ABSTRACT
We studied 95 patients who underwent standard anterior temporal lobectomy (ATL) without stimulation mapping of language areas, using neuropsychological parameters of language function preoperatively and 1 year postoperatively [Boston Naming Test and Verbal Fluency, and the Information, Comprehension, Arithmetic, Similarities, Digit Span, and Vocabulary subtests of the Wechsler Adult Intelligence Scale (WAIS)]. Verbal IQ (VIQ), Performance IQ (PIQ), Full-Scale IQ (FSIQ), and Verbal Deviation Quotient were also evaluated, as were parameters of memory function. All patients had hemisphere dominance for language assessed by an intracarotid amytal test. Fifty-three patients had a left dominant (LHDL) ATL with a mean extent of lateral resection of 4.8 cm, and 10 had a left ATL with right or mixed hemisphere dominance (RHDL, MDL). Thirty-two patients had a right nondominant ATL. Seizure outcome was 57 and 59% seizure-free for LHDH and right nondominant group, respectively, 1 year after operation. Comparison of preoperative scores showed the LHDL group to have significantly lower scores than the right nondominant group for several parameters of language function and memory. The group undergoing left dominant ATL showed no significant loss of language function postoperatively and actually showed gains in many parameters. Standard ATL without stimulation mapping of language areas and with conservative lateral resection is safe for long-term language function. In addition, evidence shows preexisting language dysfunction in patients undergoing left dominant ATL.
Subject(s)
Epilepsy, Complex Partial/surgery , Language Disorders/diagnosis , Postoperative Complications/diagnosis , Temporal Lobe/surgery , Adolescent , Adult , Female , Functional Laterality , Humans , Male , Middle AgedABSTRACT
The purpose of the study was to determine the extent to which a temporal resection may be undertaken without producing risk to temporal language areas. Patients undergoing craniotomy and placement of a subdural electrode array (SEA) for evaluation of intractable epilepsy were studied to determine the variability of distance of temporal language cortex from the temporal pole. Hemisphere dominance was determined by intracarotid sodium amytal injection. Temporal lobe speech arrest (SA) was mapped with a 64 contact point SEA. Thirty-one patients had left dominant hemisphere SEAs. Thirty had SA 5 cm to 9 cm from the temporal pole (median 7 cm). One had SA at 3 cm. Twenty-one patients subsequently had temporal lobectomy (TL). Mean extent of resection was 5.7 cm (range 3 to 9 cm). In 18 TL patients who had neuropsychometric evaluation of language function pre- and post-surgery, there was no significant deterioration. Thirty-nine patients had right non-dominant SEAs placed. Eighteen had TL. Thirteen of these had pre- and post-surgery language evaluation and there was no significant change. Comparison of preoperative scores showed significant superiority of the right non-dominant group over the left dominant group for naming. TL up to 5 cm without stimulation mapping of language areas would be safe in the majority of cases, but one subject (3%) had SA mapped anterior to this and a small number of cases may therefore be at risk to language function following a 5 cm TL. Extensive lateral resections up to 9 cm are possible with preservation of language function with stimulation cortical mapping.
