A patient with traumatic brain injury (TBI) is often associated with incidence of cognitive dysfunction as a sequela. We have conducted WAIS-R to 237 patients who were diagnosed as TBI at the Kanagawa Rehabilitation Hospital in order to assess their intellectual function. Twelve patients, whose VIQ being marked significantly lower than PIQ, were retrospectively analyzed in terms of their Functional Independence Measure (FIM), neuropsychological test results and lesions found in diagnostic images. In consequence, presence of a patient group whose VIQ level is significantly lowered due to the TBI sequela is recognized, in addition to a finding that trauma sites of cerebral contusion or other incidents are not necessarily corresponding to the results of neuropsychological test. Furthermore, based on an observation that those patients with lowered VIQ level are also associated with aggravation of PIQ 'digit symbol', Trail Making Test, or word fluency levels. This result was before similar with the result of "32 cases of DAI (diffuse axonal injury)" which authors reported, and it was guessed anew that the main factor of a cognitive dysfunction was damage on axon.