**IMACS Core Set Measures -- Case examples**

####### Myositis Damage Index (MDI)

The purpose of this exercise is to provide some guidelines in scoring
the MDI. These cases were prepared by Fred Miller, Lisa Rider, Clarissa
Pilkington, and David Isenberg. The scores provided in the 3 cases are
suggestions for your consideration and there may be some differences of
opinion. These cases particularly focus on scoring of the muscle systems
and global activity/damage VAS scores, although the discussion presents
the scoring of other involved organ systems as well.

## Case 4 - PM at Follow-up

A 52 y.o. Asian woman had the insidious onset of muscle weakness, which
was likely undiagnosed for many years after onset. She underwent a full
evaluation \-- including a muscle biopsy showing moderate numbers of
endomysial mononuclear cells without rimmed vacuoles or extreme
variation of myofiber size \-- which resulted in a diagnosis of definite
polymyositis. She refused treatment with corticosteroids or other
therapies but took herbal remedies for an additional 3 years. Two years
ago, when her muscles were very painful, she was confined to a
wheelchair and unable to swallow solids. Her family convinced her to
seek medical treatment and she was found to have very active
polymyositis. She received intravenous pulse solumedrol and was begun on
high dose oral prednisone in divided doses and methotrexate therapy.

While on high dose oral prednisone, she developed brittle
insulin-dependent diabetes that never resolved, avascular necrosis of
the left hip requiring joint replacement, and myocarditis with
subsequent congestive heart failure, which also limits her function. She
never regained much strength and at first was confined to a wheelchair,
but has been bed-bound for a year, requiring assistance for almost all
activities of daily living (HAQ = 2.8). Her myalgias resolved, but her
swallowing continued to be a worsening problem, eventually requiring a
nasogastric feeding tube to prevent aspiration. She develops severe
shortness of breath with any activity, and sometimes at rest, requiring
intermittent nasal oxygen. On exam she had severe muscle atrophy of all
limbs and 2-6/10 strength (Unilateral MMT-8 = 28 out of 80). Her CPK is
65 (normal range 15-250 U/l), serum creatinine is 0.3 (normal range 0.7
-- 1.2 mg/dl), and the rest of her laboratory testing, including CXR, is
normal. She is essentially unchanged from 6 months ago.

**MYOSITIS DISEASE ACTIVITY and DAMAGE ASSESSMENT TOOL VALUES**

**[Muscle]{.underline} Disease [Activity]{.underline} Assessment: VAS =
0 cm**

+--------------+-------------------------------------------------------+
| ####### MU   | Absent Maximum                                        |
| SCLE DISEASE |                                                       |
|              |                                                       |
| ####         |                                                       |
| ### ACTIVITY |                                                       |
+--------------+-------------------------------------------------------+

> [Example of Max score]{.underline}: Severe muscle weakness resulting
> in being bed bound and an inability to perform self care

25\. Myositis:

a\) Severe muscle inflammation **[OR]{.underline}** 0 1 2 3 4 NA

b\) Moderate muscle inflammation **[OR]{.underline}** 0 1 2 3 4 NA

c\) Mild muscle inflammation 0 1 2 3 4 NA

26\. Myalgia 0 1 2 3 4 NA

**[Global]{.underline} Disease [Activity]{.underline} Assessment: VAS =
0 cm**

+-----------+----------------------------------------------------------+
| *         | No Evidence Moderate Extreme or Severe                   |
| *GLOBAL** |                                                          |
|           |                                                          |
| **        |                                                          |
| DISEASE** |                                                          |
|           |                                                          |
| **A       |                                                          |
| CTIVITY** |                                                          |
+-----------+----------------------------------------------------------+

Overall evaluation for the totality of disease activity in **ALL**
systems (**including** muscle)

Myositis Damage Index (MDI) [Muscle Damage]{.underline} Assessment: VAS
= 10 cm

+-------------+--------------------------------------------------------+
| ###         | Absent Maximum                                         |
| #### MUSCLE |                                                        |
|             |                                                        |
| **DAMAGE**  |                                                        |
+-------------+--------------------------------------------------------+

[Example of Max score]{.underline}: Severe muscle atrophy or weakness
resulting in being bed bound and an inability to perform self care

1\. Muscle atrophy (clinical) 0 1 NA

2\. Muscle weakness not attributable to active muscle disease 0 1 NA

3\. Muscle dysfunction: decrease in aerobic exercise capacity *0* 1 NA

4\. *[Muscle atrophy assessed by radiographic methods]{.underline}* 0 1
NA

5\. *[Low serum creatinine]{.underline}* 0 1 NA

*Creatinine value = 0.3 mg/dL; lower limit normal value = 0.7mg/dL*

**Myositis Damage Index (MDI) [Global Damage]{.underline} Assessment:
VAS = 9 cm**

+------------+---------------------------------------------------------+
| #          | Absent Maximum                                          |
| ###### GLO |                                                         |
| BAL DAMAGE |                                                         |
+------------+---------------------------------------------------------+

###### 

###### [Examples of Max score:]{.underline} None

**Discussion of Case 4:**

The patient has no evidence of disease activity, but has severe damage
of many organ systems. She has severe muscle damage resulting in fixed
muscle weakness with extensive atrophy, severe functional impairment and
a bed-bound state **(MDI Muscle VAS = 10 cm)**. Other damaged organ
systems include: skeletal with avascular necrosis requiring hip
replacement **(MDI Skeletal VAS = 8 cm)**; GI system requiring a
nasogastric tube **(MDI GI VAS = 9 cm)**; pulmonary system with impaired
respiratory musculature **(MDI Pulmonary VAS = 8 cm)**; cardiac
involvement with congestive heart failure and functional impairment
**(MDI Cardiovascular VAS = 7 cm)** and endocrine system involvement
with steroid-induced, brittle insulin-dependent diabetes **(MDI
Endocrine VAS = 6 cm).** Her extremely limited function **(HAQ = 2.8 out
of 3.0 maximum)** and multiple systems with high degree of damage place
her **MDI Global Damage score at 9 cm**, but her ability to breath and
swallow without external support systems keep her from attaining a MDI
Global Damage VAS score of 10 cm.

### Case 5 -- PM at Follow-up

A 69-year-old Latino male presents with a vague history of 2-3 years of
increasing fatigue with muscle weakness in the upper and lower
extremities, unexpected falling and slowly increasing dysphagia with
solid but not liquid foods. He denies alcohol or drug use, muscle pain
and weight loss. His past medical history is unremarkable and family
history is negative for any neuromuscular or autoimmune diseases except
for SLE in a younger sister. He was seen by you a year ago and a
detailed workup then only revealed muscle weakness, proximal \> distal,
in the 6-7/10 range of the upper and lower extremities (Unilateral MMT-8
= 52 out of 80) and moderate atrophy of the shoulder, arm and thigh
muscles. His HAQ was 2.0 and he reportedly was unable to climb stairs
without assistance and could not keep up with family members when
walking. Laboratories were remarkable for a CK of 325 (normal range 20
to 250) with 100% MM, a creatinine of 0.8 (normal 0.9-1.4 mg/dl) and a
positive ANA at 1:640, speckled pattern. All of his other extensive
laboratory and autoantibody tests were negative or unremarkable. A
barium swallow examination showed moderate esophageal dysfunction but no
evidence of aspiration. His CXR and EKG were normal, but his EMG showed
evidence of active muscle inflammation in the upper and lower
extremities. A thigh muscle biopsy showed variation in myofiber size,
degeneration and regeneration, rare scattered endomysial mononuclear
cell infiltrations, fatty replacement of myofibers and increased
interstitial spaces, but no evidence of inclusion bodies or other
abnormalities. An extensive cancer work up was negative. You suggested
he begin using a cane for ambulation to minimize the risk of falling.

A year ago, he initially refused all therapy, especially corticosteroids
given his sister's negative experience with them, but after further
explanations, finally agreed to take 40 mg prednisone daily and was told
to return in 1 month for follow up; he returned 6 months later with a
normal CK but no change in muscle strength or swallowing. You begin a
slow steroid taper over the next 6 months to no prednisone today and he
remains completely unchanged in all respects from your initial
evaluation 12 months ago except for normalization of all muscle enzymes
and a creatinine of 0.7 (normal 0.9-1.4 mg/dl).

**MYOSITIS DISEASE ACTIVITY and DAMAGE ASSESSMENT TOOL VALUES**

##### 

##### [Muscle]{.underline} Disease [Activity]{.underline} Assessment: VAS = 0 cm

+--------------+-------------------------------------------------------+
| ####### MU   | Absent Maximum                                        |
| SCLE DISEASE |                                                       |
|              |                                                       |
| ####         |                                                       |
| ### ACTIVITY |                                                       |
+--------------+-------------------------------------------------------+

> [Example of Max score]{.underline}: Severe muscle weakness resulting
> in being bed bound and an inability to perform self care

25\. Myositis:

a\) Severe muscle inflammation **[OR]{.underline}** 0 1 2 3 4 NA

b\) Moderate muscle inflammation **[OR]{.underline}** 0 1 2 3 4 NA

c\) Mild muscle inflammation 0 1 2 3 4 NA

26\. Myalgia 0 1 2 3 4 NA

**[Global]{.underline} Disease [Activity]{.underline} Assessment: VAS =
0 cm**

+-----------+----------------------------------------------------------+
| *         | No Evidence Moderate Extreme or Severe                   |
| *GLOBAL** |                                                          |
|           |                                                          |
| **        |                                                          |
| DISEASE** |                                                          |
|           |                                                          |
| **A       |                                                          |
| CTIVITY** |                                                          |
+-----------+----------------------------------------------------------+

Overall evaluation for the totality of disease activity in **ALL**
systems (**including** muscle)

Myositis Damage Index (MDI) [Muscle Damage]{.underline} Assessment: VAS
= 6 cm

+-------------+--------------------------------------------------------+
| ###         | Absent Maximum                                         |
| #### MUSCLE |                                                        |
|             |                                                        |
| **DAMAGE**  |                                                        |
+-------------+--------------------------------------------------------+

[Example of Max score]{.underline}: Severe muscle atrophy or weakness
resulting in being bed bound and an inability to perform self care

1\. Muscle atrophy (clinical) 0 1 NA

2\. Muscle weakness not attributable to active muscle disease 0 1 NA

3\. Muscle dysfunction: decrease in aerobic exercise capacity *0* 1 NA

4\. *[Muscle atrophy assessed by radiographic methods]{.underline}* 0 1
NA

5\. *[Low serum creatinine]{.underline}* 0 1 NA

Creatinine value = 0.7 mg/dL; lower limit normal value = 0.9mg/dL

**Myositis Damage Index (MDI) [Global Damage]{.underline} Assessment:
VAS = 5 cm**

+------------+---------------------------------------------------------+
| #          | Absent Maximum                                          |
| ###### GLO |                                                         |
| BAL DAMAGE |                                                         |
+------------+---------------------------------------------------------+

###### [Examples of Max score:]{.underline} None

**Discussion of Case 5**

The patient has a clinical picture suggestive of, but not diagnostic of,
inclusion body myositis with initial moderate muscle disease activity,
which resolves with steroid therapy (not clear that it resolved) and
some GI involvement. He has moderate muscle disease damage with fixed
muscle atrophy, residual moderate muscle weakness, aerobic exercise
limitations, functional impairment and decreased creatinine with no
evidence of active myositis **(MDI muscle damage VAS = 6 cm)**. His
dysphagia is also fixed and represents a **MDI GI VAS score of 5 cm**.
No other organ systems are affected with disease damage. His **MDI
Global damage score is 5 cm**.

## Case 6 -- JDM at Follow-up

During the one-and-a-half years after Case 3 (see Case 3 in Global
Disease Activity handout) presented, the child received oral
corticosteroids, photoprotection and physical therapy and was treated as
an outpatient; no additional therapy was needed. Prednisone was
eventually tapered and discontinued because she developed moderate
transient hypertension requiring treatment and bilateral cataract
formation, which impaired her vision. Her strength showed gradual
improvement but she complains of not being back to normal, having
difficulty keeping up with classmates at recess, and of getting tired
more easily than before her illness started.

Today she appears well with normal vital signs; there are mild atrophic
skin changes over the 2nd and 3rd knuckles, a mild heliotrope rash and
slightly enlarged periungual capillaries along with 2 small superficial
plaques of calcinosis over her elbows. Abdominal strength is grade 8/10,
neck and arm flexors have mild atrophy and are grade 8/10, but strength
is otherwise normal (MMT-8=76 out of 80). CK is 110 (normal 20 to 215
U/l), aldolase is 4 (normal 1 to 9 U/l), and creatinine is 0.7 (normal
0.7 -- 1.2 mg/dl). Essentially, she is unchanged from 6 months ago.

**MYOSITIS DISEASE ACTIVITY and DAMAGE ASSESSMENT TOOL VALUES**

##### 

##### [Muscle]{.underline} Disease [Activity]{.underline} Assessment: VAS = 0 cm

+--------------+-------------------------------------------------------+
| ####### MU   | Absent Maximum                                        |
| SCLE DISEASE |                                                       |
|              |                                                       |
| ####         |                                                       |
| ### ACTIVITY |                                                       |
+--------------+-------------------------------------------------------+

> [Example of Max score]{.underline}: Severe muscle weakness resulting
> in being bed bound and an inability to perform self care

25\. Myositis:

a\) Severe muscle inflammation **[OR]{.underline}** 0 1 2 3 4 NA

b\) Moderate muscle inflammation **[OR]{.underline}** 0 1 2 3 4 NA

c\) Mild muscle inflammation 0 1 2 3 4 NA

26\. Myalgia 0 1 2 3 4 NA

**[Global]{.underline} Disease [Activity]{.underline} Assessment: VAS =
1 cm**

+-----------+----------------------------------------------------------+
| *         | No Evidence Moderate Extreme or Severe                   |
| *GLOBAL** |                                                          |
|           |                                                          |
| **        |                                                          |
| DISEASE** |                                                          |
|           |                                                          |
| **A       |                                                          |
| CTIVITY** |                                                          |
+-----------+----------------------------------------------------------+

Overall evaluation for the totality of disease activity in **ALL**
systems (**including** muscle)

Myositis Damage Index (MDI) [Muscle Damage]{.underline} Assessment: VAS
= 2 cm

+-------------+--------------------------------------------------------+
| ###         | Absent Maximum                                         |
| #### MUSCLE |                                                        |
|             |                                                        |
| **DAMAGE**  |                                                        |
+-------------+--------------------------------------------------------+

[Example of Max score]{.underline}: Severe muscle atrophy or weakness
resulting in being bed bound and an inability to perform self care

1\. Muscle atrophy (clinical) 0 1 NA

2\. Muscle weakness not attributable to active muscle disease 0 1 NA

3\. Muscle dysfunction: decrease in aerobic exercise capacity *0* 1 NA

4\. *[Muscle atrophy assessed by radiographic methods]{.underline}* 0 1
NA

5\. *[Low serum creatinine]{.underline}* 0 1 NA

Creatinine value = 0.7 mg/dL; lower limit normal value = 0.7mg/dL

**Myositis Damage Index (MDI) [Global Damage]{.underline} Assessment:
VAS = 2 cm**

+------------+---------------------------------------------------------+
| #          | Absent Maximum                                          |
| ###### GLO |                                                         |
| BAL DAMAGE |                                                         |
+------------+---------------------------------------------------------+

###### [Examples of Max score:]{.underline} None

**Discussion of Case 6**

One-and-a-half years later her disease is improved, with normalization
of muscle enzymes and without evidence of muscle disease activity
**(Muscle disease VAS = 0 cm)**, but there is mildly active skin disease
based upon the finding of a persistent heliotrope rash and periungual
capillary changes (Cutaneous MDAAT numerical score = 2 \[feature is the
same\], Cutaneous VAS activity = 2 cm); and continued mild fatigue
(Constitutional MDAAT numerical score = 2 \[feature is the same\],
Constitutional VAS activity = 1 cm). Her **Global disease activity VAS =
1 cm)**.

Evidence of damage is present. She has stable, persistent muscle
weakness with atrophy, as well as aerobic exercise impairment, without
other known cause (such as steroid myopathy) and no evidence of muscle
disease activity **(MDI Muscle damage VAS = 2 cm)**. Regarding her skin,
she has atrophic Gottron's lesions from prior active disease and several
superficial plaques of calcinosis **(MDI Cutaneous VAS = 2 cm)**. She
also has bilateral cataract formation with impaired vision **(MDI Ocular
VAS = 5 cm).** She has no other evidence of damage, giving her a **MDI
Global Damage Assessment VAS = 2 cm**.