Voyer and colleagues (2016) report an interesting and important comparison of ten attention/concentration tests for DSM-5 delirium. I have a number of questions and comments as follows:

1. (1) What training did the research assistants have? DSM-5 diagnosis is generally regarded as a decision by medical specialists. When the person has prior dementia, identifying delirium is a high-level medical skill. Behavioral and psychological symptoms of dementia can closely mimic delirium unless the examiner focuses on behavioral triggers and the speed of cognitive decline.

2. (2) The requirement of taking medications twice a day may have eliminated some delirium patients with impaired swallowing or refusal to take medications.

3. (3) Lumping dementia, confusion, and disorientation into one label “cognitive impairment” is problematic and reduces the usefulness of Table 3.

4. (4) The authors used prior diagnosis of dementia as a gold standard when in fact many people with that label have mild cognitive impairment.

5. (5) The ten “concentration” subtests in the Hierarchic Dementia Scale (HDS) (Cole and Dastoor, 1987) are not purely indices of concentration. Serial seven subtraction is impaired in low education with normal concentration. Months of the year backwards is often ranked as both an attention and executive function test and it requires semantic knowledge. Digit span forward is a rapid attention test missing from the HDS which has been of great value in my delirium research.

6. (6) As expected DSM-5 delirium was more common among medical inpatients than long-term care residents (14.9% vs. 4.0%, Table 1).

7. (7) The Central Coast Australia Delirium Intervention Study (Regal, 2015) supported the gold standard to prove delirium was the speed and amplitude of both onset and recovery. In CADIS, the mean recovery of five-digit span forward was two days, six-DSF 5.6 days and Delirium Index 8.0 days.

Arnaoutoglou et al. (2017) reported that “Ishihara Color Vision Test – 38 Plate” was useful for the differential diagnosis of dementia between Alzheimer's Disease (AD) and Vascular Dementia (VaD). The authors used sensitivity/specificity analysis, presenting 80.6% and 87.5% to discriminate AD and VaD patients when an optimal (32.5) cut-off value of performance was used. The authors cited a reference of the fact that AD patients suffered from a non-specific type of color blindness (Pache et al., 2003), and I have a query on their study with special reference to statistical method.

Information on efficacy and safety of electroconvulsive therapy in patients with dementia is sparse. The current case report describes a patient suffering from severe depression and dementia who received electroconvulsive therapy with S-ketamine anesthesia at our psychiatric intensive care unit for the treatment of her therapy-resistant catatonic stupor. The patient's condition improved remarkably through the treatment. By the end of 16 electroconvulsive therapy sessions, her catatonic symptoms remitted entirely, her affect was brighter and she performed markedly better at the cognitive testing.

The authors would like to apologise for an error made in the acknowledgement of the above mentioned article.

In the acknowledgement section of the article, paragraph ‘This project was funded by the Deanship of Scientific Research (DSR), at King Abdulaziz University, Jeddah, under grant no. (G-282/ 724246/1436). The authors, therefore, acknowledge with thanks DSR for technical and financial support’.

Should read:

This project was funded by the Deanship of Scientific Research (DSR), at King Abdulaziz University, Jeddah, under grant no. (G-282-246-36). The authors, therefore, acknowledge with thanks DSR for technical and financial support’.

We present a 56-year-old patient suffering from frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). The history included a three-generation pedigree and the patient was found to be a mutation carrier. The diagnosis was hindered by late appearance of the hypokinetic movement disorder. For clinicians, it is important to consider rare neurodegenerative disease variants in early-onset familial dementia syndromes with behavioral, cognitive, and motor symptoms.

We read the findings by Cecato et al. (2016) with great interest. In their study, naming the rhinoceros discriminated between patients with amnestic mild cognitive impairment (aMCI) and Alzheimer's disease (AD) but not healthy controls (HC). Of note, HC participants were significantly younger than aMCI and AD patients. All participants were administered the original version of the Montreal Cognitive Assessment (MoCA) instrument.

The prevalence of major depression ranges from 1% to 16% among elderly living in private households or in institutions, and in similar settings “patients” with clinically relevant depressive symptoms vary between 7.2% and 49% (Djernes, 2006). Community studies looking at point prevalence of depression in older people suggest rates between 10% and 20% depending on cultural situations (Rodda et al., 2011).