Skull Base Surgery of the Posterior Fossa

179

headache, and other lower cranial nerve deficits
[ 19 ]. Hydrocephalus may ensue via compression
or blockage of the aqueduct of Sylvius or fourth
ventricular outflow channels. Clinical presenta-
tion is ultimately determined by tumor location.
Highly vascular metastatic tumors may have apo-
plectic onset of symptoms with associated hem-
orrhage, compression, and brainstem herniation.
Rapidly decompensating and lethargic patients
exhibiting signs of hydrocephalus may require
urgent placement of an extraventricular drain
(EVD) before preoperative planning or operative
intervention. In fact, some patients with multiple
metastatic lesions and hydrocephalus may require
placement of ventriculoperitoneal shunt before
undergoing radiosurgery or whole-brain radio-
therapy (WBRT) (Fig. 13.1).
The most common overall presentation of
patients with SBM includes a worsening, ipsilat-
eral cranial nerve deficit, or craniofacial pain,
depending on the extent and location of the
lesion. Physicians and neurosurgeons should

have a high index of suspicion for SBM in a

patient with known metastatic disease presenting

with progressive cranial nerve deficits or facial

pain. Greenberg et al. [ 11 ], and others since, have

described as many as five clinically distinct syn-

dromes in patients that occur at different frequen-

cies: orbital, parasellar, middle fossa, jugular

foramen, and occipital condyle syndromes.

Middle fossa syndrome predominated (35%) in

one cohort of 43 patients [ 11 ], whereas parasellar

and sellar syndromes predominated (29%) in the

meta-analysis by Laigle-Donadey et al. [ 17 ],

although up to 33% of patients in that review had

an undefined clinical syndrome. In this chapter,

we will focus our discussion on the two syn-

dromes stereotypically affecting patients with

posterior fossa SBM: the jugular foramen syn-

drome and the occipital condyle syndrome.

The jugular foramen syndrome is character-

ized by a lesion compressing cranial nerves IX,

X, XI, and occasionally XII, depending on the

size and exact location of the tumor. Patients may

Fig. 13.1 Images of a breast cancer patient with multiple
metastatic lesions. (a–d) Preoperative axial T1-weighted,
contrast-enhanced MRIs demonstrating posterior fossa
lesions and multiple supratentorial lesions. This patient
had mild ventriculomegaly on imaging but severe nausea

and vomiting requiring placement of ventriculoperitoneal

shunt before further treatment. (e–h) Axial T1-weighted

MRIs with gadolinium enhancement obtained at 6-month

follow-up after patient underwent ventriculoperitoneal

shunt placement and WBRT

13 Metastasis to the Posterior Fossa