Villaret Syndrome

Villaret Syndrome
Other Names	Retroparotid space syndrome
Identifiers
ICD-9	352.6
ICD-10	G52.7

Overview

Villaret syndrome, sometimes described as retroparotid space syndrome, is a collection of ipsilateral cranial nerve palsies (IX, X, XI, and XII) as well as Horner's syndrome.

History

Villaret syndrome is named after a French neurologist named Maurice Villaret (1877-1946), who first described the syndrome in 1916.

Pathophysiology

Relevant Anatomy

Villaret syndrome is typically the result of a skull base mass or lesion affecting CN IX, X, XI, and XII as they exit the jugular foramen and hypoglossal canal at the skull base. The mass or lesion needs to extend to the lateral aspect of the spinal column to affect the symathetic chain.

• 

  Skull base foramina, superior and inferior views

• 

  Skull base foramina

• 

  Cranial Nerves IX, X, and XII exiting the skull base

• 

  Superior view of the skull base with hypoglossal canals highlighted.

• 

  Target end-organs of the sympathetic nervous system.

Disease Etiology

The etiology of Villaret syndrome can be divided into neoplastic and non-neoplastic causes:

Neoplastic

• Jugular Paraganglioma
• Meningioma
• Schwannoma
• Metastatic Disease

Non-Neoplastic

• Trauma
• Paget Disease
• Osteomyelitis of the Skull Base<
• Vascular Disease

Diagnosis

Patient History

Patient should be screened for the following symptoms:

• Dysphagia
• Voice changes
• Aspiration
• Shoulder / arm weakness
• Altered taste
• Tongue mobility issues
• Unilateral facial flushing

Pertinent history to assess for:

• History of head trauma
• History of malignancy
• History of aspiration pneumonia
• Prior head and neck radiation
• Family history of glomus tumors / paragangliomas

Physical Examination

Horner's syndrome patient with ptosis and miosis

All cranial nerves should be assessed in the workup of Villaret to rule out other cranial nerve involvement (potentially leading to a different diagnosis). Cranial nerves IX, X, XI, and XII are expected to be weak or paralyzed, as well as an ipsilateral Horner's syndrome.

• Altered sense of taste (CN IX)
• Diminished gag reflex (CN IX, X)
• Vocal cord weakness / immobility (CN X)
• Weakened shoulder shrug (CN XI)
• Weakened arm abduction over 90 degrees (CN XI)
• Tongue deviation to the side of weakness on tongue protrusion (CN XII)
• Ipsilateral Horner's syndrome
  • Constricted pupil (Miosis)
  • Eyelid droop (Ptosis)
  • Decreased sweating (Anhidrosis)

Laboratory Tests

Laboratory testing may not be necessary in patients with a low index of suspicion for infectious causes. In patients where you suspect an infectious etiology, such as osteomyelitis of the skull base, routine infectious laboratory workup is warranted:

• Complete blood count (CBC) with differential
• C-Reactive Protein (CRP) / Erythrocyte Sedimentation Rate (ESR)
• Blood cultures

Imaging

In many instances, patients will already have a CT Brain at the time of ENT consultation to rule out a central cause of their cranial nerve deficits. MRI of the skull base with and without contrast will be the ideal imaging modality in most neoplastic causes of Villaret syndrome. For patients with a traumatic etiology, CT skull base will identify any fractures or bone chips resulting in the nerve palsies. Consider CT angiogram of the carotid system if there is trauma to the skull base as there may be concomitant injury to the carotid canal.

Differential Diagnosis

There are several named syndromes differentiating the various cranial nerve deficits that can result from skull base masses and lesions. These should be considered based on cranial nerve involvement.

• Vernet Syndrome
• Collet-Sicard Syndrome
• Tapia Syndrome
• Jackson Syndrome
• Schmidt Syndrome

These syndromes and their respective cranial nerve involvement are outlined in the table below.

Cranial Nerve Involvement in Skull Base Masses

Syndrome	CN IX	CN X	CN XI	CN XII	Sympathetics
Vernet Syndrome	✔	✔	✔
Collet-Sicard Syndrome	✔	✔	✔	✔
Villaret Syndrome	✔	✔	✔	✔	✔
Tapia Syndrome		✔	±	✔	±
Jackson Syndrome		✔	✔	✔
Schmidt Syndrome		✔	✔