Article Text

PDF

A difficult psychiatric patient

Statistics from Altmetric.com

Q1: What is the diagnosis in this patient and what would you also consider?

The differential diagnosis in this patient was very wide.

  • Despite the lack of obvious signs, focal sepsis such as a chest infection or a urinary tract infection would explain these symptoms in this patient.

  • In this age group a significant proportion of myocardial infarcts are silent and could explain the drowsiness and loss of vigour.

  • Elderly people often present with problems caused by their prescribed medication. These can include drug interactions (which increase in likelihood with increasing polypharmacy), accidental underdosing (for example Madopar), accidental overdosing (for example lithium), and in a patient with a history such as this non-accidental overdose may also be a possibility.

  • A further cerebrovascular accident could have occurred.

  • Fluctuating confusion can be part of Lewy body dementia which might have been the explanation for his parkinsonism combined with cognitive impairment.

  • Less likely metabolic disturbances such as hypothyroidism, hypothermia, or the onset of diabetes mellitus should be considered.

  • With this man's history a relapse of a depressive disorder is a strong possibility—this was what his family and community psychiatric nurse initially thought.

  • The role of alcohol in this man's presentation was not clear but intoxication or withdrawal could have exacerbated any of the above.

  • The actual diagnosis in this man was a chronic subdural haematoma (see fig 1).

Figure 1

Non-contrast computed tomogram showing bilateral subdural haematomas, the right greater than the left with midline shift. The right subdural haematoma is exerting quite a marked mass effect with effacement of the cerebral sulci.

Q2: What particular risk factors for this condition were present in this patient?

The factors are:

  • Age: more common in the elderly with a peak incidence in the seventh decade.

  • Sex: more common in males (ratio 2:1–5:1).

  • Risk of falls: more common than violent trauma in this age group as a cause of subdural haemorrhage. This man's cerebrovascular disease, Parkinson's disease, history of alcohol misuse, and his prescribed drugs all increase his risk of falling. In fact when this man's family were contacted to gain additional information they reported that the patient had fallen out of bed three weeks previously but he had not appeared hurt and they had not linked it with his presenting complaint.

  • Subdural haematomas are more common in those with a history of alcohol misuse.

  • Aspirin: well documented increased risk in those on antiplatelet or anticoagulant medication.

  • Pre-existing cerebral atrophy increases the strain on bridging veins whose rupture leads to the haematoma itself.

Q3: How is this condition normally managed?

Referral to a neurosurgeon. The haematoma can be drained using burr holes.

Despite his age and cognitive impairment this man was accepted by the local neurosurgeons who evacuated his haematoma via burr holes. Although he had a difficult postoperative period, he was eventually discharged home.

Key lessons

  • Always obtain an informant history if presented with a confused patient

  • Not all behavioural disturbance in psychiatric patients is due to psychiatric illness

  • Remember chronic subdural haematoma in confused patients especially the elderly

Discussion

Chronic subdural haematoma has been described as “the great neurological imitator”.1 It can obscure underlying disease or be obscured by it and it can simulate another neurological condition—for example, Parkinson's or even drug intoxication. The stereotypical patient is rarely seen due to difficulties obtaining a full history, the influence of comorbid illness, and the inherent variability in presentation—for example, 30% have no history of trauma and 60% have no neurological signs.2 The diagnosis may be particularly easy to miss in patients with a psychiatric history in whom behavioural disturbance is commonly ascribed to their psychiatric illness.

In one study of 88 subdural haematomas the correct diagnosis was made on admission in only 28%.3 In a smaller series 8/21 subdural haematomas were only picked up at postmortem examination.4 This was a classic problem in psychiatric hospitals in the era before computed tomography. In a study of 200 postmortems on psychiatric patients Cole found 14 subdural haematomas, only one of which had been diagnosed in life.5 The importance of the diagnosis rests with the fact that the condition is usually treatable with burr hole drainage and the majority do well afterwards.

The most common reason for failure to diagnose a chronic subdural haematoma is the failure to consider it in the differential diagnosis when faced with an elderly confused patient, particularly when there are a number of diagnostic distractions.

Final diagnosis

Chronic subdural haematoma.

References

View Abstract

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.