Table 2.

Standard Scores on Intellectual and Vocabulary Assessments.^*

Assessment	Patient 1	Patient 2
Differential Ability Scales
Verbal†	65	93
Nonverbal reasoning	65	70
Spatial ability	70	68
General conceptual ability	62	73
Special nonverbal composite	65	67
Vocabulary
PPVT-III	82	106
EVT‡	40	104

^*The Differential Ability Scales provide specific information about a child’s strengths and weaknesses across a wide range of intellectual activities. The six core subtests for school-aged children are divided into three clusters: verbal and nonverbal reasoning and spatial ability. The general conceptual ability (similar to IQ) score is based on the performance on the six core subtests. The special nonverbal composite is based on the four core subtests included in the nonverbal reasoning and spatial clusters. The third edition of the Peabody Picture Vocabulary Test (PPVT-III) measures receptive vocabulary. The Expressive Vocabulary Test (EVT) measures the ability to label pictures and to produce synonyms for words presented by the examiner in the context of a picture illustrating the word. For each of these assessments, the population average score is 100.

^†Patient 1 responded with a combination of words, manual signs, gestures, and pantomime; all these modes were acceptable for the Differential Ability Scale verbal cluster, provided his meaning was clear.

^‡For Patient 1, responses composed of words or word approximations and manual signs (but not gesture or pantomime) were acceptable for the EVT.