Das Auge als Zugang zur Pathophysiologie von Parkinson-Syndromen

Abstract

Although dysfunction of the visual system and dysfunctional eye movements during sporadic Parkinson's disease have been reported for more than 40 years, they have never been the focus of early and/or differential diagnosis. To date Parkinson's disease-related α-synuclein aggregates, i.e., Lewy pathology, are not known to develop either in the retina or in other components of the visual system. In a clinical context it is currently possible to test the involvement of the respective functional systems by means of optical coherence tomography and video oculography. Moreover, non-motor-related abnormalities are detectable both during psychophysical testing of visuospatial function as well as in the form of measurable deficits of color perception. These deficits of the visual and oculomotor systems could prove to be suitable candidates for diagnosing sporadic Parkinson's disease in its early phase in a non-invasive manner. This article is intended to provide an overview of the fundamental pathophysiological principles and clinical aspects of visual system involvement in sporadic Parkinson's disease together with currently available differential diagnostic options.

Ursachen visueller Halluzinationen bei der Parkinson-Krankheit

“…In den letzten Jahren häuften sich die Befunde in Bezug auf den mangelhaften visuellen Input bei der PK [ 26 , 63 ]. PK-Patienten mit VH weisen eine dünnere retinale Nervenfaserschicht auf als PK-Patienten ohne VH [ 36 ], möglicherweise sekundär nach Befall der retinalen ganglionären Zellschicht [ 34 ]. Beim Vorliegen von VH zeigt die Magnetspektroskopie eine reduzierte GABA-Konzentration im primären visuellen Kortex.…”

Structural and Functional Brain Mapping Correlates of Impaired Eye Movement Control in Parkinsonian Syndromes: A Systems-Based Concept

“…Figure 2 illustrates a possible concept of mapping patterns of eye movement disturbances to brain structure and function. Oculomotor control examination is ideally performed at the time of MRI investigations in a dedicated oculomotor laboratory which allows a detailed investigation of eye movement control using state-of-the-art video-oculographically based tracing of eye movements in an acoustically shielded atmosphere ( 31 ) Deficits in eye movement control are generally present in parkinsonian syndromes ( 32 ). The patterns are characteristic for the phenotype but not disease-specific ( 22 ); under this prerequisite, quantification of eye movements is increasingly used as a functional investigation tool in the differential diagnostic framework ( 18 ).…”