Examination: introduction

Introduction

In training medical students and doctors how to examine the nervous system there is an entirely appropriate emphasis on technique. It is important to learn how to elicit physical signs correctly. However, this can lead to the students tending to think more about technique and less about what information they are meant to be getting from the examination. Students often dive into the active part of the neurological examination and miss important physical signs that can be seen if looked for, for example the relative facial immobility in Parkinson’s disease.

The examination is used, like the history, as a screening test and as an investigative tool (Fig. 1). In patients in whom you anticipate a normal examination (e.g. migraine or epilepsy), a simple screening examination is appropriate (Box 1). The examination is used to investigate the hypotheses generated by the history and to clarify and understand any abnormalities found on the screening examination. For example, sensory examination of the hand will need to be done carefully in a patient with sensory symptoms affecting the hand; this would not be done in the same detail in a patient who presented with blackouts.

Fig. 1 Approach to neurological examination.

Box 1 Screening neurological examination

Gait

Pupils – direct and consensual reactions

Test fields to hand movements

Fundoscopy

Eye movements to pursuit on upgaze and lateral gaze

Facial sensation to light touch with finger tip in all three divisions of the trigeminal nerve

Facial movement – ‘screw up your eyes, show me your teeth’

Mouth – ‘open your mouth (look at tongue) and say ‘arrh’ (observe palate). Please put out your tongue’

Test neck flexion

Arms

– look for wasting

– test tone at wrist and elbow

– observe outstretched arms with eyes closed

– test power (shoulder abduction, elbow flexion and extension, finger extension and abduction and abductor pollicis brevis)

– reflexes (biceps, triceps arid supinator)

Legs

– look for wasting

– test tone at hip

– test power (hip flexion and extension, knee flexion and extension, foot dorsiflexion and plantarflexion)

– reflexes (knee and ankle and plantar response)

Sensation

– test joint position sense in toes and fingers

– test vibration sense on toes and fingers

– test light touch and pinprick distally in hands and feet

Coordination

– test finger–nose and heel–shin

When considering the examination as a whole you should try to answer the following questions:

Are there any abnormalities?

Can the abnormalities be explained by a single lesion?

Can the abnormalities be explained by several discrete lesions?

Do the abnormalities conform to a recognizable syndrome?

These observations then need to be integrated with the history to lead to a diagnosis or differential diagnosis.

The following sections will explore how to examine the nervous system and highlight some of the patterns of abnormality that can be found. These brief descriptions should only be regarded as an outline to be augmented by bedside teaching. Various areas of importance will be further highlighted in a later section, which deals with particular problems.

The type of neurological examination carried out will vary according to the clinical problem. Any description of neurological examination technique will inevitably include brief excursions into blind alleys that are only occasionally important. In the following sections describing examination, a few conditions will be briefly discussed as they provide specific signs and are not dealt with elsewhere.

General examination

The general examination (Fig. 2) is important for several reasons. It may provide clues to the cause of the neurological disorder or uncover risk factors. For example, finding a breast mass in a woman with a progressive hemiparesis suggests there are cerebral metastases; raised blood pressure and hypertensive retinopathy indicate hypertension as a significant risk factor in a patient with a stroke. General examination may reveal conditions associated with the neurological problem, for example finding peripheral vascular disease in a patient with transient ischaemic attacks. General examination can also find other unrelated important diseases that may affect the management of the neurological condition: for example, a patient with difficulty walking and lumbar canal stenosis who was also found to have significant osteoarthritis of the hip may benefit more from a hip replacement than from lumbar canal decompression.

Fig. 2 General medical signs important in neurological diagnosis.

For most patients with neurological disease the general examination is simply a screening examination. There are exceptions, for example:

Patients in whom stroke or a transient ischaemic attack is being considered in the differential diagnosis need a careful examination of the cardiovascular system.

Patients who present with possible metastases need examination to try to identify the likely primary tumour.

Patients complaining of dizziness need an examination of their ears and hearing.

There are several conditions that come to mind as soon as you see the patient – if they don’t come to mind then they can be difficult to find. These include hypothyroidism, acromegaly, myotonic dystrophy and Parkinson’s disease.

Organization of the examination

Neurological examination findings are presented in a traditional way (Box 2). This has developed because it is easier to make sense of what can be quite a large amount of information if it is provided in a standard way. While most neurologists will examine patients broadly following this conventional order, most have developed their own habits. One I know starts his examination at the feet! You need to develop (and practise) your own order and system of examination.

Box 2 Presentation of neurological examination findings

General examination

Mental state

Higher function

Cranial nerves in order

Limbs (arms then legs), appearance, tone, power

Tendon reflexes

Sensory findings

Coordination

Gait

Conclusion

Mental state examination

The mental state examination is an assessment of the patient’s mood and thoughts. This is not undertaken formally on every neurological patient. However, it is important to be aware of the possibility of psychiatric disease while taking the history. Abnormalities of mental state can occur for three reasons:

The mental state examination is conducted along with the history. It is useful to have a mental framework for areas to consider in a patient with an altered mental state (Table 1). In patients in whom the changes result from neurological disease, it is important to obtain independent corroboration of any change in personality, delusions and so on.

Table 1 Framework for mental state testing

The psychiatric diagnoses most commonly seen in neurological practice are neuroses, depression and anxiety. Patients with psychoses, illness characterized by delusions and hallucinations, are usually seen when there is a concern that these reflect an underlying neurological disease, the organic psychoses. Patients with organic psychoses (e.g. dementia, confusional states) have an altered mental state examination. There are associated abnormalities in higher function, which will be considered in the next section.

Personality changes usually result from frontal disease. This can result in two extremes of behaviour, either apathy, loss of interest in appearance and mental slowness or disinhibition, and overfamiliar and at times outrageous behaviour. There is usually little insight into these changes.

Hallucinations can be defined as sensations without a physical basis that are perceived to be real. These need to be distinguished from illusions, where there is a misinterpretation of a physical sensation (the dressing gown on the door in half-light looks like a person). Hallucinations can occur in all sensory modalities. Olfactory, visual and tactile hallucinations are more commonly organically determined. Auditory hallucinations are usually associated with psychiatric disease. A hallucination can be described as being elementary (e.g. a flash of light) or complex (seeing the face of a man). Simple hallucinations are more commonly organic.

Delusions are fixed beliefs not amenable to argument and outside those accepted within the culture of the patient. These usually occur in psychiatric disease, though when they occur in organic disease there are usually other significant higher function deficits.

These more dramatic abnormalities of mental state are rare. In general neurological practice it is important not to miss the opportunity to treat patients who have either a physical presentation of anxiety or depression or have anxiety or depression relating to their neurological problems.

Examination introduction

General examination can provide information about the aetiology of, or risk factors for, neurological disease.

Some diagnoses are made by looking at the whole patient.

Mental state examination is important in selected patients.