Carpal tunnel syndrome

General

Clinicals - History

Fact Explanation
Numbness and tingling The carpal tunnel is formed by the flexor retinaculum that stretches over the carpal bones. The Median Nerve and the flexor tendons traverse the carpal tunnel. Compression of the Median Nerve within the carpal tunnel disrupts nerve transmission causing a sensation of numbness.Pins and needles of the index and middle fingers is by far the most common presenting symptom. The little finger is almost never involved as it is innervated by the Ulnar Nerve. Numbness and tingling
The carpal tunnel is formed by the flexor retinaculum that stretches over the carpal bones. The Median Nerve and the flexor tendons traverse the carpal tunnel. Compression of the Median Nerve within the carpal tunnel disrupts nerve transmission causing a sensation of numbness.Pins and needles of the index and middle fingers is by far the most common presenting symptom. The little finger is almost never involved as it is innervated by the Ulnar Nerve.
Pain in the forearm Usually radiates upwards from the wrist along the medial border of the forearm, this is described as an aching pain and not associated with pins and needles. Neurological features are never found proximal to the wrist, and it present should raise the possibility of a different diagnosis. Pain in the forearm
Usually radiates upwards from the wrist along the medial border of the forearm, this is described as an aching pain and not associated with pins and needles. Neurological features are never found proximal to the wrist, and it present should raise the possibility of a different diagnosis.
Weakness of grip As the compression of the Median Nerve increases there is damage to the axons and signs of nerve damage begin to appear. There is often a weakness of fine dexterity of the hand due to weakness of the abductor policis brevis muscle, therefore actions such as picking up a needle, sewing and knitting become difficult. Evidence of symptoms is seen more prominently in the dominant hand though fifty percent of patients will exhibit bilateral symptoms. Weakness of grip
As the compression of the Median Nerve increases there is damage to the axons and signs of nerve damage begin to appear. There is often a weakness of fine dexterity of the hand due to weakness of the abductor policis brevis muscle, therefore actions such as picking up a needle, sewing and knitting become difficult. Evidence of symptoms is seen more prominently in the dominant hand though fifty percent of patients will exhibit bilateral symptoms.
Exacerbation of symptoms at night Characteristically, attacks of symptoms are nocturnal. Though the reason for this remains unexplained, the presentation is so typical that it may even be considered pathognomonic. Exacerbation of symptoms at night
Characteristically, attacks of symptoms are nocturnal. Though the reason for this remains unexplained, the presentation is so typical that it may even be considered pathognomonic.
Loss of motor function This will occur at a late stage in the disease with continued severe compression of the Median Nerve. Presents as weakness and paralysis of the muscles of the thenar eminence and the lateral two lumbricals. Loss of motor function
This will occur at a late stage in the disease with continued severe compression of the Median Nerve. Presents as weakness and paralysis of the muscles of the thenar eminence and the lateral two lumbricals.
Improvement of symptoms with shaking (Flick Sign) Patients often say that symptoms improve when the hand is shaken vigorously or when held in a downward facing position. Patients may also complain that they feel as if their hands are swollen but on examination there is no objective swelling. Improvement of symptoms with shaking (Flick Sign)
Patients often say that symptoms improve when the hand is shaken vigorously or when held in a downward facing position. Patients may also complain that they feel as if their hands are swollen but on examination there is no objective swelling.
History of diabetes Carpal tunnel syndrome is common among patients with type I or II diabetes, especially among those with diabetic poly neuropathy. History of diabetes
Carpal tunnel syndrome is common among patients with type I or II diabetes, especially among those with diabetic poly neuropathy.
Associated conditions Diabetes, hypothyroidism, rheumatoid arthritis, osteoarthritis, amyloidosis, obesity, and pregnancy are all associated with an increased risk of carpal tunnel syndrome. Associated conditions
Diabetes, hypothyroidism, rheumatoid arthritis, osteoarthritis, amyloidosis, obesity, and pregnancy are all associated with an increased risk of carpal tunnel syndrome.

Clinicals - Examination

Fact Explanation
Hypalgesia There is diminished perception of painful stimuli along the palmar aspect of the index finger when compared to the little finger. This is because the sensory innervation of the palmar aspect of the thumb, index, middle and ring finger is by the Median Nerve. Hypalgesia
There is diminished perception of painful stimuli along the palmar aspect of the index finger when compared to the little finger. This is because the sensory innervation of the palmar aspect of the thumb, index, middle and ring finger is by the Median Nerve.
Two point discrimination test The lack of two point discrimination can be noted along the sensory distribution of the Median Nerve on the palmar aspect of the affected hand. Two point discrimination test
The lack of two point discrimination can be noted along the sensory distribution of the Median Nerve on the palmar aspect of the affected hand.
Wrist flexion test (Phalen's Sign) The patient is asked to keep both wrists flexed for a period of sixty seconds. In more than fifty percent of those with Carpal tunnel syndrome there will be exacerbation of parasthesia of the affected hand. Wrist flexion test (Phalen's Sign)
The patient is asked to keep both wrists flexed for a period of sixty seconds. In more than fifty percent of those with Carpal tunnel syndrome there will be exacerbation of parasthesia of the affected hand.
Tinnel's percussion test Upon percussion of the Median Nerve over the flexor retinaculum there is hyperasthesia over the distribution of the Median Nerve. Despite having high specificity (75%) it has a relatively low sensitivity (36%) Tinnel's percussion test
Upon percussion of the Median Nerve over the flexor retinaculum there is hyperasthesia over the distribution of the Median Nerve. Despite having high specificity (75%) it has a relatively low sensitivity (36%)
Wasting of the thenar eminence Often seen in advanced cases. In longstanding cases of carpal tunnel syndrome there is atrophy of the thenar eminence, as these muscles are supplied by the Median Nerve. It is often easier to appreciate the loss of muscle bulk if palpation is performed during contraction of the muscles. Wasting of the thenar eminence
Often seen in advanced cases. In longstanding cases of carpal tunnel syndrome there is atrophy of the thenar eminence, as these muscles are supplied by the Median Nerve. It is often easier to appreciate the loss of muscle bulk if palpation is performed during contraction of the muscles.
Weakness of thumb movements There is weakness of thumb abduction, adduction and opposition as the thenar muscles become progressively weaker. Weakness of thumb movements
There is weakness of thumb abduction, adduction and opposition as the thenar muscles become progressively weaker.
Evidence of secondary causes of carpal tunnel syndrome Look for features of secondary causes of carpal tunnel syndrome in the general examination. Possible features noted maybe hypothyroidism, rheumatoid arthritis, osteoarthritis, previous Colles fracture and acromegaly. Evidence of secondary causes of carpal tunnel syndrome
Look for features of secondary causes of carpal tunnel syndrome in the general examination. Possible features noted maybe hypothyroidism, rheumatoid arthritis, osteoarthritis, previous Colles fracture and acromegaly.

Investigations - Diagnosis

Fact Explanation
Magnetic Resonance Imaging (MRI) MRI features of carpal tunnel syndrome are: enlargement of the median nerve, this is often observed within the proximal carpal tunnel. More distally over the carpal tunnel the nerve becomes flattened with bowing of the flexor retinaculum. In addition it is also useful to exclude a possible space occupying lesion of the carpal tunnel that can cause similar symptoms. Magnetic Resonance Imaging (MRI)
MRI features of carpal tunnel syndrome are: enlargement of the median nerve, this is often observed within the proximal carpal tunnel. More distally over the carpal tunnel the nerve becomes flattened with bowing of the flexor retinaculum. In addition it is also useful to exclude a possible space occupying lesion of the carpal tunnel that can cause similar symptoms.
High resolution Ultrasound (HRUS) High resolution ultrasound (HRUS) has emerged as a simple, low-cost, rapid, accurate, and noninvasive imaging method for evaluating the Median Nerve. In addition to the detection of increased cross sectional area of the Median Nerve. Ultrasound is also useful for identifying ganglia, fibromata, neural tumors, and tenosynovitis that can cause similar symptoms. Ultrasound can also be used to guide steroid injections into the tunnel. High resolution Ultrasound (HRUS)
High resolution ultrasound (HRUS) has emerged as a simple, low-cost, rapid, accurate, and noninvasive imaging method for evaluating the Median Nerve. In addition to the detection of increased cross sectional area of the Median Nerve. Ultrasound is also useful for identifying ganglia, fibromata, neural tumors, and tenosynovitis that can cause similar symptoms. Ultrasound can also be used to guide steroid injections into the tunnel.
Nerve conduction study Abnormalities of electrophysiologic testing, in addition to specific symptoms and signs, are needed in the diagnosis of carpal tunnel syndrome. Nerve conduction study (NCS) is more valuable than needle electromyography (EMG) study in general because of the underlying pathology of focal demyelination. Electrophysiological assessment also provides a an idea of the severity of the damage inflicted on the Median Nerve and thereby guides subsequent therapeutic interventions. Nerve conduction study
Abnormalities of electrophysiologic testing, in addition to specific symptoms and signs, are needed in the diagnosis of carpal tunnel syndrome. Nerve conduction study (NCS) is more valuable than needle electromyography (EMG) study in general because of the underlying pathology of focal demyelination. Electrophysiological assessment also provides a an idea of the severity of the damage inflicted on the Median Nerve and thereby guides subsequent therapeutic interventions.

Investigations - Management

Fact Explanation
Electrophysiological investigations Staging is based on clinical and electrophysiologic criteria. Staging is as follows: Early - symptoms for less than one year, no permanent weakness and nerve conduction velocity increased by 1-2 ms. Intermediate- permanent weakness, prolonged latency. Advanced- permanent loss of sensory and motor function. This system of staging is useful in guiding the therapeutic interventions. Electrophysiological investigations
Staging is based on clinical and electrophysiologic criteria. Staging is as follows: Early - symptoms for less than one year, no permanent weakness and nerve conduction velocity increased by 1-2 ms. Intermediate- permanent weakness, prolonged latency. Advanced- permanent loss of sensory and motor function. This system of staging is useful in guiding the therapeutic interventions.

Management - Supportive

Fact Explanation
Avoid repetitive hand movements Repetitive movements may exacerbate symptoms and make symptom relief difficult. Should also avoid the use of vibratory tools. Ergonomic measures such as improved wrist positioning when using a keyboard maybe useful. Avoid repetitive hand movements
Repetitive movements may exacerbate symptoms and make symptom relief difficult. Should also avoid the use of vibratory tools. Ergonomic measures such as improved wrist positioning when using a keyboard maybe useful.
Wrist splints Splinting the wrist at a neutral angle may help relieve symptoms. This works by reducing repetitive rotation and flexion and reducing the soft tissue swelling and tenosynovitis. Recommended for a period of four weeks. Wrist splints
Splinting the wrist at a neutral angle may help relieve symptoms. This works by reducing repetitive rotation and flexion and reducing the soft tissue swelling and tenosynovitis. Recommended for a period of four weeks.
NSAIDS Recommended as an adjunct to ergonomic measures and wrist splinting. NSAIDS
Recommended as an adjunct to ergonomic measures and wrist splinting.
Nerve and tendon gliding exercises Useful in patients with mild to moderate symptoms. Nerve and tendon gliding exercises
Useful in patients with mild to moderate symptoms.

Management - Specific

Fact Explanation
Corticosteroid injection Steroid injections are very effective in resolving symptoms of carpal tunnel syndrome in the short term, particularly if symptoms are mild and intermittent. Those with mild symptoms of short duration have more benefit than those with more protracted or severe symptoms. Corticosteroid injection
Steroid injections are very effective in resolving symptoms of carpal tunnel syndrome in the short term, particularly if symptoms are mild and intermittent. Those with mild symptoms of short duration have more benefit than those with more protracted or severe symptoms.
Ultrasound Limited benefit in providing relief from symptoms. Ultrasound
Limited benefit in providing relief from symptoms.
Supraretinacular endoscopic carpal tunnel release Reduced pain and early return to work following surgery when compared to the conventional technique. Should be considered if non surgical treatment fails to alleviate symptoms. Supraretinacular endoscopic carpal tunnel release
Reduced pain and early return to work following surgery when compared to the conventional technique. Should be considered if non surgical treatment fails to alleviate symptoms.
Carpal tunnel release and Median Nerve decompression Traditional surgery is an out patient procedure that utilizes regional anesthesia. Surgery is indicated if symptoms do not respond to non surgical therapy and nerve conduction reveals severe entrapment neuropathy. Possible complications are injury to the palmar cutaneous or recurrent motor branch of the median nerve, hypertrophic scarring, laceration of the superficial palmar arch, and tendon adhesion. Carpal tunnel release and Median Nerve decompression
Traditional surgery is an out patient procedure that utilizes regional anesthesia. Surgery is indicated if symptoms do not respond to non surgical therapy and nerve conduction reveals severe entrapment neuropathy. Possible complications are injury to the palmar cutaneous or recurrent motor branch of the median nerve, hypertrophic scarring, laceration of the superficial palmar arch, and tendon adhesion.

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