Today Collab topic (OT) Given by Haritha Occupational Therapy Uppal facility Topic: GYANS CANAL :
Topic: GYANS CANAL :
Guyon's Canal
Guyon Canal syndrome which is also known as Ulnar Tunnel Syndrome is a relatively rare peripheral ulnar neuropathy. Guyon canal syndrome is also known as ulnar tunnel syndrome or handlebar palsy.[1]It is defined as a compression of the distal ulnar nerve at the level of the wrist as it enters the hand through a space called ulnar tunnel or Guyon canal. The clinical presentation can be purely sensory, purely motor or both depending on the location of the nerve compression.
The ulnar nerve is one of the major nerves of the hand and travels down the neck through the medial epicondyle, than passes under the forearm muscles than to the little finger along side the palm.
Causes:
*Ganglion cysts, they’re one of the most common causes of Guyon canal syndrome
*Tumors
*Anatomical anomalies, can be hypertrophic muscle of normal anatomy or unusual location
*Ulnar artery thrombosis or aneurysm (e.g., Hypothenar Hammer Syndrome)
*Fractures or dislocations (e.g., The hook of hamate Fracture/Displacement)
Repetitive trauma (e.g., repetitive trauma to the hypothenar by the handlebar in cyclists)
*Carpel tunnel syndrome, it can lead to anatomical changes ,leading to functional impairments
Clinical Presentation :
Guyon’s canal is divided into 3 zones, compression on the ulnar nerve at each zone results in specific symptoms.
Zone 1
Zone 1 compression refers to compression at the proximal end of Guyon’s canal, proximal to the bifurcation of the ulnar nerve into sensory and motor branches.
Compression at zone 1 leads to mixed sensory and motor symptoms resulting in sensory dificits over the hypthenar, little finger and the medial half of the ring finger and motor weakness of all ulnar innervated intrinsic muscles.
Zone 2
Zone 2 compression refers to compression only at the deep motor branch of the nerve, distal to the bifurcation.
Only motor symptoms would develop resulting in motor weakness in the hand muscles innervated by the ulnar nerve.
Compression at zone 2 may occur at pisohamete hiatus after the nerve to abductor digit minimi takeoff, which would result in weakness in the intrinsic muscles of the hand with possible sparing of the hypothenar muscles.
Zone 3
Zone 3 compression refers to compression at the superficial sensory branch, it manifests as sensory deficits on the palmer side of the ring finger and the palmer-medial side of the ring finger without hypthenar and interosseous weakness.
Compression on the ulnar nerve in zone 1 at the palmer aspect of the nerve can also result in pure sensory symptoms.
Diagnosis:
Diagnosis can be difficult due to the wide range of presenting signs and symptoms that can vary depending on the location of the nerve compression. The first step is a detailed assessment of the patient's medical history and the onset and severity of symptoms. In order to confirm the diagnosis the following tests may be indicated:
*Classical radiographs including posteroanterior and lateral views.
*Computed tomography scan (CT) is useful in cases of suspected hook of hamate fracture.
*MRI and ultrasound are useful in the diagnosis.
Nerve conduction studies are useful in confirming the diagnosis and localizing neuropathies.
Treatment:
Management of Guyon canal syndrome is similar to that of carpel tunnel syndrome, it includes conservative management or surgical decompression.
Conservative treatment is recommended for mild and moderate symptoms with duration of less than 3 months. Surgical treatment is recommended for moderate to very severe symptoms with duration of at least 2 months.
Physical Therapy Management:
Conservative treatment consists of patient instructions and splinting. Ultrasound (US) and nerve glide exercise can be added depending on patient’s situation and personal preferences.
Ulnar nerve glide exercise based on the Butler concept for the ulnar nerve is as follows: Wrist extension, forearm pronation elbow flexion, glenohumeral lateral rotation, glenohumeral depression, shoulder abduction.
The patient is instructed to avoid activities that cause repetitive stress at Guyon’s canal such as weight bearing or cycling or modification of the bicycle handlebars. Also, to avoid static postures or repetitive movements that places mechanical overload such as prolonged wrist extension.
The patient is instructed to wear resting hand splint to place the wrist in neutral position. The splint should be worn for 1-12 weeks during nighttime and at daytime during aggravating activities.
Surgical Decompression:
The aim of the surgery is to decrease the pressure on the ulnar canal in Guyon's canal by removing the roof of the Guyon canal or removing the structures compressing the nerve.
During the early post-operative period (up to 10-15 days after surgery), the patient is advised to elevate his hand, provide appropriate rest of the hand, do gradual hand and wrist movements without resistance as tolerated and to avoid applying heavy loads on the hand or doing forceful activities.
The post-surgical instructions include scar care, edema control, hand and wrist mobilization and ergonomics advice to avoid putting mechanical load on the nerve.
Splinting after surgery is not routinely indicated, it is indicated only for patients with severe pain after surgery and patients who are likely to put mechanical load on the canal.
Post-surgical exercises is indicated for patients with reduced hand mobility in a case of hand edema or the patient fearing using the hand, to promote nerve glide and to strengthen the muscles of the hand.
