Vol 9, No 3 (2015)

Comparison of the results of 20 autopsy cases of ischemic strokes developed during atherosclerosis with 20 autopsy cases of ischemic strokes associated with atherosclerosis in combination with type 2 diabetes mellitus (T2DM) provided data indicating a high significance of T2DM in the development of severe changes in the cerebral arteries, causing cerebral infarctions of various size and localization. A significant prevalence in the number of atherosclerotic plaques in the cerebral arteries, including those causing stenosis of the lumen by 50% or more, was found in the case of T2DM compared to cases without T2DM. Cerebral infarctions in T2DM were mostly of the multiple nature that was determined by a combination of fresh or organizing extensive, large or medium, infarction with one/several organized medium, small deep, and small surface infarctions. More severe atherosclerosis of the cerebral arteries in T2DM caused a higher rate of infarctions due to occlusive atherothrombosis, arterio-arterial embolism, and tandem atherostenosis in these patients compared to cases without T2DM. In the absence of T2DM, infarctions occurred more often due to embolism of the cerebral arteries from the heart with coronary heart disease compared to cases with T2DM.

The dynamics of cerebral blood flow in acute ischemic stroke was studied with allowance for a pathogenic classification of stroke. Analysis of the ultrasound parameters demonstrated that particular attention should be given to quantitative, rather than qualitative, parameters of blood flow. The dynamics of cerebral blood flow in different etiologies of cerebral stroke is reflected in specific changes in the linear velocities, which relates a stroke subtype to the factors determining the need for extended monitoring. Clinical and instrumental assessment of the development of hemodynamic disorders during reperfusion after stroke by means of Doppler ultrasound demonstrated that, depending on the etiology of ischemic stroke, recovery of the intracerebral hemodynamics parameters to normal values occurs differently and has its features that, if timely detected, may affect correction of the strategy and tactics of treatment. Based on these data, we suggest a differentiated algorithm of extended Doppler monitoring of cerebral blood flow in acute ischemic stroke.

Huntington’s disease (HD) is an autosomal dominant neurodegenerative disease characterized by choreic hyperkinesia, cognitive decline, behavioral disorders, and progressive neuronal death affecting primarily the striatum. The fatal nature of HD makes searching for new effective methods of treatment topical, which requires the development of experimental models of the disease. This model can be created on the basis of 3-nitropropionic acid (3-NPA) that is a neurotoxin causing characteristic changes in motor skills and memory impairment in animals due to induction of oxidative stress, impaired glutathione defense, and destruction of striatal cells. HD in rats was simulated by chronic intraperitoneal administration of 3-NPA daily for 17 days. Systemic administration of a low dose of 3-NPA (10 mg/ kg) induced hyperactivity of the animals in the open field test (including movement redundancy as a hyperkinesia analogue) and had no effect on the behavior of the animals in the X-maze test. On the contrary, rats administered with a toxic dose of 3-NPA (20 mg/kg) demonstrated a significant decrease in the motor activity an cognitive decline in behavioral tests. Histopathological analysis revealed damage and loss of neurons and decreased expression of dopaminergic markers (tyrosine hydroxylases and plasma membrane dopamine transporter) in the striatum. Also, a gliotoxic effect of 3-NPA in the striatum was found, which was confirmed by immunohistochemical staining for astrocytic proteins: GFAP, glutamine synthetase, and aquaporin-4. This HD model may be helpful for testing new experimental therapies at various stages of neurodegeneration of the Huntington type, including those based on cell neurotransplantation.

The evidential base of major neuroprotective drugs (piracetam, cytoflavin, ethylmethylhydroxypyridine succinate, choline alphoscerate, cortexin, cerebrolysin, citicoline, actovegin) in chronic cerebral ischemia is critically reviewed in the article.

Cerebrotendinous xanthomatosis is a rare autosomal recessive disorder of cholesterol and bile acid metabolism associated with the sterol 27-hydroxylase gene CYP27A1. The disease is characterized by a varying age of the onset, progressive course, and wide range of the neurological and extraneural symptoms. MRI of the brain plays an important diagnostic role. Measurement of the serum cholestanol level and DNA analysis are verification methods. Timely started chenodeoxycholic acid replacement therapy enables slowing down the disease progression and, in some cases, preventing neurological disability.

References

Cognitive impairments are an important medical and social problem associated with a high prevalence of this disease in the population. 46% of patients develop dementia within 5 years after the diagnosis of mild cognitive impairments (MCIs). Voxelbased morphometry (VBM) is a modern neuroimaging technique well-proven in studying dementia. VBM in a combination with neuropsychological examination of patients enables clarifying the genesis of mild cognitive impairments (MCIs) and predicting further development of the disease as early as the initial stage of the pathology.

Monomelic amyotrophy (MMA) is a rare variant of lower motor neuron disease with benign progression. The disease is characterized by muscular weakness and atrophy in the hand and forearm on one side or asymmetrical lesion of both upper limbs with the presence of cold paresis, fasciculations, and fine tremor of the fingers. Sensory disorders, pyramidal symptoms, and involvement of the leg muscles are not typical of it. The final diagnosis of MMA can be made only on the basis of clinical neurological and electrophysiological tests as well as long-term follow-up of the patient. Timely recommendations for correction of the movement pattern and prevention of flexion compression may slow down the disease progression in some cases and, thereby, improve the quality of life of patients. The article describes two clinical cases with a probable diagnosis of MMA.