A Super-selective Wada Test Successfully Detected an Artery That Supplied Broca's Area in a Case of Left Frontal Lobe Glioblastoma: Technical Case Report

Super-selective injection of propofol into the intracranial arteries enables Patient's self-evaluation of expected neurological deficit

INTRODUCTION

It is hard to realize the extent of the expected postoperative neurological deficit for patients themselves. The provision of appropriate information can contribute not only to examining surgical indications but also to filling the gap between patient and expert expectations. We hypothesized that propofol infusion into the intracranial arteries (ssWada) could induce focal neurological symptoms with preserved wakefulness, enabling the patients to evaluate the postsurgical risk subjectively.

METHODS

Presurgical evaluation using ssWada was performed in 28 patients with drug-resistant epilepsy. Based on anatomical knowledge, propofol was super-selectively infused into the intracranial arteries including the M1, M2, and M3 segments of the middle cerebral artery (MCA), A2 segment of the anterior cerebral artery, and P2 segment of the posterior cerebral artery to evaluate the neurological and cognitive symptoms. We retrospectively analyzed a total of 107 infusion trials, including their target vessels, and elicited symptoms of motor weakness, sensory disturbance, language, unilateral hemispatial neglect (UHN), and hemianopsia. We evaluated preserved wakefulness which enabled subjective evaluations of the symptoms and comparison of the subjective experience to the objective findings, besides adverse effects during the procedure.

RESULTS

Preserved wakefulness was found in 97.2% of all trials. Changes in neurological symptoms were positively evaluated for motor weakness in 51.4%, sensory disturbance in 5.6%, language in 48.6%, UHN in 22.4%, and hemianopsia in 32.7%. Six trials elicited seizures. Multivariate analysis showed significant correlations between symptom and infusion site of language and left side, language and MCA branches, motor weakness and A2 or M2 superior division, and hemianopsia and P2. Transient adverse effect was observed in 8 cases with 12 infusion trials (11.2 %).

CONCLUSION

The ssWada could elicit focal neurological symptoms with preserved wakefulness. The methodology enables specific evaluation of risk for cortical resection and subjective evaluation of the expected outcome by the patients.

Assessment of language lateralization in epilepsy patients using the super-selective Wada test

BACKGROUND

The classical Wada test (cWada), performed by injecting a short-acting anesthetic through the intracarotid route, helps determine language dominance. In the cWada, adverse effects are observed in 10-30% of trials, hindering accurate assessments. In this study, we assessed the effectiveness of the super-selective Wada test (ssWada), a more selective approach for anesthetic infusion into the middle cerebral artery (MCA).

METHODS

We retrospectively examined the data of 17 patients with epilepsy who underwent ssWada via anesthetic injection into one M1 segment of the MCA and at least one contralateral trial.

RESULTS

The ssWada identified 12 patients with left language dominance, 3 with right language dominance, and 2 with bilateral language distribution. Nine trials on the language dominant side resulted in global aphasia for patients with left- or right language dominance. Of the 13 trials conducted on the non-dominant language side, 12 revealed intact language function and one resulted in confusion. Among these, the outcomes of global aphasia or no language impairment were confirmed in the contralateral trials. Among the 22 trials of unilateral M1 injections in patients with unilateral language dominance, 21 (95.5%) showed either global aphasia or no language impairment, indicating language dominance.

CONCLUSIONS

The ssWada yields clear results, with a high rate of over 90% in determining the language dominant hemisphere with few side effects.

Bilateral and asymmetrical localization of language function identified by the superselective infusion of propofol in an epilepsy patient with a mild malformation of cortical development: illustrative case

BACKGROUND

Atypical localization of language function can result in unexpected postsurgical deficits after cortical resection, but it is difficult to predict the risk in the presurgical evaluation. The authors experienced a rare case of the bilateral and independent existence of different components of language function identified by segmented evaluation of anatomical anterior and posterior language areas using the superselective infusion of propofol.

OBSERVATIONS

A 32-year-old right-handed female presented with drug-resistant epilepsy. Comprehensive epilepsy evaluation suggested that the epileptic foci involved the whole left frontal lobe but provided less evidence of structural abnormality. To estimate the extent of functional deterioration likely to be caused by an extended left frontal lobectomy, the authors evaluated segmented cortical function in the ipsi- and contralateral hemispheres by the superselective infusion of propofol into the branches of the intracranial artery. The results revealed bilateral and asymmetrical localization of language function because the patient presented with different components of aphasia in each hemisphere. Based on the authors' assessment of her functional tolerance, an extended left frontal lobectomy was performed and resulted in neurological deficits within the anticipated range.

LESSONS

An accurate understanding of the correlations between vascular and functional anatomy and the highly specific evaluation of language function provides more advanced presurgical assessment, allowing more tailored planning of cortical resection.

Determination of language areas in patients with epilepsy using the super-selective Wada test

The Wada test is the gold standard for determining language-dominant hemisphere. However, the precise determination of language areas in each patient requires more invasive methods, such as electrocortical stimulation. Some studies have reported the use of anesthetic injection into selective cerebral arteries to predict postoperative function. To assess the function of the anterior and posterior language areas separately, we developed an advanced test named the “super-selective Wada test” (ssWada). The ssWada procedure is as follows: an endovascular neurosurgeon identifies the arterial branches of the middle cerebral artery (MCA) perfusing the anterior language area of the inferior frontal gyrus and the posterior language area of the posterior part of the superior temporal gyrus using angiography. Behavioral neurologists assess language symptoms before and after propofol administration using a microcatheter tip in the selected arterial branch. From 30 serial patients with epilepsy who underwent ssWada test at Tohoku University Hospital, we retrospectively reviewed patients in whom multiple areas in the bilateral MCA region was examined. Eight cases were identified in this study. All eight cases had been considered for resection of the area overlapping the classical language area. Three of the eight cases were left-dominant, and the within-hemisphere distribution was also considered typical. One case was determined to be left-dominant but atypical in the intra-hemispheric functional distribution. Two cases were right-dominant, and the intra-hemispheric functional distribution was considered a mirror image of the typical pattern. The remaining two cases were considered atypical, not only in terms of bilateral language function, but also in terms of anterior-posterior functional distribution. This case series demonstrates the potential utility of ssWada in revealing separate function of the anterior and posterior language areas. The ssWada allows simulation of local surgical brain resection and detailed investigation of language function, which potentially contributes to planning the resection area. Although indications for ssWada are quite limited, it could play a complementary role to noninvasive testing because it provides information related to resection using a different approach.

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The super-selective Wada test (ssWada) injects anesthetic locally into the brain.

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The ssWada simulates states of post-resection functional impairment.

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The ssWada successfully localized different components of language separately.

Childhood Obesity: A Potential Key Factor in the Development of Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is a malignant primary tumor type of the central nervous system (CNS). This type of brain tumor is rare and is responsible for 12-15% of all brain tumors. The typical survival rate of GBM is only 12 to 14 months. GBM has a poor and unsatisfactory prognosis despite advances in research and therapeutic interventions via neurosurgery, radiation, and chemotherapy. The molecular heterogeneity, aggressive nature, and occurrence of drug-resistant cancer stem cells in GB restricts the therapeutic efficacy. Interestingly, the CNS tumors in children are the second most usual and persistent type of solid tumor. Since numerous research studies has shown the association between obesity and cancer, childhood obesity is one of the potential reasons behind the development of CNS tumors, including GBM. Obesity in children has almost reached epidemic rates in both developed and developing countries, harming children's physical and mental health. Obese children are more likely to face obesity as adults and develop non-communicable diseases such as diabetes and cardiovascular disease as compared to adults with normal weight. However, the actual origin and cause of obesity are difficult to be pointed out, as it is assumed to be a disorder with numerous causes such as environmental factors, lifestyle, and cultural background. In this narrative review article, we discuss the various molecular and genetic drivers of obesity that can be targeted as potential contributing factors to fight the development of GBM in children.