Sensory System Examination
Detailed examination of sensory system is a time consuming and difficult assessment and is rarely tested in the exam. In case, you need to perform the sensory exam (e.g. child with sensory symptoms, spinal cord lesion or peripheral nerve disorder) unexpectedly, the following section will help you to cover the basics. The sensory exam includes testing for spinothalamic tract (pain, light touch and temperature), posterior column (position sense or proprioception and vibration) and cortical senses (stereognosia, graphesthesia, and extinction). Nerve fibres carrying the pain and temperature impulses enter the spinal cord and crossover to the opposite spinothalamic ...view middle of the document...
Lumbar and sacral segments are found between vertebral levels T10 – T11 and T12 - L2 respectively.
o For the rough dermatome guide, refer table
o Always assess the cortical senses after establishing the intactness of the main senses and, only, when a parietal lesion is suspected.
o Always explain the procedure to the child before performing them to decrease the anxiety and avoid repetition of testing.
o While testing, ask the child to avert their gaze or close their eyes.
• Spinothalamic tract senses
o Pain: is almost never tested in the exam unless it is absolutely necessary. Two types of pain sensation are tested during routine examination.
Superficial pain: With a new, disposable neurological pin that does not penetrate the skin, touch a normal area and demonstrate the relatively sharp sensation with eyes open and ask them 'Does this feel sharp or blunt?'. Following this ask the child to close the eyes and assess the pinprick sensation. Do not use a hypodermic needle. Explain and demonstrate that the ability to feel a sharp pinprick is being tested. Show the patient each object and allow them to touch the needle and brush prior to beginning to alleviate any fear of being hurt during the examination.
Deep pain: This is tested by squeezing the calf muscles or muscles or by applying pressure to the nail bed. Ask the child to report when they feel discomfort.
o Light touch: Following the principles of sensory examination discussed above, gently touch the skin with a cotton wisp in various places at irregular interval. Ask the child to close the eyes and respond with a "yes" each and every time they feel the sensation. Do not stroke the skin with the cotton wool.
o Temperature: Ask the child to close the eyes, touch the skin with cold tuning fork (which can be cooled by running it under cold water) and ask ‘Does it feels cold?’
• Posterior column
o Vibration: In contrast to spinothalamic senses, posterior column senses are tested from distal to proximal direction, as distal areas are the first ones to lose the sensation. Strike a 128 Hz tuning fork on your hand and place the handle of the vibrating tuning fork on the child’s sternum to demonstrate the vibration 'Can you feel the vibration (buzzing)? Tell me when it stops'. Test the vibration sense over the great toe, medial malleolus of the ankle, patella, knees and the anterior superior iliac spines in the lower limb and distal phalanx, styloid process of the radius, olecranon process...