Brown-Séquard Syndrome; Cause, Symptom, Treatment

• Persons with Brown Sequard Syndrome will manifest the following symptoms:
• Interruption of the lateral corticospinal tracts
  • Ipsilateral spastic paralysis below the level of the lesion
  • Babinski sign ipsilateral to the lesion
  • Abnormal reflexes and Babinski sign may not be present in acute injury.
• Interruption of the posterior white column:
  • Ipsilateral loss of tactile discrimination, vibratory, and position sensation below the level of the lesion
• Interruption of lateral spinothalamic tracts:
  • Contralateral loss of pain and temperature sensation. This usually occurs 2-3 segments below the level of the lesion.

• Temperature sensation deficit
• Contralateral pain
• Ipsilateral hemiplegia or half of the body is paralyzed
• Loss of sensation of half of the body or hemianesthesia
• Babinski sign
• Abnormal reflexes
• Loss of vibration
• Horner’s syndrome
• Sphincter disturbances
• Loss of position sense
• Loss of tactile discrimination

According to various symptoms of BSS are listed below:

• Clonus
• Babinski sign
• Hemiparaplegia
• Hemianesthesia
• Loss of vibration
• Abnormal reflexes
• Horner’s syndrome
• Loss of position sense
• Ipsilateral hemiplegia
• Increased deep reflexes
• Sphincteral disturbances
• Thermanesthesia below lesion
• The sensory loss at the level of the lesion
• Reduced tactile discrimination abilities
• Segmental atrophy at the level of the lesion
• Contralateral analgesia below the lesion
• Increased muscle tone around the side of the lesion
• Paralysis of the voluntary muscles below the level of the lesion

Examination of the Sensory System

Examination of each of the sensory modalities:

Light touch

• Use the light touch of a finger, a piece of cotton wool or a piece of tissue paper.
• It is important to touch and not to stroke, as a moving sensation, such as rubbing and scratching, is conducted along pain pathways.
• Ask the patient to close their eyes and tell you when they feel you touching them.
• Compare each limb in the same position.
• Keep the timing of each touch irregular to avoid anticipation by the patient.
• A logical progression is required. You may want to start testing over the shoulder and to move along the lateral aspect of the arm and up the medial side, as this moves progressively from C4 to T3 dermatomes.
• Note any areas of hypoaesthesia or dysaesthesia.

Sharp touch (pinprick)

• Test using a dedicated disposable pin. A disposable hypodermic needle is too sharp.
• Use the sternal area to establish a baseline for sharpness before you begin.
• Follow the same progression as with light touch with the patient’s eyes closed, comparing both upper limbs.
• Ask the patient to report hypoaesthesia (feels blunter) or hyperaesthesia (feels sharper).

Temperature

• This is often overlooked but it can be important.
• An easy and practical approach is to touch the patient with a tuning fork as the metal feels cold.
• Compare the quality of temperature sensation on arms, face, trunk, hands, legs, and feet.
• Containers of warm and cool water may be used for a more accurate assessment. Ask the patient to distinguish between warm and cool on different areas of the skin with their eyes closed.

Joint position sense (proprioception)

• Test at the distal interphalangeal joint of the index finger.
• Hold the middle phalanx with one thumb and finger and hold the medial and lateral sides of the distal phalanx with the other. Move the distal phalanx up and down, showing the patient the movement first.
• Ask the patient to close their eyes and move the distal phalanx up and down randomly. Ask the patient to tell you the direction of the movement each time.
• Test on both hands.
• If there is an abnormality, move back to the proximal interphalangeal joint and so on until joint position sense is normal.

Vibration Sense

• Use a 128 Hz tuning fork and ensure the tuning fork is vibrating.
• Place it on the sternum to start with so that the patient can feel the sensation.
• Then place it on one of the distal interphalangeal joints of one of the fingers.
• If no vibration is sensed, move backward to the metacarpophalangeal joint, the wrist, etc.
• Asking the patient to tell you when the tuning fork stops vibrating can be helpful if there is a doubt that their vibration sense is intact.

Two-point discrimination

• There are specific two-point discriminators available. If you don’t have one, use a paper clip that you can open out.
• Ask the patient to close their eyes.
• Take the patient’s index finger in one of your hands.
• Using the discriminator or paper clip, touch the pulp of the finger with either one or two of the testing tips.
• The patient must tell you whether they can feel one or two stimuli.
• Find the minimum distance at which they can discriminate the two tips. Normal is at 3-5 mm.
• Compare both index fingers and repeat for both thumbs.

Examination of the motor system

Tone

• This is the resistance felt when a joint is moved passively through its normal range of movement.
  • Ask the patient to let their shoulders and arms ‘go floppy’.
  • Flex and extend their shoulder passively and feel for abnormality of tone.
  • Repeat for the elbow and wrist.
• Hypertonia is found in upper motor neuron lesions; hypotonia is found in lower motor neuron lesions and cerebellar disorders.
• Cogwheel rigidity may be found in Parkinson’s disease.

Power

• A robust assessment of power is required.
• The Medical Research Council (MRC) has a recommended grading system for power (see table). It has been shown to have good reliability. Some express doubts over the wide range of grade 4.
• Ask the patient to contract the muscle group being tested and then you as the examiner try to overpower that group.

Test the following

• Abduction, adduction, flexion, and extension of the shoulder.
• Flexion and extension of the elbow.
• Flexion and extension of the wrist.
• Supination and pronation of the forearm.
• Extension of the fingers at the metacarpophalangeal and interphalangeal joints.
• Flexion, extension, adduction, and abduction of the fingers and thumbs.

Deep tendon reflexes

• Ensure that the patient is comfortable and relaxed and that you can see the muscle being tested.
• Use a tendon hammer to strike the tendon of the muscle and look for muscle contraction.
• Compare both sides.
• Reflexes can be hyperactive (+++), normal (++), sluggish (+) or absent (-). ± is used when the reflex is only present on reinforcement (see below).

In the upper limbs

• Test the biceps jerk (C5, C6) – with their arm relaxed, hold the patient’s elbow between your thumb and remaining fingers, your thumb being anterior and directly over the biceps tendon. Ideally, the elbow should be held at 90°. Elicit the reflex by tapping on your thumb.
• Test the triceps jerk (C6, C7) – with their arm relaxed, hold the patient’s arm across their lower chest/upper abdomen with one of your hands. Elicit the reflex by tapping over the triceps tendon just above and behind their elbow.
• Test the supinator jerk (C5, C6) – ask the patient to relax their arm across their abdomen. Elicit the reflex by tapping over the supinator tendon just above the wrist.
• Test the finger jerk – with their hand relaxed, place the tips of your index and middle fingers across the palmar surface of the patient’s proximal phalanges. Tap your fingers lightly with the tendon hammer. There should be slight flexion of the patient’s fingers. If there is hyperreflexia, this flexion is exaggerated.
• Test the Hoffmann’s reflex – rest the distal interphalangeal joint of the patient’s middle finger on the side of your right index finger. Use the tip of your right thumb to flick down on the patient’s middle fingertip. Watch for any movement of the patient’s thumb as their fingertip springs back up. Normally there is no movement; in hyperreflexia, thumb flexion can be seen.

• If a reflex is difficult to elicit, try ‘reinforcement’ (the Jendrassik maneuver). Ask the patient to clench their teeth or squeeze their knees together while you try to elicit the reflexes again.

Interpretation

• Upper motor neuron lesions usually produce hyperreflexia.
• Lower motor neuron lesions usually produce a diminished or absent response.
• Isolated loss of a reflex can point to a radiculopathy affecting that segment – eg, loss of biceps jerk if there is a C5-C6 disc prolapse.

Examination of co-ordination

• The cerebellum helps in the coordination of voluntary, automatic and reflex movement. Tests of cerebellar function, however, are only valid if power and tone are normal, and that failure to perform them may also be related to power and tone abnormalities in the upper limb rather than a cerebellar problem. These include

The finger-nose test

• The patient should keep their eyes open.
• Hold one of your fingertips up in front of and a short distance (about 30-40 cm) from the patient.
• Ask the patient to touch the tip of their nose and then to touch your fingertip alternately and repeatedly. You can continuously change your fingertip position to make the test more difficult.
• You can then test for sensory ataxia by asking the patient to close their eyes and to touch the tip of their nose using their outstretched finger.
• Repeat these tests on the other side.
• Look for intention tremor and past-pointing as the patient touches the examiner’s fingertip, which can indicate disease of the cerebellar hemispheres.

Rapid alternating movement

• The patient needs to have one palm facing upwards.
• They need to touch this palm with the palmar and then dorsal sides of the fingertips of the other hand as quickly as possible. Note that they must lift the second hand between each movement and touch the same point on the other palm without rolling the hand.
• Test both sides. It is normal for the dominant hand to be a little faster at this test.
• Look for dysdiadochokinesis. This is in coordination or slow movement when trying to perform this test.

A note about sensation in the hand

• The hand may require more intensive testing. It may be useful to return to it after testing the rest of the arm.
• Test sensation on both the palmar and the dorsal aspects.
• Be aware of the distribution of the median, ulnar and radial nerves:^[1]
  • The radial nerve supplies sensation to the skin on most of the dorsum of the hand.
  • The ulnar nerve supplies sensation to the palmar aspect of the little finger and the palmar aspect of the medial half of the ring finger. It also supplies the distal half of the dorsal aspect of these fingers.
  • The median nerve supplies sensation to the palmar aspect of the thumb, index and middle fingers and the lateral half of the ring finger. It also supplies the distal half of the dorsal aspect of these fingers.

Interpreting the findings

The site of any lesion can be determined by looking at the pattern of any dysfunction found. The dermatomal (segmental) and peripheral nerve innervation is labeled in the diagrams above.

• All of the sensory modalities can be affected in peripheral neuropathies and nerve injuries, cervical radiculopathy, and spinal injuries.
• If an individual nerve or sensory root is affected, all sensory modalities can be reduced.
• If there is a spinal cord lesion, there may not be equal diminution across all of the sensory modalities: light touch, vibration, and joint position sense may remain intact while sharp touch and temperature are lost. This is because the lateral spinothalamic pathways may be damaged while the dorsal columns remain intact. Cervical syringomyelia is an example where this may happen.
• Problems with joint position sense or vibration usually occur distally first.
• Vibration sense can be lost before joint position sense in peripheral neuropathy or myelopathy affecting the dorsal columns.
• Parietal lobe lesions can also cause impairment of two-point discrimination.

Ask about the Symptoms

• What are they?
• Which part of the body do they affect? Are they localized or more widespread?
• When did they start?
• How long do they last for?
• Were they sudden, rapid or gradual in onset? Is there a history of trauma?
• Are the symptoms static or deteriorating, or are there exacerbations and remissions? For example, worsening of symptoms with hot environments – eg, sauna, hot bath or hot weather in demyelinating disorders (called Uhthoff’s sign).
• Does anything trigger the symptoms – eg, exercise, sleep, posture or external stimuli such as light or smell?

Ask about any associated symptoms (other features of neurological disease)

• A headache.
• Numbness, pins and needles, cold or warmth.
• Weakness, unsteadiness, stiffness or clumsiness.
• Nausea or vomiting.
• Visual disturbance.
• Altered consciousness.
• Psychological changes – eg, agitation, tearfulness, depression or elation, sleep disturbance.
• For children, ask about performance at school.

Try to understand how the symptoms may affect the patient’s life – ask about activities of daily living. The distal parts of the limbs tend to be affected in polyneuropathy, the legs usually being involved before the arms. A ‘glove and stocking’ effect is produced.

• Note any problem with articulation (dysarthria). Here comprehension is retained and speech construction is normal. There is usually weakness or incoordination of the orolingual muscles. Ask the patient to say ‘West Register Street’ if you are uncertain.
• Note any problem with phonation (dysphonia). This is usually due to laryngeal problems which can cause voice hoarseness. There may be reduced speech volume.
  • Look at the patient’s gait as they enter the room.
  • Note if there evidence of, for example, hemiparesis, foot drop, ataxic gait, a typical Parkinsonian gait.
  • See separate Abnormal Gait and Gait Abnormalities in Children articles. Note any problem with language function (dysphasia). This is due to a lesion in the language areas of the dominant hemisphere.
    Chiropractic manipulation – Rare, but reported

There is more than one way of performing a neurological examination and a clinician should develop their own technique. Poor technique will fail to elicit signs or will produce false results.

Observation of the patient

Involuntary movements

Establish whether there is evidence of involuntary movements – for example, tremor, tics, chorea, hemiballismus, or orofacial dyskinesias.

History

Specific emphasis should be placed on the following:

Past medical history

Some neurological problems can present years after a causative event.

• Enquire about other medical problems, past and present. These may give clues to the diagnosis. For example:
  • A person in atrial fibrillation may be producing multiple tiny emboli.
  • There may be vascular problems or recurrent miscarriage to suggest antiphospholipid syndrome.
  • There may be diabetes mellitus.
• Ask about pregnancy, delivery, and neonatal health.
• Ask about any infections, convulsions or injuries in infancy, childhood or adult life. Particularly ask about the head or spinal injury, meningitis or encephalitis.

Systematic Inquiry

The systematic inquiry is very important here. For example

• Loss of weight and appetite may suggest malignancy and this may be a paraneoplastic syndrome.
• The gain in weight may have precipitated diabetes mellitus.
• Polyuria may suggest diabetes mellitus. The difficulty with micturition or constipation may be part of the neurological problem but was not volunteered in the general history. In men, enquire about erectile dysfunction.

Social history

• Note smoking and drinking habits. Alcohol is a significant neurotoxin, both centrally and peripherally.
• Ask about drugs, including prescribed, over-the-counter and illicit (such as cocaine usage that can be linked to cardiovascular problems). This includes complementary and alternative medicines.
• Ask about occupation and what it involves. There may be exposed to toxins. Is repetitive strain injury likely? Is there prolonged visual work which may predispose tension-type headache migraine? The job may involve driving but the patient has admitted to convulsions. He/she may work at heights or in a dangerous environment.
• Ask about marital status. Has there been recent bereavement or divorce which may have affected symptoms?
• Ask about sexual orientation and consider the likelihood of sexually transmitted infection – eg, syphilis, HIV.

Family history

Consider if there may be a genetic basis or predisposition. For example:

• A cousin with Duchenne muscular dystrophy or Becker’s muscular dystrophy would be very important for a boy who cannot run like his peers.
• Huntington’s chorea is unusual in that it is a familial disease that does not present until well into adult life.
• A family history of, for example, type 2 diabetes mellitus, cerebral aneurysm, neuropathies, epilepsy, migraine or vascular disease may be important.

Examination of speech

• Look for spontaneous speech, fluency and use of appropriate words during conversation.
• Ask the patient to name objects.
• Ask the patient to carry out some commands to assess their comprehension.
• Ask the patient to read aloud. This can show evidence of any dyslexia.
• Ask the patient to repeat a simple sentence. Inability to do this suggests a conduction dysphasia.
• Look at the patient’s handwriting. There may be problems with the form, grammar or syntax, which may suggest a more global language problem and not just a speech disorder.

Examination of the Neck

Examine the neck movements

• Is there evidence of degenerative disease which may be producing radicular symptoms in the upper limbs? Examine flexion, extension, and rotation.
• Look for Lhermitte’s sign: neck flexion causes an electric shock-like feeling on the limbs. It is due to disease in cervical spinal cord sensory tracts (seen in, for example, multiple sclerosis, syringomyelia, tumors).
• Is there any neck stiffness? This can be a sign of meningeal irritation. The chin can normally touch the chest when the neck is flexed but this is not possible if neck stiffness is present. This may be a sign of meningitis or subarachnoid hemorrhage.

Palpate the supraclavicular fossae

• Look for enlarged lymph nodes or cervical ribs.

Listen for any bruits

• Listen at the carotid bifurcation at the angle of the jaw for carotid bruits.
• Listen over the supraclavicular fossa for vertebral or subclavian bruits.
• A common carotid bruit may be heard by listening between these two sites.
• Listen with the bell of the stethoscope over a closed eyelid for bruits due to cerebral arteriovenous malformations.
• Listen for cardiac murmurs to ensure that any bruit heard is not just due to the transmission of these.
• Note that just because a bruit is not heard, it does not mean that there is no significant stenosis present.