All these primitive reflexes may be found in normal people. They occur more frequently in patients with frontal pathology and diffuse encephalopathy. If unilateral, they strongly suggest contralateral frontal lobe pathology.

2 SUPERFICIAL REFLEXES

Cremasteric reflex

This reflex can be performed in men. The inner aspect of the upper thigh is stroked downward. The movement of the testicle in the scrotum is watched. Cremasteric contraction elevates the testicle on that side.

• Afferent: femoral nerve L1, L2

• Efferent: L1, L2.

What you find

• Present: normal

• may occur with non-neurological local pathology or previous local surgery

• lesion in reflex arc

• pyramidal lesion above L1.

Anal reflex

What to do

Lie the patient on his side with the knees flexed. Lightly stroke the anal margin with an orange stick.

What you find

• Visible contraction of the external anal sphincter.

What it means

This tests the integrity of the reflex arc with segmental innervation of S4 and S5 for sensory and motor components. If no contraction seen this indicated a lesion in this reflex arc. Most commonly a cauda equina lesion.

3 TESTS FOR MENINGEAL IRRITATION

Neck stiffness

What to do

N.B. Not to be performed if there could be cervical instability—for example, following trauma or in patients with rheumatoid arthritis.

The patient should be lying flat.

Place your hands behind the patient’s head.

• Gently rotate the head, moving the head as if the patient was indicating no. Feel the stiffness.

• Gently lift the head off the bed. Feel the tone in the neck.

• Watch the legs for hip and knee flexion.

What you find and what it means

• Neck moves easily in both planes, with the chin easily reaching the chest on neck flexion: normal.

• Neck rigid on movement: neck stiffness.

– Indicates meningeal irritation. Common causes: viral and bacterial meningitis, subarachnoid haemorrhage. Rarer causes: carcinomatous, granulomatous, fungal meningitis.

– May also occur in severe cervical spondylosis, parkinsonism, with tonsillar herniation.

N.B. Proceed to test for Kernig’s sign.

• Hip and knee flexion in response to neck flexion: Brudzinski’s sign (Fig. 25.1). This indicates meningeal irritation.

Figure 25.1 Brudzinski’s sign

TIP

Cervical lymphadenopathy and severe pharyngitis may simulate neck stiffness, but stiffness is usually only on flexion and appropriate physical signs of these pathologies are easily found.

Testing for Kernig’s sign

What to do

The patient is lying flat on the bed.

• Flex the leg at the hip with the knee flexed.

• Then try to extend the knee.

• Repeat on the other side (Fig. 25.2).

Figure 25.2 Kernig’s sign

What you find and what it means

• Knee straightens without difficulty: normal.

• Resistance to knee straightening: Kernig’s sign—bilateral indicates meningeal irritation; if unilateral, may occur with radiculopathy (cf. straight leg raising).

N.B. Kernig’s sign is absent with other causes of neck stiffness.

Head jolt test

A newer sensitive (but not very specific) test for meningeal irritation.

What to do

Ask the patient to turn his head horizontally at a frequency of two or three times a second.

What you find

• No effect: normal.

• Worsening of baseline headache: positive test.

What it means

• Positive test suggests meningeal irritation is possible.

• Negative test makes meningeal irritation very unlikely.

4 TESTS OF RESPIRATORY AND TRUNK MUSCLES

Respiratory muscles

The intercostal muscles and diaphragm can be involved especially in neuromuscular disorders. Clinical examination can be useful in evaluating respiratory muscle weakness but is of limited value. If respiratory muscle weakness is present, or seriously considered, then physiological measures, particularly vital capacity (which may need to be done lying and standing) and inspiratory mouth pressures, are important and regular monitoring may be needed.

Testing will generally be undertaken if:

• The patient has, or is thought to have, a neuromuscular disorder known to involve respiratory muscles—examples including Guillain–Barré syndrome, myasthenia gravis, motor neurone disease, muscular dystrophy.

• The patient has breathlessness or respiratory failure potentially due to respiratory muscle weakness.

Bedside testing

Is the patient breathless on sitting? Or only on lying flat—when the diaphragm movement is limited by the pressure from the abdominal contents?

Can they talk normally or are they limited to single sentences or only a few words?

Ask them to count—how far can they count on a single breath?

What is the respiratory rate?

Are they using accessory muscles of respiration?

Is the chest expansion normal?

Watch the abdomen—normally the diaphragmatic contraction on inspiration forces the abdomen to go out. If the diaphragm is weak, this is reversed and the abdomen is drawn in on inspiration—paradoxical respiration. This can be unilateral with phrenic nerve palsy.

Axial and trunk muscles

These will be rarely tested formally but are tested indirectly during other elements of the examination—for example when the patient sits up unsupported or walks.

Rarely, patients can present with weakness of axial muscles, for example head drop, when the head hangs forward as a result of weakness of the cervical erector spinae, or camptocormia, when the patient flexes at the waist from weakness of thoracolumbar erector spinae.

Erector spinae can be tested: ask the patient to lie on his front and lift his head up (cervical erector spinae), and then lift his shoulders up (thoracic erector spinae). Then ask him to rest down again and then lift his feet off the couch (lumbar erector spinae).

5 MISCELLANEOUS TESTS AND SIGNS

Tinel’s test

Percussion of a nerve at putative site of compression (usually using a tendon hammer). It is positive when paraesthesiae are produced in the distribution of the nerve concerned. Commonly performed to test for median nerve compression at the wrist.

Lhermitte’s phenomenon

Forward flexion of the neck produces a feeling of electric shock, usually running down the back. The patient may complain of this spontaneously or you can test for it by flexing the neck. Occasionally, patients have the same feeling on extension (reverse Lhermitte’s).

This indicates cervical pathology—usually demyelination. It occasionally occurs with cervical spondylitic myelopathy or cervical tumours.

Straight leg raising (Fig. 25.3)

Test for lumbosacral radicular entrapment.

Figure 25.3 Straight leg raising

With the patient lying flat on the bed, lift the leg, holding the heel. Note angle attained and any difference between the two sides.

• Normal > 90 degrees; less in older patients.

• Limitation with pain in back suggests nerve root entrapment.

Head impulse test

The vestibular ocular reflex (VOR) keeps the eyes stable when we move. If it is lacking, our vision jumps up and down like a home-made video (referred to as oscillopsia). The main inputs to this reflex come from the vestibular system in the inner ear and proprioception from the neck muscles. The information is integrated in the brainstem and leads to eye movements to balance the effect of any movement.

The head impulse test is used to examine fast VOR mediated by the lateral semicircular canal and looks at the ability of the eyes to remain stable with rapid movements. It is useful in patients with vertigo.