Investigating The Weak Baby

Question 1

Floppy weak baby VS floppy strong baby Central problem

Answer 1

Likely a lower NM problem

Alert baby
Not moving
Absent reflexes
Lack of antigravity movement

Question 2

Central problem. Strong floppy baby hypotonic

Answer 2

1 decreased alertness 
2 seizures
3 macro/micro head size
4 reflexes normal/brisk
5 dysmorphic eg Down’s syndrome

Question 3

4 causes of NM disorders

Answer 3

1 anterior horn problem. Spinal muscular atrophy
2 Muscle problems Muscular dystrophy
3 peripheral nerve problem eg Charcot Marie tooth syndrome
4 NM junction problems Myasthenia gravis

Question 4

Spinal muscular dystrophy SMA

Answer 4

Floppy weak baby
Absent reflexes 
Marked prox weakess 
Tongue fasciculation
EMG shows patter enervation 
Grade 1 sever 
Grade 2 6-18months 
Grade 3 3 years to adult mile 
All caused by the same gene 
Gene testing and treat with gene therapy

Question 5

Muscular dystrophy

Answer 5

Hypotonic absent or reduced reflexes 
Pattern of weakness is characteristic
Gower’s movement classic way of getting up of the floor prox muscle wasting 
Calf hypertrophied 
Pes cavis

Question 6

Duchene muscular dystrophy

Answer 6

X linked recessive
Boys 1/3500
Presents early childhood weakness hard to keep up with peers
Progressive weakness
Cardiomyopathy. Respiratory problems
Disorder of distrophin causes muscle damage
Raised CK

Gene deletion is out of frame
Dystrophin absent

Treat with steroids 
Prolong walking 
Improved cadiac and resp function 
Less scoliosis surgery 
Multi team approach rehab/ ortho/ resp  allied health ST/ physio

Question 7

Duchene MD and Bechers MD diffences

Answer 7

Both MD

Bechers there is some dystrophin reduced cf Duchenes MD NO dystrophin

Question 8

Peripheral Nerve disorders eg Charcot Marie tooth syndrome

Answer 8

Hereditary motor and sensory neuropathy
1/2500
Distal weakness and sensory loss
Gait abnormal high stepping gait

Question 9

Diagnostic approach to a weak floppy baby with absent reflexes etc

Answer 9

If examination very suggestive and history
The new approach is to #phenotype CMA chromosomal microarray
Limited other ix EMG,CK, muscle nerve bx
MRI of head

Question 10

Congenital myasthenia gravis

Answer 10

NM junction problem
RARE but Treatable
Ptosis delayed motor milestones
Stridor