Skull

The Los Angeles
Neurosurgical Institute

The Skull Base Program at the Los Angeles Neurosurgical Institute (LANSI) consists

of a

multidisciplinary group of professionals providing the utmost care for patients with

skull

base problems. Please visit

our team page

Using minimally invasive techniques with precise accuracy, our surgeons use the

newest

techniques in endoscopy to minimize surgical trauma and length of hospital

stay.

Tumors of the Skull Base

These include tumors such as pituitary tumors, colloid cysts, acoustic

tumours,

menigiomas,

chordomas, esthesioneuroblastomas, craniopharyngiomas,

optic nerve and

orbital tumors

Pediatric Skull Difformities- Craniostenosis- Craniosynostosis
Facial Reconstruction

Facial and skull base reconstruction, Facial Paralysis (Bell’s palsy), facial

Facial Spasm and Pain (hemifacial spasm, trigeminal neuralgia or "tic douloreux"),caused
by vascular lesions (aneurysms, hemangiomas, vascular loops).

TUMORS OF THE SKULL BASE

PITUITARY TUMORS- ADENOMAS

A pituitary adenoma is a specific type of brain tumor that arises from the pituitary

gland.

This

gland is situated directly behind the nose, under the frontal lobes of the

brain. It

controls the

regulation of many different hormones and is vital to life. These

adenomas

secrete hormones,

some active others not, and symptoms depend on

the type of hormone

secreted. The most

common hormone produced by one of

these tumors is

PROLACTIN

which can cause

impotence in males and infertility in

females. The next most common is an

INACTIVE

HORMONE

that usually causes

symptoms related to the size of the tumor and

the pressure it

causes on surrounding

structures such as the visual pathways, the normal

pituitary gland and

the brain

itself. The next most common adenoma produces GROWTH

HORMONE which

can

cause excessive growth in children or acromegaly in adults. The

least common

hormone

secreted by a pituitary adenoma is

ACTH

which causes

Cushing's

Disease

. Most adenomas

are benign and can be cured with either surgery,

medicine,

radiotherapy or combinations of all

3 treatments. Tumors of the pituitary

gland have

traditionally been treated either with

medicine

or by surgical removal.

Surgical removal

commonly takes the form of

transsphenoidal excision.

Until

recently, this required making a

cut under the lip or within the

nose. While highly

effective, this surgery has been improved

by incorporating the

neuroendoscope.

Most

surgeries can be performed endoscopically

through the nostril using an

endonasal approach.

For the patient, this means a quicker

surgery that is less

invasive with

fewer complications and

reduced discomfort.

Hospitalization is

typically two days or less.

COLLOID CYSTS

Colloid cysts are rare tumors that occur within the fluid containing ventricles of the brain.

Because of their location they can block the flow of cerebrospinal fluid. Symptoms may

include

headache, visual problems, short term memory loss, or loss of conciousness. In some

cases

these tumors can be life-threatening. When treatment is required, surgery is currently

the only

option. Traditionally, this type of surgery has been lengthy (4 hours or more) and

entailed

large

opening of the skull and significant disruption of the brain itself. More recently,

advanced

endoscopic techniques allows these same tumors to be removed through minimally

invasive

means. Surgical incisions are less than an inch and the opening in the skull is about

the size

of a

dime. Surgery usually takes less than an hour and hospitalizations most

commonly are

less than

2 days compared to 4 days or more with traditional methods.

ACOUSTIC TUMORS

Acoustic tumors or more properly called Vestibular Schwannomas account for 8% of all

intracranial tumours. They are more common in females, usually present with unilateral

hearing

loss or ringing in the ear, and are mostly slow growing (approx. 1 mm per year). The

prognosis is

usually very good when they are treated. In most cases this requires surgery. If

the

patient is

opposed to surgery or is unfit for surgery because of advanced age or

associated

medical

problems

then watching them for a while is not unreasonable. If the growth

rate is

slow then they

may never get big enough to cause any other problem apart from

hearing loss.

If, however, the

tumor grows bigger while being followed, then surgery and

radiotherapy are

riskier. The major

risk from surgery is hearing loss, which is not that

disturbing in most

patients who present with

hearing loss, and facial nerve damage, which

causes asymmetry of

the face. The risk is directly

related to the size of the tumour and the skill

of the operating

surgeon. Radiosurgery using

focused beams of radiation such as that with

the Gamma Knife

has been successful in arresting

the growth of some tumors, but may only

have a limited

effect and may cause delayed damage

to the facial nerve. If the tumor is

incompletely

removed it will recur. Other complications of

surgery include, spinal fluid leakage,

chronic

headache and persistent ringing in the ear if the

damaged acoustic nerve is

preserved.

MENINGIOMAS

CHORDOMAS, GLOMUS JUGULARE TUMORS
ESTHESIONEUROBLASTOMAS and CRANIOPHARYNGIOMAS

OPTIC NERVE AND ORBITAL TUMORS

Optic Nerve Decompression

The optic nerve leaves the orbit and travels through a bony canal at the root of the eye.

The

medial wall of this canal separates it from the nasal sinuses. Traumatic injury to this area

causes

not only swelling of the nerve in the confines of the

osseous

canal ,

but bony

fragments may impinge on the nerve.

This area may

be accessed through intranasal

endoscopic approach. The bony medial wall

of the orbit can

be removed along with any bone

fragments thus decompressing the nerve

and preventing any

further injury

leading to blindness.

Orbital Decompression

Thyroid dysfunction, specifically Grave’s disease, leads to thyroid ophthalmopathy. Afflicted

patients suffer from a characteristic wide stare that result from deposition of material in

orbital

tissue and thus a protuberant eye. Previously, open approaches were used to remove

parts

the orbital wall that would allow the enlarged orbital tissue to decompress partly in

the nasal

cavity and the globe to recesses back into the orbit. Advanced endoscopic

techniques allow

access to the orbital walls through the nose. This minimally invasive

approach show

immediate

results with minimal risks and a speedy recovery.

TRIGEMINAL NEURALGIA

Trigeminal neuralgia (TN) is a disorder characterized by severe electrical pain involving the

face.

Usually arising in middle age, this form of facial pain is most commonly, although not

exclusively,

seen in women. The discomfort can be brought on by brushing of the teeth,

stoking of the face or

even exposure of the face to wind. In many cases, the symptoms can

mimick dental disease

resulting in unnecessary tooth extractions. The first line treatment for

trigeminal neuralgia is

medical. Only when a patient fails medical treatment or cannot tolerate

medicine is surgery

necessary. Surgical alternatives include percutaneous methods (insertion

of needles to

anesthesize the nerve), radiation (stereotactic radiosurgery) or microvascular

decompression

(MVD). It is generally believed that most cases of typical TN are causes by an

artery, or less

commonly a vein, compressing the nerve that gives sensation to the face, the

trigeminal nerve.

By rubbing and pressing on the nerve the artery causes a type of short

circuiting, call ephaptic

transmission, that results in the electrical pain experienced by the

patient. Microvascular

decompression surgery consist of exposing the trigeminal nerve where

it enters the brainstem

and identifying the artery that is compressing the nerve. A small piece

of Teflon or similar tissue

is placed between the artery and nerve to act as a shock absorbing.

Using endoscope-assisted

techniques this surgery can be performed in a less invasive

manner

with excellent results.

HEMIFACIAL SPASM

Uncontrollable twitching and spasms of one side of the face can be minor or in many cases

quite

disfiguring. Frequently, the person who suffers from Hemifacial Spasm (HFS) becomes

so self-

concious about their appearance that they resort to limited person to person

interaction. This can

have a tremendous personal and professional impact. In many cases this

can be adequately,

although temporarily, controlled using medications (injected). However,

minimally invasive,

endoscope-assisted surgery can result in permanent significant

improvement or cure in the

majority of patients with HFS. Similar to trigeminal neuralgia, it is

known that the majority of

patients with HFS have an artery comprssing the facial nerve

where

it exits the brainstem. By

rubbing and pressing on the nerve the artery causes a type of

short

circuiting, call ephaptic

transmission, that results in the electrical pain experienced by

the

patient. Microvascular

decompression surgery consist of exposing the trigeminal nerve

where

it enters the brainstem

and identifying the artery that is compressing the nerve. A small

piece

of Teflon or similar tissue

is placed between the artery and nerve to act as a shock

absorbing.

Reconstructive Skull Base Surgery
Pediatric Skull difformities- Craniostenosis- Craniosynostosis
Facial and Skull Base reconstruction

THE SKULL BASE PROGRAM AT THE LANSI