FACIAL PARALYSIS

Facial paralysis is a disfiguring disorder that has a great impact on the patient. Facial nerve paralysis may be congenital, neoplastic, or result from infection, trauma, toxic exposures, or iatrogenic causes. The most common cause of unilateral facial paralysis is Bell palsy, also known as idiopathic facial paralysis. Bell palsy is thought to account for approximately 60-75% of cases of acute unilateral facial paralysis.

Pathophysiology: The course of the facial nerve is tortuous, both centrally and peripherally

The facial nerve nucleus lies within the reticular formation of the pons, adjacent to the fourth ventricle. The facial nerve roots include fibers from the motor, solitary, and salivatory nuclei. The fibers of the facial nerve then course around the sixth cranial nerve nucleus and exit the pons at the cerebellopontine angle. The fibers go through the internal auditory canal along with the vestibular portion of the eighth cranial nerve. The narrowest portion of the internal auditory canal is the labyrinthine segment. This is the location that is thought to be the most common site of compression of the facial nerve in Bell palsy.

The facial nerve passes through the stylomastoid foramen in the skull and terminates into the zygomatic, buccal, mandibular, and cervical branches. These nerves serve the muscles of facial expression, which include frontalis, orbicularis oculi, orbicularis oris, buccinator, and platysma. Other muscles innervated by the facial nerve include stapedius, stylohyoid, posterior belly of the digastric, occipitalis, and anterior and posterior auricular muscles.

Bell palsy is thought to be caused by edema and ischemia resulting in compression of the facial nerve in its course through the bony canal. The cause of the edema and ischemia is still being debated. In the past, cold exposure (eg chilly wind, cold air conditioning, or driving with the car window down) were considered the only triggers to Bell palsy. However, most authors believe that the herpes simplex virus (HSV) is the most likely cause.

Frequency:

• Internationally: Most population studies generally show an annual incidence of 15-30 cases per 100,000 populations.

Mortality/Morbidity:

• The majority of patients who suffer from Bell palsy have neurapraxia or local nerve conduction block. These patients are likely to have a prompt and complete recovery of the nerve.
• Patients with axonotmesis, with disruption of the axons, have a fairly good recovery but it is usually not complete.
• The risk factors thought to be associated with a poor outcome in patients with Bell palsy include (1) age greater than 60 years, (2) complete paralysis, and (3) decreased taste or salivary flow on the side of paralysis (usually 10-25% compared to the patient's normal side). Other factors thought to be associated with poor outcome include pain in the posterior auricular area and decreased lacrimation.

• Patients generally have a good prognosis; approximately 80-90% of patients recover without noticeable disfigurement within 6 weeks to 3 months. Patients aged 60 years or older have an approximately 40% chance of complete recovery. Patients younger than 30 years have only a 10-15% chance of less than complete recovery. If no recovery occurs by 4 months, then the patient is more likely to have sequelae from the disease, which include synkinesis, crocodile tears, and rarely hemifacial spasm.
• Synkinesis is an abnormal contracture of the facial muscles while smiling or closing the eyes. It may be mild and result in slight movement of the chin when the patient blinks, eye closure with smiling, or contracture around the mouth while blinking. Crocodile tears are observed; patients shed tears while they eat.
• Facial spasm is a very rare complication of Bell palsy. It occurs as tonic contraction of one side of the face. Spasms are more likely to occur during times of stress or fatigue and may occur during sleep.
• Diabetic patients are 30% more likely than nondiabetic patients to have only partial recovery; recurrence of Bell palsy is also more common among diabetic patients.

• Bell palsy recurs in 10-15% of patients. It may recur on the ipsilateral or contralateral side of the initial palsy. Recurrence usually is associated with a family history of recurrent Bell palsy. Approximately 30% of patients with recurrent ipsilateral facial palsy were found to have tumors of the seventh nerve or parotid gland.

Sex:

• Bell palsy appears to affect the sexes equally. However, young women aged 10-19 years are more likely to be affected than men in the same age group.

• Pregnant women have a 3.3 times higher risk of being affected by Bell palsy than nonpregnant women (due to more chances of edema formation); Bell palsy occurs most frequently in the third trimester.

Age: The lowest incidence is found in persons younger than 10 years and the highest incidence in persons aged 60 years or older.

History: Bell palsy is a diagnosis of exclusion. The diagnosis must be made on the basis of a thorough history and physical examination and use of diagnostic testing when necessary.

• Symptoms of Bell palsy

• Acute onset of unilateral upper and lower facial paralysis (over a 48-h period)

• Posterior auricular pain

• Decreased tearing

• Taste disturbances

• The paralysis must include the forehead and lower aspect of the face. The patient may report inability to close the eye or to smile on the affected side. He or she also may report increased saliva on the side of the paralysis. If the paralysis involves only the lower portion of the face, a central cause should be suspected (ie, supranuclear). If the patient complains of contralateral weakness or diplopia in conjunction with the supranuclear facial palsy, a stroke or intracerebral lesion should be strongly suspected.

• Half of the patients affected with Bell palsy may complain of posterior auricular pain. Ask the patient if he or she has experienced trauma, which may account for the pain and facial paralysis.

• One sixth of patients experience decreased lacrimation.

• If a patient has gradual onset of facial paralysis, weakness of the contralateral side, or history of trauma or infection, other causes of facial paralysis must be strongly considered. Patients who have bilateral facial palsy must be evaluated for GBS, Lyme disease, and meningitis.

• Recurrent ipsilateral facial paralysis must raise the suspicion of a tumor of the seventh nerve or parotid gland. If the patient reports sudden onset of hearing loss and severe pain with the onset of facial paralysis, Ramsay Hunt syndrome must be considered.

Physical:

• Initial inspection of the patient demonstrates flattening of the forehead and nasolabial fold on the side affected with the palsy.

• When the patient is asked to raise the eyebrows, the side of the forehead with the palsy will remain flat.

• When the patient is asked to smile, the face becomes distorted and lateralizes to the side opposite the palsy.

• The patient is not able to close the eye completely on the affected side. On attempted eye closure, the eye rolls upward and inward on the affected side. This is known as Bell phenomenon and is considered a normal response to eye closure.

• A careful examination of the head, ears, eyes, nose, and throat (HEENT) must be carried out in all patients with facial paralysis.

• The external auditory canal must be inspected for vesicles, injection, infection, or trauma.

• The patient may have decreased sensation to pinprick in the posterior auricular area.

• Bell phenomenon is observed on attempted eye closure.

• With weakness/paralysis of the orbicularis oculi muscle (facial nerve innervation) and normal function of the levator muscle (oculomotor nerve innervation), eye closure may be partial or absent. The patient may have decreased tearing and susceptibility to corneal abrasion and dryness of the eye. The patient may appear to have loss of corneal reflex on the affected side; however, the contralateral eye blinks when testing the corneal reflex on the affected side.

• A careful oral examination must be performed.

• Taste and salivation are affected in many patients with Bell palsy.

• Taste may be assessed by holding the tongue with gauze and testing each side of the tongue independently with salt, sugar, and vinegar. The mouth must be washed after testing with different substances. The affected side has decreased taste as compared to the normal side.

• Careful neurologic examination is necessary in patients with facial paralysis. A neurologic abnormality warrants neurologic referral and further testing such as MRI of the brain, lumbar puncture, and electromyography (EMG) where appropriate.

Medical Care: In general, persons with true Bell palsy have an excellent prognosis. The goals of treatment are to improve function of the facial nerve and reduce neuronal damage. Many issues must be addressed in treating patients with Bell palsy. The most important consideration is the onset of symptoms. Treatment may be considered for patients who have the onset of paralysis within 1-7 days of the initial office visit. The American Academy of Neurology published a practice parameter in 2001 stating that steroids are probably effective and acyclovir (with prednisone) is possibly effective for treatment of Bell palsy.

The most widely accepted treatment for Bell palsy is corticosteroids. However, the use of steroids is still controversial because most patients recover without treatment.

• The recommended dose of prednisone is 1 mg/kg or 60 mg/d for 6 days, followed by a taper, for a total of 10 days.
• When using corticosteroids for the treatment of Bell palsy, caution should be used in patients with tuberculosis, peptic ulcer disease, diabetes mellitus, renal or hepatic dysfunction, or malignant hypertension.

• Since HSV is widely accepted as the likely etiologic agent of Bell palsy, trials using acyclovir have been conducted. The dose of acyclovir is 400 mg orally 5 times per day.

• Whether to use prednisone alone or combination therapy is left to the discretion of the physician. For patients who have a contraindication to steroid therapy, acyclovir may be given as solitary treatment.

• That eye care is imperative in Bell palsy is accepted universally. The patient's eye is at risk for drying, corneal abrasion, and corneal ulcers. Eye care includes artificial tears for use during the day as well as eyeglasses or shields. At night, eye lubricants may be used. If artificial tears are not effective during the daytime, then lubricants may be used; however, they may cause blurring of vision.

Surgical Care: Surgery for Bell palsy is controversial. In the past, surgical decompression of the facial nerve was considered for patients whose facial muscles demonstrated less than 90% of normal activity on electrophysiologic studies. Surgical decompression of the facial nerve involves a middle fossa craniotomy with an extradural approach. However, recent trials suggest this is not beneficial in patients with Bell palsy.

Complications:

• Approximately 30% of patients with Bell palsy experience sequelae of the paralysis, which include incomplete motor recovery, incomplete sensory regeneration, and parasympathetic impairment.

• Incomplete motor recovery may manifest as oral incompetence or epiphora.

• Incomplete sensory recovery may result in dysgeusia (impairment of taste) or ageusia (loss of taste).

Prognosis:

• The natural course of Bell palsy varies from early complete recovery to substantial nerve injury resulting in persistent paralysis.

• One third of patients regain complete recovery of facial motor function.

• The remainder of patients have permanent neurological and cosmetic abnormalities.

Patient Education:

• To prevent corneal abrasions, the patient should be educated concerning eye care.

• They also should be encouraged to do facial muscle exercises using passive range of motion as well as actively closing their eyes and smiling.

GUILLAIN BARRE SYNDROME

• Guillain-Barré syndrome (GBS) may be described as a collection of clinical syndromes manifested by an acute inflammatory polyradiculoneuropathy with resultant weakness and diminished reflexes.
• GBS is considered to be a postinfectious immune-mediated disease targeting peripheral nerves. Up to two thirds of patients report an antecedent illness prior to the onset of neurologic symptoms. Respiratory infections are reported most frequently, followed by gastrointestinal infections.
• Campylobacter jejuni is the most common pathogen isolated in several studies.
• Both gastrointestinal and upper respiratory tract symptoms can be observed with C jejuni infections.
• Pathological findings in GBS include lymphocytic infiltration of spinal roots and peripheral nerves, followed by macrophage-mediated multifocal stripping of myelin. This phenomenon results in defects in the propagation of electrical nerve impulses with eventual conduction block and flaccid paralysis.

Symptoms

Antecedent illness

• Up to two thirds of patients with GBS report an antecedent illness or event 1-3 weeks prior to the onset of weakness.
• Upper respiratory and gastrointestinal illnesses are the most commonly reported conditions. Symptoms generally have resolved by the time of medical presentation for the neurologic condition.

Weakness

• The classic clinical picture of weakness is ascending and symmetrical in nature.
• The lower limbs usually are involved before the upper limbs.
• Proximal muscles may be involved earlier than the more distal ones.
• Trunk, bulbar, and respiratory muscles can be affected as well.
• Weakness develops acutely and progresses over days to weeks. Severity may range from mild weakness to complete tetraplegia with ventilatory failure.
• Peak deficits are reached by 4 weeks after initial development of symptoms. Recovery usually begins 2-4 weeks after progression ceases.

Sensory changes

• Most patients complain of paresthesias, numbness, or similar sensory changes.
• Sensory symptoms often precede the weakness.
• Sensory symptoms frequently are ascending in nature and are more pronounced in a distal distribution.
• Sensory symptoms are usually mild. Objective findings of sensory loss tend to be minimal and variable in most cases.

Reflex changes

• Reflexes are absent or hyporeflexic early in the disease course and represent a major clinical finding on examination of the patient with GBS.
• Pathologic reflexes, such as Babinski, are absent.
• Hypotonia can be observed with significant weakness.

Pain

The mechanism of pain is uncertain and may be a product of several factors. Pain can be due to direct nerve injury or the paralysis and prolonged immobilization.

• Most patients complain of back and leg pain, often described as aching or throbbing in nature. The mechanism of pain is thought to be inflamed nerve roots.
• Dysesthetic symptoms are observed in approximately 50% of patients during the course of their illness. Dysesthesias frequently are described as burning, tingling, or shocklike sensations and are often more prevalent in the lower extremities than in the upper extremities.
• Other pain syndromes in GBS can include myalgic complaints with cramping and local muscle tenderness, visceral pain, and pain associated with conditions of immobility (eg, pressure nerve palsies, decubitus ulcers).

Autonomic changes

• Autonomic nervous system involvement with dysfunction in the sympathetic and parasympathetic systems can be observed in patients with GBS.
• Autonomic changes can include the following:
• Tachycardia
• Bradycardia
• Facial flushing
• Orthostatic hypotension
• Autonomic changes rarely persist in the patient with GBS.

Respiratory involvement

• Upon presentation, 40% of patients have respiratory or oropharyngeal weakness.
• Typical complaints may include the following:
• Dyspnea on exertion
• Shortness of breath
• Difficulty swallowing
• Ventilatory failure with required respiratory support is observed in up to one third of patients at some time during the course of their disease.
• GBS-related deaths usually occur in ventilator-dependent patients due to complications such as pneumonia, sepsis, etc.

Treatment Principles

• The goals of the therapy programs are reducing the functional deficits and targeting the impairments and disabilities resulting from GBS.
• Early in the acute phase of the disease course, patients may not be able to participate fully in an active therapy program.
• At that stage, patients benefit from daily range of motion (ROM) exercises and proper positioning to prevent muscle shortening and joint contractures.
• Addressing upright tolerance and endurance also may be a significant issue during the early part of rehabilitation.
• Active muscle strengthening then can be introduced slowly and may include isometric, isotonic, or progressive resistive exercises.
• Mobility skills, such as bed mobility, transfers, and ambulation, are targeted functions.
• Patients should be monitored for hemodynamic instability and cardiac arrhythmias, especially upon initiation of the rehabilitation program.
• The intensity of the exercise program also should be monitored, as overworking the muscles, paradoxically, may lead to worsening weakness.
• Energy conservation techniques and work simplification also may be helpful, especially if the patient demonstrates poor strength and endurance.

THORACIC OUTLET SYNDROME

Thoracic outlet syndrome (TOS) refers to compression of the neurovascular structures at the superior aperture of the thorax. The brachial plexus (95%), subclavian vein (4%), and subclavian artery (1%) are affected.

Pathophysiology: The brachial plexus trunks and subclavian vessels are subject to compression or irritation as they course through 3 narrow passageways from the base of the neck toward the axilla and the proximal arm. The most important of these passageways is the interscalene triangle, which is also the most proximal. This triangle is bordered by the anterior scalene muscle anteriorly, the middle scalene muscle posteriorly, and the medial surface of the first rib inferiorly. This area may be small at rest and may become even smaller with certain provocative maneuvers. Anomalous structures, such as fibrous bands, cervical ribs, and anomalous muscles, may constrict this triangle further. Repetitive trauma to the plexus elements, particularly the lower trunk and C8-T1 spinal nerves, is thought to play an important role in the pathogenesis of TOS.

The second passageway is the costoclavicular triangle, which is bordered anteriorly by the middle third of the clavicle, posteromedially by the first rib, and posterolaterally by the upper border of the scapula.

The last passageway is the subcoracoid space beneath the coracoid process just deep to the pectoralis minor tendon.

Frequency:

3-80 cases per 1000 people.

Sex: The sex ratio varies depending on the type of TOS (eg, neurologic, venous, arterial). Overall, the entity is approximately 3 times more common in women than in men.

• Neurologic - Female-to-male ratio approximately 3.5:1

• Venous - More common in males than in females

• Arterial - No sexual predilection

Age: The onset of symptoms usually occurs in persons aged 20-50 years.

History:

• Neurologic symptoms occur in 95% of cases. The lower 2 nerve roots of the brachial plexus, C8 and T1, are most commonly (90%) involved, producing pain and paresthesias in the ulnar nerve distribution.

• The second most common anatomic pattern involves the upper 3 nerve roots of the brachial plexus, C5, C6, and C7, with symptoms referred to the neck, ear, upper chest, upper back, and outer arm in the radial nerve distribution.

• Neurologic

• Pain, particularly in the medial aspect of the arm, forearm, and the ring and small digits

• Paresthesias, often nocturnal, awakening the patient with pain or numbness

• Loss of dexterity

• Cold intolerance

• Headache

• Venous - Pain, often in younger men and often associated with strenuous work

• Arterial

• Pain

• Claudication

• Often in young adults with a history of vigorous arm activity

Physical: In most cases, the physical examination findings are completely normal. Other times, the examination is difficult because the patient may guard the extremity and exhibit giveaway-type weakness.

• The elevated arm stress test (EAST) is the most reliable screening test. It evaluates all 3 types of thoracic outlet syndrome (TOS).

• To perform this test, the patient sits with the arms abducted 90 degrees from the thorax and the elbows flexed 90 degrees. The patient then opens and closes the hands for 3 minutes.

• Patients with TOS cannot continue this for 3 minutes because of reproduction of symptoms. Patients with carpal tunnel syndrome experience dysesthesias in the fingers, but do not have shoulder or arm pain.
• Adson's Test: With the patient in a sitting position, hands resting on thighs, the examiner palpates both radial pulses as the patient rapidly fills the lungs by deep inspiration and, with breath held, hyperextends the neck and turns the head toward the 'affected' side. If the radial pulse on that side is decidedly or completely obliterated, the result is considered positive.

Causes: The 3 major causes of TOS are anatomic, trauma/repetitive activities, and neurovascular entrapment at the costoclavicular space.

• Anatomic

• Scalene triangle: Anterior scalene muscle frontally, middle scalene muscle posteriorly, and the upper border of the first rib inferiorly account for most cases of neurologic and arterial TOS.

• Cervical ribs are found in most arterial cases but rarely in venous and neurologic cases.

• Congenital fibromuscular bands are noted in as many as 80% of patients with neurologic TOS.

• Transverse process of C7 is elongated.

• Trauma or repetitive activities

• Motor vehicle accident hyperextension injury, with subsequent fibrosis and scarring

• Effort vein thrombosis (ie, spontaneous thrombosis of the axillary veins following vigorous arm exertion)

• Playing a musical instrument: Musicians can be particularly susceptible owing to their need to maintain the shoulder in abduction or extension for long periods.

• Neurovascular entrapment: This occurs in the costoclavicular space between the first rib and the head of the clavicle.

Imaging Studies:

• Cervical radiography - May demonstrate a skeletal abnormality

• Chest radiograph

• Cervical or first rib

• Clavicle deformity

• Pulmonary disease

• Color flow duplex scanning for suspected vascular thoracic outlet syndrome (TOS)

Consultations:

• Neurologic, orthopedic, or vascular surgery consultation(s) may be indicated depending on the type of pathologic condition.

• Physical medicine and rehabilitation physicians are needed for outpatient workup.

Anticoagulants -- These agents prevent recurrent or ongoing thromboembolic occlusion of the vertebrobasilar circulation.

Tricyclic antidepressants (TCAs) -- If analgesic treatment is ineffective, a short, monitored course of TCAs can be helpful if the time course and symptoms suggest a protracted pain syndrome. The primary care physician or neurologist should be the one to prescribe such therapy.

Analgesics -- Pain control is essential to quality patient care. It ensures patient comfort, promotes pulmonary toilet, and enables physical therapy regimens. Many analgesics have sedating properties, which are beneficial for patients who have sustained injuries.

• Cortisone
  Injected into a joint or muscle, cortisone can help relief and lower inflammation
• Botox injections
  Short for Botulinum Toxin A, Botox binds nerve endings and prevents the release of neurotransmitters that activate muscles. A small amount of Botox injected into the tight or spastic muscles found in TOS sufferers often provides months of relief while the muscles is temporarily paralyzed.

Further Outpatient Care:

• For most patients, conservative treatment is recommended. Stress avoidance, work simplification, and job site modification are recommended to avoid sustained contraction and repetitive or overhead work that exacerbate symptoms.

• Address myofascial or chronic pain elements through exercise programs, good posture, and self-management.
• Posture- TOS is rapidly aggravated by poor posture. Active breathing exercises and ergonomic desk setup can both help maintain active posture. Often the muscles in the back become weak due to prolonged (years) hunching. Active breathing and postural exercises are part of a program developed and advanced by Dr. Peter Edgelow of Hayward, CA.

• Maximize the potential outlet space through a program of stretching and strengthening of the shoulder-elevating mechanism.

• Trapezius and rhomboid strengthening (eg, shoulder shrugs and bilateral shoulder retraction while standing or lying prone)

• Shoulder mobilization (eg, hand circles and standing corner pushups)

• Postural exercises (eg, cervical and lumbar spine extension)
• Stretching- The goal of self stretching is to relieve compression in the thoracic cavity, reduce blood vessel and nerve impingement, and realign the bones, muscles, ligaments, and tendons causing the problem.
• Moving shoulders forward (hunching) then back to neutral, followed by extending them back (arching) then back to neutral, followed by lifting shoulders then back to neutral.
• Tilting and extending neck opposite to the side of injury while keeping the injured arm down or wrapped around the back.
• Ice/Heat
  Ice can be used to decrease inflammation of sore or injured muscles. Heat can also aid in relieving sore muscles by improving circulation to them. While the whole arm generally feels painful, some relief can be seen when ice/heat is applied to the thoracic region (collar bone, armpit, or shoulder blades).

This syndrome causes a compression of a large cluster of nerves, resulting in the impairment of nerves throughout the arm. By performing nerve gliding exercises one can stretch and mobilize the nerve fibers.

• Extend your injured arm with fingers directly outwards to the side. Tilt your head to the otherside, and/or turn your head to the other side. A gentle pulling feeling is generally felt throughout the injured side. Initially, only do this and repeat. Once this exercise has been mastered and no extreme pain is felt, begin stretching your fingers back. Repeat with different variations, tilting your hand up, backwards, or downwards.

Complications:

• Neurologic - Chronic pain

• Arterial

• Thrombosis, Thromboembolism, Acute ischemia

• Venous - Thrombosis

Peripheral Neuropathies

Classification of Traumatic Peripheral Neuropathies

Seddon’s Clinical Classification of nerve injury is defined by mechanical trauma. Neurotmesis (“Cutting of Nerve”) refers to severance of all essential structures, including the axon; a visible disruption may not be apparent and the epineurium may be intact. Axonotmesis is a lesion to the axon severe enough to cause degeneration of the axon distal to the lesion, but with no interruption of continuity of the endoneurium. Neurapraxia (“nonacting nerve”) is injury to the nerve, causing some degree of paralysis but no peripheral degeneration.

Clinically Neuropraxia may result in decreased (or loss of) strength and absent tendon reflexes below the level of the lesion, slight sensory loss (confined to large diameter fibers) and no change in sympathetic function. There is no damage to the axon itself. Recovery is generally spontaneous and occurs within 3 months.

Axonotmesis result is variable loss of sensory, motor, and sympathetic function. Both myelinated and unmyelinated fibers may be involved. Muscle atrophy may occur and areflexia may be involved. These lesions generally occur as a result of closed-crush or percussion injuries. The axon is damaged, but the Schwann cell basal lamina remains intact along with the endoneurial connective tissue. Although Wallerian degeneration occurs distal to the lesion, regeneration is generally effective because Schwann cell integrity is maintained. Recovery is generally slow (several months to more than 1 year), with axonal regeneration occurring at a rate of 1 to 8 mm per day, depending on the specific nerve.

Neurotmesis commonly result from stab wounds, high-velocity projectiles, or nerve traction that disrupts the connective tissue components of the nerve along with complete transaction of the nerve trunk. Wallerian degeneration occurs distal to the lesion. Regeneration may occur, but because of damage to connective tissue and Schwann cells, sprouting may occur randomly. As a result, proper end-organ function may not be restored, and the formation of neuromas is not uncommon.

Pathogenesis of Peripheral Neuropathies

Primarily, after injury, the axon shrinks, fragments and becomes irregular in shape. Secondarily, if myelin is present, breaks down and associated cells undergo change. This myelin breakdown involves chemical alteration of myelin lipids and is accompanied by retraction of the myelin sheath from the axon at the nodes of Ranvier and breakdown of the sheath into ellipsoid or digestive chambers.

Fragments of axon and myelin debris are broken down by lysosomal vacuoles in Schwann cells and to some extent within macrophages that migrate in to the nerve during early stages of degeneration. Loss of protein within the first 24 hours is the basic chemical change of axonal and myelin degeneration. These changes reflect a cessation of normal axonal flow with disintegration of cell organelles.

At the time of and shortly after injury, there is a proliferation of Schwann cells, which then form columns of cells (bands of Bungner) that serve to guide the regenerating axons to their termination. The entire process of Wallerian degeneration prepares the nerve stump for regeneration and may also cause the elaboration of neurotrophic factors that promote this goal.

The Schwann cell continues to be active during the first 24 hours after injury and beyond. Reactive changes within the cell lead to proliferation through mitosis and formation of columns of cells (bands of Bungner) takes place along the endoneureal tube. Essentially the function of these columns is to guide the regenerating axonal sprouts to their target tissue. The Schwann cell may also provide trophic material (i.e., neural growth factor in umyelinated and autonomic fibers) through axoplasmic flow during the period of regeneration. The axonal sprouts grow from the proximal stump to the distal stump, the rate and progress dependent on the extent and/or type of injury.

Rates of regeneration vary from 1-8mm per day, depending on the specific nerve and location. As regeneration continues distally, axons may become myelinated and some eventually may reestablish peripheral connections.

Surgical Repair of Peripheral Nerve Injury

Surgical repair of peripheral nerve injuries is done by either nerve suturing (most effective) or use of a nerve graft. End-to end suturing of peripheral nerves is possible when the transected nerve ends can be closely approximated. If there is a considerable gap between the severed ends of the nerve, nerve suturing may not be effective and a graft may be considered.

There are many factors influencing the success of a nerve suture procedure. Success or failure depends on the age of the patient, location and/or level of the injury, extent or size of the defect, delay time from injury to repair, they type of nerve (motor or sensory), extent of paralysis, and surgical or technical factors.

Treatment Procedures

Patient Education

It is the most essential to maximize functional return and avoid secondary conditions resulting from sensory neglect.

Weakness/paralysis

- Treatment by neuromuscular electrical stimulation should begin as soon as possible after the injury because the rate of atrophy is greatest immediately following the injury. Denervated muscle has no motor point and so the current must pass through the bulk of the muscle to cause a contraction. As a result, interrupted galvanic currents is recommended. Stimulation should be strong enough to produce 15-20 strong contractions per session and the sessions should be repeated three to four times per day. This approach will help to retard muscular atrophy.

- Once there is regeneration and the muscles can be seen to contract, faradic currents to the motor point can be given in order to strengthen the muscle contraction. Patients are encouraged to continue contraction along with the muscle stimulation.

- Strengthening exercises to the partially denervated muscle generally can be given either by using a pattern of group of exercises (as in Proprioceptive Neuromuscular Facilitation) or by individual muscle contractions.

Sensory impairment

- Physiotherapy treatment of the sensory-impaired area should include extensive patient education about limb neglect. The patient should learn to regularly inspect the affected area in an attempt to reduce further trauma to the area. Monitoring the redevelopment and quality of returning sensations can be helpful in assessing the repair and regeneration of the injured nerve.

Vasomotor Disturbances

Though vasoconstrictor paralysis cannot be directly altered, the edema produced by the paralysis can be addressed.

- Reduction of edema can be accomplished by various techniques, including massage, compression and elevation. These techniques are means of assisting venous and lymphatic return from an extremity.

Soft Tissue Changes

Connective tissues and contractile tissue become progressively shorter when not stretched regularly.

- The most effective treatment program uses preventive measures such as ROM exercises. These exercises may initially be done by the therapist as passive or active-assisted exercises. However, as soon as possible the patient is taught how to do the appropriate exercises independently. Stretching should be given in a slow manner.

- Mobilization techniques can be utilized in order to increase any range that is restricted.

Orthotic Appliances

- Orthoses can be used to protect bony structures and articular structures as well as muscles, ligaments and nerves during periods of rehabilitation. The orthotic appliances assists in preventing deformities and limiting pathological motor patterns that can develop with muscular weakness and improper sensory input.

PARKINSON’S DISEASE

Parkinson’s disease is a chronic, progressive disease of the nervous system characterized by the cardinal features of Rigidity, Bradykinesia, Tremor and Postural instability.

James Parkinson first described Parkinson disease (PD) in 1817. PD is one of a number of chronic, progressive, neurodegenerative central nervous system (CNS) diseases that typically occur in adults older than 65 years.

The basic pathophysiology is a lack of dopamine-producing cells in the basal ganglia.

Epidemiology

Overall incidence of PD, based on several worldwide studies, is about 100-200 cases per 100,000 population.

The male-to-female ratio for PD is 3:2 or sometimes equally.

The prevalence of PD increases with age. In patients younger than 40 years, the prevalence is 5 cases per 100,000 population, increasing to 300-700 cases per 100,000 population in the seventh decade and rising to more than 700 cases per 100,000 population in persons older than 70 years.

Pathophysiology

PD is a disorder of the extrapyramidal system (ie, motor structures in the basal ganglia which include caudate,putamen, globus pallidus, subthalamic nucleus and the substantia nigra).

Basal ganglia plays an important role in the planning and programming of movement by selecting and inhibiting specific motor synergies. Motor programs are consolidated into efficient goal-directed motor plans, translating thought into willed movements and regulating levels of kinetic activity, muscle tone and muscle force.

PD may be caused by degeneration of dopamine-producing cells in the substantia nigra, resulting in decreased levels of dopamine in the striatum.

Symptoms of PD usually begin to appear when dopamine levels drop by at least 50%. Associated hyperactivity of cholinergic neurons in the caudate nuclei results in an imbalance in the normal dopamine-to-acetylcholine ratio, which contributes to the symptoms.

Causes

The exact cause of PD remains unclear. A combination of factors probably is responsible for the condition's development. Various theories include the following:

• Accelerated aging
• Normal aging is associated with clinical features that may resemble PD.
• Aging is associated with a decline of pigmented neurons in the substantia nigra and with decreased levels of striatal dopamine and dopa decarboxylase.
• Some authorities believe that PD may result from the effects of aging superimposed on an insult to the nigrostriatal system earlier in life.

• Oxidative stress
• PD patients may suffer the combined effects of multiple factors, culminating in damage from free radicals.
• Dopamine oxidation can result in the formation of hydrogen peroxide, as well as the superoxide anion radical.
• Hydrogen peroxide can undergo reactions with ferrous ions, resulting in formation of the highly toxic hydroxyl radical.
• These hydroxyl radicals can cause cell membrane damage.
• Genetic susceptibility
• Genetic factors seem to play a greater role in PD that has an earlier onset.
• An increased incidence of a family history of PD is observed in affected individuals (16% vs 4% of control population).
• Environmental toxins include the following:
• Cyanide
• Manganese
• Carbon disulfide
• Pesticides
• Well water
• Lead
• Methanol
• Organic solvents

• Medications that can cause parkinsonian symptoms but not PD itself include the following:
• Metoclopramide
• Domperidone
• Reserpine-containing antihypertensives
• Neuroleptics
• Increased BMI was shown in one study to be associated with an increased risk of PD development. This effect was found to be graded (the greater the BMI, the higher the risk) and independent of other risk factors.

Clinical Presentation

Symptoms and signs of PD typically begin in one extremity or side but eventually involve the other limbs and trunk.

• Muscle Rigidity - it is often the initial presentation that is seen. Patients frequently complain of heaviness and stiffness of their limbs. Two types of rigidity are identified: Cogwheel and Lead Pipe type of rigidity.

Rigidity is often asymmetrical. It typically affects proximal muscles first, especially the shoulders and neck, and it progresses to involve muscles of the face and extremities. Prolonged rigidity results in decreased range of motion (ROM) and serious secondary complications of contracture and postural deformity.

• Bradykinesia - General slowing of movements and difficulty in maintaining movements. Moments of freezing may occur and are characterized by a sudden break or block in movement. Movements are typically reduced in speed, range and amplitude.
• Resting Tremor – it is an involuntary oscillation of a body part occurring at a slow frequency of 4 to 6 Hz. It is typically seen at rest and disappears with voluntary movement. This is usually manifest as a pill-rolling tremor of the hand, although it can progress to forearm, jaw and head and trunk (postural tremor).
• Postural Instability - Assumption by patient of a stooped-forward posture is seen. Narrowing of the base of support increases postural instability. Frequent falls and fall injuries are the results of progressive loss of balance.
• Festinating gait pattern (stumbling forward) with decreased arm swing during ambulatory activity.
• Painful dystonia, usually occurring in the early morning
• Dementia, often a late feature, ultimately occurring in about one third of patients
• Autonomic symptoms
• Slowed enteric motility and constipation
• Urinary retention and incontinence
• Orthostatic hypotension
• Masklike face
• Micrographia
• Hypokinetic dysarthria
• Olfactory dysfunction (hyposmia), which may be present prior to motor symptoms and often is not recognized by the patient
• Dysphagia
• Depression
• Akathisia, a sense of an inner restlessness and need to move (inability to sit still).
• Seborrheic dermatitis, usually of the face and scalp

Clinical Course:

An estimate of the stage and severity of disease can be made using a staging scale.

The most widely used is the Hoehn-Yahr Classification of Disability Scale.

Stage	Character of Disability
I	Minimal or absent; unilateral if present
II	Minimal bilateral or midline involvement. Balance not impaired.
III	Impaired righting reflexes, unsteadiness when turning or rising from chair, some activities are restricted but patient can live independently and continue some forms of employment.
IV	All symptoms present and severe. Standing and walking possible only with assistance.
V	Confined to bed or Wheel chair.

Medical Management:

Pharmacological management –

a) Neuroprotective Therapy: Monoamine Oxidase Inhibitors (MAOs) to improve metabolism of intracerebral dopamine.

b) Symptomatic Therapy:

- Levodopa (L-dopa) is the mainstay drug. It is a metabolic precursor of dopamine that is able to cross the blood-brain barrier and raise the level of striatal dopamine in the basal ganglia.

- Dopamine Agonists – are administered along with L-dopa. They act on the postsynaptic dopamine receptors. The greatest benefit being reduction of rigidity and bradykinesia.

- Anticholinergic agents – (Trihexyphenidyl, Bentropin)

Surgical Management –

a) Abative surgery: Pallidotomy and thalamotomy.

b) Deep Brain Stimulation: involves implantation of electrodes into the brain where they block nerve signals that cause symptoms.

c) Neural Transplantation: transplantation of cells capable of surviving and delivering into striatum of patients with advanced PD is an experimental treatment.

PHYSICAL THERAPY MANAGEMENT:

Examination and Evaluation:

A comprehensive examination is required to determine the level of impairments and degree of function.

Elements of the examination for a patient with Parkinson’s disease-

Patient History –

- Age, sex, education

- Social History: behaviors, family and caregiver resources, social support systems.

- Occupational History

- Living environment : home/work barriers

- Hand dominance

- General health status

- Family history

- Medical/surgical history

- Chief complaints

- Functional status and activity level

Systems Review:

- Neuromuscular

- Musculoskeletal

- Cardiovascular/ Pulmonary

- Integumentary

Tests and Measures/Impairments:

- Cognition: mental status, memory

- Oromotor function: communication, swallowing

- Psychosocial function: motivation, anxiety, depression

- Anthropometric characteristics: BMI, girth, length, edema

- Aerobic capacity and endurance

- Sensory integrity

- Pain: intensity and location

- Joint integrity: ROM (Active and passive), muscle length and soft tissue extensibility

- Posture: alignment and position, symmetry

- Muscle performance: strength, power, endurance

- Motor function: tone, voluntary movements, slowness, arrest of movements

- Gait: pattern and speed

- Functional status: Hoehn- Yahr classification of disability, basic and instrumental ADL, FIM levels.

Aims of Treatment:

1) Patient counseling and Education

2) Early intervention

3) Reduce Tone/Rigidity

4) Improve Movement and activity

5) Improve muscle strength and exercise capacity

6) Reduce tremors

7) Improve Posture and Balance

8) Improve Gait pattern

9) Increase functional activities and independence

Physiotherapy Intervention:

ð Patient, Family, and Caregiver Education :

Education of patients, family members and caregivers is critical to attaining optimal outcomes. Education should be given about the clinical presentation, medications, and preventive measures to minimize secondary complications & impairments.

They should be taught about effective solutions to regular exercise participation and its benefits. Strategies for energy conservation and activity pacing are explained.

ð Early Intervention:

Early intervention is critical in preventing the devastating musculoskeletal impairments Parkinson’s patients are so prone to develop.

ð Motor Learning Strategies:

In the early stages of disease, practice can be expected to improve learning and performance while in the more advanced stages and in the presence of pronounced cognitive deficits, training will likely be less successful. The therapist needs to structure treatment sessions to optimize motor learning. Repetitions are included to develop skills. Long and complex movements should be avoided or broken down into parts.

External cues are effective in triggering sequential movements and improving movement characteristics in individuals with mild to moderate PD. These cues appear to facilitate movements by utilizing different brain areas. Visual and auditory cues are used more frequently.

ð Relaxation Exercises:

Gentle rocking exercises can be used to produce generalized relaxation of excessive muscle tension due to rigidity.

During therapy, slow, rhythmic, rotational movements of the extremities and trunk (lower trunk rotation, sidelying rolling) can be considered and should precede interventions such as ROM, stretching and functional training.

Diaphragmatic breathing exercises can be given to promote relaxation. Gentle yoga and Tai Chi can be effective for patients with PD because of emphasis on combining slow, steady stretching with maintenance of postures and movement forms.

ð Flexibility Exercises:

Both active and passive ROM exercises are used to improve flexibility.

Exercises should focus on strengthening the weak muscles while lengthening the tight muscles.

Traditional stretching techniques can be used to elongate muscles. Special consideration should be given to the gentle stretching of elbow flexors, hip and knee flexors and ankle plantar flexors. Stretching can be combined with joint mobilization techniques to reduce tightness of the joint capsule or of ligaments around a joint.

Passive positioning can also be used to stretch tight muscle and soft tissues. Patients in late-stage PD are likely to demonstrate severe flexion contractures of the trunk and limbs (Phantom-Pillow posture). So patients may benefit from prone lying. Mechanical low load stretching can also be used with passive positioning to stretch the tight muscles.

Because these patients have a minimum of energy to expend, they may benefit from ROM exercises in physiological patterns of motion. PNF patterns can be used as they combine several motions at once while emphasizing rotation.

ð Strength Training:

Strengthening exercises are indicated for patients with primary muscle weakness and insufficient central activation of the motor unit as well as for disuse weakness associated with prolonged inactivity. Strength training has been shown to improve motor function, functional mobility, balance, gait and in reducing fall risks.

ð Functional Training:

The overall emphasis is on improving mobility function with specific emphasis on improving mobility of axial structures, the head, trunk, hips, and shoulders.

Patients may benefit from assisted movements progressing to active movements to improve initial motor performance.

Mat activities emphasizing on rolling and transitions from one position to another (like sitting to standing, prone kneeling to sitting) helps in reducing truncal rigidity and bradykinesia.

Anterior and posterior pelvic tilts, side-to-side tilts, pelvic clock exercises can be practiced while sitting on a therapy ball. These activities help in improving pelvic mobility thus facilitating good posture while sitting and standing.

Weight shifts and rotational movements in standing should be practiced. Standing with upper extremities extended and hands weightbearing on a wall can be used to promote upper trunk extension.

Mobilizing facial muscles is important because the patient will have social interaction. The patient can be instructed to practice lip pursuing, movements of the tongue, swallowing, and facial movements such as smiling, frowning etc.,

ð Balance Training:

Balance training should emphasize practice of dynamic stability tasks e.g., weight shifts, reaching, axial rotation of head and trunk, axial rotation combined with reaching, etc.,

Seated activities include sitting on a therapy ball. Challenges to balance can be introduced by varying arm position (i.e., arms out to side, arms folded across chest), varying foot/leg position (i.e., feet apart, feet together) or adding voluntary movements (e.g., arm clapping, arms overhead, single leg raises, head and trunk rotations).

Training should focus on achieving faster initiation and execution movement times supported by the use of appropriate cueing strategies.

Strategies for varying environmental demands include altering the support surface (e.g., standing on foam), visual inputs (e.g., reduced lighting, eyes closed), or challenging the patient with a variable open environment (e.g., busy clinic setting).

Kitchen sink exercises – standing and performing heel rises and toe offs, partial wall squats or back-kicks, and marching in place.

ð Gait Training:

Gait training focuses on primary gait impairments which typically include slow speed, shuffling gait pattern, diminished arm swing and trunk movements, and an overall attitude of flexion while walking.

Training programs are designed to

- lengthen stride,

- broaden base of support,

- improve stepping,

- improve heel-toe gait pattern,

- increase contralateral trunk movement,

- increase arm swing, and

- increase speed.

Training should also be given in varying environmental demands by altering the support surface, impairing visual inputs etc.

ð Cardiopulmonary training:

Respiratory dysfunction is common due to postural changes, inactivity and rigidity of muscles.

Training program should include diaphragmatic breathing exercises and exercises that recruit neck, shoulder and trunk muscles. Deep breathing exercises helps in improving chest mobility and vital capacity.

ð Group and Home exercises:

Group exercise classes can be valuable for patients with PD. Patients benefit from the positive support, camaraderie, and communication the group situation offers. Selecting the patients with similar levels of disability is often advisable.

The patients can begin in the seated position and progress to standing. Stretching exercises can be given as a warm up exercises.

Use of a wand or cane can be effective in promoting overhead activities.