History

Fact Explanation
Dull pain in the volar aspect of the forearm Due to a lesion to the anterior interosseous branch in the forearm. Seen in Anterior interosseous nerve syndrome Pronator syndrome.
Acute weakness of distal phalanx flexion of the thumb and/or index finger, middle finger, and forearm pronation. Due to a lesion to the anterior interosseous branch in the forearm.The deep flexor muscles of these fingers are innervated by the anterior interosseous nerve.
Tingling, numbness and acute pain along the distribution of the median nerve (i.e., thumb, index finger, and middle finger) 1) Carpal tunnel syndrome :-No specific cause exists Seen in Carpal tunnel syndrome. Lack of blood supply due to compression of the median nerve in the carpal tunnel leads to depletion of nutrients and oxygen to the nerve causing it to slowly lose its ability to transmit nerve impulses.Scar and fibrous tissue eventually develop within the nerve. Symptoms often are worse at night and are exacerbated by repetitive flexion and extension of the wrist, strenuous gripping, or exposure to vibration. At times, these symptoms may occur in all the fingers, but should not occur in the dorsum or palm of the hand.Pain and paresthesias may radiate proximally into the forearm, and even into the arm and shoulder.
History of causative factor. 1) Carpal tunnel syndrome :-No specific cause exists for primary CTS. They are generally women in the age group of 30–50 years.Carpal tunnel syndrome may result from any process that causes compression of the median nerve in the carpal tunnel. The potential causes of compression include various congenital, inflammatory, infectious, and metabolic or endocrine processes and conditions (eg, diabetes, pregnancy, and hypothyroidism) as well as trauma(most commonly associated with a fracture of the radius) and mass lesions (eg, ganglion, lipoma, neurofibroma, fibrolipomatous hamartoma). CTS also seen in Workers using vibratory tools. 2) Anterior interosseous nerve syndrome:- The most frequent causes are direct traumatic damage(result of surgery, venous puncture, injection, or cast pressure) and external compression(caused by various anomalies, including a bulky tendinous origin of the ulnar (deep) head of the pronator teres muscle, a soft-tissue mass such as lipoma or ganglion, an accessory muscle, a fibrous band originating from the superficial flexor, or a vascular abnormality). 3) Pronator syndrome :- IS results from entrapment or compression of the median nerve between the humeral (superficial) and the ulnar (deep) heads of the pronator teres muscle, at the bicipital aponeurosis (lacertus fibrosus), or at the arch of the origin of the flexor digitorum superficialis. Compression and entrapment may result from anatomic constraints due to congenital abnormalities in the involved tendons or muscles, such as hypertrophy of the pronator teres muscle bellies or aponeurotic prolongation of the biceps brachii muscle. Less common causes of pronator syndrome include posttraumatic hematoma, soft-tissue masses, prolonged external compression, and fracture of the elbow (eg, Volkman fracture)
Affected activities of daily living Loss of strength when gripping or performing certain tasks such as buttoning shirts, writing, combing hair, and driving a car.
References
  1. ANDREISEK GUSTAV, CROOK DAVID W., BURG DORIS, MARINCEK BORUT, WEISHAUPT DOMINIK. Peripheral Neuropathies of the Median, Radial, and Ulnar Nerves: MR Imaging Features1. RadioGraphics [online] 2006 September, 26(5):1267-1287 [viewed 19 November 2014] Available from: doi:10.1148/rg.265055712
  2. PHAM M., BAUMER P., MEINCK H.-M., SCHIEFER J., WEILER M., BENDSZUS M., KELE H.. Anterior interosseous nerve syndrome: Fascicular motor lesions of median nerve trunk. Neurology [online] December, 82(7):598-606 [viewed 19 November 2014] Available from: doi:10.1212/WNL.0000000000000128
  3. AROORI S, SPENCE RA. Carpal tunnel syndrome Ulster Med J [online] 2008 Jan, 77(1):6-17 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2397020
  4. LEBLANC KE, CESTIA W. Carpal tunnel syndrome. Am Fam Physician [online] 2011 Apr 15, 83(8):952-8 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21524035
  5. THATTE MUKUNDR, MANSUKHANI KHUSHNUMAA. Compressive neuropathy in the upper limb. Indian J Plast Surg [online] 2011 December [viewed 20 November 2014] Available from: doi:10.4103/0970-0358.85350
  6. OSTERMAN MEREDITH, ILYAS ASIF M., MATZON JONAS L.. Carpal Tunnel Syndrome in Pregnancy. Orthopedic Clinics of North America [online] 2012 October, 43(4):515-520 [viewed 24 November 2014] Available from: doi:10.1016/j.ocl.2012.07.020

Examination

Fact Explanation
Ecchymosis, abrasions or surgical scars on the wrists and hands Suggest an acute injury to the tissue, including the median nerve, as the etiology.
Bony abnormalities Boutonniere deformity, swan neck deformity, and ulnar deviation of the wrist, suggest rheumatoid arthritis whereas carpal or distal phalanx bossing suggests osteoarthritis as the secondary cause for CTS.
Thenar atrophy Usually occurs only with severe, chronic carpal tunnel syndrome ,with associated loss of thumb abduction and opposition strength. Due to involvement of the motor component of median nerve.
Weakness of abductor pollicis brevis. Due to involvement of the motor component of median nerve. Can observe this weakness by instructing the patient to raise his or her thumb perpendicular to the palm as the physician applies downward pressure on the distal phalanx, resisting thumb abduction.
Tinel's sign Seen in carpal tunnel syndrome.Tapping the flexor aspect of the wrist causes tingling and pain.(Tingling sensation occurred when an injured nerve was percussed over its proximal stump and speculated that this was a sign of axonal degeneration.)
Positive phalen's test. Seen in carpal tunnel syndrome. Flexion of the wrist causes compression of the nerve between the transverse carpal ligament (TCL) and flexor tendons in the carpal tunnel, causing paresthesia in the median nerve distribution reproducing the patient's symptoms. Can be positive in pronator Teres Syndrome.
Circle sign Patients with anterior interosseous nerve syndrome and pronator Teres Syndrome.are not able to form an “O” with the thumb and index finger. Is due to a lack of innervation of the flexor pollicis longus muscle or the flexor digitorum profundus muscle.
Signs of hypo/hyperthyroidism Hyperthyroidism :-tachycardia, the presence of goiter, and a tremor. Signs of ophthalmopathy (eyelid retraction or lag and periorbital edema, Exophthalmos) may be present in those with Graves’ disease. Hypothyroidism :-coarse skin, decreased sweating, or puffiness.
References
  1. ANDREISEK GUSTAV, CROOK DAVID W., BURG DORIS, MARINCEK BORUT, WEISHAUPT DOMINIK. Peripheral Neuropathies of the Median, Radial, and Ulnar Nerves: MR Imaging Features1. RadioGraphics [online] 2006 September, 26(5):1267-1287 [viewed 19 November 2014] Available from: doi:10.1148/rg.265055712
  2. LEE HO JIN, KIM ILSUP, HONG JAE TAEK, KIM MOON SUK. Early Surgical Treatment of Pronator Teres Syndrome. J Korean Neurosurg Soc [online] 2014 December [viewed 19 November 2014] Available from: doi:10.3340/jkns.2014.55.5.296
  3. AROORI S, SPENCE RA. Carpal tunnel syndrome Ulster Med J [online] 2008 Jan, 77(1):6-17 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2397020
  4. LEBLANC KE, CESTIA W. Carpal tunnel syndrome. Am Fam Physician [online] 2011 Apr 15, 83(8):952-8 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21524035
  5. BOELAERT K., TORLINSKA B., HOLDER R. L., FRANKLYN J. A.. Older Subjects with Hyperthyroidism Present with a Paucity of Symptoms and Signs: A Large Cross-Sectional Study. The Journal of Clinical Endocrinology & Metabolism [online] 2010 June, 95(6):2715-2726 [viewed 24 November 2014] Available from: doi:10.1210/jc.2009-2495
  6. WEETMAN ANTHONY P.. Graves' Disease. N Engl J Med [online] 2000 October, 343(17):1236-1248 [viewed 24 November 2014] Available from: doi:10.1056/NEJM200010263431707
  7. ZULEWSKI HENRYK, MüLLER BEAT, EXER PASCALE, MISEREZ ANDRé R., STAUB JEAN-JACQUES. Estimation of Tissue Hypothyroidism by a New Clinical Score: Evaluation of Patients with Various Grades of Hypothyroidism and Controls . The Journal of Clinical Endocrinology & Metabolism [online] 1997 March, 82(3):771-776 [viewed 24 November 2014] Available from: doi:10.1210/jcem.82.3.3810

Differential Diagnoses

Fact Explanation
Brachial neuritis May mimic the clinical manifestations of an AIN neuropathy
A rupture of the flexor pollicis longus(FPL) tendon is also possible in patients with rheumatoid arthritis Clinical presentation with an isolated palsy of the FPL muscle is difficult to distinguish from a closed tendon rupture,To exclude this, the wrist should be passively flexed and extended to confirm that the patient has an intact tenodesis effect.
Cervical radiculopathy (C6) These patients present with neck pain, numbness only in thumb and index finger.
Ulnar or cubital tunnel syndrome (tardive ulnar neuritis). These patients present with Intermittent tingling paresthesia,Weak grip strength, muscle atrophy, failure of the fingers to adduct and abduc. But dorsal interosseous weakness comes first. They also have fourth and fifth digit paresthesias.
Thoracic outlet syndrome Patients present with pain and numbness in their fingers, hands, or arms on the affected side.There is usually a sensory loss in a lower brachial plexus distribution, weakness of ulnar-innervated muscles, and tenderness and/or a bruit in the supraclavicular space. A delay of median nerve distal latency or focal median nerve slowing of conduction distally is not found.
Raynaud phenomenon These patients present with pain and discoloration in fingertips. Their history of symptoms are related to cold exposure.
TIA they present with weakness of a arm. But they may also have difficulty speaking and weakness of face and/or leg in same side. And also these symptoms resolve in few minutes.
References
  1. ULRICH DIETMAR, PIATKOWSKI A., PALLUA NORBERT. Anterior interosseous nerve syndrome: retrospective analysis of 14 patients. Arch Orthop Trauma Surg [online] December, 131(11):1561-1565 [viewed 19 November 2014] Available from: doi:10.1007/s00402-011-1322-5
  2. MORRIS HH, PETERS BH. Pronator syndrome: clinical and electrophysiological features in seven cases. J Neurol Neurosurg Psychiatry [online] 1976 May, 39(5):461-464 [viewed 19 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC492308
  3. FREISCHLAG JULIE, ORION KRISTINE. Understanding Thoracic Outlet Syndrome. Scientifica [online] 2014 December, 2014:1-6 [viewed 19 November 2014] Available from: doi:10.1155/2014/248163
  4. RODGERS MICHAEL. Primary Raynaud's Phenomenon. N Engl J Med [online] 2013 April, 368(14):1344-1344 [viewed 20 November 2014] Available from: doi:10.1056/NEJMicm1209600
  5. QING CUI, ZHANG JIANHUA, WU SHIDONG, LING ZHAO, WANG SHUANCHI, LI HAORAN, LI HAIQING. Clinical classification and treatment of cubital tunnel syndrome. Exp Ther Med [online] 2014 September [viewed 20 November 2014] Available from: doi:10.3892/etm.2014.1983
  6. LEBLANC KE, CESTIA W. Carpal tunnel syndrome. Am Fam Physician [online] 2011 Apr 15, 83(8):952-8 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21524035
  7. JOHNSTON S. CLAIBORNE. Transient Ischemic Attack. N Engl J Med [online] 2002 November, 347(21):1687-1692 [viewed 24 November 2014] Available from: doi:10.1056/NEJMcp020891

Investigations - for Diagnosis

Fact Explanation
Electrodiagnostic studies 1) Nerve conduction study :-Any focal conduction delay implies a demyelinative lesion. In severe carpal tunnel syndrome, a focal conduction block or secondary axon loss results in reduced nerve sensory and motor amplitudes. The conduction studies are normal in AIN syndrome. 2) Electromyography :- Can see denervation in median-innervated muscles.Electromyography is often paired with nerve conduction studies to differentiate primary muscle conditions from muscle weakness caused by neurologic disorders. A typical pattern of muscle denervation is a key for the diagnosis of Pronator Teres Syndrome.
MRI patients with Pronator Teres Syndrome and typical anterior interosseous nerve syndrome with acute or subacute onset, axial T2-weighted fat-suppressed or STIR images depict increased signal intensity in the flexor pollicis longus, flexor digitorum profundus, and pronator quadratus muscles. In carpal tunnel syndrome, can evaluate enlargement and flattening of the median nerve and can see increased nerve signal intensity on T2-weighted fat-suppressed or STIR images and bowing of the flexor retinaculum at the level of the hook of the hamate.
US scan As 13–27% of patients will have a normal NCS, alternative diagnostic tests such as ultrasound (US) and magnetic resonance imaging (MRI) are useful. USS measured the cross-sectional area (CSA) of the median nerve, bowing of the flexor retinaculum (FR) and flattening of the flexor retinaculum. The CSA of the median nerve and bowing of the FR were significantly increased in patients with NCS.
X-ray of forearm Acute carpal tunnel syndrome is most commonly associated with a fracture of the radius. Also in a case of carpal tunnel syndrome due to excessivepressure in the tunnel caused by an osteophyte, axial x-ray views of the tunnel is important in diagnosis.
Investigations to assess the etiology. 1) Thyroid function test :-Hypothyroidism increase(70%) risk of CTS. Uncontrolled hypothyroidism is associated with myxedematous deposition and thickened synovial fluid, which are thought to entrap the median nerve in the carpal tunnel. 2) HbA1c :-Diabetes is a significant risk factor of CTS (40% increase in risk).Diabetes causes a peripheral neuropathy through abnormal glycosylation of protein end products; however, it is doubtful that diabetic neuropathy is the primary cause of CTS in these patients. Diabetic vascular changes and tendinopathies may also predispose toward CTS. 3) ESR and Rheumatoid factor :- Inflammatory arthritis conferred a nearly threefold increase in risk of carpal tunnel surgery. Inflammatory tenosynovitis associated with crystal arthritis can cause compression of the median nerve in the carpal tunnel. 4) BMI :- In obese individuals increased fat deposit in the carpal canal and increased hydrostatic pressure in the carpal tunnel can cause carpal tunnel syndrome.
References
  1. ANDREISEK GUSTAV, CROOK DAVID W., BURG DORIS, MARINCEK BORUT, WEISHAUPT DOMINIK. Peripheral Neuropathies of the Median, Radial, and Ulnar Nerves: MR Imaging Features1. RadioGraphics [online] 2006 September, 26(5):1267-1287 [viewed 19 November 2014] Available from: doi:10.1148/rg.265055712
  2. ULRICH DIETMAR, PIATKOWSKI A., PALLUA NORBERT. Anterior interosseous nerve syndrome: retrospective analysis of 14 patients. Arch Orthop Trauma Surg [online] December, 131(11):1561-1565 [viewed 19 November 2014] Available from: doi:10.1007/s00402-011-1322-5
  3. PHAM M., BAUMER P., MEINCK H.-M., SCHIEFER J., WEILER M., BENDSZUS M., KELE H.. Anterior interosseous nerve syndrome: Fascicular motor lesions of median nerve trunk. Neurology [online] December, 82(7):598-606 [viewed 19 November 2014] Available from: doi:10.1212/WNL.0000000000000128
  4. LEE HO JIN, KIM ILSUP, HONG JAE TAEK, KIM MOON SUK. Early Surgical Treatment of Pronator Teres Syndrome. J Korean Neurosurg Soc [online] 2014 December [viewed 19 November 2014] Available from: doi:10.3340/jkns.2014.55.5.296
  5. LEBLANC KE, CESTIA W. Carpal tunnel syndrome. Am Fam Physician [online] 2011 Apr 15, 83(8):952-8 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21524035
  6. AROORI S, SPENCE RA. Carpal tunnel syndrome Ulster Med J [online] 2008 Jan, 77(1):6-17 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2397020
  7. ENGEL J, ZINNEMAN H, TSUR H, FARIN I. Carpal tunnel syndrome due to carpal osteophyte. The Hand [online] 1978 October, 10(3):283-284 [viewed 20 November 2014] Available from: doi:10.1016/S0072-968X(78)80051-5
  8. KOMURCU HATICE FERHAN, KILIC SELIM, ANLAR OMER. Relationship of Age, Body Mass Index, Wrist and Waist Circumferences to Carpal Tunnel Syndrome Severity. Neurol. Med. Chir.(Tokyo) [online] 2014 December, 54(5):395-400 [viewed 20 November 2014] Available from: doi:10.2176/nmc.oa2013-0028
  9. SOLOMON DANIEL H., KATZ JEFFREY N., BOHN RHONDA, MOGUN HELEN, AVORN JERRY. Nonoccupational risk factors for carpal tunnel syndrome. J Gen Intern Med [online] 1999 May, 14(5):310-314 [viewed 20 November 2014] Available from: doi:10.1046/j.1525-1497.1999.00340.x
  10. EL MIEDANY YASSER, ASHOUR SAMIA, YOUSSEF SALLY, MEHANNA ANNIE, MEKY FATMA A.. Clinical diagnosis of carpal tunnel syndrome: Old tests–new concepts. Joint Bone Spine [online] 2008 July, 75(4):451-457 [viewed 20 November 2014] Available from: doi:10.1016/j.jbspin.2007.09.014
  11. DE RIJK M. C, VERMEIJ F. H, SUNTJENS M., VAN DOORN P. A. Does a carpal tunnel syndrome predict an underlying disease?. Journal of Neurology, Neurosurgery & Psychiatry [online] 2007 June, 78(6):635-637 [viewed 20 November 2014] Available from: doi:10.1136/jnnp.2006.102145
  12. AHMED TAHIR, BRAUN ALAN I.. Carpal tunnel syndrome with polymyalgia rheumatica. Arthritis & Rheumatism [online] 1978 March, 21(2):221-223 [viewed 20 November 2014] Available from: doi:10.1002/art.1780210207

Management - General Measures

Fact Explanation
Splint 1) Wrist splint at night have significant short-term benefit in mild and moderate carpal tunnel syndrome.There is good evidence supporting the use of neutral and cock-up wrist splints, with similar symptom relief outcomes with both styles. 2) At least several months, In Pronator syndrome and anterior interosseous nerve syndrome unless a motor deficit is noted.
Conservative therapy 1) Anterior interosseous nerve syndrome:-observation with an avoidance of aggravating activities, rest, has been suggested before decompression . Most of the patients with AIN syndrome have an improvement without any surgical intervention 2) Carpal tunnel syndrome:- Lifestyle Modification. Avoiding repetitive motions, avoidance of vibratory tools, using ergonomic equipment (e.g., wrist rest, mouse pad), taking breaks, using keyboard alternatives (e.g., digital pen, voice recognition and dictation software), and alternating job functions
Physiotherapy 1) Anterior interosseous nerve syndrome:-should be directed specifically towards the pattern of pain and symptoms. Soft tissue massage, stretches and exercises in order to directly mobilise the nerve tissue may be used.
References
  1. ULRICH DIETMAR, PIATKOWSKI A., PALLUA NORBERT. Anterior interosseous nerve syndrome: retrospective analysis of 14 patients. Arch Orthop Trauma Surg [online] December, 131(11):1561-1565 [viewed 19 November 2014] Available from: doi:10.1007/s00402-011-1322-5
  2. KIM POONG-TAEK, LEE HYUN-JOO, KIM TAE-GONG, JEON IN-HO. Current Approaches for Carpal Tunnel Syndrome. Clin Orthop Surg [online] 2014 December [viewed 20 November 2014] Available from: doi:10.4055/cios.2014.6.3.253
  3. LEBLANC KE, CESTIA W. Carpal tunnel syndrome. Am Fam Physician [online] 2011 Apr 15, 83(8):952-8 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21524035
  4. AROORI S, SPENCE RA. Carpal tunnel syndrome Ulster Med J [online] 2008 Jan, 77(1):6-17 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2397020
  5. HATTE MR, MANSUKHANI KA. Compressive neuropathy in the upper limb Indian J Plast Surg [online] 2011, 44(2):283-297 [viewed 24 November 2014] Available from: doi:10.4103/0970-0358.85350

Management - Specific Treatments

Fact Explanation
Surgical management 1)Carpal tunnel syndrome:- When conservative treatment fails, surgical treatment is considered. Despite the equivocal nature of CTS etiology, simple decompression of the median nerve by division of the transverse carpal ligament (TCL) is the treatment of choice and is considered to yield excellent results in 75% of the patients. For distal radial fracture:- open reduction with internal fixation. 2) Anterior interosseous nerve syndrome :- For patients who have a space-occupying mass in the area, or who fail a several month course of nonsurgical treatment, surgical decompression has been recommended.If motor function does not recover, tendon transfer will restore the function satisfactorily.The transfer of the tendon of FDP of the ring or middle finger to that of the index finger at the wrist can provide satisfactory flexion of the distal phalanx of the index finger.
Medical management 1) Anterior interosseous nerve syndrome:- Anti inflammatory medication for several months 2) Oral corticosteroids :- suppresses migration of polymorphonuclear leukocytes and reduces capillary permeability leading to decreased inflammation 3) Local steroid injection in the wrist :- Give relief in mild carpal tunnel syndrome.Corticosteroid treatment is effective in reducing inflammation and edema of synovium and tendons.
References
  1. ULRICH DIETMAR, PIATKOWSKI A., PALLUA NORBERT. Anterior interosseous nerve syndrome: retrospective analysis of 14 patients. Arch Orthop Trauma Surg [online] December, 131(11):1561-1565 [viewed 19 November 2014] Available from: doi:10.1007/s00402-011-1322-5
  2. KIM POONG-TAEK, LEE HYUN-JOO, KIM TAE-GONG, JEON IN-HO. Current Approaches for Carpal Tunnel Syndrome. Clin Orthop Surg [online] 2014 December [viewed 20 November 2014] Available from: doi:10.4055/cios.2014.6.3.253
  3. LEBLANC KE, CESTIA W. Carpal tunnel syndrome. Am Fam Physician [online] 2011 Apr 15, 83(8):952-8 [viewed 20 November 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/21524035
  4. CHAUHAN AAKASH, BOWLIN TIMOTHY C., MIH ALEXANDER D., MERRELL GREGORY A.. Patient-reported outcomes after acute carpal tunnel release in patients with distal radius open reduction internal fixation. HAND [online] December, 7(2):147-150 [viewed 24 November 2014] Available from: doi:10.1007/s11552-012-9400-x