Brain-Behavior Relationships

Overview of Topics

Symptoms produced by Lesions
Tests to Measure the Deficits
References

Supramarginal Gyrus

1. Ideomotor apraxia: disruption of organization of complex acts
   • Results from left hemisphere lesion
   • Usually affects both sides, may be worse on right side (2)
   • Can affect the face (buccofacial) and/or the limbs (1)
2. Conduction aphasia: results from left hemisphere lesion if the underlying arcuate fasciculus is cut (2)
   • Severely defective repetition
   • Paraphasia in repetition and in spontaneous speech
   • Normal comprehension
   • Impaired writing, spontaneous and to dictation, errors in spelling, word choice, syntax (3)
3. Astereognosis: impairment of somatosensory discrimination (4)
   • Left hemisphere lesion: both hands affected(2)
   • Right hemisphere lesion: deficit - left hand (2)
4. Finger agnosia: inability to recognize, name, and point to individual fingers on self and others (left hemisphere lesion) (5).
5. Right-left disorientation (1)
   • Can't distinguish right from left on self or env.
   • More common with left hemisphere lesion (1)
6. Acalculia (6)
   • Loss of ability to understand & order numbers
   • More severe with left hemisphere lesion
7. Tactile perceptual disability: results from contralateral lesion (6)
8. Gerstmann's syndrome: Researchers disagree as to the lesion site for this syndrome, but the supramarginal and/or angular gyrus is usually involved. This left hemisphere, inferior parietal disorder includes: (7, 8, 9)
   • Right-left disorientation
   • Finger agnosia
   • Agraphia
   • Acalculia
9. Lesion of right hemisphere supramarginal gyrus can cause:
   • Constructional apraxia (4)
   • Mild left side neglect and/or denial (10)
   • Inability to interpret maps (9)

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B. Tests to measure the Above Deficits

1. Ideomotor apraxia
   • Carrying out motor acts to command: buccofacial (1) (blow out a match, protrude tongue, drink through a straw)
   • Carrying out motor acts to command: limb (1, 3) (salute, use a toothbrush, flip a coin, hammer a nail, comb hair, snap fingers, kick a ball, crush out a cigarette)
2. Conduction aphasia
   • Repetition of words, phrases, & sentences (3)
   • Write to dictation (letters, words, sentences) (11)
   • Ask patient to write sentences describing a Job, the weather, or a picture (1)
   • Confrontation naming of objects, clothing, body parts, parts of objects (1)
3. Astereognosis (with eyes closed)
   • Patient identifies by touch such common objects as a coin, paperclip, pencil, or key (each hand tested separately) (6)
   • Patient judges the relative size of a series of coins (6)
   • Patient judges the texture of a series of objects, such as cloth, wire, sandpaper (6)
4. Finger agnosia
   • In-between test, Two-Point Finger Test, and Match Box Test (12)
   • Identifying named fingers on examiner's hands and naming fingers on self (1)
5. Right-left disorientation
   • Identification of right and left limbs on self and examiner (6)
   • Crossed commands on self and examiner (1)
6. Acalculia
   • Written addition, subtraction, multiplication, and division problems (6)
   • Verbal complex problems (4)
7. Fingertip number writing (6)
8. Gerstmann's syndrome
   • Right-left disorientation (1, 6)
   • Finger agnosia (1, 12)
   • Agraphia: writing to dictation (1) and writing sentences describing scenes in pictures (11)
   • Acalculia (1, 6)
9. Lesions of right hemisphere supramarginal gyrus
   • Constructional apraxia
     • copying designs (3 4)
     • match stick tests (l3)
     • block construction test (14)
   • Left-side neglect
     • glove test: ask the patient to put on a pair of gloves (4)
     • drawing to command: clock, bicycle, flower in pot (3)
     • behavioral observations
   • Have patient locate cities on a map (6)

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References

1. Strub, R.L., & Black, F.W. The mental status exam in neurology. Philadelphia: F. A. Davis, 1977.
2. Geschwind, N. Disconnexion syndromes in animals and man. Brain, 1965, 88, 585-644.
3. Brown, J.W. Aphasia, apraxia, and agnosia. Clinical and theoretical aspects. Springfield, Illinois: Charles C. Thomas, 1972.
4. Critchley,N. The parietal lobes. New York: Hafner, 1966.
5. Kinsbourne, M., Warrington,E.K., A study of finger agnosia. Brain, 1962, 85, 47-66.
6. Lezak, M.D. Neuropsychological assessment. New York: Oxford University Press, 1976.
7. Critchley, N. The enigma of Gerstmann's syndrome. Brain, 1966, 89, 183-198.
8. Fogel, M.L. The Gerstmann syndrome and the parietal symptom complex. Psychological Record, l962, 12, 85-99.
9. Curtis, B.A., Jacobson, S., & Marcus, E.N., An introduction to the neurosciences. Phil: W. B. Saunders, 1962.
10. Peele, T.L. The neuroanatomical basis for clinical neurology. Mew York: McGraw-Hill, 1961.
11. Lhermitte, F., & Gautier, J.D. Aphasia, In P.J. Vinken & G.W. Gruyn (Eds.), Handbook of clinical neurology, Vol. 3. New York: J. Wiley, 1969.
12. Kinsbourne, M., & Harrington, E.K. A study of finger agnosia. Brain, 1962, 85, 47-66.
13. Benson, D.J., & Barton, M. I. Disturbances in constructional ability. Cortex. 1970, 6, 19-46.
14. Benton, A.L., & Fogel, N.L. Three-dimensional constructional apraxia. Archives of Neurology, 1962, 7, 347-354.