36 3 The Neurological Examination

the Rydel−Seiffer model, which allows grading in eighths. This is mostly unnecessary, as there is an easier method: as soon as the patient reports that the vibration is no longer felt, the examiner tests his or her own vibration sense with the same tuning fork at an analogous position. If the examiner still clearly feels the vibration, then the patient unquestionably has a deficit of vibration sense (the rarely used scholarly terms are pallhypesthesia for a partial deficit, pallanesthesia for a total deficit). Milder deficits can usually be detected only in the periphery (e. g., at the ankles), while more severe ones are evident further up the trunk. Vibration sense usually declines by oneor two-eighths over the course of normal aging.

The examiner tests position sense by passively moving some part of the patient’s body (in the hands, usually the middle finger) and asking the patient in which direction it is being moved. The patient should not, of course, be able to observe the movement visually.

Temperature sense (thermesthesia) should be tested particularly when a central lesion is suspected, because the pain and temperature pathways run separately from those of the other sensory modalities in the spinal cord

and brainstem, and do not join them until the level of the thalamus (p. 74).

A lesion that affects the spinothalamic tract in the spinal cord or brainstem, but spares the other sensory pathways, produces a dissociated sensory deficit: pain and temperature sensation are impaired in the corresponding part of the body, but the sense of touch is preserved. A partial deficit of temperature sense is called thermhypesthesia, a total one thermanesthesia.

To test the sense of temperature, the examiner fills two test tubes or special-purpose metal containers with cold and warm water and applies them to different parts of the patient’s body. Thermal stimuli can be delivered in graded fashion, if desired, by varying their temperature, area, and duration.

The ability to feel pain (algesia) should be tested by pinching a fold of skin, never by pinprick. A partial deficit is called hypalgesia, a total one analgesia.

Allesthesia or allocheiria is the perception of a tactile stimulus somewhere other than the site at which it was delivered. This phenomenon can occur in normal individuals and is of uncertain significance. (Alloesthesia and allochiria are variant spellings.)

Examination of the Trunk

The back and spine are examined with the patient standing. Inspection may reveal scoliosis or an alteration of the normal lordosis or kyphosis of particular segments of the vertebral column. Protruding ribs on one side (often visible only when the patient bends forward) are a sign of torsional scoliosis. As one looks at the patient from behind, there is a triangular gap to either side of the patient’s waist, formed by the dependent arm, the rib cage, and the upper border of the pelvis; asymmetry of this gap is a further sign of scoliosis. A plumb line from the spinous process of C7 should overlie the natal cleft; deviations should be measured and documented (preferably in centimeters, rather than finger breadths). One should also look for stepping of the lumbosacral vertebrae (e. g., in spondylolisthesis, p. 260) or tenderness of the spinous processes to pressure or percussion. Techniques for testing the mobility of the cervical spine were described above in Examination of the Head and Cranial Nerves (p. 16). The mobility of the thoracolumbar spine is tested by having the patient bend the trunk forward, backward, and to either side, and then rotate it to either side. On forward bending with extended knees, young patients should be able to touch the ground (finger-to- ground distance 0 cm). Spinal mobility can be quantified with the two Schober tests: the small Schober index pertains to the lumbosacral spine, the large Schober index to the thoracic spine. To measure the small Schober index, place a mark on the patient’s skin 10 cm above the spinous process of L5, have the patient bend forward as far as possible, and measure the distance again; it should now be at least 15 cm. The large Schober index is measured similarly, starting from a point 30 cm below

the spinous process of C7, which on maximal forward bending should move to at least 32 cm below it. Any diminution of the normal cervical lordosis is best seen when the patient stands with shoulders and heels to the wall and bends the head as far back as possible. The back of the patient’s head normally touches the wall; if not, the distance from the occipital protuberance to the wall should be measured in centimeters. An abnormality of this type is found, e. g., in ankylosing spondylitis.

Reflexes. The abdominal skin reflexes are extrinsic muscle reflexes. They are tested by rapid stroking of the abdominal skin (e. g., with a wooden stick) from lateral to medial, at three different segmental levels, on either side. They can be enhanced, if necessary, by having the patient lift his or her head off the headrest. Diminution of the abdominal skin reflexes indicates a lesion of the pyramidal pathway. A diminished or absent reflex at only one level on one side suggests a segmental peripheral lesion. Total bilateral absence is usually an artifact of deficient examining technique, but may also be caused by an obese or flaccid abdominal wall (e. g., after pregnancy). “True” bilateral absence of all abdominal skin reflexes is seen in bilateral lesions of the pyramidal pathway; an accompanying sign in such patients is unusual briskness of the intrinsic reflexes of the abdominal musculature. These are tested by tapping at the sites of muscle attachment, e. g., at the costal margin or the symphysis pubis. Alternatively, the examiner can place his or her own hand on the abdomen and tap on it. The cremaster reflex is tested (in males) by stroking the medial surface of the thigh or by forceful pressure with a finger near the origin

Mumenthaler / Mattle, Fundamentals of Neurology © 2006 Thieme All rights reserved. Usage subject to terms and conditions of license.