Imaging is not justified in patients with mild symptoms or those under the age of 65 [3]. In more severe cases plain X-rays, CT or MRI scans are often performed but rarely demonstrate any abnormality. Most patients with mild pain can be reassured and advised to lead a normal life without restrictions [3].

With more severe pain a period of abstinence from intense training and sporting activities is recommended. Simple analgesia or a non-steroidal anti-inflammatory drug (NSAID) can be prescribed. In patients with severe pain it is important to advise them that recovery is very likely to occur but may take months and, in these cases, lifestyle including work is often restricted.

The role of physical therapy is controversial. The Bone and Joint Decade 2000–2010 Task Force on Neck Pain and its Associated Disorders concluded that ‘best evidence suggests that therapies involving manual therapy and exercise are more effective than alternative strategies for patients with neck pain’ [9].

Management of cervical nerve root compression is discussed in the section ‘Pain with or without focal neurological symptoms in the shoulder and upper arm’ in this chapter.

Cervical radiculopathy

Cervical radiculopathy arising from the 3rd and 4th cervical nerve roots is very rare. Unilateral pain in the suboccipital region, extending to the back of the ear, and in the dorsal or lateral aspect of the neck occurs with radiculopathy of the 3rd cervical nerve root. C4 radiculopathy results in unilateral pain that may radiate to the posterior neck and trapezius region and to the anterior chest but does not typically radiate into the upper extremity [7]. Neither is associated with any discernible weakness although neurological symptoms may occur with sensory symptoms in the distribution of the C3 or C4 nerve root and, in the very rare occurrence when a radiculopathy is associated with spinal cord compression, an upper motor neuron pattern of weakness in all four or just the lower limbs with or without sensory symptoms and a possible sensory level may result. The term ‘sensory level’ refers to the level within the central nervous system that the spinothalamic dermatomal sensory loss extends up to on the trunk or in the limbs.

PROBLEMS AROUND THE SHOULDER AND UPPER ARM

This section discusses common neurological and non-neurological conditions affecting the shoulder and upper arm that can result in pain with or without focal neurological symptoms or focal neurological symptoms in the absence of pain.

Pain with or without focal neurological symptoms in the shoulder and upper arm

There are a number of conditions, both neurological and non-neurological, that can cause pain in and around the shoulder. These include:

• nerve root compression of the 4th, 5th and 6th cervical nerve roots

• brachial neuritis

• suprascapular nerve entrapment syndrome

• arthritis of the shoulder joint

• adhesive capsulitis

• bursitis

• rotator cuff pathology.

Pain in the shoulder and upper arm most often relates to diseases of the joints, ligaments or bones where pain occurs in the absence of neurological symptoms and is aggravated by movement of the affected joint or there is localised tenderness at the site of the pain. The presence of joint swelling and/or tenderness is another clue that the pain is not of neurological origin.

Figure 11.1 lists the common causes of pain in the region of the shoulder.

FIGURE 11.1 Painful conditions affecting the shoulder region

NEUROLOGICAL CAUSES

Radicular pain: Pain from nerve root compression, if associated with weakness and/or sensory disturbance in the distribution of the nerve root, is readily diagnosed. However, pain may occur in the absence of or precede neurological symptoms by days or even weeks. Although radicular pain may affect the upper (C4–C5) arm, it is more common in the lower (C6–8) arm.

Numbness and/or localised shoulder pain not influenced by movement of the shoulder suggests a possible C5 nerve root problem. Where neurological symptoms and signs develop, the numbness is located over the top of the shoulder along its mid-portion and extends laterally to the upper arm but not into the forearm. There may be weakness of the supraspinatus, infraspinatus and deltoid muscles [7].

Brachial neuritis or neuralgic amyotrophy: The diagnosis should be suspected when severe shoulder pain aggravated by movement of the shoulder is associated with weakness and sensory disturbance in the arm. Van Alfen et al [10] have described the clinical details in a large series of patients. As there is no ‘gold standard’ diagnostic test for brachial neuritis, the clinical features of neuralgic amyotrophy are likely to evolve.

• Ascertain whether the arm pain is aggravated by movement of the arm, suggesting local pathology in the arm, or aggravated by movement of the neck, indicating possible referred pain from nerve root compression.

• Pain occurring simultaneously with neurological symptoms is very likely to be related to a neurological cause. The pain may not be neurological in origin when it occurs in the absence of neurological symptoms.

• If testing the strength of muscles around a joint evokes marked pain, this may cause the patient not to exert a full effort and give the incorrect impression that there may be associated weakness when it is the pain that is limiting the effort, not the weakness.

SYMPTOMS: The classic symptoms begin with the subacute onset over weeks of increasingly severe constant unilateral pain predominantly in the shoulder girdle; less commonly, the pain may come on rapidly. Rarely, bilateral cases occur but one side is usually affected for some hours or up to 2 days before the other side is involved [11]. This constant pain persists on average for approximately 3–4 weeks but may last as little as a few days or up to 60 days or more. In many patients it may be followed by a movement-evoked severe stabbing pain that can persist for months. In a small proportion of cases the pain can radiate from the shoulder to the arm, the cervical spine or neck down into the arm, the scapular or dorsal region to the chest wall and/or arm, or be confined to a lower plexus distribution (e.g. medial arm and/or hand, axilla).

The shoulder pain is aggravated by movement of the shoulder, not the neck, but here there are neurological symptoms such as weakness and sensory disturbance in the arm that indicate a neurological cause for the pain. Although local heat to the shoulder region occasionally provides some relief from the pain, this is non-specific and cannot be used in diagnosis. Individual nerves can be affected in brachial neuritis, in particular the suprascapular, axillary, musculocutaneous, long thoracic and radial nerves [11].

Progressive weakness developing over days may commence within 24 hours after the onset of the pain or may be delayed for up to 4 weeks [11]. Although any part of the plexus can be involved, the upper brachial plexus is more commonly affected in males whereas the middle and lower brachial plexus is more commonly affected in females. Wasting may occur with prolonged symptoms. Recovery can take months or even years. Sensory involvement is common and sensory symptoms can be very diffuse and non-localising.

Recurrence is rare but can occur and familial cases, termed hereditary neuralgic amyotrophy, have been described. Hereditary neuropathy with pressure palsy can also cause neuralgic amyotrophy and is related to a defect in the peripheral myelin protein 22 and is regarded as a distinct disorder [12].

Axillary nerve lesion: Axillary nerve lesions are usually related to traumatic dislocation of the shoulder joint as a result of either a sporting injury or secondary to a tonic–clonic seizure. Less commonly they occur with a fracture of the neck of the humerus or following shoulder surgery. As with all single nerve (mononeuritis) lesions, some are idiopathic (unknown cause).

EXAMINATION: There is weakness of shoulder abduction beyond the first 30° (the initial 30° is supplied by the supraspinatus muscle) due to weakness of the deltoid muscle (see Figure 11.2). There may be a small patch of numbness over the lower aspect of the deltoid muscle. When the lesion relates to dislocation, there is often pain in the shoulder aggravated by movement of the shoulder. The presence of pain and weakness with a history of trauma to the shoulder is a strong pointer to the diagnosis. The prognosis for recovery is variable [13].

FIGURE 11.2 Testing the deltoid muscle (the arrow points to the deltoid muscle/axillary nerve)

Suprascapular nerve entrapment: The suprascapular nerve arises from the junction of the 5th and 6th cervical nerve roots and traverses an oblique course across the supraspinatus fossa, relatively fixed on the floor of the fossa and tethered underneath the transverse scapular ligament, to the scapular notch and supplies the supraspinatus and infraspinatus muscles. Most often the suprascapular entrapment syndrome relates to local compression by the suprascapular ligament although it may be idiopathic in origin or due to rarer causes [14]. Although very rare, it is a diagnosis not to be missed as prompt treatment is more likely to result in resolution of the problem.

SYMPTOMS: The pain is deep and diffuse, localised to the posterior and lateral aspects of the shoulder and may be referred into the arm, neck or upper anterior chest wall. Certain scapular motions may be painful, causing the patient to restict shoulder movement. Adduction of the arm across the body tenses the nerve and may increase the pain. Occasionally, the patient may complain of burning, aching or crushing pain.

EXAMINATION: It is important to test the supraspinatus and infraspinatus muscles, looking for weakness confined to those muscles. Remember, pain may give the appearance of weakness with the patient not exerting a full effort as a result of the pain. The clue that the weakness relates to pain from the shoulder is that, in addition to the supraspinatus and infraspinatus appearing weak, the deltoid and subscapularis muscles will also appear weak. Severe suprascapular nerve entrapment results in atrophy and permanent weakness of the supraspinatus and infraspinatus muscles (see Figure 11.3).

FIGURE 11.3 Suprascapular entrapment with marked wasting of the supraspinatus and infraspinatus muscles

FIGURE 11.4 A Method of testing the supraspinatus. The arm is abducted approximately 20–30° away from the chest wall while the examiner pushes on the elbow, trying to force the arm back against the chest wall.
B Method of testing the infraspinatus. The elbow is kept next to the chest wall and the semi-flexed forearm is externally rotated against resistance.
C Method of testing the subscapularis. The arm is bent at a right angle at the elbow and the forearm is semi-pronated. The elbow is kept at the side and the patient is asked to rotate the forearm in towards the body while the examiner tries to prevent this by pushing the forearm in the opposite direction.

TREATMENT of SUPRASCAPULAR NERVE ENTRAPMENT

Confirmation of the diagnosis depends on the electromyogram. Some authorities [15] feel that a normal result of an electromyogram is consistent with the diagnosis of suprascapular nerve entrapment, whereas others [16] think that a positive result of an electromyogram is essential in confirming the diagnosis. The diagnostic finding is a prolonged latency from stimulation at Erb’s point to the recording needle in either the supraspinatus or infraspinatus muscle. Treatment is surgical decompression [14].

NON-NEUROLOGICAL CAUSES OF SHOULDER PAIN

The following section may seem out of place but neurologists are frequently asked to see patients with pain of non-neurological origin when the patient would more appropriately be referred to a rheumatologist or orthopaedic surgeon. It is hoped that a detail discussion will aid the non-neurologist to sort out the neurological and non-neurological causes of pain.

Pain that radiates past the elbow to the hand is usually not related to shoulder pathology.

Ascertain whether the arm pain is aggravated by:

• movement of the arm, suggesting local pathology in the arm

• movement of the neck, indicating possible referred pain from nerve root compression.

Adhesive capsulitis: Adhesive capsulitis or the ‘frozen shoulder’ results in a gradual onset of pain and stiffness that leads to a restricted range of movement at the shoulder joint. It is usually seen in patients over the age of 40. A normal range of movement of the shoulder is incompatible with the diagnosis and X-rays are usually normal. The aetiology of this condition is unclear but it is not uncommon in the setting of a hemiplegia.

Rotator cuff syndrome: Probably the commonest cause of pain affecting the shoulder joint is non-neurological and is related to rotator cuff syndrome, also referred to as impingement syndrome. There are four tendons in the rotator cuff and these tendons are related individually to the following muscles: teres minor, subscapularis, infraspinatus and supraspinatus. The rotator cuff is compressed against the acromium causing bursitis, tendinitis and eventually a rotator cuff tear. Partial or complete tears or inflammation (tendinitis, tendinosis, calcific tendinitis) associated with rotator cuff injury occur in the region near where these tendon/muscle complexes attach to the humerus [17]. Other causes of pain in the shoulder joint include adhesive capsulitis and arthritis.

SYMPTOMS: Symptoms are generally those of pain, initially after and then during activity. The pain can often be relieved by rest. Patients over 40 years of age are more susceptible to rotator cuff tendinosis with overuse. In this age group the most prominent complaint is pain with overhead use and athletic activities. Night pain and an inability to lie on that side are also common [17]. Although the pain may radiate into the arm and the neck it is clearly related to movement of the shoulder and not the neck, indicating local shoulder pathology and not radicular pain. Pain in the shoulder between 60° and 180° of elevation is typical of a rotator cuff problem and is termed the painful arc syndrome (see Figure 11.5).

FIGURE 11.5 Testing of the painful arc and the impingement test

MANAGEMENT of ROTATOR CUFF SYNDROME

Plain X-rays can be helpful to diagnose calcific tendinitis, acromial spur, humeral head cysts or superior migration of the humeral head, but in most cases are typically normal. Arthrography, ultrasound, CT and MRI are the definitive tests in the diagnosis of rotator cuff injury. Arthrography and ultrasound of the shoulder can help determine whether or not there is a full tear in the rotator cuff. An MRI can detect a full or partial tear, chronic tendinosis or other cause of the shoulder pain [18].

• Physiotherapy is superior to NSAIDs alone [19]. Physical therapy in the form of stretching exercises will lead to improvement in the majority of patients but the pain may take several months to subside [20].

• Subacromial corticosteroid injections are recommended for non-responders [21]; however, these injections are difficult to give and the needle is not always placed accurately [22]. Corticosteroid injections may, however, increase the subsequent risk of tendon rupture and repeated injections are associated with a higher failure rate for surgical repair of ruptured tendons [23]. Corticosteroid injection is the preferred and definitive treatment for trochanteric bursitis [24].

• Surgery is recommended for patients who fail to respond to non-surgical measures after 3 months. Subacromial decompression has been recommended for the impingement syndrome but has not been shown in randomised trials to be more beneficial than physical therapy [25, 26]. Surgical repair of rotator cuff tears can result in less pain and increased strength and movement but recovery can take up to 6 months [27].

Painless weakness affecting the shoulder region and upper arm

The two conditions that cause painless weakness around the shoulder and upper arm are nerve root compression and winging of the scapula. Rarely, axillary nerve palsy can result in painless weakness of the deltoid muscle.

CERVICAL NERVE ROOT COMPRESSION

Cervical nerve root compression more commonly affects the lower cervical nerve roots (C7–T1), but rarely compression of the C5 and/or C6 nerve root or an upper cord brachial plexus problem [28] can result in painless weakness in the shoulder and upper arm region [29, 30]. The weakness will affect all C5 and C6 innervated muscles around the shoulder: supraspinatus, infraspinatus, subscapularis, deltoid, biceps and brachialis. If C6 is the major component, brachioradialis will also be weak. In general, a radiculopathy is more likely to be associated with pain.

WINGING OF THE SCAPULA

Most patients with a mononeuritis of the long thoracic nerve to the serratus anterior muscle are not aware of the problem until someone points out that their shoulder blade is protruding (see Figure 11.6). Occasional patients notice difficulty reaching up to high places with the affected arm with or without mild shoulder pain [31]. Most patients recover spontaneously but this may take up to 2 years.

FIGURE 11.6 Winging of the scapula due to weakness of the serratus anterior muscle

Examination: This test is performed by having the patient’s arm horizontal to the floor and pushing against the examiner’s hand while the examiner looks to see if the scapular comes off the chest wall, indicating weakness of the serratus anterior muscle.

Painless numbness affecting the shoulder and upper arm

Sensation over the lower aspect of the neck, shoulder and upper arm is supplied via the 3rd to 5th cervical nerve roots. As degenerative disease predominantly affects the lower aspect of the cervical spine (C6, C7, C8 and T1), it is uncommon to see isolated sensory loss in the distribution of these nerve roots. If it does occur the sensory loss will be in a dermatome pattern as shown in Figures 1.12 and 1.13.

PROBLEMS IN THE FOREARMS AND HANDS

Numbness in the hand, forearm or both

The commonest problems are carpal tunnel syndrome (CTS) at the wrist and an ulnar nerve lesion at the elbow (tardy ulnar palsy). Median nerve lesions are sometimes confused with a C6 radiculopathy and an ulnar nerve lesion may be confused with a C8–T1 radiculopathy or a lower cord brachial plexus lesion.

CARPAL TUNNEL SYNDROME

Carpal tunnel syndrome is one of the most common neurological conditions encountered in clinical practice. The annual incidence is approximately 3–4 per 1000 patients. It is more common during pregnancy and may resolve spontaneously after delivery. It is also more common in patients who gain excessive weight and may resolve with weight loss. It is important to exclude hypothyroidism. There is a high incidence of CTS in patients with diabetes, although it is rarely the presenting symptom of that diagnosis.

Symptoms: Carpal tunnel syndrome presents in two ways.

1. In most patients the symptoms arise as a result of irritation and compression of the median nerve at the wrist by the flexor retinaculum of the carpal tunnel. Patients experience paraesthesia (numbness, pins and needles or tingling) or dysaesthesia (an unpleasant sensation). The sensory branches of the median nerve innervate the lateral 3½ digits, but many patients find it difficult to localise the sensory symptoms and often describe sensory disturbance well beyond the lateral 3½ digits [32]. The duration of altered sensation varies from a few minutes up to 30 minutes or rarely longer.

2. A second presentation is usually encountered in older patients who present with either persistent altered sensation within the median nerve distribution in the hand or marked wasting of the thenar eminence (the muscles at the base of the thumb), with little in the way of nocturnal sensory symptoms.

The characteristic and almost pathognomonic (diagnostic for a particular disease) complaint is waking in the middle of the night or in the morning with altered sensation in one or particularly both hands (other than CTS little else causes paroxysmal numbness in both hands simultaneously) that is relieved by shaking, moving or hanging the arm and hand out of the side of the bed. Other activities that may precipitate the symptoms include driving, knitting, reading, mowing the lawn or using hand tools.

Some patients complain of pain in the hand and at times up the arm even as far as the shoulder [33]. If the pain occurs only when the patient is experiencing sensory symptoms, it is reasonable to accept that the pain may be related to CTS. On the other hand, if the patient experiences pain at times when there are no sensory symptoms, this pain is less likely to be related to CTS and the patient may have two conditions, e.g. arthritis or occupational overuse syndrome. Patients should be advised that this pain may not be due to CTS and therefore may not resolve with appropriate treatment of CTS. The presence of pain, swelling and tenderness is not typical of CTS and suggests that either the CTS is secondary to the development of rheumatoid arthritis or the patient is not suffering from CTS.

Examination: In young patients there is usually no wasting or sensory loss, and the only abnormalities that may be found are a positive Tinel’s and/or Phalen’s sign (see Figure 11.7A–C). Tinel’s sign² is the precipitation of a fleeting pain or sensory symptoms radiating into the palm and fingers when the median nerve is tapped at the wrist. Phalen’s sign [35] is the presence of altered sensation in some or all of the lateral 3½ digits precipitated by forced flexion of the wrist. The wrist may need to be flexed for up to 60 seconds. Occasionally, patients with a negative Phalen’s sign may develop the sensory symptoms when the wrists are extended.

FIGURE 11.7 A Tinel’s sign. The median nerve is tapped using the tendon hammer several times from the proximal portion of the hand across the wrist for 2–3 cm.
B, C Phalen’s sign. The classic description is that the wrist is flexed (B) for up to 60 seconds and, if positive, the patient will experience transient altered sensation in the fingers and hand within the distribution of the median nerve. Some patients do not experience paraesthesia in the hands with wrist flexion but may with wrist extension (C).

The sensitivity of clinical examination by a neurologist for the diagnosis of this syndrome is 84% with a specificity of 72%. The sensitivity and specificity of Tinel’s sign were 0.60 and 0.67, respectively, and of Phalen’s sign were 0.75 and 0.47, respectively [36].

The electrophysiological diagnosis is discussed in Appendix H, ‘Nerve conduction studies and electromyography’.

CARPAL TUNNEL SYNDROME VERSUS C6 RADICULOPATHY

Carpal tunnel syndrome is far more common than a C6 radiculopathy. Both may result in paraesthesia affecting the lateral aspect of the hand and both may result in pain in the hand and arm, although pain radiating down the arm is more in keeping with a C6 radiculopathy. Figure 11.8 highlights the difference between these two entities.

FIGURE 11.8 The clinical features of carpal tunnel syndrome versus C6 radiculopathy

ULNAR NERVE LESIONS

Ulnar nerve lesions at the elbow present with unilateral symptoms (bilateral cases are extremely rare). Intermittent symptoms can occur if the patient leans the elbow on a desk or the arm of a chair. Isolated sensory symptoms may precede weakness for

• Abnormalities consistent with the diagnosis of CTS demonstrated on nerve conduction studies (NCS) do not imply that some or all of the patient’s symptoms are related to CTS. Asymptomatic median nerve compression detected by NCS is not uncommon.

• Normal NCS do not exclude a mild CTS.

months or even years but this is unusual. The more common presentation is the gradual onset of numbness and/or pins and needles affecting the medial 1½ digits and the medial aspect of the hand on both the palmar and dorsal surfaces. Pins and needles or numbness is the initial symptom in most patients with ongoing compression weakness and eventually wasting of the hypothenar eminence (base of the 4th and 5th digits) and the interossei and medial two lumbricals (the small muscles between the digits). An ulnar nerve lesion at the elbow is sometimes referred to

THERAPEUTIC OPTIONS FOR TREATING CARPAL TUNNEL SYNDROME

If the symptoms are not too severe and the patient is tolerating them a conservative approach can be taken, and in some patients the symptoms will resolve, particularly after pregnancy or with weight loss.

• Splinting the wrists at night can provide symptomatic benefit [37]. In a randomised controlled trial surgery was better than splinting [38].

• Corticosteroid injection into the wrist is beneficial in some patients, although long-term benefit is unproven [39]. Repeat injections (8 weeks after the first) are of no value [40]. In an open randomised study surgical carpal tunnel release resulted in better symptomatic and neurophysiological outcome than corticosteroid injections [41] and was more cost effective [42].

• Surgery provides long-term benefit and is recommended in patients with more severe symptoms, regardless of the severity of the NCS abnormalities. Nocturnal or day time paraesthesiae resolve completely in more than 90% of patients [41]. Surgery is also recommended in patients with severe NCS abnormalities regardless of the severity of the symptoms. The results of surgery in elderly patients who present with permanent wasting and sensory disturbance with no sensory response on NCS are less favourable [43]. Some authors state that surgical carpal tunnel decompression has a significant failure rate [44]. This was based on a retrospective questionnaire where patients stated whether they were better, unchanged or worse after surgery. NCS can predict the response to surgery, with patients who have mid-range severity abnormalities having better results than those with either very severe or no abnormality [44]. Response to surgery has been assessed using the Global Symptom Score (GSS). This is a scoring system that rates symptoms on a scale of 0 (no symptoms) to 10 (severe) in five categories: pain, numbness, paraesthesia, weakness/clumsiness and nocturnal awakening. The sum of the scores in each category is the GSS [45].

Note: For an explanation of NCS, see Appendix H, ‘Nerve conduction studies and electromyography’.

as ‘tardy ulnar palsy’. Compression of the ulnar nerve at the level of the wrist will affect the deep branch of the ulnar nerve and will not produce any sensory disturbance.

IDIOPATHIC SENSORY DISTURBANCE

A number of patients complain of intermittent paraesthesia, fluctuating in severity with variable intensity and distribution predominantly affecting the medial aspect of the forearm and hand. The paraesthesia is never associated with any weakness or objective loss of sensation and, despite extensive investigations, its cause cannot be established. The cause of this problem is unclear; it can mimic the symptoms of an ulnar nerve lesion, a lower cord brachial plexus problem or a C8–T1 radiculopathy.

Weakness with or without numbness in the hand and forearm

The commonest condition affecting the hand is CTS. Weakness is not usually a feature of CTS as it is only the abductor pollicus brevis muscle that is affected and patients are usually not aware of any weakness. Ulnar nerve lesions at the elbow and a C8–T1 radiculopathy produce almost identical symptoms and signs but there are subtle differences that enable a diagnosis at the bedside. Weakness of the extensor muscles of the wrist and hand can result from radial nerve lesions or a C7 radiculopathy and, once again, there are subtle differences that enable the diagnosis to be established at the bedside.

ULNAR NERVE LESIONS

Occasionally, patients with compression of the ulnar nerve at the elbow will present with progressive weakness in the hand with little in the way of sensory disturbance. Compression of the deep branch of the ulnar nerve at the wrist will result in weakness of the abductor digiti minimi (abduction of the little finger), the small interosseous muscles (abduction and adduction of the digits) and the 3rd and 4th lumbricals (flexion of the metacarpophalangeal joints). Sensory symptoms are absent.

ULNAR NERVE LESION AT THE ELBOW VERSUS C8–T1 RADICULOPATHY

Both conditions can present with a gradual onset of weakness of the hand associated with altered sensation affecting the medial two digits and the medial aspect of the forearm, although often with ulnar nerve lesions the numbness is confined to the fingers and hand. The hand weakness is usually more marked with a radiculopathy as more muscles used to grip objects are affected. In neither will there be any change in the reflexes. Figure 11.9 lists the differences between these two entities. Figures 11.10 and 11.11 show how to test the long flexors of the distal phalanges of the medial four digits. Very rarely, the lower cord of the brachial plexus may be affected, e.g. with a tumour in the apex of the lung, and in this situation the sympathetic ganglion may also be affected resulting in an ipsilateral Horner’s syndrome.

FIGURE 11.9 The clinical features that differentiate a C8–T1 radiculopathy from an ulnar nerve lesion at the elbow ^∗A C8–T1 radiculopathy can be painless.

FIGURE 11.10 Testing the long flexors of the lateral two digits. The examiner’s other hand is used to prevent the patient from flexing the fingers at the proximal interphalangeal joint by flexor digitorum superficialis that is supplied by the median nerve

FIGURE 11.11 Testing the long flexors of the medial two digits. The examiner’s other hand is used to prevent the patient from flexing the fingers at the proximal interphalangeal joint by flexor digitorum superficialis that is supplied by the median nerve

Examination: A careful examination of the pattern of weakness will differentiate these two entities. With an ulnar nerve lesion at the elbow there will be weakness of the abductor digiti minimi, the interossei, the medial two lumbricals and only the long flexors (bending the tips of the fingers at the distal interphalangeal joint) of the medial two digits (the medial aspect of the flexor digitorum profundus). Both the medial and lateral aspect of the flexor digitorum profundus is affected with C8–T1 radiculopathy. A nerve root or lower cord brachial plexus lesion will result in weakness of the long flexors of the medial four digits.

The fingers are prevented from flexing at the proximal phalangeal joint (supplied by the median nerve to the flexor digitorum superficialis) and the examiner asks the patient to bend the tips of their fingers while the examiner attempts to straighten them. The lateral two (Figure 11.10) are supplied by the median nerve and the medial two (Figure 11.11) by the ulnar nerve.

THORACIC OUTLET SYNDROME

The reason for discussing thoracic outlet syndrome (TOS) [48] is that it is frequently suspected by non-neurologists in patients with paraesthesia affecting the medial aspect of the forearm and hand in the absence of an ulnar nerve lesion [49]. Thoracic outlet syndrome is a controversial entity. It can occur in children and young adults [50, 51]. There are three types: arterial, venous and neurogenic. Neurogenic TOS is the commonest but in itself is exceedingly rare. It relates to brachial plexus compression, usually from scarred scalene muscles secondary to neck trauma. Compression can also occur with a cervical rib; however, the absence of a cervical rib on X-ray does not exclude the diagnosis as compression may be due to a fibrous band.

The most frequent neurological symptom is aching pain in the side or back of the neck extending across the shoulder and down the arm. Tingling and numbness are common in the forearm and hand in the ulnar (C8–T1) distribution. Paraesthaesia in the medial forearm and hand is a common complaint (90%), with the little finger involved four times as often as the thumb. One clue to the diagnosis is the precipitation of the paraesthesia with overhead activity or carrying heavy objects [52]. Objective sensory loss is uncommon and muscle weakness and wasting are late signs; once they develop the prognosis for recovery is poor. Sensory signs can occur without weakness and vice versa.

There is no reliable laboratory diagnostic test to confirm or exclude the diagnosis. The presence of a cervical rib is not proof as this is a common incidental finding in asymptomatic individuals.

RADIAL NERVE PALSY (saturday night palsy)

The term ‘Saturday night palsy’ refers to the intoxicated patient who falls asleep in the chair and awakens with a wrist drop due to radial nerve compression in the radial groove of the humerus in the upper arm. The typical story is a patient awakening with a painless wrist drop with an inability to extend the wrist and fingers occasionally associated with mild sensory loss at the base of the first and second digits on the dorsal surface (see Figure 1.14).

Classical teaching has recommended a conservative approach with a wrist splint while the patient makes a complete recovery within days to weeks. Alternative pathology should be considered in patients who present with radial nerve palsy but who have not ‘slept on their arm’. In two cases the author has seen alternate pathology was present. In the first, a fibrous band caused progressive weakness over several weeks and surgery led to a complete resolution. In the second, the radial nerve weakness was of sudden onset during the day and was due to torsion of the nerve. A delay in the diagnosis resulted in a poor outcome despite surgery.

Symptoms:

• The patient will have weakness of the supinator (turning the forearm from the hand pointing to the ground to pointing to the ceiling), brachioradialis (flexing the elbow with the forearm semi-pronated) and the extensors of the wrist, fingers and thumb.

• The apparent weakness of the small muscles of the hand is due to the wrist drop. Strength in the adductor and abductor muscles of the fingers is normal when tested with the hand flat on a hard surface eliminating the wrist drop (see Figure 11.13F).

• The triceps reflex is preserved.

• The brachioradialis reflex is reduced or absent.

• The degree of weakness of wrist and finger extension is severe, resulting in the wrist drop.

RADIAL NERVE PALSY VERSUS A C7 RADICULOPATHY

Patients with a C7 radiculopathy may also present with weakness of wrist and finger extension but it is usually less severe and radicular arm pain is more prominent. Figure 11.12 lists the differences between a C7 radiculopathy and a radial nerve lesion. Figure 11.13 shows how to determine on clinical examination if it is a radial nerve palsy and how to test finger abduction when the finger and wrist extension are very weak.

FIGURE 11.12 Differentiating between a C7 radiculopathy and a radial nerve lesion

Figure 11.13 A Method of testing the triceps. Ask the patient to extend the elbow from 90° of flexion. It is important NOT to fully bend the elbow when testing the triceps as this will produce a false positive weakness of elbow extension (normal strength).
B Method of testing the biceps (arrow). The forearm is fully supinated and the patient is asked to bend the elbow (normal strength).
C Method of testing the brachioradialis. The arm is semi-pronated and flexed at the elbow, and the patient is asked to bend the arm at the elbow (weak).
D Method of testing the extensor muscles of the wrist. The patient is asked to extend the wrist and the back of the examiner’s hand is placed over the back of the patient’s hand and both exert a full effort (weak).
E Method of testing the extensor muscles of the fingers. The examiner places the metacarpophalangeal (MCP) joints across the patient’s 5th digit, and the patient’s MCP joints are placed across the examiner’s 5th digit so that both the patient and the examiner are using the same muscles to test finger extension. Both should push as hard as possible. If the strength is normal, neither the patient nor the examiner can overcome finger extension. A common method used by many is pushing down on the extended fingers with the ulnar border of the hand, but it is hard to be sure how hard the examiner should push (weak).
F1, F2 Method of testing finger abduction and adduction in the presence of wrist drop. A wrist drop can give the false impression of weakness of the ulnar innervated muscles that abduct and adduct the fingers. Ask the patient to place the palm on a firm surface so that the fingers are touching the surface and then test adduction and abduction. The strength will be normal with a radial nerve lesion.

RADIAL TUNNEL SYNDROME OR POSTERIOR INTEROSSEOUS NERVE ENTRAPMENT

Radial tunnel syndrome is an extremely rare cause of weakness affecting the extensor muscles of the wrist and hand. Once again, a delay in recognition is more likely to result in a poor outcome with treatment. It is due to a compressive neuropathy of the posterior interosseous nerve (a branch of the radial nerve). The posterior interosseous nerve is compressed in an aponeurotic (deep fascia attached to muscle) cleft in the supinator muscle.

The pain of radial tunnel syndrome is similar to the pain of tennis elbow and is located 3–4 cm distal to the lateral epicondyle on the dorsal aspect of the forearm. With more prolonged compression, progressive weakness and wasting of the extensor muscles occurs (excluding the extensor carpi radialis, a muscle that deviates the wrist laterally with extension) in the absence of any sensory symptoms.

Pain in the forearm

Forearm pain is most often unrelated to any neurological cause but is more often due to lateral epicondylitis (tennis elbow), tenosynovitis or occupational overuse syndrome. If the pain is of neurological origin it is likely to be a C6, C7 or C8 radiculopathy. Although the ulnar and radial nerves innervate the muscles and skin of the forearm, lesions of these nerves rarely if ever cause pain.

TENNIS ELBOW OR LATERAL EPICONDYLITIS

Although referred to as tennis elbow, this condition is not confined to tennis players. It produces pain and tenderness over the lateral aspect of the elbow, radiating into the proximal forearm extensor muscles. The pain is aggravated by the patient clenching the fist, e.g. while lifting heavy objects. There is no sensory disturbance or weakness, although the pain may limit the patient’s ability to exert a full effort giving the impression of weakness. It is an overuse injury involving the extensor radialis brevis muscle, which originates on the lateral epicondylar region of the distal humerus.

TREATMENT of LATERAL EPICONDYLITIS

Although many treatments for lateral epicondylitis have been advocated, there is little clear consensus on which modality (conservative or operative) works best. Rest, use of counterforce supportive forearm bracing and non-steroidal anti-inflammatory drugs (NSAIDs) often provide relief of symptoms. Wrist splinting is sometimes necessary but efficacy is uncertain. In many patients the problem eventually resolves spontaneously.

OCCUPATIONAL OVERUSE SYNDROME

Repetition strain injury (RSI) or occupational overuse syndrome (OOS) is a controversial entity and describes a range of conditions characterised by discomfort or persistent pain in muscles, tendons and other soft tissues with or without physical manifestations. RSI is caused or aggravated by repetitive movement, sustained constrained postures and/or forceful movements. This condition occurs among workers performing tasks involving either frequent repetitive and/or forceful movements of the limb, for example keyboard operators, machinists etc.

Pain is the predominant symptom and is diffuse occurring in the hand, wrist, forearm, elbow, shoulder, scapular region and neck, clearly beyond the distribution of any single nerve or nerve root. There is also diffuse tenderness of muscles, joints and ligaments in the forearm and less commonly the upper arm [53].

The aetiology is uncertain and treatment limited.

TENDINOSIS OR TENOSYNOVITIS

Tendinosis is a term preferred by some as it does not imply an inflammatory aetiology; tendonitis and tenosynovitis (inflammation of the tendon sheath) are terms used by others. There is pain aggravated by movement of the tendon, with swelling and crepitus on palpation of the affected tendons or tendon sheath. The most commonly affected tendons are the dorsal extensors of the wrist. Pain occurs in the absence of any sensory disturbance or actual weakness, although the pain can be severe enough to prevent the patient from exerting a full effort when testing strength.

FOREARM PAIN RELATED TO CERVICAL RADICULOPATHY

Forearm pain can occur with C7 and C8 radiculopathies. The site of pain can indicate the likely nerve root involved.

Relationship between symptoms and nerve root involvement: Sensory symptoms, if present, will be in the distribution of the nerve roots (see Figures 1.12 and 1.13).

The particular nerve root involved will influence the pattern of weakness.

• In the forearm pain occurs along the lateral border (radial side) of the forearm with C6 lesions.

• Pain involving the whole arm radiating into the 3rd digit suggests C7 (as the C7 nerve root supplies the periosteum of bone, the pain is more diffuse affecting the whole limb).

• Pain on the medial (ulnar side) indicates C8 nerve root pathology.

• Upper arm or shoulder pain may also occur with a C6, C7 or C8 radiculopathy. Suprascapular pain (C5 or C6), interscapular pain (C7 or C8) or scapular pain (C8).

Cervical radiculopathy may be acute or chronic:

• Acute cervical radiculopathy with significant pain is more common in younger patients and is usually the result of a tear in the annulus fibrosis and subsequent prolapse of the nucleus pulposus (jelly-like substance in the middle of the spinal disc) or the disc itself.

• Subacute radiculopathy occurs in patients with preexisting cervical spondylosis. These patients experience occasional neck pain and develop insidious symptoms, which are often polyradicular in nature.

• Chronic radiculopathies occur either spontaneously or when acute or subacute radiculopathies fail to respond to treatment. The gradual onset of wasting and weakness of the small muscles of the hand and forearm, sometimes associated with fasciculations is seen in the elderly and this sometimes leads to the suspicion of motor neuron disease.

Radicular pain is often accentuated by activities that stretch the involved nerve root, such as coughing, sneezing, Valsalva and certain cervical movements or positions. It is NOT influenced by movement of the arm. C7 nerve root compression is the commonest while C6 is the second most common. Very rarely, the radiculopathy is due to malignancy or benign neural tumours such as neurofibroma or meningioma.

The clue to the diagnosis, although not always present, is that in most patients the arm pain is NOT influenced by moving the arm but is exacerbated by turning the neck in certain but not in all directions.

It is important to remember that the first seven cervical nerve roots emerge above the corresponding vertebra and the 8th below the 7th cervical vertebrae. Thus, C6 nerve root compression will occur between the 5th and 6th cervical vertebrae.

Confirming the diagnosis of cervical nerve root compression:

• A plain X-ray of the cervical spine with anteroposterior, lateral and oblique views will often demonstrate narrowing of the disc space or degenerative changes causing the problem. It is important to request oblique views to see the foramen through which the nerve roots emerge.

• If the pain does not settle with conservative (non-surgical) treatment, an MRI scan can usually identify the underlying pathology.

• A plain CT scan (i.e. without myelography) only occasionally identifies the underlying pathology and is not recommended in this situation.

• When the main complaint is arm pain, surgery almost invariably relieves the pain. The weakness and sensory loss may take some months to resolve and in some cases never resolve.

COMPLEX REGIONAL PAIN SYNDROME

Although this condition is extremely rare it is one of those diagnoses THAT MUST NOT BE MISSED. The consequences of a delay in diagnosis are often severe and prolonged problems.

Symptoms can recur once or many times months or even years later.

A variety of terms have been used to describe this entity, including causalgia, shoulder–hand syndrome, reflex sympathetic dystrophy and Sudeck’s atrophy. The current nomenclature refers to complex regional pain syndrome (CRPS) types I and II, where the only difference between types I and II is the presence of a nerve lesion in type II with the

PRINCIPLES of MANAGEMENT FOR CERVICAL NERVE ROOT COMPRESSION

Treatment will be determined by the patient’s ability to tolerate pain. Motor and sensory symptoms in isolation are not indications for surgery, as one cannot guarantee resolution of such symptoms.

• Some patients who have little tolerance of pain request surgery as soon as possible. If patients can be persuaded to tolerate the pain it often resolves within 4–6 weeks.

• If moving the neck aggravates the pain a collar that immobilises the neck can provide symptomatic benefit until the pain resolves.

• Analgesics and precise fluoroscopically guided transforaminal placement of corticosteroids close to the disc–nerve root interface and near the dorsal root ganglia have been shown to be of benefit [54].

• Despite the lack of scientific evidence of benefit some patients appear to settle with oral corticosteroids (50 mg per day of prednisolone for 10 days) with some relapsing when the steroids are withdrawn.³

Pain improves faster with surgery than with conservative treatment but at 1 year there is no difference [55]. A Cochrane review concluded that data from the reviewed trials were inadequate to provide reliable conclusions on the balance of risk and benefit from cervical spine surgery for spondylotic radiculopathy or myelopathy [56].

³ Personal unproven observation.

latter termed causlagia⁴ [Greek: kausos(heat) + algos (pain)]. Causalgia is burning pain, allodynia (pain evoked by innocuous stimulatio of the skin) and hyperpathia (an abnormal exaggerated response to a painful stimulus), usually in the hand or foot after partial injury of a nerve or one of its major branches. Pain is more severe in type II.

Clinical features: The problem may appear after a trivial injury and sometimes complicates minor surgery, e.g. for carpal tunnel. The essential clinical features include:

• persistent pain developing within days to weeks after the injury or surgery and pain that is not clearly confined to the distribution of a single nerve or nerve root

• initially increased temperature, then fluctuating between a sense of increased heat or coldness and subsequently persistent coldness

• swelling in the region of the pain

• changes in the colour of the skin, often described as mottled

• less frequently, excessive or reduced sweating [59].

Figure 11.14 lists the clinical features of some of the problems affecting the forearm and hands. It separates them into those that cause paroxysmal and those that cause persistent symptoms. Occasionally pain is absent and the patient presents with the other clinical features after an injury such as isolated coldness or altered sweating [54].

MANAGEMENT of COMPLEX REGIONAL PAIN SYNDROME

A variety of treatments have been advocated for CRPS type 1 but evidence to support these treatments is lacking [60, 61]. These include:

FIGURE 11.14 Some of the essential diagnostic clues in patients with symptoms in the forearms and hands

• corticosteroids [62] in the form of oral prednisolone 40 mg/day for 14 days, followed by 10 mg/week taper

• intravenous guanethidine [63, 64]

• chemical and surgical sympathectomy, although a Cochrane review concluded that there was no evidence of benefit [61].

Some have argued that, with so little to offer therapeutically, it seems not unreasonable to consider one or two sympatholytic procedures on an empirical basis [58]. Drug treatment is based, not unreasonably, on experience gained in the treatment of neuropathic pain in general. Drugs such as opioids, gabapentin and tricyclic antidepressants are recommended but have not yet been shown in randomised controlled trials to be effective in CRPS. Bisphosphonates, including pamidronate, clodronate and alendronate, have been advocated by some authorities [65]. Phenoxybenzamine (intravenous [66] and oral [67]) has also been reported to result in resolution of early CPRS type I. (It is important to warn men of the side effect of retrograde ejaculation.)