What is Gerstmann-Straussler-Scheinker Syndrome

Gerstmann-Sträussler-Scheinker syndrome

Synonyms: GSS syndrome, Gerstmann-Sträussler-Scheinker disease
English: Gerstmann – Sträussler – Scheinker syndrome

1 definition

The Gerstmann-Sträussler-Scheinker syndrome, short GSSS or GSS, is a rare form of transmissible spongiform encephalopathy (TSE) with the formation of prions mainly in the cerebellum.

2 classification

Together with Creutzfeldt-Jakob disease (CJD) and fatal familial insomnia (FFI), Gerstmann-Sträussler-Scheinker syndrome is counted among the human prion diseases.

3 epidemiology

The Gerstmann-Sträussler-Scheinker syndrome occurs worldwide and mainly affects people between the ages of 40 and 50. Women and men are affected roughly equally often.

4 genetics

The disease is inherited as an autosomal dominant trait and shows almost one hundred percent penetrance. The causes are multiple point mutations (typically P102L, P105L, P105T, A117V, Q145X, F198S and Q217R) as well as insertion mutations in the area of ​​the octapeptide repeat site in the prion protein gene (PRNP gene) on chromosome 20. Depending on the location of the mutation, the clinical one varies Picture.

5 pathogenesis

Prions are faulty proteins. There is a conformational change of the physiological protein PrPC. (Alpha-helix structure) to the pathological form PrPSc (Beta sheet structure). The change in the tertiary structure causes a chain reaction that leads to an accumulation and aggregation of the misfolded protein in the form of spongiform fibrils and amyloid plaques. In Gerstmann-Sträussler-Scheinker syndrome, these develop predominantly in a multicentric manner in the area of ​​the cerebellum (spinocerebellar, corticospinal, posterior cords).

The aggregation of the prions also leads to the destruction of nerve cells and is the cause of the formation of "spongy" or holey brain tissue.

6 clinic

Initially, there are mostly cerebellar symptoms such as stance and gait ataxia. Later on, extremity ataxia, oculomotor disorders, dysarthria, bradykinesia, pyramidal tract signs and anterior horn cell involvement can also occur. Progressive dementia usually only shows up late. In addition, myoclonus, epileptic seizures, and blindness and deafness are rare.

7 Diagnosis

The Gerstmann-Sträussler-Scheinker syndrome can primarily be identified by means of a genetic test for mutations in the PRNP gene differential diagnosis.

The suspected diagnosis is based on a positive family history and can also be supported by various methods. The CT is used to visualize protein deposits in the brain, while the MRI is used in the later stages to visualize structural changes. In addition, abnormal brain waves can be recorded using electroencephalography (EEG). Characteristic pathological proteins can be examined with the help of a CSF puncture.

8 therapy

Due to the lack of causal therapy, the Gerstmann-Sträussler-Scheinker syndrome cannot be cured. Symptomatic treatment is used to relieve symptoms and slow down the progressive course.

In order to maintain the quality of life, adequate care of the increasingly dependent patients is necessary.

9 forecast

In the context of the chronically progressive course of the disease, the average survival rate after diagnosis is around 5 years.

10 literature

  • A Hufschmidt, CH Lücking, S Rauer. Neurology compact. For clinic and practice. 8th edition, Thieme (2020)