Multiple tests are used to check muscle weakness and reflexes, nerve sensation and sensory changes. If the physical therapist suspects GBS, samples of the patient’s spinal fluid will be examined. 
In a study performed by Forsberg, 2006, instruments and tests were used to assess some of the motor impairments common in the GBS patient’s.
To evaluate muscle strength it was used the Medical Research Council 0-5 grading scale, and the movements that were tested, in the upper body, were neck flexion and extension, shoulder abduction, elbow flexion and extension, wrist flexion and extension, and thumb abduction. In the lower body, the hip flexion, extension and abduction, the knee flexion and extension, the foot flexion and extension, and toe extension. To evaluate the respiratory muscles, peak expiratory flow (PEF) was used in the sitting position with a handheld spirometer. 
Paresis of the cranial nerves is common in the acute stages of GBS. The facialis nerve (7th cranial nerve) is most often affected. To test the integrity of this nerve, the patients were asked to wrinkle the forehead, shut the eyes, pucker the lips, smile and yawn. 
Grip strength was measured with a Vigorimeter, using the medium-sized ballon. It consists of a rubber bulb connected by a tube to a manometer. 
To assess the gait, the patients were asked to walk 10 meters as fast as possible, and the time taken was recorded with a stopwatch. If the environment did not allow walking 10 meters, the patients’ were requested to walk 5 meters, turn, and walk 5 meters back. Walking aids were allowed. Gait speeds below 1.5 m/s for men and 1.4m/s for women were regarded as subnormal .
Manual dexterity was measured using a modified Nine Hole Peg Test. The patient was seated at a table and the time was recorded from the moment when the patient touched the first peg until all holes had been filled with pegs, one-handed. 
Balance was assessed using the Berg Balance Scale, which focuses on the ability of a person to maintain balance when asked to perform a series of movements, such as sitting to standing unsupported, change of position from sit to stand and vice-versa, transfers from one chair to another, standing with eyes closed, standing with feet together, tandem standing, standing on one leg, turning trunk, retrieving object from the floor, turning 360 degrees, stool stepping and reaching forward while standing .
Motor performance was tested using the Lindmark Motor Capacity Assessment (LMCA): active performance with the arms and legs, mobility, rapid movements and passive movements. 
To get a description of the amount of fatigue, it was used a self-rated evaluation, between “no fatigue” and “worst imaginable fatigue”. 
GBS can affect several sensory systems, and a variety of tests were therefore chosen. Paraesthesia such as numbness, tingling or hyperaesthesia in the extremities or face, was graded by the patients themselves as either present or absent. Pinprick and light touch were assessed in the hands and feet, with eyes closed, and were graded as wither affected or not affected. Vibration sense was measured with a biothesiometer, bilaterally at the ulnar styloid process of the wrist and the medial malleolus of the ankle.
At each evaluation, complicating events or conditions were assessed, such as falls, pressure sores, deep-vein thromboses or disturbances of urinary, bowel or autonomic function. 
Treatment includes, in an earlier phase, supportive care, like a ventilator support for people with breathing problems and difficulties, due to respiratory muscle weakness, and initial mobilization, performed by the physical therapist, to prevent secondary problems like joint stiffness and muscle contractures. According to several studies, acute phase rehabilitation could also include transcutaneous electrical nerve stimulation for pain management. 
After this phase, the patient will still then start an intense physical therapy program, to achieve the maximum independence possible. It could be included an electromyographic feedback for improving muscle function, treadmill training with partial body weight support for task-specific training of gait, podiatron for muscle strengthening and neurodevelopmental sequencing for promoting gross motor skills. In later stages, exercise programs may be helpful in combating fatigue, increasing muscle strength and improving cardio-pulmonary function. 
Some respiratory complications from GBS encountered are: COPD, restrictive respiratory disease from pulmonary scarring and pneumonia, trachitis from chronic intubation and respiratory muscle insufficiency. Restrictive pulmonary function is associated with sleep hypercapnia and hypoxia during REM sleep. Night time saturation records with pulse oximeter and BiPAP may be indicated for patients with hypoxia and hypercapnia. Physical therapy helps clearing respiratory secretions to reduce the effort while breathing and to prevent over fatigue of the respiratory muscles. Patients with cranial nerve involvement are more prone to aspiration and respiratory complications. 
Deep venous thrombosis
It has been reported in up to a third of patient with GBS. Patients are encouraged to be active and wear compression stockings. Progressive mobilizations to improve bed mobility, practicing sitting up from bed, and safer transfers, with or without equipment, is a priority. 
Prolonged immobilization leads to reduction of blood volume and postural hypotension. Physical therapy provides an important role with maintenance of the patient’s posture and alignment; maintain the joints range of motion (passive, active assisted, and active), improving endurance through repetitive exercises with low resistence, strengthening of different muscle groups, improving flexibility, advance from bed mobility to use of the wheelchair, to walking with aids. Other problems due to prolonged immobilization include compression nerve palsies (ulnar, peroneal and cutaneous femoral nerve); pressure sores, due to the loss of muscle mass combined with sensory loss; and heterotopic ossification (pericarticular bone formation the muscle plans). 
Fatigue and pain
De-afferent pain syndromes and muscle pain can be presenting symptoms in GBS. Symptoms of depression and mental fatigue are also common. 
 New Jersey Department of Health and Senior Services (2006). Guillain-Barre Syndrome
 Forsberg, A. (2006). Guillain-Barré Syndrome: disability, quality of life, illness experiences and use of healthcare. Karolinska Institutet, Stockholm, Sweden.
 Khan, F. (2004). Rehabilitation in Guillian Barre Syndrome. Australian Family Physician; 12(33): 1013-1017