Angularis Syndrome
| Classification according to ICD-10 | |
|---|---|
| R48.0 | Dyslexia and alexia |
| R48.1 | Agnosia |
| R48.8 | Other and unspecified tool malfunctions |
| H53.4 | Visual field defects |
| ICD-10 online (WHO version 2019) | |
As angularis syndrome ( lat. Angular = angular) refers to a complex of neurological symptoms, due to the failure of the function of the angular gyrus of the language dominant (usually left) hemisphere arises. It consists of the following symptoms:
- (amnestic) aphasia
- Alexia
- Agriculture
- Acalculia
The term Gerstmann syndrome is often used synonymously . This was described by Josef Gerstmann in 1924 and consists of alexia, agraphia, acalculia, right-left weakness and finger agnosia (without aphasia). In neurology, the use of both terms is vague, as they are very rare in their pure form and the various symptoms instead appear in the most varied of combinations. Just a few years ago, angularis syndrome was viewed as a Gerstmann syndrome with amnesic aphasia and alexia. The symptom complex of agraphia , acalculia , optical agnosia , homonymous hemianopsia and asomatognosia is also referred to as angularis syndrome in (non-neurological) standard reference works.
Anatomical
By definition, the angular gyrus of the left hemisphere, which lies at the posterior end of the superior temporal sulcus, is affected . It corresponds to the Brodmann area 39. This is where the parietal , temporal and occipital lobes meet.
The angular gyrus is supplied by the angular artery and a terminal branch of the posterior parietal artery, both branches of the middle cerebral artery . The (rare) isolated infarction of these blood vessels leads accordingly to the so-called angularis syndrome. Bleeding, tumors, inflammation, injuries and similar damage can also be the cause.
Physiological
The angular gyrus is one of the higher association areas of the cerebral cortex. It plays a decisive role in the networking of higher visual and hearing centers with higher sensory and motor areas. He is thus decisively involved in functions such as writing, reading and arithmetic. But higher human cognitive performances such as the ability to abstract are also attributed to him.
Current
The American neurologist Vilayanur Ramachandran put these higher associative functions in the context of synesthesia : Since the visual color center V4 is in the direct vicinity of the angular gyrus, the color assignment of numbers typical for synesthesia could be adequately explained. Ramachandran sees the abilities of abstraction and language as a property of humanity based on the function of the angular gyrus and the higher association centers surrounding it.
Historical
In 1892, the French neurologist Joseph Jules Dejerine first described a module for written language in the left angular gyrus, the damage of which was not accompanied by disorders of spoken language. Previously, from Paul Broca and Carl Wernicke other language centers have been discovered.
Individual evidence
- ^ Pschyrembel: Clinical Dictionary. 257th edition. 1994.
- ^ Roche Lexicon Medicine. 5th edition. 2003.
- ↑ a b Martin Trepel: Neuroanatomy. 1st edition. Urban & Schwarzenberg, 1995, ISBN 3-541-13431-3 .
- ^ Mathias Bähr, Michael Frotscher: Duus' neurological-topical diagnostics. 8th edition. Georg Thieme Verlag, 2003, ISBN 3-13-535808-9 , p. 393.
- ↑ a b V. Ramachandran: Purple Numbers and Hot Cheese. In: A Brief Journey through the Mind and Brain. Rowohlt Taschenbuch Verlag, 2005, ISBN 3-499-61987-3 , pp. 73ff.
- ^ JJ Déjerine: Contribution à l'étude anatomo-pathologique et clinique des différentes varietés de cécité verbale. In: Mémoires de la Societé de Biologie . 1896; 4, pp. 61-90.
