A Study to Show That the Change of Attention Measure is Correlated With the Changes of Caregiver's Burden After Treatment With Galantamine in Patients With Alzheimer's Disease

• Change from baseline in Attention Questionnaire at Week 16 [ Time Frame: Week 1 (baseline), Week 16 ] [ Designated as safety issue: No ]
  Attention questionnaire evaluates the attention of patients with dementia and is designed for their caregivers to evaluate the patients' attention directly. It has 15 questions devised to be suitable for cultural characteristics of Korea through the standardization study considering education and gender/culture gap.
  
  

• Change from baseline in Burden interview (BI) at Week 16 [ Time Frame: Week 1 (baseline), Week 16 ] [ Designated as safety issue: No ]
  BI is designed to evaluate subjective stress dementia patients' caregivers experience in relation to caregiving. It has total 22 questions with 4 options each and the calculated scores are from 1 to 88 (0-20 = Little or no burden, 21-40 = Mild to moderate burden, 41-60 = Moderate to severe burden, 61-88 = Severe burden).
  
  
• Change from screening in Mini Mental State Exam (MMSE) at Week 16 [ Time Frame: Week -2 (screening), Week 1 (baseline), Week 16 ] [ Designated as safety issue: No ]
  MMSC is a brief 30-point questionnaire test that is used for the assessment of dementia patients' cognitive impairment. Evaluation of points are as: 24-30 = No cognitive impairment, 18-23 = Mild cognitive impairment, 0-17 = Severe cognitive impairment.
  
  
• Change from baseline in Clinical Dementia Rating Scale (CDR) at Week 16 [ Time Frame: Week 1 (baseline), Week 16 ] [ Designated as safety issue: No ]
  CDR is a 5-point scale to evaluates the clinical patterns and severity of the patients suspected or diagnosed as dementia in 6 areas: memory, orientation, judgment and problem solving ability, social activity, domestic living and hobbies, and hygiene and dressing up, where 0 = no cognitive impairment, 0.5 = very mild dementia, 1 = mild, 2 = moderate, and 3 = severe.
  
  
• Number of patients with adverse events as a measure of safety and tolerability [ Time Frame: Week -2 (screening), Week 1 (baseline), Week 16 ] [ Designated as safety issue: Yes ]
  

This is an open-label (all people know the identity of the intervention), prospective (in which the participants are first identified and then followed forward as time passes), observational (study in which the investigators/ physicians observe the patients and measure their outcomes), multi-center (study conducted at multiple sites) study. The study mainly consists of 2 phases including, the screening phase (14 days before administration of study medication) and treatment phase (16 weeks). In the treatment phase, patients will receive galantamine 8 mg/day for the first 4 weeks and later on the dose will be increased up to 24mg (if tolerable). Safety evaluations will include assessment of adverse events. The total duration of the study will be 18 weeks.