LECTURES AND REVIEWS
Evaluation and interpretation of electrophysiological phenomena often plays an important role in the diagnosis of neuromuscular diseases. Motor nerve conduction block is a reduction of either amplitude or area of the compound motor action potential elicited by proximal to distal motor nerve stimulation. Today, the value of conduction block in the diagnosis of demyelinating and axonal neuropathies, as well as the diagnostic criteria for these disorders, are still under discussion.
Objective of the review of the literature is to highlight the value of conduction block as an electrophysiological phenomenon in the light of clinical manifestations. There is no consensus in the literature which motor response parameters should be used as partial conduction block criteria. The diversity of pathogenic forms in which conduction block can be registered does not allow to consider the phenomenon as a sign of only demyelinating lesions, and the term conduction block should be considered as a pure electrophysiological phenomenon. Different pathophysiological mechanisms of conduction block formation should be studied separately within each nosology. Conduction block detection does not allow to specify a particular diagnosis, however, in conjunction with clinical and anamnestic data, it may be the main argument in the diagnosis of a number of peripheral nerves diseases.
Today the description of phenomenon of the focal “hourglass-like constriction” of the peripheral nerves in patients with acute pain mononeuropathy is often found in literature. The use of additional imaging techniques of peripheral nerves such as high-resolution ultrasound and magnetic resonance imaging allowed to detect this pathology more often. The purpose of the review is to summarize information about the phenomenon of the focal “hourglass-like constriction”. We analyzed 30 publications in PubMed database by key words: “Hourglass like construction of peripheral nerve” with the description of 158 patients with the focal “hourglass-like constriction”.
Today intravenous immunoglobulins are used increasingly in the management of patients with neurological conditions. The efficacy and safety of intravenous immunoglobulins treatment in chronic inflammatory demyelinating polyradiculoneuropathy, Guillain–Barre syndrome and multifocal motor neuropathy have been established in randomized controlled trials and declared in systematic reviews. There are discussions about the dose, timing, duration and necessity of repeated infusions in these disorders. The intravenous immunoglobulins treatment is an option in myasthenia gravis crisis and exacerbations the disease, stiff-person syndrome, a second-line therapy in dermatomyositis and some patients with polymyositis. The use of intravenous immunoglobulins in patients with multiple sclerosis, inclusion body myositis, resistant epilepsy is not finally proved. The review discussed the data of immunoglobulins efficacy in neurological disorders based on informative studies with an emphasis on the main criteria for choosing a drug for effective high-dose intravenous immunotherapy.
ORIGINAL REPORTS
Background. In children with cerebral palsy, high risk of cognitive impairments connected with sensory disintegration – delayed visual and auditory perception.
The objective – assessment of temporary and amplitude characteristics brainstem auditory evoked potentials of children with cerebral palsy.
Materials and methods. Neurological examination, retrospective analysis of magnetic resonance imaging data of brain and 2-channel brainstem auditory evoked potentials registration with left- and right-ear stimulation and analysis was performed for 60 children aged 4–17 years, with mean age 11.80 ± 0.56 years.
Results. There are no significant difference in brainstem auditory evoked potentials latencies of children’s with cerebral palsy age subgroups. A significantly increasing of III–V peak latencies of brainstem auditory evoked potentials and also I–III and I–V interpeak latencies was observed in children with cerebral palsy in comparison of control group. Latencies of different brainstem auditory evoked potentials peaks were significantly higher in children with uni- and bilateral form of cerebral palsy and speech impairment. Group with periventricular leucomalation (on magnetic resonance imaging) is characterized by significantly increased brainstem auditory evoked potentials latencies and normal interpeak intervals. These abnormalities may be linked to non-progressive impairment of brainstem acoustic afferentation.
Conclusion. Impairment of brainstem auditory evoked potentials maturation and it’s difference in various cerebral palsy forms may be potentially clinical applicable for assessment of the children and early detection of sensory impairment.
Introduction. Neurophysiological examination in patients with spinal cord injury is advisable to determine the end of the period of spinal shock. F-wave is a late electromyographic phenomenon realized by activating a pool of motor neurons of the anterior horns of the spinal cord. In the state of spinal shock, the duration of which is variable, F-waves are not recorded. The presence of F-waves from the tibial nerves indicates the completion of spinal shock and restoration of electrical excitability of motor neurons of the anterior horn of the spinal cord. The appearance of F-waves is a marker for diagnostic transcranial magnetic stimulation to assess the viability of the cortical-spinal tract in the early stages of spinal shock.
Study aim. To analyze the representation of F-waves in patients in different periods of spinal shock, depending on the level, volume and duration of the lesion.
Materials and methods. There were a total of 15 patients with spinal trauma in age from 19 to 29 years enrolled. All patients affected were localized in segments C4–C7. The examination included stimulation electroneuromyography: registration of motor responses, sensory responses and F-waves from the median, ulnar, fibular and tibial nerves on both sides.
Results. In 5 patients: 3 in acute, 1 in early and 1 in late periods of spinal cord injury, spinal shock was clinically diagnosed: electromyographic revealed the absence of F-waves for all tested nerves. In 4 patients in the early period of spinal cord injury F-waves were registered only with n. tibialis, the first spontaneous movements in the limbs were clinically observed; in 6 patients in the intermediate and late periods of spinal cord injury f-waves were recorded from all the nerves under study with constant latency. The end of spinal shock was clinically verified, with the presence of a minimum volume of movements and restoration of sensitivity in individual segments.
Conclusion. Registration of F-wave should be a mandatory component of stimulation electromyographic in the verification of spinal shock, the duration of which is not correlated with the periods of spinal cord injury. The presence of f-waves is a diagnostic marker for transcranial magnetic stimulation to assess the viability of the cortical-spinal tract.
The article discusses aspects of drug-induced falls in elderly comorbid patients against the background of polypragmasy and also assesses the role of drug interactions that are highly dangerous according to the risk of falling. A drug audit of the obtained pharmacotherapy database was performed in patients with comorbid pathology older than 75 years, in order to identify fall-risk-increasing drugs, ranked according to the degree of risk of falling, their significant interactions and with using the traffic light classification. The data on the analysis of the contribution of psychotropic, cardiological drugs and their combination on the risk of developing a fall in the hospital in comorbid patients of old age against polypragmasy are presented.
CLINICAL DISCUSSION
PParry–Romberg syndrome, also known as progressive hemifacial atrophy, is a rare clinical entity of unknown origin with atrophy of skin and subcutaneous fat changes. A classic case of Parry–Romberg syndrome in a woman age 43 is presented. Initial facial changes appeared at the age of 20 years amid complete well-being and in the next 21 years a subcutaneous fat atrophy of the left half face developed, resulting in characteristic deformity changes. No other complaints and manifestations of the disease (epileptic seizures, headache, involvement of the other half of the face and/or extremities) were present at the timeof survey. The analysis of blink reflex, galvanic skin reflex, needle electromyography of the m. orbicularis oris from two sides, computed tomography of the skull bones revealed no pathological changes. The face infrared thermography confirmed asymmetric reduction of temperature on the ipsilateral side. Magnetic resonance scan showed hypotrophy of the left masticatory muscle, the left submandibular salivary gland, thinning of subcutaneous fat layer, changes in the white matter of the brain. Despite the typical clinical features the Parry - Romberg syndrome is a diagnostic challenge known and it is necessary to inform doctors about the latest achievements in the study of etiology, management and prognosis of the disorder.
A description of the clinical and genetic characteristics of the syndrome of congenital contractures of the limbs and face in combination with muscular hypotonia and psychomotor retardation of 2 patients from Russia is presented. As a result of full-exome DNA sequencing, 2 heterozygous missense mutations c 4355T C and c.3541C G were found in the NALCN gene, leading to amino acid substitutions at the functionally important center of the protein molecule. The effect of identified mutations in the NALCN gene on the function of its protein and approaches to the differential diagnosis of congenital contracture syndrome of the extremities and face in combination with muscular hypotonia and psychomotor retardation with monogenic variants of distal arthrogryposis with autosomal dominant type of inheritance are discussed.
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