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FINAL PREPARATIONS FOR RECOMPRESSION THERAPY

Physical Examination

Sensory Systems

Dorsal columns and medial lemnisci

Reflecting the functional integrity of the dorsal columns of the spinal cord and the medial lemnisci of the brainstem (and its communications with the thalamus and hence the cortex) are the senses of discriminative/light touch, vibration, and position. Importantly, damage to the dorsal columns produces sensory deficits on the same side of the body; damage to the medial lemniscus or more rostral structures produces sensory deficits on the opposite side of the body. To assess discriminative/light touch, one may place the tips of two pins separated by varying distances (i.e., a few to several millimeters) on any of several regions of the body (e.g., feet and hands). The objective is to determine the minimum separation of the tips that permits the correct experience of two pins. Dysfunction is revealed when the patient mistakenly perceives only one pin, even when the pins are greatly separated. The failure of an individual to detect light contact between his/her skin and a wisp of cotton may also signal dysfunction of the dorsal columns or the medial lemniscus. To assess vibrational sense, the patient is required to determine whether a tuning fork placed against the skin over a bony eminence is vibrating. Position sense is intact when the patient accurately identifies (with the eyes closed) the relative position of his/her appendages when moved by the examiner (e.g., "my toe is pointing up; my finger is pointing down").