neuromuscular Diseases by Dr Ali Hazim Mohammed Aljoubori

1. Neuromuscular Diseases
By : Ali Hazim Mohammed

2. INTRO
Neuromuscular diseases are a broadly defined group of
disorders that all involve injury or dysfunction of peripheral
nerves or muscle.
The site of injury can be in the ;
- Cell bodies (amyotrophic lateral sclerosis [ALS])
- Axons (axonal peripheral neuropathies)
- Schwann cells (chronic inflammatory demyelinating
polyradiculoneuropathy).
- Neuromuscular junction (myasthenia gravis).
- Muscle (muscular dystrophy).

3. Disorders of the Motor Unit
• 1- Peripheral nerve disorders
• 2- Motor neuron disease
• 3- Neuromuscular junction disease
• 4- Muscle disease

5. Peripheral Nerve Disorders
• Mononeuropathy
Pattern of weakness and sensory loss conforms
to the distribution of a single nerve
• Carpal tunnel syndrome
• Peroneal palsy at the fibular head
• Mononeuritis multiplex
Multiple nerves affected in a random pattern
• Acute onset, frequently painful
• Diabetes mellitus, vasculitis
• Polyneuropathy (peripheral neuropathy)
Distal, symmetric

6. Peripheral Neuropathy

7. Polyneuropathies
Symptoms of a Polyneuropathy
• Sensory symptoms
– Start in feet, move proximally
– Gain of Function (Positive)
• Pins and needles
• Tingling
• Burning
– Loss of function (Negative)
• Numbness
• Deadness
• “Like I’m walking with thick socks on”

8. Exams of Peripheral neuropathy
Sensory impairment akroparesthesias or tactile
hypestesias glove or sock distribution.

9. Exams of Peripheral Neuropathy
Bed side tests
• A - Tactile
• B - Vibration
• C – Thermal
• D - Myotatic reflexes

10. Exams Of Peripheral Neuropathy

11. Tactile Exam

12. Myotatic Reflexes Exam

13. Clinical features of polyneuropaties
• Atrophies of distal muscles
• Deformities pes cavus
• Walk on heels
• Normal muscles strenght at proximal muscles

14. Clinical features of polyneuropaties

15. Clinical features of polyneuropaties

16. Classification of Polyneuropathies
• By types of fibers involved
– Pure sensory
– Sensory motor
– Pure motor
– Autonomic
• By pathology
– Demyelinating
– Axonal
– Mixed
• By tempo
– Acute
– Subacute
– Chronic

17. Acute Polyneuropathies
Barré – Guillain Syndrome
• Most common cause of rapidly progressive
weakness.
• Demyelinating neuropathy.
• Ascending weakness which may include cranial
neuropathies.
• Exam reveals symmetric weakness with areflexia
and large fiber sensory loss.
• Bowel and bladder usually preserved.

18. Barré – Guillain Syndrome
• Respiratory failure can be precipitous
• Other causes of morbidity and mortality
– Autonomic instability
– DVT
– Infection
• Immune mediated, may be post infectious
• Treatment
– Plasma exchange
– Intravenous immunoglobulin

19. Subacute Polyneuropathies
• Vasculitis
– Can be isolated to peripheral nerves or part
of a more systemic process.
• Paraneoplastic
– May be presenting symptom of the cancer.
• Chronic inflammatory demyelinating
polyneuropathy
– With or without a gammopathy
• Toxins
• Drug

20. Chronic Polyneuropathies
• Metabolic
– Diabetes mellitus
– Chronic renal failure
– Chronic liver failure
– Thyroid disease
• Nutritional
– B12 deficiency
• Infections
– HIV
– Leprosy
• Inherited – Charcot Marie Tooth disease since 1886

21. Evaluation of a Polyneuropathy
• Lab work
• Nerve conduction study/electromyography
– Distinguishes between axonal and
demyelinating
– Helps ascertain severity
• Nerve biopsy
– Frequently non-diagnostic
– Can establish the dx in certain disorders,
such as vasculitis and amyloidosis

22. Evaluation of a Polyneuropathy
• Electromyography (functional diagnostic method)
Conduction studies
Needle EMG
Test of NM transmision

23. Conduction study of peroneal n.

24. Conduction study of sural n.

25. Evaluation of a Polyneuropathy
• Needle electromyography

26. Evaluation of a Polyneuropathy

27. 2- Motor neuron disease

28. Motor neuron disease
• Diseases that can involve Betz cells of the motor cortex, the
lower CN motor nuclei, and/or the anterior horn cells.
– Amyotrophic Lateral Sclerosis (ALS) – 80%
– Progressive bulbar palsy – 10%
– Progressive muscular atrophy, spinal muscular atrophy – 8%
– Primary lateral sclerosis – 2%

29. ALS – clinical features
• Loss of motor neurons in the cortex, brainstem and spinal
cord.
• Mix of upper motor neuron and lower motor neuron findings
– Weakness, atrophy, fasciculations
– Slurred speech, difficulty swallowing, shortness of breath
• Can start in any extremity or the bulbar musculature.
• Relentlessly progressive.

30. ALS - prognosis
• 50 % dead in 3 years,
• 80% dead in 5 years,
• 5 - 10% live more than 10 years.
• Death usually from respiratory failure.

31. Diagnostic algorhitm in ALS
• Clinical symptoms
• Electromyography
• MRI brain + C spinal cord
• Liquor evaluation (infection)
• Sometimes paraneoplastic exams

32. Treatment of ALS
• Causative treatment is not available
• Neuroprotective treatment
riluzol - inhibitor of glutamate acid
antioxidans – koenzym Q10 + vitamin E

33. Treatment of ALS
Symptomatic-paliative treatment – most
important today
1. Mobility -sticks, wheelchair, multifunctional
bed
2. Nutrition – PEG + Nutrizone
3. Communication – tables, books,vocal
communicators, PC
4. Anxiety and depresion – antideperesive
drugs, psychotherapy
5. Respiration – non-invasive BiPAP or invasive
6. Whole family care

34. 3- Neuromuscular Junction Disease
• The neuromuscular junction is a specialized synapse between
a neuron and the muscle it innervates.
• It allows efferent signals from the nervous system to contact muscle
fibers causing them to contract.
• Neuromuscular Junction disease is a medical condition where
the normal conduction through the neuromuscular junction fails to
function correctly.

35. Classification of NMJ disease
• There are two ways to classify neuromuscular diseases. The
first relies on its mechanism of action, or how the action of
the diseases affects normal functioning (whether it is through
mutations in genes or more direct pathways such as
poisoning).
• This category divides neuromuscular diseases into three
broad categories: immune-mediated disease, toxic/metabolic
and congenital syndromes.

36. Classification of NMJ disease
• The second classification method divides the diseases
according to the location of their disruption.
• In the neuromuscular junction, the diseases will either act on
the presynaptic membrane of the motor neuron,
• the synapse separating the motor neuron from the muscle
fiber, or the postsynaptic membrane (the muscle fiber).

37. Most common NMJ diseases
Myasthenia gravis
• Myasthenia gravis is the most common
neuromuscular disease affecting function of the
end plate in patients.
• It is present in 1 people out of 10,000 in the
population, and its onset is usually in either
younger or older individuals.
• Important observations were made by Patrick
and Lindstrom in 1973 when they found that
antibodies attacking the acetylcholine receptors
were present in around 85% of cases of
myasthenia gravis.

38. Myasthenia Gravis
• Drug-induced myasthenia gravis is also a very rare
condition in which pharmacological drugs cause a
blockade or disruption of the NMJ machinery.

39. Other NMJ diseases
• Neuromyotonia
• Congenital myasthenia
• Botulism
• Lambert-Eaton myasthenic syndrome (LEMS)

40. Diagnosis of NMJ Diseases
Tests :
• Repetitive nerve stimulation
• Electromyography (EMG)
• Nerve conduction studies
• Exercise testing
• Single-fiber EMG

41. NMJ Disease Treatment
• Symptomatic treatment
- Cholinesterase inhibitors at AChR
• Immunosuppressive treatment
- Thymectomy
Medical therapy: corticosteroids, non-steroidal immunosuppression
Short-term treatment: plasmapherisis, IVIG

42. 4 - Muscle

43. Muscular dystrophy
• is a group of inherited diseases that damage and
weaken muscles over time.
• Muscular dystrophy can occur at any age, but most
diagnoses occur in childhood.
• This damage and weakness is due to the lack of a
protein called dystrophin, which is necessary for
normal muscle function.
• The absence of this protein can cause problems
with walking, swallowing, and muscle coordination.
• Young boys are more likely to have this disease than
girls.

44. Symptoms
symptoms include:
• trouble walking
• loss of reflexes
• difficulty standing up
• poor posture
• bone thinning
• breathing difficulties
• swallowing problems
• lung and heart weakness

45. Muscular dystrophy

46. Treatment
• There’s currently no cure for muscular dystrophy, but
treatments can help manage symptoms and slow the
progression of the disease.
Treatment options include:
• corticosteroid drugs, which help strengthen muscles
and slow muscle deterioration
• assisted ventilation if respiratory muscles are affected
• medication for heart problems
• surgery to help correct the shortening of muscles
• surgery to repair cataracts

47. Myositis
• is a rare group of diseases characterized by
inflamed muscles, which can cause prolonged
muscle fatigue and weakness.
• The group includes dermatomyositis and
polymyositis, as well as inclusion body myositis
(IBM).
• These diseases, sometimes referred to as
inflammatory myopathies, can affect the internal
organs, skin and multiple muscle groups of
patients.

48. Symptoms
• Difficulty standing up from a seated position
• Difficulty climbing stairs
• Difficulty lifting the arms
• Fatigue after standing or walking a long time
• Trouble swallowing or breathing
• Muscle pain that does not subside within a
few weeks

49. Treatment
• Treatments may include both nondrug and drug-
based therapies,
• including medications such as
immunosuppressants or corticosteroids, which
slow the body’s immune system and reduce the
body’s attack on its muscles, skin and organs.
• Physical therapy also may be included as a
treatment to help improve the patient's physical
activity and quality of life.

50. Thank You