to record data that a computer uses to construct images of the active regions of the brain. The subject is injected with a radioactive tracer which is rapidly taken up to the brain but does not redistribute. It shows the cerebral blood flow at the time of the injection and is especially useful for epilepsy imaging. Like PET it is used to differentiate the different kinds of disease processes which cause dementia. The moral doctrine of diagnosis disclosure is based on the patient’s benevolence, ability to self-govern and make their own decisions and obligation not to inflict harm. Physicians who have to disclose this information to patients have various concerns such as the fear of destroying hope and concern about certain detrimental outcomes like depressive illness, ruinous reaction and even suicide. This leads to the debate of whether it is ethical not to disclose information like this to an individual. Legal issues associated with the diagnosis of dementia include naming of beneficiaries in a will and making decisions about when and why medical treatment should be stopped. Legal documents should be signed by an individual with the mental capacity to make decisions with full comprehension of the implications. According to the Mental Health Act 1983, compulsory admission to hospital of an individual diagnosed with dementia for his or her own safety or for the safety of others. This involves emergency admission for assessment for up to 72 hours, admission with or without treatment for up to 28 days and admission for treatment for up to six months. It gives a doctor holding power to prevent a client from discharging themselves when it’s not in the client’s best interest.Under the NHS and community Care Act 1990, local authority social services departments in England and Wales have a duty to carry out assessments for people who are in need of certain services in the case that the current care giver cannot support the patient due to funding limitation. The local authority contributes a certain amount based on the financial status of the patient and the patient has to pay the rest. The social services department has a legal obligation to care for the vulnerable adults and meet their needs and hence social services cannot withdraw their services in the case that an individual fails to pay for home care. 2.0 Tests and Assessment Interviews and various tests are essential in diagnosing the neurocognitive aspects Mr. G’s disorder. The various categories of neurocognitive abnormalities are HIV-associated dementia (HAD), HIV-associated minor cognitive-motor disorder and asymptomatic neurocognitive impairment based on the degree of the patient’s impairment. Cherner et al (2007) found increased particularity, sensitivity and a positive predictive value using these three diagnostics in predicting HIV-related neuropathology during autopsy. The deficit in controlled attentional processing shows impairment in Mr. G’s lack of attention, reduced mental flexibilityand verbal retrieval. Repeated battery for the Assessment of Neuropsychological Status (RBAN) is a screening tool for measuring immediate and delayed memory, attention, language and visual skills in a patient.it is a pencil and paper test with a booklet as stimuli and a record form for administration and scoring. It lasts less than thirty minutes and is used for the detection and neurocognitive delineation of different dementia. The assessment of Mr. G’s cognitive speed would best be done by understanding the subtests within the comprehensive battery tests which would provide the necessary information for screening tool development. The combination of tests tapping verbal memory and psychomotor speed (Digit-Symbol Test).The Trail Making Test is made up of two parts consisting of part A and B. The difference in time between the part A and part B is an indication of problems in divided attention. The ratio of time to complete both trails and errors made is the variables of interest and this would show the level of infection in Mr. G. To assess Mr. G’s ability in two and three dimensional construction, the block arrangement test from the Welcher Adult Intelligent Scale (WAIS) III Battery test which involves block design and Tinkertoy Test which involves assembly of tinkertoys would be used to test for visual and motor skills. The Rey-Osterreith Complex Figure involves drawing shapes of diagrams in two dimension from memory. The spatial memory test using the Rey-Osterreith Complex Figure examines the patient by asking them to reproduce a complicated line drawing first by copying and then from memory. The patient is then required to give the shape of diagrams as they had seem them. They are also required to use their memory to draw the diagrams again after a few days. The California Verbal Learning Test (CVLT) is a verbal test that would help test for immediate and delayed recall in the patient. In assessing Mr. G’s verbal fluency, the Boston Naming test would be used to determine the level of word retrieval and hence evaluate the extent of dementia effect on his ability to communicate. The F-A-S test in which the patient would be required to orally produce as many words as possible starting with F, S and A within a prescribed time frame would help to measure the phonemic fluency of Mr. G. In testing the intellectual ability and achievement on Mr. G, the wide range achievement test (WRAT) would be used to test his ability to read words, spell, understand sentences and solve mathematic problems. The picture arrangement test from the WAIS III Battery test is a test of the ability to plan, interpret and anticipate events within a certain context. It is sensitive to brain damage in right anterior temporal lobe areas that disrupt non-verbal skills and low scoring patients in this test tend to have difficulty making decisions and planning ahead, process information slowly and have problems in social relationships. A subject’s inability to choose correctly would be proof of damage to the frontal lobe. The Wisconsin Card Sorting Test (WCST) is a test used to assess persistence and abstract thinking and is regarded as a measure of executive function due to its sensitivity to dysfunction in the frontal lobe. This test is important due to its ability to help identify particular sources of difficulty in conceptualization and failure to maintain focus. The instructor usually sitting opposite the patient can observe and evaluate cognitive skills of the patient. The interactive Stroop effect test involves saying the color in which a colored word is written and not what the word says. It measures the level of interference in the reaction time as it takes longer to name the color of the word and the patient is more prone to errors. The Tinkertoy test would evaluate executive functioning in the patient which include planning, initiating and structuring of behavior as well as his constructional ability. It involves letting the patient create a toy out of an assortment of fifty tinkertoys in a limited time frame and they would be required to correctly name what they had made. Minnesota Multiphasic Personality Inventory (MMPI) would be important in assessing the personality of patient G. It contains several scales which test the patient’s; perception and preoccupation with their health status, depressive symptoms, emotionality, rebellion against control, stereotype, inability to trust, anxiety levels and tendencies, perceptual experiences, level of energy and whether the patient is comfortable being around people. Rivermead Behavioral Memory Test (RBMT) would help to predict the progressive memory impairment in Mr. G. it involves remembering names, hidden belongings and appointments, picture and face recognition, prose recall ,recalling a route and orientation. The Test of Memory malingering (TOMM) is a visual recognition test that would help determine whether patient G is malingered or has had true memory impairment. Digits Forward/Backwards test is used to test the memory span of the patient and involves the patient repeating in correct order of digits immediately after a presentation either in the original or reverse order. 3. Recommendation Mr. G’s inactivity, lack of alertness and communication shows advanced dementia which affects various parts of his brain. I would recommend that he be enrolled in interactive group exercises to help him stimulate his brain, deal well with his health status as well as to encourage him. I would also recommend a transfer to a psychiatric hospital for the criminally insane where a specialized and higher level of care and treatment for the patient would be more possible. 4.0 Prognosis Neurologic disease is the first diagnostic HIV infection in about twenty percent of patients while sixty percent of patients with advanced HIV will have clinically evident neurologic dysfunction during the course of their illness. Increased proliferation of HIV in the brain is believed to be necessary for development of AIDS Dementia complex. Soluble factors in macrophages found in the peripheral blood of patients with AIDS dementia kill brain cells in culture and lead to neuropsychological deficiencies. With proper treatment, using antiretroviral drugs that can penetrate the blood-brain barrier, the viral load would be reduced. The CD4 count will increase and the patient will be healthy. If untreated, Mr. G’s condition would deteriorate as the nervous system opportunistic infections would increase with the multiplication of the macrophages in the brain. The pathogens would destroy more brain cells causing more problems in his noetic abilities. The CD4 count in his blood will reduce and his viral load would increase causing exposure to opportunistic illnesses and eventually death. 5. Conclusion Conducting early and routine neuropsychological testing with people living with HIV/AIDS is most practically fulfilled with one of several available neuropsychological screening instruments andthe use of antiretroviral drugs that penetrate the blood-brain barrier would be beneficial in limiting systemic reseeding of the virus from the central nervous system. References Cherner M, Cysique L, Heaton RK, et al; (2007) HNRC Group. Neuropathologic confirmation of definitional criteria for human immunodeficiency virus-associated neurocognitive disorders. J Neurovirol. Jones, R.M. (2004). Mental Health Act Manual, 9th Edition, London:Sweet & Maxwell. Lingard, J. and Milne, A. (2004) Integrating older people’s mental health services: Community mental health teams for older people, London: Department of health. Simioni, S., Cavassini, M., Annoni, J., Rimbaultte, A., Bourquin, I., Shifer, V., Calmy, A., Chave, J., Giacobini, E., Ezio, H., Hirschel, B., &DuPasquier, R. (2010). Cognitive dysfunction in HIV patients despite long-standing suppression of viremia. AIDS. Read More