[Hand motor dexterity as one of neurological status assessing indicators].

OBJECTIVE: To assess the degree of hand motor dexterity preservation (on the example of cursive writing) in healthy subjects (HS), depending on age and gender, the severity of cognitive impairment (CI), with damage to hand peripheral nerves (on the example of tunnel hand neuropathy (HN)), of motor hand impaired function with hyperkinesis (on the example of writer's cramp (WC)).

MATERIAL AND METHODS: The examined patients and the HS included in the study gave written informed consent to participate in the study. All the subjects were right-handed. Groups of subjects: 1st group- HS (n=140) at the age of 37.7±15.9 years (20-75 years), 2nd group - HN (n=52) at the age of 48.7±10.4 years (20-67 years), 3rd group - CI (n=87) at the age of 64.3±7.0 years (50-75 years), 4th group - WC (n=91) at the age of 39.9±12.9 years (12-66 years). The study followed a single Protocol for performing written tasks: to write a standard passage of text at a moderately fast pace under dictation, the time was recorded using an electronic stopwatch.

RESULTS: Writing speed: HS was 26.5±3.9 sec, men write significantly slower with age (p=0.048) than women (27.3±3.4 sec vs 25.8±3.6 sec, respectively); HN - 26.4±3.7 sec; CI (whole group) - 34.4±5.5 sec, with mild CI (MCI) - 32.7±4.3 sec, with non-mild / moderate CI (nMCI) - 39.9±6.1 sec; WC (whole group) - 47.1 ±15.3 sec, WC spastic form - 37.9±14.2 sec, WC tremulous form - 47.6±16.4 sec. HS women, unlike HS men, retain constant cursive writing at different age periods; without central mechanisms involvement of act of writing implementation (as median / ulnar nerves neuropathy), cursive changes are not observed; cursive writing with CI decreases depending on CI degree severity (MCI or nMCI), but regardless of gender; the most pronounced decrease in cursive writing it is observed in WC, to a greater extent in the tremulous form, and in men. With WC, there are violations in the central mechanisms of the motor engram realization, with dystonia formation, there is a gradual destruction of the writing program.

CONCLUSIONS: The proposed method of cursive assessment can indirectly help in the differentiation of neurological disorders, become a predictor in the assessment of the development of CI in the elderly or the initial manifestations of dementia in Parkinson's disease. The obtained results of the study require further research in order to study the disintegration of the motor program in neurological diseases and in the process of involution.