[Clinical features of mental disorders in amyotrophic lateral sclerosis]

To investigate the clinical features of associated mental disorders in amyotrophic lateral sclerosis (ALS).

Twenty-seven patients (9 men and 18 women, mean age 59.8±11.9 years) with the upper and lower motor neuron lesions were studied. The average duration of the disease at the time of examination was 3.2±2.4 years. Clinical psychopathological and follow-up methods were used. The severity of cognitive impairment was measured with the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). The Montgomery-Asberg Depression Rating Scale (MADRS) was used to assess the severity of depression.

Most patients (88.9%) had cognitive impairments. Amnestic disorders were primarily presented by hypo- and dysmnesia. These patients showed slow thinking, torpidity combined with circumstantiality and a tendency to detail. In addition to attentional fluctuations, we observed reduced attentional capacity, higher distractibility, and difficulty concentrating. The later stages of the disease were accompanied by the overall decline of thinking ability and intelligence with severe perseverations, and failure in the adequate self-assessment. More than half of the patients also developed the symptoms, such as dynamic aphasia, as well as functional speech disorders, i.e. gnosis and praxis. The vast majority of the patients had affective disorders (92.3%). So far as the symptoms of the underlying neurological condition worsened, the associated depressive symptoms prevailed (62.9%). Particular attention should be given to the clinical cases of ALS associated with psychotic disorders such as acute schizophrenia-like psychotic disorders.

Presence of affective, cognitive and behavioral disorders, as well as a specific neuroimaging pattern, are considered as a whole as the manifestation of the behavioral variant of frontotemporal dementia (FTD). This provides support for the current opinion suggesting the similarity of ALS and FTD, which allows for considering these diseases as different phenotypic manifestations of a single pathological process.