Psychiatry for Physicians-Dementia - Dementia of Alzheimer's Type
Among all the patients with progressive cognitive decline about 50% suffers from Dementia of Alzheimer's Type (DAT). The risk of developing DAT increases with age. Other risk factors including genetics are also present. Macroscopic features of a DAT brain are cortical atrophy, widening of sulci, and ventricular enlargement. Microscopic features of the same are -
1. Neuronal loss
2. Neurofibrillary tangles
3. Neuropil threads
4. Neuritic plaques
5. Dystrophic neuronal processes
6. Granulovacuolar degeneration
7. Amyloid angiopathy
In DAT the most severe pathological change occurs in medial temporal lobe. The first changes are seen in the entorhinal cortex. The location and number of lesions are the main factors behind clinical features of DAT.
DAT usually starts after the age of 50 years. It's progression it too silent to be noted by the family members initially. Initially the patients are more rigid, inflexible, less adventurous, more irritable, and less spontaneous. The overall quality of performance declines and patient becomes gradually dependent on others. The patient deteriorates over months or years, very especially on the aspect of cognitive function. In case of patients with concurrent medical illnesses dramatic deterioration may occur. Independence of the patient's daily activity gets severely hampered. Psychotic features like delusion, hallucination often develop. Ultimately the patient fails to recognize their family members or even their own face. Seizures are seen at the late stage of the disease. The final stage of the disease is usually characterized by the followings -
1. Incontinence of urine and feces
2. Loss of intelligible vocabulary
3. Difficulty in walking and sitting up
The diagnosis of DAT mainly requires gradual, progressive development of multiple cognitive deficits. Both memory impairment and cognitive disturbances are included in these deficits. Patient fails to remember three unrelated words for 3 minutes. Cognitive disturbance patterns are more or less consistent with those described in the introductory portion of dementia.
For the purpose of treatment the following steps are necessary -
1. Control of abnormal behavior related to the disease
2. Attempts to restore cognitive functions
3. Attempts to delay cognitive decline
The above three purposes are connected with pharmacotherapy in the line of the biological abnormality present. Other environmental approaches are also important.
Dr. Mohammad Samir Hossain PhD is a researcher teacher of Psychiatry and a Psychotherapist in Bangladesh. He is renouned for his educational and research activity in mental health sector nationally and internationally. The Dictionary of International Biography cites his brief biography starting from its 33rd edition. One of the best educational institutions involved with his educational activity is the Harvard Medical School of USA. Visit his personal page at http://www.samirhossain.org.