Magnetic resonance imaging and neuropsychological testing after middle fossa vestibular schwannoma surgery.

OBJECTIVE

To analyze temporal lobe gliosis and temporal lobe dysfunction after middle fossa vestibular schwannoma surgery.

STUDY

DESIGN

Temporal lobe analysis of a series of cases.

SETTING

Tertiary referral center.

PATIENTS: Thirty-two patients after enlarged middle fossa surgery (EMFS) and 20 subjects for control (preferably husbands/wives).

INTERVENTIONS: Magnetic resonance evaluation of the temporal lobe and neuropsychological testing.

MAIN OUTCOME MEASURES: Magnetic resonance imaging of the temporal lobe 1 year after treatment and neuropsychological testing (Berliner Amnesia Test [BAT], Boston Naming Test [BT], Token Test, Beck Depression Inventory, Freiburger Personality Inventory).

RESULTS

Temporal lobe gliosis after EMFS was observed in 22 of 32 analyzed patients (degree of gliosis: 11, slight; 9, moderate; 2, severe). Neuropsychological testing of 23 of the 32 previously analyzed patients after EMFS compared with control subjects (n=20) found only in few subdomains (figural score, personality test) statistically significant worse test results, but no major disturbances of the temporal lobe function compared with the control group. Only one patient with a finding of severe temporal lobe gliosis was proven in the BAT and BT to have a temporal lobe deficit.

CONCLUSION

In a significant number of patients, temporal lobe gliosis has to be expected after EMFS; however, the gliosis is only slight or moderate in most of the patients and not associated with essential functional deficits of the temporal lobe. Nevertheless, the possibility of a severe temporal lobe gliosis with functional deficits in the BAT and BT has to be taken into consideration.