Trigeminal and auditory evoked responses in minor head injuries and post-concussion syndrome.

Forty patients who sustained minor head trauma were investigated by brainstem trigeminal and auditory evoked potentials (BTEP, BAEP) and middle-latency auditory evoked potentials (MLAEP). The patients were evaluated within the first 48 h following their admission and at 3 months after the injury. Outcome was scored at the follow-up examination according to six complaints: failure to resume previous professional activity, headache, memory disorders, dizziness and vertigo, behavioural and emotional disturbances, and other symptoms of a neurological nature. Post-concussion syndrome (PCS) was defined by the presence of four or more of the listed features. All three evoked potential modalities showed significantly increased latencies at the initial assessment, disclosing disseminated axonal damage. Unlike the BTEPs and the BAEPs, the MLAEPs proved to correlate to outcome at 3 months, especially in its psychocognitive aspects. These findings suggest that organic diencephalic-paraventricular primary damage may account for the occurrence of PCS.