�������� ����� ��

Contralateral Brachial Plexus Palsy and Horner Syndrome Following Vestibu-lar Schwannoma Resection: A Complication of Patient Positioning

Matthew R. Fusco M.D., Joel K. Cure M.D., Kristen O. Riley M.D.

PII: S2214-7519(14)00016-4DOI: doi: 10.1016/j.inat.2014.04.001Reference: INAT 9

To appear in:

Received date: 19 March 2014Revised date: 6 April 2014Accepted date: 12 April 2014

Please cite this article as: , Contralateral Brachial Plexus Palsy and Horner SyndromeFollowing Vestibular Schwannoma Resection: A Complication of Patient Positioning,(2014), doi: 10.1016/j.inat.2014.04.001

This is a PDF file of an unedited manuscript that has been accepted for publication.As a service to our customers we are providing this early version of the manuscript.The manuscript will undergo copyediting, typesetting, and review of the resulting proofbefore it is published in its final form. Please note that during the production processerrors may be discovered which could affect the content, and all legal disclaimers thatapply to the journal pertain.

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT1

TITLE:

CONTRALATERAL BRACHIAL PLEXUS PALSY AND HORNER SYNDROME FOLLOWING

VESTIBULAR SCHWANNOMA RESECTION: A COMPLICATION OF PATIENT POSITIONING

Authors:

Matthew R. Fusco, M.D1, Joel K. Cure, M.D.

2, and Kristen O. Riley, M.D.

1

Affiliations:

University of Alabama at Birmingham Division of Neurosurgery, Department of General Surgery1

and Department of Radiology2

1720 2nd

Avenue South

Birmingham, Alabama, 35294

Correspondence/Reprints:

Matthew R. Fusco

110 Francis St, Suite 3B

Boston, MA 02115

Phone: (617) 632-9712

Fax: (205) 934-6507

Email: mfusco@bidmc.harvard.edu

Running Title: Contralateral brachial plexus palsy and Horner syndrome following vestibular schwannoma resection

Key Words: Neurosurgical positioning, skull base tumor, sialadenitis, translabyrinthine craniectomy

The authors report no conflicts of financial or material support. The material presented here has neither been

presented nor published prior.

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT2

ABSTRACT

Background: Skull based neurosurgical cases often require some degree of head rotation during patient positioning to

facilitate operative exposure. Extreme head rotation may lead to occlusion of submandibular gland secretions and

impaired venous return from the neck, rarely leading to submandibular gland inflammation.

Methods: An uncomplicated translabyrinthine resection of a vestibular schwannoma was undertaken.

Results: Severe submandibular gland inflammation and impaired venous return opposite the site of translabyrinthine

vestibular schwannoma resection occurred in the post-operative period. This led to upper brachial plexopathy and Horner

syndrome.

Conclusions: We present the first known cases of submandibular gland inflammation and hemorrhage resulting in

brachial plexopathy and Horner syndrome opposite the site of tumor resection. This case underscores the importance of

adequate and safe patient positioning in skull based neurosurgical procedures.

Running Title: Contralateral brachial plexus palsy and Horner syndrome following vestibular schwannoma resection

Key Words: Neurosurgical positioning, skull base tumor, sialadenitis, translabyrinthine craniectomy

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT3

Neurosurgical operations often require unique patient positions to facilitate operative exposure. These complex

positions can add their own morbidities in addition to those related to the operative field. Rarely, extreme head rotation

can create contralateral neck swelling due to submandibular gland inflammation. If significant enough, this can create

upper brachial plexus palsy. We present just the fourth such reported case, and the first severe enough to cause a Horner

syndrome as well.

CASE REPORT

History: A 31 year old female presented with high pitched right ear ringing for three months. She also noted

right facial numbness and gait imbalance. She denied any past medical or surgical history, current medications, or family

history of intracranial tumors.

Physical examination: The patient stood 5’1” and weighed 67.59 kg. Her body mass index (BMI) was 28.2.

Cranial nerve examination demonstrated nystagmus with right lateral gaze, decreased right V2 and V3 sensation, and

House-Brackmann scale II right facial weakness. Diminished hearing was present on the right. All other cranial nerve

testing was normal. Deep tendon reflexes were 3+ bilaterally in upper and lower extremities. A positive Hoffman’s

reflex was noted on the left. Motor strength and peripheral sensory examinations were unremarkable. Cerebellar testing

demonstrated right sided dysmetria. Her gait was ataxic.

Diagnostic evaluation: Audiography demonstrated normal hearing bilaterally. Magnetic resonance imaging

(MRI) revealed a large (2.7 x 3.2 x 2.8 cm) right cerebellopontine angle mass consistent with a vestibular schwannoma

(Fig 1).

Treatment: Surgical resection through a right translabyrinthine craniectomy was undertaken. Anesthetic

induction was followed by placement of a 7.0 oral endotracheal tube. Mayfield pins were applied. Her head was turned

45 degrees to the left and secured to the bed while a shoulder bump was placed under the right shoulder. An

uncomplicated right sided trans-labyrinthine craniectomy was carried out with complete tumor resection. Total operative

time secured in Mayfield pins was 11 hours and 23 minutes. Twenty milligrams of dexamethasone were administered.

Pathology was consistent with World Health Organization (WHO) Grade I schwannoma.

The patient remained intubated on transfer to the neuro-intensive care unit and was extubated 30 minutes later.

No respiratory difficulty was noted and her neurologic exam was unchanged from pre-operative testing. Approximately

4.5 hours after extubation the patient acutely developed labored breathing and rapidly progressive left sided neck

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT4

swelling. She was emergently re-intubated for airway protection and ranitidine, diphenhydramine, and dexamethasone

were scheduled. Non-contrasted computed tomography (CT) scan of the neck demonstrated an enlarged submandibular

gland with associated hemorrhage and significant surrounding edema (Fig 2). Proximal left upper extremity weakness

was evident. No evidence of pupillary asymmetry was noted. Over the next 48 hours the submandibular swelling abated

and the patient was able to be re-extubated. Her neurologic exam remained consistent with primarily upper brachial

plexus palsy. The patient progressed with therapy until she was transferred to an acute rehab center on post-operative day

6.

At just over one week post-operatively the patient reported decreased sweating over the left side of her face and

left eye drooping. Examination revealed full right-sided facial strength but left sided ptosis and miosis, residual left neck

swelling, and proximal left upper extremity paresis at 4/5. Distal left upper extremity strength was 5/5. The left sided

ptosis and miosis was not present at the time of discharge to the rehab facility. At 3 months post-operatively very subtle

left sided ptosis remained while her left upper extremity strength was normal.

DISCUSSION

Skull based tumor resections often require a unique set of surgical approaches for adequate exposure and effective

treatment. This may predicate patients to be placed in various positions including the supine, lateral, three-quarters

lateral, park bench, prone, or even sitting positions. These positions can produce their own set of morbid complications.

Contralateral neck swelling due to submandibular gland inflammation, i.e. sialadenitis, is one such, albeit uncommon,

complication following skull base surgery. Rarely, sialadenitis has been reported to cause post-operative brachial

plexopathy. No previous reports of contralateral submandibular gland edema causing brachial plexopathy and Horner

syndrome following skull base surgery exist.

Contralateral sialadenitis has been reported to occur in 0.84% of skull based procedures (0.9% of retrosigmoid

and 0.8% of far-lateral procedures by a single surgeon). Sialadenitis likely occurs due to extreme rotation of the head

with resultant compression both of the tongue against the endotracheal tube and of the submandibular gland itself.

Tongue compression can occlude Wharton’s duct resulting in stasis of salivary secretions. Glandular compression can

result in pressure ischemia due to impaired venous return. Multiple factors appear to increase the risk for post-operative

sialadenitis including diabetes mellitus, hepatorenal failure, hypothyroidism, Sjӧgren’s syndrome, depression,

malnutrition, dehydration, and use of anti-cholinergic medications. Surprisingly, increased age, obesity, and excessive

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT5

surgical length have not been reported as consistent risk factors in the setting of skull base surgery. Treatment strategies

for post-operative sialadenitis include airway protection, hydration, steroids, and antibiotics targeted towards the most

common bacterial agents (i.e.Streptococcus or Haemophilus species) 4.

Contralateral sialadenitis, if severe enough, can also affect the brachial plexus. The submandibular gland is

associated with the lateral pharyngeal space within the superficial layer of the deep cervical fascia, just anterior to the alar

fascia. The alar fascia forms part of the border of the retropharyngeal space, which extends from the skull base to the

cervico-thoracic junction1. The brachial plexus sits immediately posterior to the retropharyngeal space between the

anterior and middle scalene muscles5. Importantly, many of these compartments have incomplete fascial layers so

increased pressure or inflammation may be transmitted from one space to another quite easily. Therefore, submandibular

gland edema may transmit from the lateral pharyngeal space into the retropharyngeal space and ultimately affect the

scalene muscles and brachial plexus1.

Horner syndrome, classically described as lid ptosis, pupillary miosis, and facial anhidrosis, results from

interruption of the sympathetic innervation to the eye from the superior cervical ganglion. This sympathetic trunk lies

within the deep layer of prevertebral fascia, immediately posterior to the carotid sheath, anterior to the cervical spine

transverse processes, and consists typically of white rami communicate from the C8 and T1 spinal nerves along with

superior cervical, middle cervical, and stellate ganglia. The sympathetic innervation courses near the apex of the lung

then turns cephalad until it becomes deeply invested within the adventitia of the carotid vasculature. Inflammation or

compression anywhere along this course can lead to at least a partial Horner syndrome3. The delayed onset in this report

suggests inflammation rather than direct compression of the sympathetic trunk leading to the Horner syndrome.

Three previous reports of brachial plexus palsies due to contralateral post-craniotomy neck swelling exist (Table

1)1,2,6. Described procedures in these cases include translabyrinthine resection of a vestibular schwannoma

1, suboccipital

craniotomy in the park bench position for posterior fossa meningioma resection6, and frontal craniotomy for tumor

resection in the supine position2. Surgical times appear longer (> 10 hours in most cases, including this one) in reports of

contralateral neck swelling leading to brachial plexus palsy following craniotomies than in reports of contralateral

sialadenitis alone 1,7. In addition, neck compression causing not just sialadenitis but also significant venous congestion is

described in 3 of 4 cases (including this case) of brachial plexus palsy in addition to submandibular swelling 1,6. No other

report describes such acute and rapid progression of edema – one describes swelling noted upon case completion1,6 while

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT6

the remaining two describe more gradual worsening of edema following post-operative onset

1,6. Imaging in the present

case seems to support glandular compression with poor venous outflow and subsequent glandular rupture as the

precipitating cause for the resultant edema. The acute onset of brachial plexus palsy suggests a compressive etiology

while the delayed onset of Horner syndrome likely suggests an inflammatory cause. It may be reasonable to theorize

simple sialadenitis occurred initially in all reported cases of brachial plexus palsy but increased operative length lead to

significant impairment of venous return. After case completion and neutral head position was restored, significant

submandibular gland hyperemia may have occurred and worsened the edema severity leading to local involvement of the

brachial plexus. However, as only 4 such cases of brachial plexus involvement exist, this theory is purely speculative.

CONCLUSIONS

Few surgical subspecialties outside neurosurgery require such a wide range of patient positions for operative

success. Complications due to patient positioning are well known causes of morbidity and must be protected against by

all surgical team members. Excessive head turning away from the surgical side can create contralateral soft tissue

compression, obstruction of salivary ducts, and venous stasis. If severe enough, this can produce submandibular gland

inflammation or ischemia leading to significant post-operative neck swelling. In rare cases this swelling can lead to upper

brachial plexus inflammation and palsy. Here, we present the first case of contralateral neck swelling leading to upper

brachial plexus palsy and Horner syndrome. All reported cases, including this case, appear self-limiting and unlikely to

create permanent neurologic deficits. Because of the rare nature of this positioning complication, it would appear

unwarranted to alter the patient’s positioning (outside of the standard shoulder bump, gentle head turning, etc.) to

prevent sialadenitis as altering the head position would likely prevent safe surgical exposure. However, knowledge of this

rare entity can greatly aid in complication management if it should arise.

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT7

DISCLOSURE

The authors report no conflicts of financial or material support. The material presented here has neither been

presented nor published prior.

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT8

REFERENCES

1. Bhardwaj D, Peng P: An uncommon mechanism of brachial plexus injury. A case report. Can J Anaesth 46:173-

175, 1999.

2. Hebert-Blouin MN, Chowdhry SA, Abrahams PH, Spinner RJ: An unusual anatomical explanation for

contralateral upper extremity weakness after frontal craniotomy. Clin Anat 22:840-845, 2009.

3. Huang YG, Chen L, Gu YD, Yu GR: Histopathological basis of Horner's syndrome in obstetric brachial plexus

palsy differs from that in adult brachial plexus injury. Muscle Nerve 37:632-637, 2008.

4. Kim LJ, Klopfenstein JD, Feiz-Erfan I, Zubay GP, Spetzler RF: Postoperative acute sialadenitis after skull base

surgery. Skull Base 18:129-134, 2008.

5. Nash L, Nicholson HD, Zhang M: Does the investing layer of the deep cervical fascia exist? Anesthesiology

103:962-968, 2005.

6. Shimizu S, Sato K, Mabuchi I, Utsuki S, Oka H, Kan S, et al: Brachial plexopathy due to massive swelling of the

neck associated with craniotomy in the park bench position. Surg Neurol 71:504-508; discussion 508-509, 2009.

7. Singha SK, Chatterjee N: Postoperative sialadenitis following retromastoid suboccipital craniectomy for posterior

fossa tumor. J Anesth 23:591-593, 2009.

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT9

FIGURE LEGENDS

Figure 1. Pre-operative axial post-contrast enhanced T1 MRI demonstrates 2.7 x 3.2 x 2.8 cm mass at right

cerebellopontine angle. Imaging characteristics consistent with vestibular schwannoma include diffuse

enhancement, extension to the porus acusticus, and internal heterogeneity with cystic components.

Figure 2. Post-operative axial post-contrast enhanced neck CT demonstrates heterogeneous enhancement of the left

submandibular gland and considerable edema within the left submandibular region and subcutaneous fat

stranding. No evidence of ductal obstruction was present. Note the significant asymmetry in the soft

tissue and rightward deviation of the trachea.

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT10

Figure 1

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT11

Figure 2

ACC

EPTE

D M

ANU

SCR

IPT

ACCEPTED MANUSCRIPT12

Table 1. Previous reports of contralateral neck swelling following intracranial surgery.

Case

report Patient BMI

Surgical

pathology

Operative

position

Operative

length (in

hours)

Time to neck

swelling

from

surgery end

(in hours)

Proposed

mechanism of

edema

Neurologic

deficit

Bhardwaj,

et al, 1999 32

Acoustic

neuroma

Supine, head

turned 45° with

slight neck flexion

for

translabrynthine

approach

12 Next

morning

Poor venous

drainage due to

excessive head

rotation

Upper

trunk

brachial

plexus

palsy

Shimizu,

et al, 2007 18

Posterior fossa

tentorial

meningioma

Park bench, slight

neck flexion, 20°

head rotation

towards floor, 10°

lateral bend

towards floor

10 2

Poor venous

drainage,

internal jugular

vein

thrombosis

Upper

trunk

brachial

plexus

palsy

Hebert-

Blouin, et

al, 2009

Not

described

Frontal lobe

metastasis Not described

Not

described Immediately

Submandibular

gland

sialadenitis

Upper

trunk

brachial

plexus

palsy

Singha, et

al, 2009 23

Cerebellar

convexity

meningioma

Extreme lateral

position for

retromastoid,

suboccipital

craniectomy

5 Immediately

Submandibular

gland

sialadenitis

None

Kim, et al,

2008

Only

described as

“not

morbidly

obese”

3 posterior

fossa

meningiomas,

1 acoustic

neuroma, 1

brainstem

cavernous

malformation

Park bench

position for 4

retrosigmoid

craniotomies and

1 far-lateral

suboccipital

craniotomy

3-6

Immediately

to within 4

hours

Submandibular

gland

sialadenitis

None

Present

case 28

Acoustic

neuroma

Supine, head

turned 45° with

ipsilateral

shoulder bump

for

translabyrinthine

approach

11.5 4.5

Poor venous

drainage,

submandibular

gland

reperfusion

hemorrhage

Upper

trunk

brachial

plexus

palsy,

Horner

syndrome