Awake Craniotomy for intra operative cortical stimulation of language sensitive areas: clinical and neurolinguistic results of a prospective, longitudinal evaluation of 153 cases

Objective: The feasibility of intra operative language mapping has been demonstrated; detailed neurolinguistic outcome data, however, are still lacking. Therefore, the current prospective study (1991–2005) was conducted.

Methods: Patients with lesions within/near to suspected language-relevant areas were evaluated before surgery, within the first mouth and within one year after surgery (Aachener Aphasie Test). After intra operative stimulation and neurolinguistic testing language sensitive areas were marked; the surgical approach and extend of resection were accordingly adapted.

Results: 153 patients were included. Awake craniotomy was possible in all patients. Language-related areas could be identified in 93.4%. The surgical approach and/or extend of resection were modified in 94.9% and 89.2%, respectively. Early postoperative testing revealed new deficits in 30% of the preoperatively unimpaired patients. Patients with neurolinguistic deficits already existing before treatment (14%) had a significant risk to deteriorate further (p<0.01). After 1 year a significant reduction of the language-related morbidity was seen (11%, p<0.01): mainly mild lexical impairments were observed.

Conclusion: Awake craniotomy with neurolinguistic testing revealed to be feasible and safe in a routine clinical setting. Surgical strategy could be modified according to stimulation results. However, not all aspects of speech and language can be adequately tested during surgery at this moment.