Carpal tunnel syndrome.

Arch Neurol 2000 May;57(5):754-5

Simovic D, Weinberg DH.

Division of Neurology, St Elizabeth’s Medical Center, Tufts University School of Medicine, Boston, Mass, USA.

Carpal tunnel syndrome (CTS) is the most frequently encountered mononeuropathy in the clinical practice. Although now a well recognized entity, it took almost 100 years from the initial observations until the pathophysiology of the disorder was finally accepted as a median nerve compression at the wrist.

Sir James Paget (1854)1 was the first to describe the clinical features of CTS. In his first case, a man developed pain and impaired sensation in the hand from the trauma of a cord drawn tightly around his wrist. In his second case, a tardy median nerve palsy was a consequence of a distal radius fracture. This patient improved with wrist immobilization and thus was also the first description of treatment with a neutral wrist splint , a method still in use today. Three decades later James Putnam (1880)2 presented a clinical series of 37 patients with “… disturbances of a subjective sensibility of the skin, giving rise to what is popularly known as numbness recurring periodically, coming on especially at night … in some cases simply letting the arm hang out of the bed or shaking it about for some moments would drive the numbness away…J.Putnam 1880 “ 2. This vivid description of CTS is quite remarkable considering it was one of the initial clinical observations and that it occurred at the end of the 19th century.Publication Types:

  • Historical Article

PMID: 10815148 [PubMed – indexed for MEDLINE]

Medical illustrations on this website are attributed to: and author Kjpargeter

Lateral Femoral Cutaneous Nerve


– Anatomy:    

– LFCN, as its name suggests, is purely sensory;    
– it arises from L2 and L3, travels downward lateral to the psoas muscle, crosses the iliacus muscle (deep to fascia), passes either thru or underneath the lateral aspect of the inguinal ligament, and finally travels onto innervate the lateral thigh;
– it divides into anterior and posterior branches and supplies skin on lateral aspect of thigh;
– in the study by Hospodar et al (JTO 1999), the course of the nerve was variable, but was most commonly found at 10-15 mm from the ASIS and as far medially as 46 mm from the ASIS;
– in no specimen did the nerve pass lateral to the ASIS (eventhough historically the nerve is thought to pass lateral to the ASIS in 10% of population);
– in all specimens the nerve passed underneath the ilioginal ligament and anterior to the iliacus muscle; 

– Meralgia Paresthetica: 

– entrapment syndrome of the lateral femoral cutaneous nerve causing burning, numbness, and paresthesias down the proximal-lateral aspect of the thigh;
– may be idiopathic, be a result of trauma, previous operations, and in some cases may arise from Perthes Disease abduction splints;
– in idiopathic cases, the nerve may be encased in bone by the growing apophysis of the anterior superior iliac spine, or may be entrapped in fascia either proximal or distal to the ASIS;    
– diagnosis is made by:           
– reproduction of the pain by deep palpation just below the anterior superior iliac spine and by hip extension;           
– relief of pain by localized injection of lidocaine;    
– treatment: when diagnosis is not in doubt and the symptoms are severe, consider operative decompression at the site of constriction;


Electromyography (EMG) and nerve conduction studies (NCS) are tests that measure the electrical activity of muscles and nerves. Nerves send out electrical signals to make your muscles react in certain ways. Nerves also send signals from your skin to your brain, which then processes the signals, so you can experience a variety of skin sensations.

  • An EMG Test looks at the electrical signals your muscles make when they are at rest and when they are being used.
  • A Nerve Conduction Study measures how fast and how well the body’s electrical signals travel along your nerves. EMG and nerve conduction studies are used to help diagnose a variety of muscle and nerve disorders and to quantify the severity of your condition.

An EMG test helps find out if muscles are responding the right way to nerve signals. Nerve conduction studies help diagnose nerve damage or disease. When EMG tests and nerve conduction studies are done together, they help doctors tell if your symptoms are caused by a muscle disorder or a nerve problem. With EMG and NCS studies, your doctor can next select the best therapeutic option to help you.