Dystonia

INDEX

 

 

                   Torticollis                                                         Torticaput

From: Reichel G, Stenner A, Janh A. [Cervical dystonia: clinical-radiological correlations and recommendations for the correction of botulinum therapy]. Zh Nevrol Psikhiatr Im S S Korsakova. 2012;112(1):73-9. Russian. PMID: 22678680.

Head rotation often occurs together with neck rotation. It is classically caused by activation of the ipsilateral splenius capitis, the contralateral sternocleidomastoid muscle and the ipsilateral trapezius/semispinalis capitis muscle complex. However, deep posterior neck muscles arising from the atlas and the axis including the obliquus capitis inferior, the rectus capitis posterior major and the rectus capitis posterior minor muscles are strong ipsilateral head rotators. The levator scapulae muscle is an additional but weaker ipsilateral head rotator. In head and neck rotation, the role of the sternocleidomastoid is often overestimated, whereas the role of the splenius capitis and the deep posterior neck muscles is often underestimated1
 

Two levels of movement take place: 

Torticollis
When rotation takes place at the lower level of the cervical spine, between C2 and C7, rotation of the neck takes place in relation to the trunk (torticollis).  In torticollis the larynx/Adam’s apple rotates laterally, and the head is also rotated due to the rotation of the neck.

Torticaput
When rotation takes place at the upper level of the cervical spine, between the skull and C2/C3, where muscles act at the atlanto-occipital joints, the head rotates and the neck remains in a vertical/upright position, leading to a torticaput.
In torticaput, the Adam’s apple is found largely  in a medial position.
 

Distinguishing laterocaput and and laterocollis

Distinguishing between torticollis and torticaput may be clinically difficult to achieve, and additional tests may be required, such as CT or MRI of the cervical spine.

In general, an analysis of the position of the sternal notch with relationshin to the larynx is helpful.

Should the diagnosis remain unclear, CT sections at the C1-C3 level and the C7 plane may be obtained. By comparing the position of the vertebra in both planes, torticollis and torticaput can be distinguished from one another. 

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Figure 1. Note that, for rotation, there is synergistic action between contralateral sternocleidomastoid and contralateral trapezius, and between ipsilateral levator scapulae and ipsilateral splenius. 

 

 

 

Torticollis
 

Figure 2. Patient with torticollis: the larynx and the sternum are not in line.


CT at levels C3 and C7 (note the C3 level is identified by the mandible being visible on the image)

At C3 the cervical vertebrum is in line with the skull, and away from C7

 

 

Figure 3. Torticollis: right shoulder elevation. Active muscles: left sternocleidomastoid, right splenius, right levator scapulae, right OCI

 

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Figure 3. Patient with torticollis.
The mark over the superior thyroid notch is rotated in relation to the mark over the jugular notch of the manubrium sterni.

Patient Image CT imaging of cervical spine

CT scan in this patient with torticollis shows that C1 and C2 are rotated, whereas C7 is straight. Rotation therefore occurs between C3 and C7; only muscles acting on the cervical spine are affected.

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


 Treatment

In rotational CD, the classical approach is injecting the ipsilateral splenius capitis and the contralateral sternocleidomastoid.


Sternocleidomastoid

Surface Anatomy: Injection Sites for Sternocleidomastoid muscle

Anatomy: insertion and Origin of sternocleidomastoid muscle


 

Splenius 2 x 7.5-10 u Max 50 u Botox;  2 x 30-40 max 200 u Dysport

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



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

Ipsilateral to side of lateroflexion

  1. Semispinalis cervicis
  2. Levator scapulae
  3. Splenius cervicis (secondary)
  4. Longissimus cervicis (secondary)
     

1. Semispinalis cervicis 10 u Botox per side; Max 20 u 

The muscle arises from the transverse processes of T1-T6, and inserts into the posterior spinous processes of C2-C7. It acts to extend the cervical spine (principal action), and to rotate the head contralaterally.

Gross Anatomy: Insertion and Origin of Semispinalis Cervicis muscle (#5)

Technique: (from Mezaki T. Ultrasound‐guided botulinum toxin therapy for deep muscles in cervical dystonia. Neurol Clin Neurosci 2020; 8: 3–10.)

1. Place the linear transducer on the posterior aspect of the neck horizontally at the level of the posterior spinous process of the fifth cervical (C5) vertebra.
2. The muscle is found deep within the muscle layers of the neck: from superficial to deep, the layers consist of the trapezius, the splenius capitis (and cervicis), the semispinalis capitis, and then the semispinalis cervicis are identified. (Deep to this muscle, there is the multifidus muscle)
3. Compare the muscle thickness between both sides. Since the contribution of this muscle for head rotation is usually minor, a small difference may be ignored.
4. Inject botulinum toxin above and below the C5 level, 3‐4 centimeters apart. The convenient needle size is 27 gauge, length of 38 mm.



 2. Levator scapulae

Anatomy: Insertion and Origin of  Levator Scapulae muscle Surface Anatomy: Injection Sites for Levator Scapulae muscle



3. Splenius cervicis 

Surface Anatomy: Splenius cervicis muscle


4. Longissimus cervicis 10 u Botox per side; Max 20 u .

  


 

Torticaput   

Figure 3. Patient with torticaput. In the patient, the markings (jugular notch of the manubrium sterni and the superior thyroid notch) are vertically in line with each other.
Imaging demonstrates that the base of the skull and 1st cervical vertebra are rotated whereas C2 and C7 are straight. The rotation occurs between C1 and C2 (the atlanto–axial joint); consequently only the muscles acting on the skull are involved in causing the torticaput.

 Patient Image

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

Figure 4. A patient with laterocaput: head (A) and neck (B) form an angle; the neck is perpendicular/vertical on the shoulder line2

 

Patient Image

From:  Reichel G, Stenner A, Jahn A. The phenomenology of cervical dystonia. Fortschr Neurol Psychiatr 2009; 77: 272–7.

 



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

Contralateral to side of rotation

1. Trapezius (Descending portion)

2. Sternocleidomastoid

3. Semispinalis capitis (secondary)

Ipsilateral to side of rotation

4. Obliquus capitis inferior (main)

5. Longissimus capitis (secondary)

6. Splenius capitis (secondary)

7. Additionally, obliquus capitis superior may be injected.
 



1. Contralateral Trapezius (descending portion)  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

 



2. Contralateral Sternocleidomastoid 2 x 30 u Max 60 u Botox;  2 x 30-40 max 200 u Dysport

Surface Anatomy: Injection Sites for Sternocleidomastoid muscle

Anatomy: insertion and Origin of sternocleidomastoid muscle 


 

3. Contralateral Semispinalis Capitis

One injection is given one centimeter below the hairline, and the 2nd about 2.5 cm below that, as shown in the figure.
The semispinalis is covered by the trapezius. 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



4.  Ipsilateral obliquus capitis inferior

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



5. Ipsilateral longissimus capitis

The longissimus capitis arises from transverse processes of C3-T3. It inserts into the mastoid process.

This muscle is deep to the levator scapulae muscle at the C5 level, and its depth greatly varies from patient to patient, being often unexpectedly superficial in some adults.

Technique
1. Palpate the spinous process of the axis and move the operator's finger to the third cervical (C3) spinous process.
2. Place the linear transducer horizontally at this level over the triangle formed posteriorly by the trapezius, anteriorly by the sternocleidomastoid, and inferiorly by the middle third of the clavicle.
3. Move the transducer a little dorsally and localize the transverse process of C3 on the right lower part of the screen. The longissimus capitis muscle can be seen in the direction of 10‐11 o'clock from the transverse process with a deformed and widened letter D‐chape (the vertical line of the letter D represents the fascia, discriminating it from the semispinalis capitis
muscle)
4. After the injection, repeat the procedure at the C5 level. Color Doppler imaging at this level occasionally detects an artery, which is  the superficial branch of the transverse cervical artery.

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

  



6. Ipsilateral 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) 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

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

References