From diagnosis of depression, generalized - anxiety disorder, schizoaffective disorder to diagnose of microtubule--associated protein tau mutation (MAPT) S305N presenile dementia, weaknesses of phenomenological classification
Abstract
We report a case of a 43-years old woman patient with presenile dementia with the finding of a microtubule-associated protein tau mutation (MAPT) exon 10 on chromosome 17, specifically mutation S305N. Depressive and anxiety symptoms were recognized early from 36 years of her age.
In contrast to that, subjective complaints about memory and memory deficit were overlooked, which was the cause of the late diagnose of presenile dementia. After confirming memory deficit we started the differential diagnostic process for etiology, because of her age and mixed clinical symptomatology.
Diagnosis of Alzheimer's disease with early onset before 65th year of age was supported with the finding of symmetric atrophy isolated on both hippocampi on MRI and low concentration of β-amyloid in cerebrospinal fluid, which was contrary with negative findings on β-amyloid positron emission tomography. The clinical and cognitive examination also recognized the possibility of frontotemporal lobar degeneration.
Genetic examination confirmed the diagnosis of primary tauopathy with early onset and should not be neglected in these types of cases. The main point of this clinical case is to illustrate, that patients with so-called pharmacoresistant depression or with suspicion of schizoaffective disorder in middle-age could suffer from unrecognized primary tauopathy in stages of mild cognitive impairment or mild dementia.