Response

We thank Emma Vardy and Stephen Todd for their interest in our AMC article on a clinical case review of ‘Acute presentation of dementia with Lewy bodies’ especially on contributing additional knowledge base and evidence in support. We note the comments expressed by Stephen Todd that the case does not meet the criteria for diagnosis. Based on this we revisited the clinical notes and have provided additional information below in support of our conclusion that this was a case of probable DLB using the guide by the Fourth consensus report of the DLB consortium.

Our conclusion was based on the evidence that the patient had more than one cardinal clinical feature of Parkinsonism – bradykinesia and cog wheel rigidity. These features were accentuated by the use of antipsychotics (haloperidol and risperidone) on different occasions; in retrospect these signs predated the use of medications and with heightened awareness and clinical suspicion might have been picked up earlier. The severe sensitivity to antipsychotics is a supportive clinical feature. Our article states that the patient had no visual hallucinations. This is incorrect as visual hallucinations were recorded on collateral history from family on admission and also noted on several instances on the ward. She saw dogs moving around during clinical interviews on the ward. There was also recorded evidence of fluctuating cognition during the course of her hospital admission which was not recorded in our original article. When combined, the presence of more than two core clinical features; ≥1 cardinal feature of Parkinsonism, recurrent visual hallucinations and fluctuating cognition or one core clinical feature and ≥1 indicative biomarker ie a positive biomarker (dopamine transporter scan) fits the diagnosis of probable dementia with Lewy bodies in line with the diagnostic criteria of the Fourth Consensus of the DLB Consortium as enumerated in our AMC article. The presence of microvascular changes on computed tomography or magnetic resonance imaging does not negate this conclusion more so as it is not unusual to have these changes coexist with other pathologies in older people.

The case is unique as conventional diagnosis of dementia will follow a course duration of months to years rather than weeks. The lesson of the case review is that clinicians should not be put off by a shorter period of presentation, as in this instance, albeit other causes of delirium including metabolic encephalopathies must be excluded as was done in this case. In addition, Emma Vardy’s written supplement and review on a similar case drives home some of the observations in our original article.

• © 2019 Royal College of Physicians