Garcin syndrome

Garcin syndrome, also known as hemibasal syndrome or Guillain-Alajouanine-Garcin syndrome, is characterized by progressive ipsilateral cranial neuropathies of at least seven cranial nerves, with no evidence of raised intracranial pressure, long-tract signs, or cerebellar signs, classically attributable to a malignant osteoclastic skull base lesion.

Clinical presentation

• progressive ipsilateral cranial neuropathies ^1-6

  • traditionally all twelve cranial nerves needed to be involved in the syndromic definition ^1-6

  • modern literature acknowledges involvement of all twelve nerves is very rare, and therefore, modifications to the definition have been made such that at least seven ipsilateral cranial nerves should be involved ⁴

  • this variably results in:

    • ipsilateral optic neuropathy, leading to loss of vision

    • ipsilateral complete ophthalmoplegia and ptosis, leading to diplopia

    • ipsilateral hemifacial sensory loss and weakness, with loss of corneal reflex

    • ipsilateral hearing loss

    • contralateral palatal deviation, with dysarthria and dysphagia

    • ipsilateral stenocleidomastoid and trapezius weakness

    • ipsilateral tongue weakness and deviation

• absence of ^1-6:

  • raised intracranial pressure

  • long-tract motor or sensory signs

  • cerebellar signs

• other associated symptoms:

  • headache ^2,3,6

  • other symptoms specifically attributable to the underlying etiology (e.g. cervical lymphadenopathy)

Pathology

Garcin syndrome is classically defined as being caused by a malignant process causing an osteoclastic lesion of the skull base ^1-6, which can cause cranial neuropathies through cranial nerve impingement at their skull base foraminal exits or during their extracranial paths ². In this context, a wide variety of primary malignancies have been implicated, e.g. nasopharyngeal carcinoma, hematological malignancies, or metastases ^1-6. However, the syndrome has also been more broadly attributed to a range of non-malignant pathologies which may or may not involve the bony skull base, e.g. giant cell tumor of bone, rhinocerebral mucormycosis, giant internal carotid artery aneurysm, or basal leptomeningitis and hypertrophic pachymeningitis ^1-6.

Radiographic features

CT and MRI are the ideal imaging modalities to initially evaluate Garcin syndrome. Radiographic features will vary depending on the underlying pathology.

Treatment and prognosis

Management of Garcin syndrome will vary depending on the underlying etiology.

History and etymology

The condition was described by French physicians Raymond Garcin (1897-1971), George Charles Guillain (1876-1961) and Théophile A J Alajouanine (1890-1980) in their 1926 case series ⁷.