An Approach to the Painful Upper Limb
Total Page:16
File Type:pdf, Size:1020Kb
An approach to the painful upper limb Pain in the upper limb is a common presenting complaint in the primary health care setting and the origins of such pain are wide and varied. E Mogere, MB ChB, MMed (Gen Surgery) Division of Neurosurgery, University of Cape Town and Groote Schuur Hospital, Cape Town T Morgado, MB ChB, MRCS (Eng) Division of Neurosurgery, University of Cape Town and Groote Schuur Hospital, Cape Town D Welsh, FRCS (Eng), FCS (SA) Neurosurgery Division of Neurosurgery, University of Cape Town and Groote Schuur Hospital, Cape Town Correspondence to: E Mogere ([email protected]) The pain generator in the upper limb should to the shoulder, arm or hand, suggesting upper limb may require examination of the broadly be considered as: a local musculo-tendinous/skeletal cause.[1] eyes (to exclude Horner’s syndrome), an • spinal (radiculopathy or myeloradiculopa- Alternatively, the pain may radiate from assessment of neck movement, a vascular thy) the neck down into the limb, or from the assessment, breast and axilla palpation • peripheral nerve hand up towards the upper arm, suggesting and a neurological assessment of the lower • musculo-tendinous neurological origin. limbs. This is in addition to a thorough • skeletal (appendicular). neurological and orthopaedic assessment of The pattern of radiation may follow a the limb itself. The clinical approach dermatomal (radiculopathy) or non- The clinical findings are key to pinpointing dermatomal pattern (peripheral nerve or Neurological examination includes the pain source. non-neurological source). Pain radiation assessment of muscle power and bulk, does not preclude a non-neurological tendon reflexes and sensation. Orthopaedic History source. Somatic neck pain may radiate to the examination centres on joint motion and Cervical and upper limb pain may present in shoulder and musculo-tendinous shoulder the surrounding musculature. isolation or be associated with altered sensation. pain may radiate down the arm towards the The sensory alteration may be distributed in a elbow, but seldom beyond. Differential diagnosis radicular or non-radicular pattern. Cervical radiculopathy The pattern of onset of the pain also provides Radiculopathy is characterised by pain Sensory alterations may present in the clues to the pathology. The sudden onset referred from the neck distally and sensory following ways: of symptoms may imply acute mechanical disturbance and weakness with associated • dermatomal (radiculopathy) disruptions or pathological fracture, as loss of tendon reflexes. • non-dermatomal (peripheral nerve) opposed to chronic progressive pain • cape-like (syringomyelia) pattern. associated with degenerative/inflammatory The pain is usually distributed in a conditions. dermatomal pattern (Fig. 1). Dermatomes Sensory disturbance should alert the may overlap to some degree and may also clinician to seek a neurological cause for the Pain that is initiated or worsened by vary slightly between individuals. For symptoms. Sensory disturbance may include movement may originate from any example, shoulder pain may be associated numbness, paraesthesia (pins and needles) or structure involved in motion, including with C5, C6 or C7 radiculopathies. C5 pain dysaesthesia (unpleasant burning pain and joints, capsules, nerves, ligaments and rarely radiates below the elbow. C6 - C8 hypersensitivity). Paraesthesia always occurs muscles. radiculopathies may cause pain in the whole in the anatomical distribution of the involved limb, including the forearm and hand. neural structure. This helps to differentiate A history of systemic or constitutional Subtle variations in distribution of the pain nerve root from peripheral nerve pathology. symptoms and a detailed past medical provide clues to the nerve root origin. history are useful. History of fever and/or Pain of neural origin (neuropathic pain) weight loss (infections and malignancy), The sensory disturbance may include may be associated with muscle weakness, trauma, previous surgery (degenerative or paraesthesia and numbness. In radi- altered tendon reflexes and fasciculations. surgical complications), prior malignancy culopathy, this is always discretely The association with weakness is not or endocrine disorders (hypothyroidism dermatomal in distribution and is a very pathognomonic of neurological pathology, or acromegaly) may guide further accurate guide to the nerve root of origin as this may also occur in association with investigations.[2] (Fig. 2). The C5 root may have a very small musculo-tendinous disorders. sensory ‘footprint’ over the lateral aspect of Physical examination the deltoid. The C6 root invariably supplies The distribution of the pain is a useful Physical examination is guided by the the thumb. The C7 root supplies the index guide to its origin. Pain may be confined history. A thorough examination of the and middle finger. The C8 root usually 96 CME March 2013 Vol. 31 No. 3 Pain in the upper limb C3 C4 C3 C5 C4 C6 C5 C7 C6 C8 T1 C5 Medial to the C6 T1 shoulder blade A B C6 C8 C8 C7 Posterior Anterior Fig. 2. Upper limb dermatomes. C7 C8 C D Compression syndromes (entrapment neuropathies) Fig. 1. Pain patterns in cervical radiculopathy C5 - C8. An entrapment neuropathy results from compression of a peripheral nerve, most supplies the little finger. The dermatomes highly suggestive of a radiculopathy commonly the median nerve. The effect of often overlap to a degree.[3] (Table 1). nerve compression is mediated by ischaemia and oedema. Motor disturbance is variable. Muscle Special examination wasting and fasciculation are usually techniques Carpal tunnel syndrome affects the median late findings. The presence of muscle Certain manoeuvres that are provocative nerve at the wrist, where it passes beneath weakness alone is not pathognomonic in nature assist in localising the lesion, the flexor retinaculum. of radiculopathy, as joint pathology may often by reproducing the clinical affect the local musculature.[4] However, symptomatology associated with the Patients complain of dysaethesia (burning) an associated loss of tendon reflex is pathology (Table 2). pain and paraesthesia in the radial 3 - 4 Table 1. Physical findings associated with each spinal level Root Pain distribution Weakness Sensory loss Reflex loss C5 Lateral upper arm Deltoid Lateral upper arm Biceps reflex C6 Lateral forearm Biceps, brachioradialis Thumb and index finger Supinator (+biceps) reflex Thumb, index finger Wrist extensors C7 Posterior arm, Triceps, wrist flexors Posterior forearm, Triceps reflex middle finger index and middle finger C8 Medial forearm, small finger Intrinsic hand muscles, Little finger Triceps reflex abductors, finger extension Table 2. Special examination techniques Test Description Clinical significance Spurling’s/ neck compression test Passive lateral flexion & extension of neck. Positive test is reproduction of Radiculopathy radicular symptoms distant from neck Shoulder abduction (relief) sign Active abduction of symptomatic arm, placing patient’s hand on head. Positive Radiculopathy test is relief or reduction of ipsilateral cervical radicular symptoms Neck distraction test Examiner grasps the patient’s head under the occiput and chin, while applying Radiculopathy axial traction force. Positive test is relief or reduction of cervical radicular symptoms Lhermitte’s sign Passive anterior cervical flexion. Positive test is presence of ‘electric-like Myelopathy sensations’ down spine or extremities Hoffmann’s sign Passive snapping flexion of middle finger distal phalanx. Positive test is flexion- Myelopathy adduction of ipsilateral thumb and index finger 97 CME March 2013 Vol. 31 No. 3 Pain in the upper limb Median nerve is compressed at the wrist, C5 resulting in numbness or pain C6 Middle scalene muscle C7 Anterior scalene muscle C8 Brachial plexus T1 Clavicle Subclavian artery Subclavian vein Fig. 3. Carpal tunnel syndrome. Fig. 4. Thoracic outlet syndrome. fingers, particularly after strenuous wrist movements or at night (Fig. 3). The pain may radiate proximally.[5]The symptoms are Palpation of the elbow reveals tenderness over the ulna nerve and a often bilateral, but usually start in the dominant hand. Elevation or positive Tinel sign over the elbow will cause paraesthesia in the fifth shaking of the hand may provide some relief. finger. A more sensitive provocative test is the pressure-flexion test, in which the elbow is flexed and pressure applied over the cubital Occupational risk factors (computer work), pregnancy, previous tunnel for 30 seconds, with paraesthesia being reproduced in the wrist trauma, endocrine disease or oral steroid use may alert the ulna nerve distribution. clinician to the potential diagnosis. The diagnosis is more commonly made in women in a ratio of 4:1. Thoracic outlet syndrome(TOS) is due to compression of elements of the brachial plexus (neurogenic) or subclavian vessels (vascular) in Thenar muscle atrophy may be present along with weakness of their passage from the neck to the axilla (Fig. 4).[8] The neurogenic thumb abduction. type is far more common than the vascular syndrome. The C8 and T1 roots course superiorly over the first rib, then beneath the clavicle Tenderness may be elicited along the length of the median nerve and into the upper limb. Neurogenic TOS may be associated with on palpation over the carpal tunnel. Provocative manoeuvres structural abnormalities such as a cervical rib, but more commonly, such as the Tinel sign (tapping over the carpal tunnel) or the there is no anatomical