Spinal Muscular Atrophy "SMA"

Question 1

SMA

Defined:

Answer 1

Genetic disease affecting anterior horn cells in SC

Question 2

Spinal Muscular Atrophy

Muscular:

Answer 2

Mm’s unable to receive signals from nerve cells

Question 3

Spinal Muscular Atrophy

Atrophy

Answer 3

When mm’s not active→ lose size+girth and waste away

Question 4

SMA

Causes → MAIN

Answer 4

• Defect→ Chromosome 5
  
  • Motor PRO deficiency→ SMN→ “survival of motor neuron”
    
    • 4 types

Question 5

SMA

other causes

Answer 5

• Mutations in UBE1 on X-chromosome
• Mutation of DYNC1H1 gene on chromosome 14

Question 6

SMA

Diagnosis

Answer 6

• Creatine Kinase, CK
  
  • leaks out of mm’s when deteriorating
  • nonspecific test
• Genetic Testing
  
  • blood test
• MM biopsy and NCVT
  
  • less freq.

Question 7

Symptoms of SMA:

Range: Mild→Severe

Answer 7

• Primary sx’s→ Weakness of voluntary mm’s
  
  • Prox weak>Dist weak
  • Typ symmetrical
• respiration, posture, overall mobility
• PRESERVED→
  
  • intelligence, social dev, sensation*, sphincter control

Question 8

SMA Prognosis

Answer 8

Depends on type and severity

Question 9

MOST SEVERE SMA

Answer 9

Type 1

Question 10

Type 1 SMA:

aka

Answer 10

Acute Childhood/Infantile SMA

Question 11

Type 1 SMA; Acute Childhood/Infantile SMA

*MOST severe

Answer 11

• Werdnig-Hoffman Disease
• Weakness→ @ birth or <4mos
• CN involve.
• Resp. probs and accessory mm use to breathe
  
  • continue to belly breathe due to impaired diaphragm strength
• swallow/feeding diffs
• MM fasciculations→ also tongue
• Tremor

IN GENERAL→ alert and responsive

Question 12

SMA Type 1:

Clinical Characteristics/Facts

Answer 12

• Weakness→ neck, trunk, shoulders, pelvic girdle, antigrav mm’s
• Frog legged pos.→ gravity pulls them into this
• Limtd head/trunk control
  
  • cannot clear airway in prone
  • no unassisted sitting milestone
  • scoliosis prominently seen→ early in type 1

Question 13

SMA Type 1: Childhood SMA/Infantile Onset

MSK issues

Answer 13

• MM contractures & alignment issues→ 2* weakness and not taking mm’s thru full ROM

Question 14

SMA Type 1: Childhood SMA

Life span

Answer 14

• Death from PNA or resp comps common w/in first few mos to few yrs
• Mean age of death= 6mos
  
  • some cases up to 42mos

Question 15

SMA Type 1: Tx

MAIN FOCUS

Answer 15

• Respiratory health
  
  • Chest PT reqd***
    
    • Assist cough
    • Postural drainage pos’s
    • Support devices; ex. vibration vests

Question 16

SMA Type 1: Tx

besides resp health

Answer 16

• Positioning
  
  • Supine w/ suppors
  • S/L GOOD position
    
    • +resp health and un-wts one side
    • very functional due to antigravity pos.== midline play
  • Prone avoided

Question 17

SMA Type 1: Tx cont’d

Supported Sitting

Answer 17

• Supported sitting
  
  • Abdom binder,
  • spinal alignment
  • hammocks→ great for allowing IND but supported mvmt
  • ROM for contracture mgmt
  • LIGHT strengthening in certain pos’s

Question 18

SMA Type 1 videos

Answer 18

Acute childhood SMA

see slide 12******

Question 19

SMA Type 2

aka

Answer 19

Chronic Childhood SMA aka “Intermediate SMA”

Question 20

SMA Type 2: Chronic Childhood SMA

Clinical presentation:

Answer 20

• Weakness→ typ first year of life→ typ bw 7-14mos
• Variable course
• Pearn and colleagues:
  
  • 95%→ weakness <3yo
  • 46% never walked
  • 38% ambulate unaided @ some stage
• Median age of death >10yrs
• Pulm health plays factor in life span

Question 21

SMA Type 2: Chronic Childhood SMA

Eng reports 3 subgroupings w/in Type 2

Answer 21

1. Severe
   
   1. resembles Type 1→ inability to sit, sig. impaired resp system
2. Intermediate
   
   1. sit alone but do NOT achieve amb.
3. Mild
   
   1. children amb. IND but lost ability by end of first decade

Question 22

Type 2 SMA

Weakness

Answer 22

• Prox weak> dist weak as in type 1, to a lesser degree
  
  • hip, knee exts, trunk
  • less severe but present contractures

Question 23

Type 2 SMA Tx: Infancy

Answer 23

• Baby program w/ chronic SMA similar to type 1
• Trunk control in antigravity pos’s
• Dev. activities and gross motor skills
  
  • maintain function if not achieving milestones
• Aquatic tx
• Adapted equip.
  
  • Standers→ esp if not standing by 16mos
  • TLSO→ assist w/ trunk alignment in upright pos.
    
    • slows gravity deforms

Question 24

Type 2 SMA Tx: Preschool/School Age

Answer 24

• Orthotics→ lt. wt. KAFOs
• Assisted walking programs
  
  • SAFETY! 2* incd fx risk and falls bc weakness
• Supported walking DECs:
  
  • contracture, hip disloc’s, scoliosis curve progression
• power mobility if not ambulating
• contractures 2* prolonged sitting
• progression of scoliosis high incidence
• sx for spinal stab.

Question 25

Scoliosis and TLSO

Answer 25

see pics

Question 26

THKAFO and power chair

Answer 26

Question 27

SMA Type 2: Transition into Adulthood

Answer 27

• Adulthood survival variable
• Weakness progresses
• All mobility and ADLs assistance needed
  
  • aide and/or family mbr around the clock
• Aggressive pulm hygiene program
• Continued ROM
• Vocational services

Question 28

SMA type 2 videos

Answer 28

slide 20****

Question 29

SMA Type 3 aka

Answer 29

Juvenile Onset

*Kugelber-Welander Disease

Question 30

SMA Type 3: Juvenile Onset

Clinical Presentation

Answer 30

• Weakness→ after 18mos @ least, OR late into first decade
• typ stand/walk IND, may req. aids
• Prox. LE weakness====PRIMARY FINDING***
  
  • 2* Impairs:
    
    • postural compensations, trendelenburg gait, INC lumbar lordosis, contractures, scoliosis

Question 31

Type 3 SMA: School-Age

Answer 31

• Difficulties:
  
  • rise from floor, stairs, keeping up w/ peers
• Characteristics:
  
  • waddling gait, balance defs, tremors, prox UE strength preserved

Question 32

Type 3 SMA: Juvenile Onset

School-Age

Ambulation?

Answer 32

Ambulation typ preserved as primary mode of loco.

more severe→ scooter

Question 33

Type 3 SMA: Juvenile Onset

School-Aged

PT mgmt

*similar to other types

Answer 33

• Maint. ROM
• Maint. strength
• teach adaptive equip. use

Question 34

Type 3 SMA: Transition to Adulthood

Answer 34

• Gen weakness
• Lifespan NOT shortened→ episodic PT and HEP preserves function
• Vocational counseling absolutely req’d

Question 35

Type 4 SMA: Adult Onset

Answer 35

• Onset in adulthood
• Function fairly typical prior to onset**
• Amb preserved t/o adulthood w/ weak. developing gradually over time

Question 36

Severity of SMA vs Types of SMA

Answer 36

Severity DECs as types INCs

Types I-III== PEDS

Question 37

Hallmarks in ALL FORMS of SMA

Answer 37

Prox>Distal, symmetric weakness

Contractures

Resp. health concerns***

Question 38

PTs play a major role in care/mgmt of SMA from infancy→ adulthood ***

Answer 38

!!!!!!