| History: Individuals complain of sensations of tingling, "pins and needles," prickling, electric, burning, vibrating, buzzing, crawling, or of "a limb falling asleep." Individuals may report the presence of other symptoms such as pain, numbness, weakness, stiffness, or clumsiness. Important information obtained from the history includes location of the paresthesia, how long paresthesia has been present, and if the paresthesia worsens in any one position or when engaged in a specific activity. Physical exam: The exam may reveal decreased sensation over the involved area. Tinel's sign is elicited by tapping an entrapped nerve that increases distal paresthesias, and is simply a sign of irritability of a nerve at the location stimulated by the tap. Tinel's sign may be present with carpal tunnel and cubital tunnel syndromes. Phalen's sign is elicited by flexion of the wrist that increases median nerve paresthesia. Phalen's sign may be present with carpal tunnel syndrome. Physical examination may also reveal presence of nerve root pain (radiculopathy) that is due to narrowing of the spinal canal or nerve root opening (foramen), with decreased strength, sensation, and reflexes relating to the affected nerve root. Individuals with diabetic neuropathy may reveal bilateral loss of sensation to pain, touch, temperature, vibration, and proprioception. Many paresthesia manifestations occur with multiple sclerosis. Physical examination of individuals with Guillain-Barré syndrome may reveal increasing paralysis and hyporeflexia. Tests: Electromyography (EMG) and nerve conduction tests can rule out nerve dysfunction. Specific laboratory blood testing is indicated. A vitamin B12 blood level below 200 pg/ml indicates vitamin B12 deficiency. The blood calcium level may also be abnormal. Abnormally elevated liver function tests and an elevated mean corpuscular volume may reveal alcohol abuse. Blood screening for heavy metals may also be appropriate.
In restless legs syndrome, polysomnography can demonstrate periodic movements during sleep. An MRI may be used for diagnosis of multiple sclerosis. A spinal tap is used to obtain cerebrospinal fluid samples for diagnosis of Guillain-Barré and multiple sclerosis. |
Source: Medical Disability Advisor