METHODICAL INSTRUCTIONS
FOR INDIVIDUAL WORK OF THE STUDENTS
IN PREPARATION FOR PRACTICAL CLASSES
Subject
NEUROLOGY
Topic
Professional and domestic neurointoxications.
system lesions in physical factors influence.
Year
Faculty
IV
Medical
Nervous
2
1. Topicality: In terms of civilization technical development environmental pollution that affects
industrial variants of poisoning, both acute and chronic, possess significant weight as a component of
the health of population of Ukraine as well as any other country, which predetermines the necessity of
thorough research of the given topic.
2. Specific purposes:
а) To analyze the clinics of lesion by industrial and domestic poisons in order to specify the
intoxication factor;
б) To offer an antidote and other methods of treatment.
3. Basic knowledge, skills, competences necessary for learning the topic (interdisciplinary
integration ):
Subject
Skills
Information to learn
2
Regular Physiology (neurophysiology)
3
Histology
4
Nervous diseases – clinics, diagnostics
Changes in the work of
the nervous system
during intoxications
Cellar structure of a
neuron, neuron types,
and
pathological
changes
during
intoxications.
The
clinics
of
intoxications
by
neurotropic drugs
To orient in
statements
of
mentioned subjects
To orient in
statements
of
mentioned subjects
the
the
the
the
To orient in the
statements
of
the
mentioned subjects
4. Assignments for individual work during preparation for the classes:
а) The list of basic terms, characteristics, which students must learn during the preparation for
the classes:
№
Term
Definition
1.
Neurotoxіc Substances
Neurotoxins are the substunces that cause poisoning of
nervous tissue of destructive influence. They can
selectively affect definite areas of the brain and spinal cord.
One of the most widely spread neurotoxin sources is
industial chemical compounds.
2.
The list of theoretical questions:
The clinics of the CNS lesion by metals,
Heavy metals,
Solvents,
Vegetative poisons,
Organic compounds,
Solvents
Physical factors –
Vibration
3
Ionizing radiation
с) The list of practical skills that are to be mastered at the classes:
1. establishment of the intoxicant types according to the poison clinics
2. choice of treatment and prophylactic evens.
Topical contents:
Metals. To metals defined as neurotoxins belong lead, mercury and manganese. Production conditions
in which people can undergo the influence of lead include smelting furnaces, foundries, accumulator
factories and paint and varnish industry. It is supposed that lead selectively influences motor neurons
of the spinal cord. It was thought earlier, that lead induces mental development damages in town
children, but this cause-effect relation is impossible to confidently establish.
Mercury. The fungicides that restrain mercury and are used to treat seeding material served as a
reason for main mercury poisonings. The wastes of mercury dichloride which take the form of methyl
mercury in fish and shellfish lead to serious mercury poisonings in Japan. Initial mercury poisoning
symptoms include cerebellar upsets, decrease of sight and hearing (up to their complete loss) as well as
psychical damages.
Managnese. In the USA the manganese intoxication was registered among workers involved into
development of deposits, treatment of ore crushers and production of ferromanganese alloys. The
organism undergoes the influence of manganese mostly because of inhaling dust or vapor. The toxicity
can be revealed from 4 months to 15 years after the exposure. The initial symptom of manganese
intoxication among miners is often a psychic upset characterized by irritability, mood variations and
audial and visual hallucinations. Other symptoms include apathy, developing memory decrease, upset
of gait and motor control as well as speech abnormality.
Solvents. Chronic exposure to several industrial solvents can cause the NS lesions with a characteristic
symptomatic pattern. To harmful solvents belong n-hexane, methyl-n-butylketone and toluene. In the
cases of exposure to solvents in industrial conditions the symptoms are revealed in 2 days after their
influence on organism. Muscular feebleness appears first in low extremities, and then it spreads to
upper ones. Together with the feeling of numbness the tactile sensitivity was also mentioned.
Relatively weak muscular atrophy develops together with the damage of leg reflexes. These chemical
substances induce degeneration of nerve fibers, which is proved by slowing-down of the functions of
motor and sensor nerves.
Methyl-n-butylketone. For many years it has been used as a solvent and washing utility. The
poisoning of the organism happens after inhaling or contact with skin as a vapor. Often, in the
beginning the casualty feels tingling in hands and feet. Movement strain is revealed in a form of
tiredness in feet and feebleness in hands and fingers. No lesions of CNS or cranial nerves are observed.
When the exposure ends the neurological symptoms disappear within 5-16 months.
Toluene is used as a cleaning utility as well as a component of repellents, solvents of rubber
typography paints. It can come to the organism through inhaling or vapor, absorbing through skin. The
acute poisoning symptoms include headache, nausea and poor coordination.
Organic chemicals. The acrylamide is used in paper production and as a waterproof agent. In patients
who underwent the influence of acryamide powder, the NS upset was registered. This upset develops
for several weeks after exposure and is revealed through perspiring, extremities feebleness and loss of
weight. The proofs of nerve degeneration are obtained, but however, they have reverse character: the
regeneration and restoration of functions take place within 2 to 12 months.
Carbon disulfide is used in production of artificial fabrics. The poisoning effects include loss of sight,
muscular tremor and weak form of neuropathy.
4
Gases. Among gases, those with neurotoxic effect are carbon monoxide and methyl chloride. In the
USA the carbon monoxide poisoning represents a serious problem, as it is the reason for 50% of cases
of lethal intoxications. The chronic influence of carbon monoxide on the organism induces symptoms
which are similar to those of parkinsonism: muscular tremor, masklike face and movement strain. The
carbon monoxide exposure can also lead to peripheral nerves damages. The acute methyl chloride
poisoning can induce such symptoms as somnolence, indistinct sight, confusion, unsteady gait,
indistinct speech, diplopia and cramps. In the majority of cases these effects are temporary; the
recovering may necessitate up to 3 months.
Insecticides. There exist 39 units used as insecticides that serve the reason for a great number of
poisonings among industrial and agricultural workers. The peripheral neuropathies can be induced by
malathіon, methylparathіon and mіpafox. After recovering from the acute poisoning the influence on
CNS can be preserved for months. It includes memory aggravations, depressions, psychotic behavior.
Those who survived after dіazіnon poisoning had the signs of neuropathy with degeneration of nerve
endings.
Materials for self-control:
А. Tasks for self-control (tables, schemes, pictures, graphics):
1.to innumerate the symptoms of poisonings by
 lead
 mercury,
 arsenium
 benzene
 toluene
 pesticides
2. to classify radiation disease according to its types.
Б. Tasks for self-control:
Information Sources
Lecture
1. Shcrobot S.I., Hara I.I. Neurology in lecture (Selected lectures) . Ternopil, TSMU,
«Ukrmedknyha», 2008. 319 p.
2. Reinhard Rohkamm. Color Atlas of Neurology © 2004 Thieme. 440 p.
3. Crash course Neurology by Anish Bahra and Katia Cikurel. Copyright 2006, Elsevier, Inc. 244
p.
4. Adams and Victors. Principles of neurology. © 2005 McGraw-Hill . Medical Publishing
Division.
5. Mayo Clinic Internal Medicine Review 2006-2007. Chapter 18. Editor-in-Chief Thomas M.
Habermann, MD