title: Quantitative evaluation of changes in the clock-watching behavior of a patient with semantic dementia.
abstract: BACKGROUND
  Clock-watching activity in patients with dementia has not been documented in detail.
  
  
  METHODS
  A male patient having semantic dementia was monitored at a dementia care unit in a general hospital in Japan. We used an integrated circuit monitoring system to record the distance and location of ambulation and the total number of movements that occurred outside the patient's room.
  
  
  RESULTS
  The patient was reported to clock watch a couple of years prior to monitoring. In 2011, when monitoring started, he regularly came out of his room saying, "8 o'clock" about 40 minutes into every hour. It seemed as if he could only recognize the minute hand. The median number of sensor detections increased by 4-fold at this clock-watching phase. Behavior consistent with his clock-watching patterns was also detected during the night. In 2012, clock-watching activity disappeared.
  
  
  CONCLUSIONS
  This study documented the progression of clock-watching and subsequent disappearance with worsening cognitive function.
authors.affiliation: Department of Clinical Nursing, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Nonaka
authors.affiliation: Department of Community Medicine, Nara Medical University, Kashihara, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Suto
authors.affiliation: Department of Clinical Nursing, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Japan.
authors.forename: Miyae
authors.initials: M
authors.lastname: Yamakawa
authors.affiliation: Dementia Care Center, Asakayama General Hospital, Sakai, Japan.
authors.forename: Kazue
authors.initials: K
authors.lastname: Shigenobu
authors.affiliation: Department of Clinical Nursing, Division of Health Sciences, Graduate School of Medicine, Osaka University, Suita, Japan kmakimot@sahs.med.osaka-u.ac.jp.
authors.forename: Kiyoko
authors.initials: K
authors.lastname: Makimoto
mesh_terms: D001519:Behavior / Q000502:physiology*; D018450:Disease Progression; D057180:Frontotemporal Dementia / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement; D064926:Neurophysiological Monitoring; D021641:Recognition, Psychology / Q000502:physiology
keywords: clock-watching; objective measurement; semantic dementia; sleep disturbances