Conitive assessment for clinicians

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COGNITIVE ASSESSMENT FOR CLINICIANS
i22 C M Kipps, J R Hodges
J Neurol Neurosurg Psychiatry 2005; 76(Suppl I):i22–i30. doi: 10.1136/jnnp.2004.059758

ymptoms in cognitive disorders follow location and not pathology. Thus, for example, in Alzheimer’s disease, patients may present with a focal language syndrome,instead of the more commonly appreciated autobiographical memory disturbance, despite identical pathology. In contrast, large parts of the brain have limited eloquence, and may present in a similar fashion, despite notably different pathological processes. In our approach to the cognitive assessment, we maintain a symptom oriented approach. This in turn lends itself to localisation of pathology,and subsequently clinical diagnosis, which may be supplemented by associated neurological signs, imaging or other investigations. In its broadest sense, the purpose of the cognitive examination is to separate out those patients in whom a firm clinical diagnosis can be made, from those who require further and more detailed investigation. The history forms part of the examination, and the ability torespond to conversational cues is as much part of the examination as any formal assessment. In addition, the perspective of a reliable informant is essential, as memory disturbance and impaired insight are common. In any busy clinic, time is always an issue. Full cognitive assessment, including performance of various cognitive rating scales, generally takes an hour. Whatever the time available, aclear focus is needed early in the consultation. This directs attention to the relevant cognitive domains which need specific and more detailed examination.

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HISTORY
General We start by establishing a picture of pre-morbid functioning (for example, education, employment, significant relationships). Learning a little about the patient’s interests or hobbies allows one to tailorquestions in the cognitive examination more precisely. The onset, and time course of the deterioration, is as important as the cluster of deficits, be they memory, language, visual function, behaviour, or indeed psychiatric. Often, the first noted deficit has diagnostic relevance. We try to interview both the patient and informant independently, even when the amount of information likely to be obtainedfrom the patient is minimal. Disparities between the two accounts are important as insight is often poor, and it allows a chance to assess both language and cooperation without interruption or assistance from the partner. A family history and risk factors, notably vascular, are particularly relevant, and should be specifically enquired about; considerable probing is often needed. The use of aquestionnaire filled out before the consultation can save time, and draws attention to issues in the background history. Concomitant illness and medication use frequently underlie, or complicate, cognitive complaints. Alertness and cooperation with the assessment should be noted, as these factors may impact on the subsequent findings. The level of alertness is an important clue to the presence of adelirium or the effects of medication. Delirium may be marked by both restlessness and distractibility, or the patient may be quiet, and drift off to sleep easily during the consultation. If there is any concern about the level of alertness of the patient, review of the medication list is often helpful. It may be misleading, and is frequently hopeless, to perform a detailed cognitive assessment on apatient with diminished alertness. If that is the case, documentation of orientation and attention may be as much as can be achieved initially. Memory Complaints about poor memory are the most frequent reason for referral to a cognitive disorders clinic, and provide a good starting point for the consultation despite not being very specific. A useful framework for analysing memory complaints...