Glossary of Medical Tests and Signs

GLOSSARY OF MEDICAL TESTS AND SIGNS

Abdominal Reflex: The quadrants of the abdomen are stroked towards the midline above, parallel to and below the umbilicus. In corticospinal tract lesions, the reflex contraction of the abdominal muscles is lost on the side ipsilateral (same side) as the lesion.

Achilles Reflex: (SEE Ankle Jerk Reflex)

Allochiria Tests: Errors in identifying left from right assist in locating lesions near the angular gyrus.

Ankle Jerk Reflex: The Achilles tendon is struck by the examiner to test the reflex reactions related to L5-S1.

Anosognosia Tests: In cases of non-dominant side, frontal and parietal lobe lesions, the patient denies his paralysis of an affected side or limb.

Auditory Reflex: Momentary closure of both eyes upon a sudden sound.

Autopagnosia Tests: The patient is asked to hold up, point to and identify body parts such as fingers, arms, etc. Lesions of the parietal lobe causing autopagnosia, may prompt the patient to fail in the identification of his body parts or even identify the examiners hand as his own.

Babinski Toe Sign: (SEE Plantar Reflex)

Baresthesia Tests: In testing for parietal lobe lesions, the patient holds, with eyes closed, two weights that are unequal by one to two grams. Normals can generally discriminate between the weights. Sensation of weight may be lost in the contralateral limb. (SEE also Stereognosis)

Beevor's Sign: (SEE also the Hoover Test and Thigh Adduction Test). In functional paralysis, inability to inhibit the antagonist muscles.

Biceps Reflex: The tendon of the biceps is tapped. Normally there is a contraction of the bicep muscles accompanied by a jerk of the forearm. In corticospinal tract lesions, the reflex is excessive. In lesions of the peripheral reflex arc or damage to the C5-C6 segments of the cord on the side being tested, there is a depressed or absent response.

Brachioradialis Reflex: This wrist reflex test is conducted to determine lesions at C5-C6 segments of the cord on the side being tested, there is a depressed or absent response.

Brudzinski's Sign: When the neck is flexed, flexion of the knees also occurs (present in meningeal irritation). (SEE also Kernig's Sign)

Brain Mapping: (SEE EEG)

Chewing Reflex: When a tongue depressor is placed in the mouth, the patient chews or clenches his teeth on the depressor. Reflex chewing is seen in diffuse bilateral lesions of the frontotemporal cortex and is frequently seen in cases of dementia, incomplete paralysis (generalized paresis) and brain injury related to a lack of oxygen.

Coombs' Test: For the detection of red cell antibodies.

Cortical Sensation Tests: (SEE Graphism)

Cremasteric Reflex (Males): A pin is used to stroke the inside of the thighs. In normal individuals, the testis will rise on the same side. The reflex is lost with males with damage to the corticospinal tract at or above L1-L2.

Deep Reflex: A sharp tap on a tendon or muscle produces a brief stretch of the muscle.

EEG and QEEG: (Quantitative Electroencephalograph)

Electroencephalography is a method of graphically recording the electrical activity of the brain, particularly the cerebral cortex.

EEG brain mapping is a term commonly used for several quantitative (computerized) EEG techniques. These include (a) EEG frequency analysis, (b) topographic display, (c) statistical comparisons to a normative database and (d) other similar computer-based calculations based on EEG or evoked potentials. EEG brain mapping can help highlight or identify regional features of the EEG. Occasionally this will identify subtle features that escaped identification by traditional visual inspection of the polygraph EEG alone. EEG brain mapping can also help in communication of EEG features and their localization, especially for communication to persons who are not expert in EEG. Quantification of EEG features can help in the assessment of whether some features are present to an abnormal degree. Computer based EEG processing can also calculate abstract features that cannot be visualized.

However, despite these potential advantages, the clinical application of the EEG brain mapping is still very limited. Most scientific reports on these techniques have demonstrated research applications rather than clinical usefulness. Among those clinical reports, few have been prospectively verified or reproduced. Techniques used in EEG brain mapping vary substantially among laboratories, and any clinical usefulness found with one specific technique may not apply when using a different technique. A substantial number of technical and clinical problems interfere with many simple applications. These problems can easily mislead interpretation, sometimes in subtle ways. Traditional EEG artifacts can appear in unusual and surprising ways, and new artifacts can be caused by data processing and computer processing algorithms. For example, epileptic spikes are generally overlooked or considered artifactual. Also, transient slowing can be missed or washed out. The computer may consider as "abnormal" some of the unusual EEG activity known to have clinical importance such as psychomotor variant, alpha harmonics and other normal variations. Automated assessment of normality would have to take into account the subjects age, state of alertness, medication and other facts; but ways to do this are still not defined, especially when the patient is on a central nervous system active medication. Substantial unresolved statistical issues are critical in automated assessment of normality.

Little has been published on how these various tests could impact the diagnosis or treatment of individual patients. Cerebrovascular disease is one area in which these tests may fill occasional specific needs. Several quantified EEG parameters are highly correlated with regional cerebral bloodflow. Sensitivity is high for detection of ischemia-related cerebral impairment and false positive rates are low. These tests can be quite abnormal even when the CT scan is still normal, such as in the first 2-3 days after a CVA (cerebrovascular accident) or when the degree of ischemia is mild enough to cause dysfunction without infarction. However, localization ability is very inferior to that found with CT or MRI. EEG changes are unable to differentiate infarction from hemorrhage, tumor or