Dystonia

INDEX

 

                       Retrocollis                                                      Retrocaput                                          Backward Sagittal Shift

 

Retrocollis
The neck is tilted backwards in relation to the thoracic spine; the angle between the neck and head is normal1

Retrocaput
The head is tilted backwards at an angle on the neck; the angle between the cervical and thoracic spine is normal1.

Distinguishing retrocaput and and retrocollis
Analysis of backward flexion (differentiation between retrocollis and retrocaput) can be accomplished by observation from the side of the respective angles between the cervical  and thoracic spine (retrocollis), and between the cervical spine and the base of skull (retrocaput)2.

In cases of severe retrocollis, it is difficult, in practice, to distinguish the extension of the cervical spine (hyperlordosis) from the extension of the head on cervical spine. In that case, it may be more important to choose a high dose of botulinum toxin and an appropriate needle for deeper injection rather than to try to distinguish each muscle of the posterior cervical region during the injections as all the posterior cervical muscles can be involved in the extension3.

Figure 1. Patient with severe retrocollis. 

From: Srinivasan,S. (2019, August,2). Severe retrocollis with trunk dystonia (Video). YouTube. https://www.youtube.com/watch?v=5-tv9pkQ7TA and Cooper IS. Effect of Thalamic Lesions upon Torticollis. N Engl J Med 1964; 270: 967–72.

 


 

RETROCOLLIS

Figure 2. A patient with retrocollis. 

 

Patient Image

From: Reichel G. Cervical dystonia: A new phenomenological classification for botulinum toxin therapy. Basal Ganglia [Internet] 2011;1(1):5–12. 




Treatment

Semispinalis Capitis   2 x 7.5 u; Max 50 u Botox;2 x 30-40; Max 200 u Dysport

Semispinalis capitis is a long paired muscle that belongs to the deep layer of muscles of the back. It forms the superior, and largest, component of the three-part semispinalis muscle. With semispinalis cervicis and semispinalis thoracis forming the middle and inferior divisions of the muscle, respectively.
The muscle arises from transverse processes of C3-T6, and posterior spinous processes of C3-T1. The muscles inserts between the superior and inferior nuchal lines of the occipital bone. 
The semispinalis is covered by the trapezius, below the semispinalis are the paraspinal muscles.

One injection is given one centimeter below the hairline, and the 2nd about 2.5 cm below that, as shown in the figure (Surface Anatomy: Injection Sites). If the neck is flexed (chin towards the chest) the muscle is relaxed and injections less painful; activation of the muscle is achieved by moving the head backwards against the examiner’s hand.

Surface Anatomy: Injection Sites for Semispinalis Capitis muscle

Anatomy: Insertion and Origin of Semispinalis Capitis muscle



And/or splenius capitis 
Bilateral 2 x 10-12.5 u; Max 20 u Botox;
2 x 40-50;  Max 2 x 80 u Dysport

Locate the mastoid process (marked with the semicircle in the image (Surface Anatomy: Injection Sites) and the border of the sternocleidomastoid. Posterior to the sternocleidomastoid is the splenius capitis, and the initial injection is given there. The length of the muscle is followed diagonally backwards and downwards, and the second injection given. If no EMG activity is heard, the muscle may be activated by asking the patient to turn their head to the ipsilateral side.

Surface Anatomy: Injection Sites for Splenius muscle

Anatomy: Insertion and Origin of Splenius muscle


Alternative scheme: (After: Jost WH, Tatu L. Selection of Muscles for Botulinum Toxin Injections in Cervical Dystonia. Mov Disord Clin Pract 2015;2(3):224–6)

Bilateral Semispinalis Cervicis
The semispinalis cervicis arises by a series of tendinous and fleshy fibers from the transverse processes of T1-T6.
The muscle inserts into the posterior spinous processes of C2-C7.
The muscle acts to extend the thoracic and cervical spine and produce contralateral rotation.
 

Anatomy: Insertion and Origin of Semispinalis Cervicis muscle


 

RETROCAPUT

Figure 3. A patient with retrocaput.

 

Patient Image

From: Reichel G. Cervical dystonia: A new phenomenological classification for botulinum toxin therapy. Basal Ganglia [Internet] 2011;1(1):5–12. 




TREATMENT

Bilateral  (After: Jost WH, Tatu L. Selection of Muscles for Botulinum Toxin Injections in Cervical Dystonia. Mov Disord Clin Pract 2015;2(3):224–6)

1. Obliquus Capitis Inferior
2. Semispinalis Capitis
3. Trapezius (pars descendens)
4. Splenius Capitis

1. Obliquus Capitis Inferior
Technique
1. Place the convex transducer horizontally on the posterolateral neck at a level just below the tip of the mastoid process.
2. Rotate the dorsal end of the transducer a little downward, and turn the transducer a little in a rostral direction.
3. Identify the OCI. Normally, it is sausageā€like, but may become ovoid in shape when it is hyperactive. The vertebral artery is just beneath the muscle. Confirm it with the color Doppler imaging. When the OCI is difficult to detect, because of intramuscular fibrosis the vertebral artery may help identify the muscle. There are occasionally other arteries superficial to the OCI.
4. Measure the approximate depth from the skin to the OCI and the muscle thickness before needle insertion in order to penetrate the muscle and not injure the vertebral artery.
6. After confirming the absence of any major artery along the expected needle path, insert the needle (27 gauge, 38 mm) from above the transducer. Direct the needle tip slightly downward so as to let the needle proceed within the ultrasound coverage area. Botulinum toxin is usually injected into medial and lateral portions of the muscle, but if the muscle is shortened by contraction its central portion may be the only site of injection.

Anatomy: Insertion and Origin of OCI

Ultrasound: Activation of OCI

Ultrasound: Demonstration of OCI



2. Semispinalis Capitis   2 x 7.5 u; Max 50 u Botox;2 x 30-40; Max 200 u Dysport

Semispinalis capitis is a long paired muscle that belongs to the deep layer of muscles of the back. It forms the superior, and largest, component of the three-part semispinalis muscle. With semispinalis cervicis and semispinalis thoracis forming the middle and inferior divisions of the muscle, respectively.
The muscle arises from transverse processes of C3-T6, and posterior spinous processes of C3-T1. The muscles inserts between the superior and inferior nuchal lines of the occipital bone. 
The semispinalis is covered by the trapezius, below the semispinalis are the paraspinal muscles.

One injection is given one centimeter below the hairline, and the second about 2.5 cm below that, as shown in the figure (Surface Anatomy: Injection Sites). If the neck is flexed (chin towards the chest) the muscle is relaxed and injections less painful; activation of the muscle is achieved by moving the head backwards against the examiner’s hand.

Surface Anatomy: Injection Sites for Semispinalis Capitis muscle

Anatomy: Insertion and Origin of Semispinalis Capitis muscle



3. Left Trapezius  2 x 7.5-10 u Max 50 u Botox;  2 x 30-40 max 200 u Dysport

The trapezius is superficial and is generally easily palpated at the base of the neck palpate. It is likely that the trapezius does not play a major role in causing abnormal head posture, but the muscle often seems to cause pain, which is effectively treated with botulinum toxin.

Recommended to inject trapezius at the base of the neck with one or two injections

Surface Anatomy: Injection Sites for Trapezius muscle Anatomy: Insertion and Origin of  Trapezius muscle



4. Splenius capitis  Bilateral 2 x 10-12.5 u; Max 20 u Botox; 2 x 40-50;  Max 2 x 80 u Dysport

Locate the mastoid process (marked with the semicircle in the image( Surface Anatomy: Injection Sites) and the border of the sternocleidomastoid. Posterior to the sternocleidomastoid is the splenius capitis, and the initial injection is given there. The length of the muscle is followed diagonally backwards and downwards, and the second injection given. If no EMG activity is heard, the muscle may be activated by asking the patient to turn their head to the ipsilateral side.

Surface Anatomy: Injection Sites for Splenius muscle

Anatomy: Insertion and Origin of Splenius muscle

 

Additional Muscles to consider:

Rectus capitis major
The rectus capitis major arises from the spinous process of the axis (C2) and inserts into the inferior nuchal line.
It is responsible for ipsilateral rotation of the head, and extension of the head.

Anatomy: insertion and origin of rectus capitis major



Obliquus capitis superior

The muscle arises from the lateral mass of the atlas bone. It passes superiorly and posteriorly to insert into the lateral half of the inferior nuchal line on the external surface of the occipital bone.
Obliquus capitis superior extends the head, and also results in ipsilateral head flexion.

Anatomy: insertion and Origin of obliquus capitis superior



Longissimus capitis
The muscles arises from the transverse processes of the upper five thoracic vertebrae and the articular processes of the lower four cervical vertebrae.
The muscles inserts into the posterior margin of the mastoid process, beneath splenius capitis and the sternocleidomastoid.
Longissimus capitis acting bilaterally will extend the vertebral column (acting unilaterally flexes the head and neck laterally).

Ultrasound approach for Longissimus capitis muscle Anatomy: Insertion and Origin of Longissimus capitis muscle



Sternocleidomastoid

Surface Anatomy: Injection Sites for Sternocleidomastoid muscle

Anatomy: insertion and Origin of sternocleidomastoid muscle

 

 

 

 

References

1.          Reichel G. Cervical dystonia: A new phenomenological classification for botulinum toxin therapy. Basal Ganglia [Internet] 2011;1(1):5–12. Available from: http://dx.doi.org/10.1016/j.baga.2011.01.001

2.        Reichel G. Dystonias of the Neck: Clinico-Radiologic Correlations [Internet]. In: Dystonia - The Many Facets. InTech; 2012. Available from: http://www.intechopen.com/books/dystonia-the-many-facets/dystonias-of-the-neck-clinico-radiologic-correlations

3.          Marion MH, Humberstone M, Grunewald R, Wimalaratna S. British neurotoxin network recommendations for managing cervical dystonia in patients with a poor response to botulinum toxin. Pract Neurol 2016;16(4):288–95.