Muscular dystrophies are a group of inherited disorders characterized by gradual muscle degeneration and weakness. Duchenne muscular dystrophy is the most severe and common form, caused by the absence of dystrophin, a protein essential for muscle stability. Other types, such as Becker, limb-girdle, or myotonic dystrophy, vary in onset and severity. Over time, affected individuals develop muscle wasting, difficulty walking, contractures, and scoliosis. Cardiac and respiratory muscles may also be involved, making the condition life-threatening. Orthopedic management focuses on preserving mobility through physiotherapy, bracing, tendon-release surgeries, and monitoring for spinal deformities. Neuropathies, in contrast, result from damage to the peripheral nerves. These may be hereditary, such as Charcot–Marie–Tooth (CMT) disease, or acquired from conditions like diabetes, toxins, infection, or autoimmune processes. When nerves deteriorate, the muscles they supply weaken and waste away. Patients often present with sensory loss, foot deformities (such as pes cavus), gait abnormalities, and reduced reflexes. Orthopedic problems develop due to muscle imbalance, joint instability, and chronic deformities. Management includes orthotic support, physical therapy, correction of deformities. Dr Aliya Shair Muhammad Lecturer: BUMHS, Quetta

1. Muscular Dystrophy and
Neuropathies
DR ALIYA SHAIR MUHAMMAD
BUMHS, QUETTA

2. Definition:
•A group of 30+ genetic disorders affecting muscle strength
•Leads to progressive muscle weakness and functional decline
Onset varies by type:
 At birth
 Childhood
 Adulthood
•Symptoms worsen gradually over time, impacting mobility and daily activities

3. The types of muscular dystrophy are
grouped by the:
 Extent and distribution of muscle weakness
 Age of onset
 Rate of progression
 Severity of symptoms
 Family history

4. Etiology:
Genetic Origin:
Mutations or deletions in genes responsible for muscle-membrane glycoproteins
Dystrophin Gene Defects:
•Discovered in 1986; codes for dystrophin, a key structural protein
•Dystrophin links the contractile apparatus to the sarcolemma
Absent or reduced dystrophin → structural instability → muscle fibre degeneration
Types Based on Dystrophin Mutation:
•Duchenne MD: No functional dystrophin produced
•Becker MD: Insufficient or low-quality dystrophin
•Why Mutations Occur:
Dystrophin gene = largest in the human genome → high mutation rate
Inheritance Pattern:
•Most forms are X-linked recessive, making MD more common in biological males

5. Duchenne Muscular Dystrophy:
•Duchenne muscular dystrophy (DMD) is the most common
childhood form of muscular dystrophy (MD).
•It is inherited through a mutation on the X chromosome,
making it an X-linked recessive disorder.
•Primarily affects boys, though carrier girls may show mild
symptoms.
•Caused by the absence of dystrophin, an essential muscle
protein.
•Symptoms usually appear in toddler years, often soon after
walking begins.

6. Characterized by:
 Loss of some reflexes
 A waddling gait
 Frequent falls and clumsiness (especially when running)
 Difficulty when getting up from a sitting position or when climbing stairs
 Changes to overall posture
 Impaired breathing
 Heart problems (cardiomyopathy)

7. Becker Muscular Dystrophy
 Onset & Progression
Typically appears around age 11
Can occur as late as age 25
Progression is slower and more variable than Duchenne
MD
➤ Life Expectancy
Individuals usually live into middle age or later
➤ Muscle Weakness & Atrophy
Rate of muscle decline varies greatly between individuals
Many retain ability to walk until mid-30s or later
Some lose ability to walk by their teens
➤ Pattern of Muscle Involvement
Weakness first appears in:
Upper arms and shoulders
Upper legs
Pelvis
➤ Cognitive, Behavioral & Cardiac Symptoms
Less common and less severe than in
Duchenne MD
Heart problems and mild
cognitive/behavioral issues may still occur

8. Symptoms Of Becker MD
 Walking on one's toes
 Frequent falls
 Difficulty rising from the floor

9. Congenital Muscular Dystrophy
Congenital muscular dystrophy is a group of muscular dystrophies present at birth
or becoming evident before age 2
•Degree and progression of muscle weakness and degeneration vary with the type
of disorder
•Weakness may first be noted when children do not meet developmental
milestones related to motor function and muscle control
•Muscle degeneration is restricted primarily to skeletal muscle
•Most people with this type of muscular dystrophy are unable to sit or stand without
support
•Some individuals may never learn to walk

10. Genetic Forms Of Congenital MD
 Merosin-negative disorders, in which the protein merosin (found in the
connective tissue that surrounds muscle fibers) is missing
 Merosin-positive disorders, in which merosin is present but other necessary
proteins are missing

11. congenital MD can develop:
 Contractures (shortening of muscles or tendons around joints)
 Scoliosis (curved spine)
 Breathing and swallowing difficulties
 Foot problems

12. Distal Muscular Dystrophy:
 Affects distal muscles: forearms, hands, lower legs, and feet
 Typically mild, slowly progressive, and involves fewer muscles than other MDs
 May spread to heart and respiratory muscles → ventilatory support may be needed
 Functional issues:
 Difficulty with fine hand movements
 Trouble extending fingers
 Difficulty walking, climbing stairs, standing on heels, or hopping
Onset: usually 40–60 years
Inheritance: mainly autosomal dominant; autosomal recessive forms occur (including infantile-onset)
Symptoms resemble DMD but with a different muscle involvement pattern
Infantile recessive type: noticeable weakness from around age 1, progressing very slowly through
adulthood

13. Emery-Dreifuss Muscular Dystrophy:
Primarily affects boys
Two inheritance forms: X-linked recessive & autosomal dominant
Onset:
usually by age 10, but may appear up to the mid-20s
Causes slow, progressive wasting of upper-arm and lower-leg muscles
Weakness is symmetric and generally less severe than DMD
Early contractures (before major weakness):
Elbows, ankles, knees, spine, and neck.
May lead to rigid spine and elbows locked in flexed position
Recognizable for its triad: early contractures, slowly progressive muscle weakness, and
potential cardiac involvement (arrhythmias, conduction defects)

14. symptoms include:
 Shoulder deterioration
 Walking on one's toes
 Mild facial weakness

15. Facioscapulohumeral Muscular Dystrophy:
 Affects face, shoulders, upper arms
 Autosomal dominant muscular dystrophy
 Slow progression with occasional rapid decline
 Onset: teens, but can range from childhood to age 40
 Causes asymmetric muscle weakness
 Early signs: weakness around eyes and mouth
 Later: shoulder slanting, scapular winging, upper-arm and chest
weakness
 Lower limb weakness may occur
 Reflexes reduced in affected areas
 Most patients have a normal life span

16. Conti…
 Facial changes: crooked or flat facial expression, pouting look,
mask-like face
 Functional issues: difficulty puckering lips, whistling, chewing,
swallowing, or speaking
 Respiratory involvement: weakness may affect the diaphragm
 Other symptoms: hearing loss, lumbar lordosis, occasional severe
limb pain
 Rare: contractures; cardiac involvement is uncommon
 Infant-onset FSHD: may cause retinal disease and hearing loss

17. Surgical intervention:
Category Surgical Procedure Purpose / Benefit
Notes / MD Types
Commonly Used In
1. Orthopedic Surgeries
Contracture release
(e.g., Achilles tendon
lengthening)
Reduces tightness,
improves joint
positioning and mobility
Used in many MDs with
progressive contractures
(DMD, CMD, LGMD)
Scoliosis surgery (spinal
fusion)
Stabilizes spine, improves
breathing mechanics,
reduces pain
Common in **D

18. Neuropathies

19. Neuropathy:
 Neuropathy is a collection of disorders that occurs when nerves of the
peripheral nervous system(part of the nervous system outside the brain &
spinal cord) are damaged

20. Classification of Neuropathy
 1-Mononeuropathy:May involve one nerve
 2- Mononeuropathy multiplex: Involves several nerve s but not contiguous
 3- Polyneuropathy: involves several nerves together Connected

21. 1.Mononeuropathy (single nerve
affected)
 Carpal tunnel syndrome – compression of the median nerve
 Bell’s palsy – facial nerve (CN VII) paralysis
 Ulnar neuropathy – compression of the ulnar nerve at the elbow

22. Carpal tunnel syndrome
 Perhaps the most common mononeuropathy
 Entrapment of median nerve in the wrist
 Results in paresthesia of thumb, index, and middle finger; Weakness of
the abductor pollicus brevis
 Tingling fingers, weak thumb, loss of "meat" of the APB muscle (atrophy)

23. Carpal tunnel syndrome-Causes
 Usually due to overuse
Typing probably okay (argued)
Other causes
Arthritis
Osteoarthritis,
Rheumatoid arthritis
Infiltrative diseases
Hypothyroidism
Diabetes
Pregnancy

24. CAUSES OF MONONEUROPATHY:
 1- Trauma: wrong injection into a nerve, callus compression.
 2- Infective: leprosy, herpes zoster.
 3- Vascular: polyarteritis nodosa.
 4- Metabolic: diabetes mellilus.

25. Ulnar neuropathy:
 Just distal to the elbow cubital tunnel entrapped
 Results in a claw hand if severe

26. Tarsal tunnel syndrome
Distal tibial nerve entrapment distal to the medial malleolus
Etiology: Trauma, poor shoes, cyst or ganglion, and arthritis
Symptoms include numbness on bottom of feet, pain in ankle, and weak toe
flexors
Treatment is typically surgical

27. Carpal tunnel syndrome-Treatment
 Treatment is usually surgical resection of carpal ligament
 Other treatments may help, too
Stretches
Splints
Cock-up wrist splints
Night time use only?
 Anti-inflammatory medications
Oral (non-steroidal)
Injections

28. Bell's palsy:
 Inflammation of 7th cranial nerve
 One sided facial paralysis
 Mechanism not understood Virus implicated Lyme disease?
Treatment :
May need to tape eye, especially at night
Herpes treatment/Antivirals Prednisone
Usually resolves with time

30. 2.Mononeuropathy Multiplex (multiple,
non-contiguous nerves)
Vasculitic neuropathy
 Often due to polyarteritis nodosa
 Nerve damage from ischemia secondary to vessel inflammation
 Diabetic mononeuropathy multiplex
 Multiple isolated nerve lesions in diabetic patients
 Commonly affects cranial nerves, femoral, or peroneal nerves
Leprosy neuropathy
 Selective involvement of several individual peripheral nerves
 Asymmetric thickening and sensory-motor deficits

31. 3. Polyneuropathy (many nerves,
diffuse & symmetric)
Diabetic Peripheral Neuropathy
•Most common cause.
•Slowly progressive, sensory > motor, often starts in feet.
Guillain-Barré Syndrome (GBS)
Type: Acute, immune-mediated demyelinating neuropathy
Trigger: Often follows infection (respiratory or GI)
Symptoms:
Rapidly progressive, symmetric ascending weakness
Areflexia (loss of reflexes)
Tingling or numbness; sometimes pain
Autonomic involvement: BP/HR fluctuations
Can affect respiratory muscles → may need ventilatory support
Diagnosis: Nerve studies + CSF (high protein, normal cells)
Treatment: IVIG or plasma exchange, supportive care
Prognosis: Most recover over weeks–months; residual weakness possible
.
Alcoholic Peripheral Neuropathy
 Chronic alcohol use → nutritional deficiencies (e.g., B vitamins).
 Symmetric distal sensory loss, mild motor involvement.

32. CAUSES OF POLYNEUROPATHY:
Hereditary (Familial) Polyneuropathies
 Hypertrophic Interstitial Polyneuropathy (CMT Type 1)
 Genetic disorder causing thickened peripheral nerves
 Distal sensory and motor deficits, pes cavus, reduced reflexes
 Slowly progressive, often beginning in childhood/adolescence
 Peroneal Muscle Atrophy
 Wasting of peroneal muscles → foot drop, gait abnormality
 Symmetrical, distal predominance
 Associated with hereditary motor and sensory neuropathies

33. Clinical Picture of polyneuropathy:
Symmetrical distal involvement (“stocking-glove” pattern)
Sensory: numbness, tingling, burning, loss of vibration/position sense
Motor: distal weakness, muscle wasting, loss of reflexes
Autonomic (if present): postural hypotension, GI symptoms, erectile/urinary
issues
Gait disturbance

34. Pure motor neuropathies:
 Amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease)
-Lower motor neuron disease. Death within 5 years.
Progressive neurodegenerative disorder affecting both upper and lower motor
neurons.
Leads to muscle weakness, atrophy, fasciculations, and spasticity, sparing sensory
function.
Prognosis: Rapid progression with most patients succumbing within 3–5 years of
symptom onset
 Poliomyelitis-Spinal cord disease Spinal muscular atrophies.

36. Myasthenia Gravis
 Disorder of neuromuscular junction
Antibody attack of acetylcholine receptors
As a result, less post synaptic receptors
Weakness and fatigability of muscles
Eye lids and cranial nerves with diplopia and prost 500 Deoping of the
upper eyelid in people
Peak in women 20's-30's and men 50's-60’s
Cure unknown, but treatable

37. Myasthenia gravis-Diagnosis and
Treatment:
Diagnosis:
Clinical features: Fluctuating muscle weakness, worsens with activity, improves with rest.
Antibody testing: Anti-AChR or anti-MuSK antibodies.
Electrophysiology: Repetitive nerve stimulation → decremental response.
Imaging: Chest CT/MRI to check for thymoma.
Treatment:
Symptomatic: Acetylcholinesterase inhibitors (e.g., pyridostigmine).
Immunosuppressive therapy: Corticosteroids, azathioprine, mycophenolate.
Rapid control (crisis): IVIG or plasma exchange.
Surgical: Thymectomy (especially if thymoma or generalized MG).

38. Chronic inflammatory demyelinating
polyneuropathy (CIDP)
A Gradual onset
Motor and sensory symptoms
75% recovery/Death rare
Other than slow onset, similar to GBS
Treatment same (IVIG 0.4g/kg x5days)

39. Evaluation of patient with neuropathy:
As always, requires history and physical exam
Specific attentions to neurological exam
Typically, also requires some electrical
diagnostic study

40. History of drug use:
Amiodarone
Chemotherapeutics
Cisplatin-anti-Corner
Taxol- Breest, onrein
Antibiotics
Metronidazole
INH
Anti-retrovirals
Heavy metals

41. Physical exam:
 Look for thickening of nerves (Neurofibromas)
 Decreased pinprick, sensation, or temperature
 Decreased reflexes
 Motor weakness
 Tinnel's testing

42. Lab evaluation:
 Might included CBC, Erythrocyte sedimentation rate, urinalysis, glucose
serum protein electrophoresis, thyroid function testing

43. Electrical diagnosis:
 Demyelination
Slows nerve conduction velocity
Conduction block possible
Axonal degeneration
Decreases amplitude of action potentials

44. Electrical diagnosis:
 Helps differentiate between:
Muscle vs. nerve problem vs. neuromuscular junction
Root vs. distal nerve location
Single vs. multiple nerves
Upper vs. lower motor neuron dz

45. Nerve biopsy:
 May be required to rule out:
Vasculitis
Amyloid
Leprosy
Sarcoidosislymph enberg

46. PN Testing for diagnosis
 The EMG test itself:
Nerve Conduction Studies (NCS)
EMG (Needle portion)