Mental State and Higher Function
1 MENTAL STATE
BACKGROUND
In this section, examination of higher function has been separated from examination of mental state. This is because higher function can be examined using relatively simple tests, while mental state is examined using observation of the patient and attention to points within the history.
The mental state relates to the mood and thoughts of a patient. Abnormalities may reflect:
• neurological disease, such as frontal lobe disease or dementia
• psychiatric illness secondary to neurological disease (e.g. depression following stroke).
Mental state examination attempts to distinguish:
• diffuse neurological deficit
• primary psychiatric illness such as depression or anxiety presenting with somatic symptoms
• psychiatric illness secondary to, or associated with, neurological disease.
The extent of mental-state testing will depend on the patient and his problem. In many patients, only a simple assessment will be needed. However, it pays to consider whether further evaluation is needed in all patients.
Methods of formal psychiatric assessment will not be dealt with here.
WHAT TO DO AND WHAT YOU FIND
Appearance and behaviour
Watch the patient while you take the history. Here are some questions you can ask yourself in assessing appearance and behaviour.
Are there signs of self-neglect?
Does the patient appear depressed?
Does the patient appear anxious?
Does the patient behave appropriately?
• Overfamiliar and disinhibited or aggressive: consider frontalism.
• Unresponsive, with little emotional response: flat affect.
Does the patient’s mood change rapidly?
Does the patient show appropriate concern about his symptoms and disability?
Mood
Ask the patient about his mood.
If you consider that the patient may be depressed, ask:
• During the past month have you often been bothered by:
a) feeling down, depressed or hopeless?
A positive response to either (a) or (b) along with a request for help is a sensitive and specific screening test for depression.
Patients with schizophrenia often have an apparent lack of mood—blunted affect—or inappropriate mood, smiling when you expect them to be sad—incongruous affect.
In mania, patients are euphoric.
Vegetative symptoms
Ask the patient about vegetative symptoms:
Look for symptoms of anxiety:
Delusions
A delusion is a firmly held belief, not altered by rational argument, and not a conventional belief within the culture and society of the patient.
Delusional ideas may be revealed in the history but cannot be elicited by direct questioning. They can be classified according to their form (e.g. persecutory, grandiose, hypochondriacal) as well as by describing their content.
Delusions are seen in acute confusional states and psychotic illnesses.
Hallucinations and illusions
When a patient complains that he has seen, heard, felt or smelt something, you must decide whether it is an illusion or a hallucination.
An illusion is a misinterpretation of external stimuli and it is particularly common in patients with altered consciousness. For example, a confused patient says he can see a giant fist shaking outside the window, which is in fact a tree blowing in the wind outside.
A hallucination is a perception experienced without external stimuli that is indistinguishable from the perception of a real external stimulus.
Hallucinations may be elementary—flashes of light, bangs, whistles—or complex—seeing people, faces, hearing voices or music. Elementary hallucinations are usually organic.
Hallucinations can be described according to the type of sensation:
Before continuing, describe your findings, for example: ‘An elderly unkempt man, who responds slowly but appropriately to questions and appears depressed’.
WHAT IT MEANS
In psychiatric diagnoses there is a hierarchy, and the psychiatric diagnosis is taken from the highest level involved. For example, a patient with both anxiety (low-level symptom) and psychotic symptoms (higher-level symptom) would be considered to have a psychosis (Table 3.1).
Organic psychoses
An organic psychosis is a neurological deficit producing an altered mental state, suggested by altered consciousness, fluctuating level of consciousness, disturbed memory, visual, olfactory, somatic and gustatory hallucinations, and sphincter disturbance.
Proceed to test higher function for localising signs.
There are three major syndromes:
Functional psychoses
Personality disorder
This is a lifelong extreme form of the normal range of personalities. For example:
• histrionic, deceptive, immature = borderline personality disorder.
