Nerves-Paralysis and Paresis.pptx

Nervous system

1. Diseases of Nervous System in Animals Dr. Bibek Sutradhar , PhD Professor Department of Medicine and Surgery Chattogram Veterinary and Animal Sciences University MRI

2. Introduction Veterinary neurologists treat nervous-system problems. The nervous system comprises the brain, spinal cord, muscles and the nerves that connect them. Just as in humans, neurological problems in animals can be caused by a reaction to medication, hereditary disorders, infection or trauma . Changes in behavior Not recognizing you Forgetting training or failing to obey Lethargy Aggressiveness Irritability Physical changes Weakness -Seizures and tremors Problems swallowing -Back and neck pain Deafness -Running in circles or pacing Vision problems -Head-pressing against hard Balance problems surfaces

3. Introduction Common neurologic conditions Seizure disorders (epilepsy) Brain and spinal tumors Meningitis and encephalitis Congenital disorders Disk herniation and disease Traumatic injuries N eurological exam The exam itself is gentle and non-invasive . H istory Palpation Percussion Image analysis (X-ray, CT scan, MRI etc ) Treatment options Tumors, herniated disks and traumatic injuries are often treated with surgery, but many neurological conditions also respond to medications – antibiotics, immunosuppressive drugs, anti-seizure medication, and chemotherapy. 

4. CNS - Spinal cord, Brain stem, Cerebellum, and Cerebrum (Higher centers) PNS - Neurons of the cranial and spinal nerves (26 pair spinal and 12 pair cranial) Sensory/afferent neurons – Nociception (pain), Proprioception (position), equilibrium, touch, temperature, taste, hearing, vision, and olfaction Motor/efferent neurons - Upper Motor Neurons (starts from brain) UMN from cortex – voluntary movements UMN from brain stem – flexion of limbs/inhibit extensors Lower Motor Neuron-LMN (starts from spinal cord) Spinal compression – extensor weakness /paresis / paralysis Introduction

5. Introduction

6. What is paresis? Paresis refers to a condition in which muscle movement has become weakened or impaired . (“ mild paralysis ” or “ partial paralysis ”) Although paresis affects your muscles, it usually occurs due to nerve damage . A vast network of nerves controls the movement of the muscles in our bodies. If a part of this network is damaged, muscles in the affected area may not work properly. There are several factors that can cause paresis, and there are many different types of paresis. Paresis is often categorized by the area of the body that’s impacted.

7. How is paresis different from paralysis? Paresis is characterized by muscle weakness . A patient with paresis can still move the affected muscle or muscles. However, these movements are weaker than normal. Paresis is different from paralysis. An individual who has paralysis isn’t able to move a specific muscle or muscle group at all. You may also see paresis used as a suffix to distinguish what part of the body is affected. For example, a person with monoparesis has muscle weakness affecting one limb . The corresponding suffix for paralysis is “- plegia .” Using the same example, a patient with monoplegia has paralysis that affects one limb.

8. Causes and types of paresis There are many different factors that can cause nerve damage that results in paresis . Examples of causes include : Head injury S pinal cord injury P ressure on the spinal cord or nerves due to things like inflammation, bone spurs, or a tumor Diabetes Spastic paresis

9. E xamples of different types of paresis Monoparesis. muscle weakness that affects one limb, such as a leg or an arm. Paraparesis . Paraparesis is muscle weakness that affects both legs. Hemiparesis. Hemiparesis is muscle weakness that affects one side of your body, such as the left arm and left leg. Quadriparesis . Quadriparesis is muscle weakness that affects all four limbs. Bell’s palsy . Bell’s palsy is a condition that leads to temporary weakness in your facial muscles, which can cause facial drooping and pain. Vocal cord paresis. Vocal cord paresis affects the movement of your vocal cords. Gastroparesis . Gastroparesis is a condition where the emptying of the stomach is impaired due to muscle weakness. It’s associated with symptoms like nausea, vomiting, bloating, and feeling full quickly. Todd’s paresis. Todd’s paresis is a type of paresis that occurs following a seizure. It’s often associated with paresis in one limb (monoparesis) or on one side of the body (hemiparesis). Neurosyphilis . Neurosyphilis occurs when a syphilis infection attacks the nervous system. It can cause paresis as well as headaches, changes in behavior, and dementia. Spastic paresis. Spastic paresis is a condition that causes muscle overactivity and spasticity. It’s due to nerve damage that often results from conditions like stroke; can lead to pain as well as difficulty with activities like walking or getting dressed.

10. Treatment options Treatment for paresis depends on the cause. Possible treatment options include: Physical therapy . Physical therapy uses techniques such as exercise and massage to aid in promoting mobility, improving flexibility and range of motion, and stimulating the nerves and muscles. Occupational therapy . Occupational therapy can teach the strategies for carrying out the day-to-day activities more easily while patient experiencing paresis (Human). Assistive devices . Assistive devices are items that can help with the mobility and daily activities. Examples include: walkers wheelchairs grab bars specialized handles and grips voice-activated technology Medications. In some cases, medications may help treat a condition that’s causing paresis. Examples include: antimicrobial medications for infections corticosteroids to reduce inflammation that’s putting pressure on a nerve

11. Autonomic Nervous System (ANS) Sympathetic Parasympathetic

12. Functions: Sensory motor system: Maintenance of normal posture and gait ANS : Activity of internal organs; Homoeostasis Sense organs Psychic system: Mental and behavioural state Dysfunction : Increased response to sensory stimuli Failure to respond to sensory stimuli Transmission of impulses enhanced or depressed Complete failure of transmission

13. R e fl e x Sensory neuron (PNS) – Internuncial neuron (CNS) - Lower Motor Neuron (PNS) Higher center not involved. No Perception Monosynaptic reflexes – Patellar reflex LOCATION OF LESION????.....

14. Paralysis -> Paresis Vs Plegia Paresis : Partial loss/weakness/Impaired voluntary movement Plegia or Paralysis : Inability/ complete loss of voluntary movement

15. NERVOUS DYSFUNCTION CAUSES: congenital or familial, infectious or inflammatory, toxic, metabolic, nutritional, traumatic, vascular, degenerative, neoplastic, or idiopathic Exaggerated activity: Excitation (irritation) signs Release of inhibitory control Neuropathic pain Depressed activity: Paresis or paralysis due to tissue damage Nervous shock

16. Neurologic Evaluation/Description The anatomic location(s) of disease 2)The problem may be defined as diffuse, multifocal, or focal symmetric or asymmetric painful or nonpainful progressive, regressive or static mild, moderate, or severe Clinicopathology (serum/blood/urine/feces/CSF) Plain and Contrast radiography, CT, and MRI

17. EXCITATION (IRRITATION) SIGNS Increased activity of reactor organ Increase in nerve impulses received Excitation of neurons Facilitation of passage of stimuli Motor system : Tetany, convulsions etc. Sensory system : Hyperaesthesia, Paresthesia

18. Clinical Manifestations of Diseases of the Nervous System ALTERED MENTATION - Excitation states a) Mania - acts in a bizarre way and appears to be unaware of its surroundings. Maniacal actions include licking, chewing of foreign material and sometimes themselves, abnormal voice, constant bellowing, apparent blindness, walking into strange surroundings, drunken gait, and aggressiveness in normally docile animals. Eg : Rabies, Aujeszky’s disease , nervous ketosis, pregnancy toxemia, acute lead poisoning, severe hepatic insufficiency etc

19. Frenzy - violent activity, movements are uncontrolled and dangerous eg : Hypomagnesemic tetany, Aujeszky’s disease, Acute colic, ammonia poisoning Aggressive Behavior : willingness to attack other animals, humans, and inert objects Eg : early rabies, postparturient hysteria in sows

20. Clinical Manifestations of Diseases of the Nervous System DEPRESSIVE STATES Coma Syncope Narcolepsy (Catalepsy) lassitude Somnolence COMPULSIVE WALKING OR HEAD PRESSING Eg: PEM, Increased ICP AIMLESS WANDERING **protein energy malnutrition (PEM)

21. Clinical Manifestations of Diseases of the Nervous System INVOLUNTARY MOVEMENTS Tremor: continuous, repetitive twitching of skeletal muscles If local skin only  fasciculations eg: early stages of hypocalcemia in the cow Tics : spasmodic twitching movements made at much longer intervals than in tremor. Tetany: S ustained contraction of muscles without tremor. eg: C. tetani infection Myoclonus : brief, intermittent tetanic contraction of the skeletal muscles that results in the entire body being rigid for several seconds, followed by relaxation. eg: canine distemper

22. E) Convulsions : Convulsions, seizures, fits, or ictus are violent muscular contractions affecting part or all of the body and occurring for relatively short periods. result of abnormal electrical discharges in forebrain neurons Stage I - Prodromal phase or aura (lasts for minutes to hours, restless) Stage II – Ictal phase (Proper convulsions) Stage III – Post Ictal phase (Fatigue, rest, loss of conciousness) E) Involuntary Spastic Paresis: eg: Stringhalt in Horses – hind leg flexion Clonic C onvulsions (Paddling in Meningitis) Vs Tonic Convulsions (Strychnine/Tetanus)

23. Clinical Manifestations of Diseases of the Nervous System ABNORMAL POSTURE AND GAIT Posture Abnormality: Vestibular disease Gait Abnormality : Weakness (Paresis) and Ataxia(Swaying) Hypermetria (increased range of movement/Overreaching) Dysmetria (goose stepping –pantothenate def.) Cerebellar ataxia (BVD) and Sway back (Cu def.)

24. Stimulant drugs and mild degrees of those influences that in severe form causing depression of excitability (hypoxia, inflammation, poisons, edema, increased ICP) Fluctuation in Intensity of signs due to discharge and re-accumulation of energy Sign and extension of symptoms varies with the focus of lesion

25. RELEASE OF INHIBITORY CONTROL Release of inhibitory effects of higher centres over lower nervous centers Decerebrate rigidity due to transection of brain stem Cerebellar ataxia: combined limb movements exaggerated

26. PARESIS OR PARALYSIS DUE TO TISSUE DAMAGE Destruction of nervous tissue Infection depressed metabolic activity Failure of oxygen and nutrient supply General absence Failure of local circulation Motor system : Muscular paralysis Sensory system : Anaesthesia, hypoaesthesia

27. Suprascapular Neuropathy in Horses (Sweeney)

28. Schiff-Sherrington Phenomenon Due to acute, severe lesions of the spinal cord between T2 and L3, the pelvic limb paralysis is accompanied by an extensor rigidity of the thoracic limbs

29. NERVOUS SHOCK An acute lesion of the nervous system, which causes damage to nerve cells in the immediate vicinity of the lesions, but there may be, a temporary cessation of function in parts that are not directly affected. eg: Stunning

30. Horner syndrome Sunken appearance to the eye (enophthalmia) Small pupil (miosis) Droopy upper eyelid (ptosis) Absence of sweating of the face (anhidrosis) Prominent third eyelid. Loss of Sympathetic innervations to eyes and face

31. C O N C L USIO N S Determining type of lesions is difficult: Limited range of mode of reaction Destruction of tissue or reduced nutrient supply Proper Anamnesis and Special examination is essential for proper assessment Sign - time relationship: Rapidly developing lesions : maximum disturbances Slow developing lesions : Compensation

32. References : A Text book of diseases of the cattle, sheep, goats, pigs & horses 10 th edition by Otto M Radostits, Clive C Gay, K W Hinchcliff, P D Constable. Duke’s Physiology of Domestic animals 12 th edition edited by William O Reece