Motor neuron disease

Motor neuron disease

1. MOTOR NEURON DISEASE

2. Evaluator: Mr L Anand [ Asso Professor, CON AIIMS BBSR] Presenter: Ms Shruti Shirke MSN (Neurosciences)

3. Motor neuron A motor neuron is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord and whose axon projects to the spinal cord and outside of the spinal cord to directly or indirectly control effecter organs, mainly muscles and glands.

4. Types of motor neuron

5. Upper motor neuron Upper motor neuron that starts in the motor cortex of the brain and terminates within the medulla or within the spinal cord. Lower motor neuron;- they are located in either the anterior grey column, anterior nerve root or the cranial nerve nuclei of the brainstem and cranial nerves with motor function.

6. Motor neuron disease MNDs are group of neurodegenerative disorders that selectively affect motor neurons, the cells which control voluntary muscles of the body.

7. MND MND affect both children and adults. While each MND affects patients differently, they all came with movement relate symptoms, mainly muscle weakness . Sporadic degenerative disease involving only motor system Usual age is 40-60 years CN are also controlled by upper motor neuron of the contralateral side- these are known as cortico -bulbar tract When lesion is present in the CN nucleus it is called as bulbar palsy (usually 9 10 11 12)(LMN) When lesion is present in the cortico -bulbar tract (UMN) it is called as pseudobulbar palsy

8. Progressive muscular atrophy ( duchenne-aran muscular atrophy ) Progressive muscular atrophy  ( PMA ) is a very rare subtype of  motor neuron disease  (MND) that affects only the  lower motor neurons . PMA is thought to account for around 4% of all MND cases. As result of lower motor neuron degeneration, the symptoms of PMA include: atrophy fasciculations muscle weakness

9. Types of S MA

10. Pathophysiology   Each individual has 2 SMN genes,  SMN1  and  SMN2 . More than 95% of patients with SMA have a homozygous disruption in the  SMN1  gene on chromosome 5q, caused by mutation, deletion, or rearrangement. However, all patients with spinal muscular atrophy retain at least 1 copy of  SMN2 , which generates only 10% of the amount of full-length SMN protein versus  SMN1 . This genomic organization provides a therapeutic pathway to promote  SMN2 , existing in all patients, to function like the missing  SMN1  gene.  

11. Progressive bulbar palsy PBP is a disease that attacks the nerves supplying the  bulbar  muscles. These disorders are characterized by the degeneration of motor neurons in the  cerebral cortex ,  spinal cord ,  brain stem , and  pyramidal tracts . This specifically involves the  glossopharyngeal nerve  (IX),  vagus nerve  (X), and  hypoglossal nerve  (XII ). Prognosis for PBP patients is poor. progressive difficulty with talking and swallowing. Reduced gag reflexes, weak  palatal movements , fasciculations , and weak movement of the facial muscles and tongue.

12. Progressive Bulbar Palsy ‘’Bulb’’ refers to the brainstem. The PBP used to describe MND affecting bulbar muscles, causing dysarthria and dysphagia . Involves glossopharyngeal , vagus , hypoglossal nerve.

13. Clinical manifestation Progressive difficulty with talking and swallowing. Reduced gag reflexes, weak palatal movement, of facial muscles and tongue. Unable to protrude tongue or manipulate food in their mouth. Difficulty in pronunciation, drooling saliva. Due to difficulty in swallowing food and saliva, it can be inhaled into the lungs. This can cause gagging and choking and increase risk for pneumonia. Poor prognosis, death occur after 1-3 years of onset of disease.

14. Kennedys disease S pinal and bulbar muscular atrophy  ( SBMA ), popularly known as  Kennedy's disease , is a progressive debilitating neurodegenerative disorder  resulting in muscle cramps and progressive weakness due to degeneration of  motor neurons  in the  brainstem and spinal cord.

15. Monomelic muscular atrophy Rare benign LMND restricted to one limb, usually an arm or hand rather than a leg. Also k/a Hirayama syndrome. Affects men 10 times more then women. Starts at 20 years . Weakness involves he hand and forearm C7-T 1 innervated muscles. Condition progress to 1-2 years and then seems to become arrested in most cases.

16. Monomelic muscular atrophy Monomelic   amyotrophy (MMA) is characterized by progressive degeneration and loss of motor neurons, the nerve cells in the brain and spinal cord that are responsible for controlling voluntary  muscles . It is characterized by weakness and wasting in a single limb, usually an arm and hand rather than a foot and leg.

17. Primary lateral sclerosis PLS affects the upper motor neurons (also called corticospinal neurons) in the arms, legs, and face.  It occurs when nerve cells in the motor regions of the cerebral cortex gradually degenerate, causing movements to be slow and effortful.   The disorder often affects the legs first, followed by the body, trunk, arms and hands, and, finally the bulbar muscles (muscles that control speech, swallowing, and chewing).  

18. Primary lateral sclerosis PLS is similar to ALS, but it affect only UMN. Causes weakness, stiffness in arms legs, a slowed walk, poor coordination and balance slow and slurred speech. Like ALS it usually starts in people 40-60 years old. The muscle get stiffer and weaker with time. But unlike ALS, people don’’t die from it.

19. Garland sign/ wine glass appearance

20. PLS cont.. Symptoms include weakness, muscle stiffness and spasticity, clumsiness, slowing of movement, and problems with balance and speech . PLS is not fatal. There is no cure and the progression of symptoms varies. Some people may retain the ability to walk without assistance, but others eventually require wheelchairs, canes, or other assistive devices.

21. Pseudobulbar lateral sclerosis The condition is usually caused by the bilateral damage to  corticobulbar  pathways, which are  upper motor neuron  pathways that course from the cerebral cortex to nuclei of cranial nerves in the  brain stem . characterized by the inability to control facial movements (such as chewing and speaking) and caused by a variety of neurological disorders. Patients experience difficulty chewing and swallowing, have increased  reflexes  and spasticity in tongue and the  bulbar  region, and demonstrate slurred speech

22. Pseudobulbar palsy It is a UMND characterised by inability to control facial movements (chewing, speaking) and caused by a variety of neurological disorder. Patients experience difficulty in chewing and swallowing, have increased reflexes and spasticity in tongue and the bulbar region and demonstrate slurred speech .

23. Difference between UMD & LMD

24. 1. Amyotrophic lateral sclerosis Also known as Lou Gehrig disease after the famous baseball player who had this disease in US.

25. ALS is progressive MND that involves both upper and lower motor neurons. ALS is defined by evidence of both lower motor neuron disease (weakness, wasting and fasciculation) and upper motor neuron disease (spasticity, hyperactive tendon reflex, Hoffmann signs, Babinski or donus ) in the same limbs. Amyotrophic lateral sclerosis

26. Jendrassik maneuver The jendrassik maneuver is a medical maneuver wherein the patient clenches the teeth, flexes both sets of fingers into hook like form. The tendon below the patient’s knee is then hit with a reflex hammer to elicit the patellar reflex.

27. Epidemiology Worldwide Professional athletes. Middle and late life disease. 10% begin <40 years age, 5% begin <30 years . Men:Females (1-2 times more often than females) females 2.6/100000, male 3.9/100000. The most common type of MND, amyotrophic lateral sclerosis  (ALS), probably affects up to 30,000 Americans at any given time, with over 5,600 diagnoses each year, according to the ALS Association.

28. Epidemiology cont... A 2012 study Trusted Source found that footballers have a higher risk of dying from ALS, Alzheimer's disease, and other neurodegenerative diseases, compared with other people. Experts think that this could indicate a link with recurrent head trauma.

29. Etiology Unknown. Genetics (5-10% AUTOSOMAL DOMINANT ) Mutation in Race

30. Pathophysiology Excitotoxicity excessive exposure to glutamate , leading to neuronal injury or death. Mutant SOD1 gene, environmental factors Oxidative stress Deficit in neurotrophic growth factors Mitochondrial dysfunction

31. Clinical manifestation

32. EI Escorial World Federation of Neurology

33. Clinical features Difficult body movements Bulbar palsy Difficulty in swallowing Breathing difficulty No sensory involvement Eye movement is not affected Bowel and bladder functions are normal Mentation is normal Normal sexual function Cognitive functions are normal Patients are very prone to aspiration pneumonia Weak cough is a poor prognostic feature Death after 3-5 years Terrible depression  great suicidal tendency

34. Diagnostic evaluation

35. Management Medical management- Riluzole – Action; Anti glutamate action . (Slow down the progression of disease cannot reverse the disease) Dose – 100mg resulted in 90% increase in probability of survival for 2 year when taken for 18 months. Drugs used for mx of spasticity Beclofen Tizanidine

36. Edaravone The second medication , edaravonne , was approved in 2017. Edaravone is a free radical scavenger believed to prevent motor neuron degeneration on by reducing oxidative stress. It is administered as an intravenous infusion.

37. In a select patient population (≤2 years from first amyotrophic lateral sclerosis symptom, minimal respiratory involvement, and minimal disability based on amyotrophic lateral sclerosis revised functional rating scale), edaravone was associated with slower decline over 6 months compared with placebo.

38. Nursing management Impaired Physical Mobility related to muscle wasting, weakness, and spasticity Impaired Self-Care related to muscle wasting, weakness, and spasticity Impaired Communications related to impairment of muscles of speech High Risk for Aspiration related to impaired muscles of swallowing Ineffective Breathing Pattern related to impairment of respiratory muscles Altered Nutrition, Less Than Required, related to inability to swallow

39. Supportive management 1. Sialorrhoea :- Anticholinergic agents TCA External radiation of salivary glands Injection Botulinum toxin

40. 2. Respiratory care Most common cause of death in ALS. Denervation results in weakness of respiratory muscles. Assisted ventilation Suctioning Nebulisation Oral care

41. 3. Nutritional care Dysphasia. Malnutrition, Weight loss. Risk of choking, aspiration High calorie diet and change form of diet in initials. In later stages, NG , gastrostomy insertion.

42. 4. Speech and communication management Serious factor reducing quality of life. Energy conservation techniques. Non verbal communication. Assisted and augmented devices.

43. 5. Physical rehabilitation Goal is to carry out ADL. Assistive devices like walker, wheelchair, splints.

44. 6. Spasticity Physical therapy. Therapeutic exercises, stretching, positioning, casting and biofeedback. Intrathecal Baclofen

45. 7. Insomnia & fatigue Common in final stages due to pain, cramps, respiratory impairment. Amitriptyline and zolpidem can be used . Modafinil in the treatment of fatigue in MND.

46. THANKU