Reduzierte visuelle Funktionen in neuropsychologischen Testungen bei Patienten mit Hirntumor im Bereich der radiatio optica

A brain tumor along the visual pathway may affect different domains of general visual functioning as the visual field but also visual cognitive functioning. The aim of this study was to characterize these possible deficits using neuropsychological tests covering various visual cognitive functions in patients with tumors in the projection zone of the optic radiation.

In total, data from 49 patients (23 female, mean age 51.69 years) prior to tumor surgery were included in this study. Based on the tumor location, patients were assigned to a group with tumors in the projection zone of the optic radiation (23 patients, thereof 3 patients with reported visual field impairments) and to a group with tumors with no local association to the optic radiation (26 patients).

Neuropsychological testing included Rey-Osterrieth Complex Figure - Copy (visuo-constructive functions), Rey-Osterrieth Complex Figure - 30min Recall (visual memory), Trail Making Test A (visuo-motor speed; visual attention), Digit Symbol Coding (visuo-motor speed; visual attention), and Corsi Block Span task (visual working memory). The raw scores of the individual tests were transformed into standardized z-values and subsequently into percentile ranks based on the respective norm sample taking the age of the patients into account.

When comparing the two patient groups using Mann-Whitney U tests, patients with tumors in the projection zone of the optic radiation showed lower percentile ranks in the Rey-Osterrieth Complex Figure - Copy (p = .048) and Rey-Osterrieth Complex Figure - 30min Recall (p = .005) tests. There was also a trend in the Digit Symbol Coding test (p = .081), while both patient groups showed comparable results in the Trail Making Test A and Corsi Block Span task.

Neuropsychological assessments can provide valuable information on preoperatively existing deficits, as was shown in this study using the example of brain tumors in the projection zone of the optic radiation. These patients showed reduced performance in visuo-constructive functions, visual memory, and visuo-motor speed. The results also indicate that deficits can exist throughout different domains, which emphasizes the complexity of the visual system.