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Houston, Texas

A full range of modern neurosurgical specialties and techniques are provided by top BCM neurosurgery specialists.
Department of Neurosurgery
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Definitions A-D

Acoustic Neuroma
A benign tumor arising from Schwann cells of the vestibular division of the eighth cranial nerve within the internal auditory canal. Also called vestibular schwannomas, these growths are progressively enlarging and commonly lead to progressive hearing loss, headache, ringing in the ear (tinnitus) and balance problems. Treatment options include surgical resection, stereotactic radiosurgery or fractionated radiation therapy. They may be unilateral or bilateral.

Arteriovenous Malformations (AVM)
A spectrum of congenital (developmental) blood vessel malformations. An AVM occurs when brain or spinal cord arteries attach directly to veins without the blood passing through the capillary network. AVM's can cause bleeding within the nervous system (a kind of stroke), or progressive neurologic deficits, headaches or seizures. They occur in a variety of brain locations, sizes and shapes. Treatment can consist of observation, surgical resection, embolization or radiosurgery. (See also Spinal Cord Arteriovenous Malformation.)

A nervous system tumor that grows from astrocytes (astrocytomas are a type of glial cell, glial cells are the supporting cells of the nervous system). They can occur in children and young adults and sometimes in older people. Astrocytomas can sometimes become large before causing symptoms. A diagnosis is made either after surgical resection or with a guided (stereotactic) biopsy. Treatment can consist of surgical excision, radiation therapy or chemotherapy. Some patients with minimal symptoms may be observed with serial imaging studies.

An abnormality of coordination -- particularly affects walking; gait is typically very unsteady.

Movement disorder indicated by slow, writhing motions of the fingers and hands. Occurs in approximately 5% of people with cerebral palsy. Athetosis was used commonly a few years ago, but now, many of the people who were previously diagnosed as having athetosis are considered to have dystonia. We believe the two disorders are different, in that athetosis affects muscles of the fingers, hands, and around the mouth, causing slow, twisting, writhing motions that are more continuous than dystonic movements.

Atypical Trigeminal Neuralgia
Pain syndrome with characteristics of typical trigeminal neuralgia as well as characteristics of other facial pain syndromes.

Brachial Plexus
The network of spinal nerves (from the lower cervical spine and upper dorsal spine) that innervate the arm, forearm and hand. Located in the neck-shoulder region

Brain Contusion
An injury (bruise) to the brain. This usually occurs in the setting of a head injury but can occur after other kinds of trauma. Contusions sometimes lead to focal neurologic deficit. They can be single or multiple. If the bruise enlarges, a focal hemorrhage can lead to a decline of the patient and require surgical removal.

Brain Metastasis
A tumor, which spreads from one part of the body to another. The most common metastatic tumors in the brain come from lung cancer, breast cancer, skin cancer (melanoma), kidney cancer (renal), or gastrointestinal tract tumors. They can cause seizures, headaches or neurologic deficits. Treatment consists of either tumor irradiation (stereotactic radiosurgery or whole brain radiation therapy), surgical resection, or corticosteroid therapy, alone or in combination.

Brain Tumor
A tumor or neoplasm refers to a "new growth" of cells that already exist in a certain part of the body. Many different tumors can occur in the nervous system. They often cause headaches, seizures or neurological deficits. Tumors can be both benign or malignant. Malignant tumors are referred to as cancers. Tumor treatments can consist of surgical resection or biopsy, radiation approaches or drug treatment approaches (chemotherapy). Other tumors can be treated with modification of the body's own immune system (immunotherapy).

Blood vessel procedure where blood is shunted from one blood vessel to another without passing through a diseased segment. This is usually performed if a certain portion of the brains blood supply is significantly compromised. A bypass allows a higher volume of blood to enter the brain in an attempt to prevent a stroke. The most common bypass is an EC-IC (extracranial - intracranial) bypass.

Carotid Endarterectomy
Procedure where an artery is opened and a portion of atherosclerotic disease (plaque) is removed. Arthrosclerosis refers to the "hardening of the arteries" that can occur with advanced age. Patients particularly prone to this are those with risk factors including high blood pressure, smoking, hypercholesterolemia, or family history. Patients who have a carotid endarterectomy usually have significant narrowing of the carotid artery (one of the main arteries supplying the brain with blood). Many patients have symptoms from arterial narrowing such as transient ischemic attacks or stroke.

Carotid Stenosis
Narrowing of the carotid artery caused by atherosclerosis. A plaque forms within the artery leading to it's narrowing (stenosis). The stenosis can be opened by removal of the plaque (endarterectomy) or distention of the plaque (angioplasty).

Carpal Tunnel
Compression of the median nerve at the wrist. This causes numbness in the hand, thumb, and fingers.

Cavernous Malformation
Small tangle of thin walled blood vessels. There is no functioning brain tissue within the malformation. These malformations can bleed causing focal neurologic deficits. In some patients seizures or headaches may occur. Treatment often consists of simple observation, resection, or in some cases radiosurgery.

Cerebral Hemorrhage
(Bleeding inside the head). Bleeding inside the head can result from trauma or rupture of a weak or abnormal blood vessel, such as an aneurysm or arteriovenous malformation. High blood pressure may also rupture blood vessels. Neurosurgical treatment of a cerebral hemorrhage attempts to diagnose and treat the cause of the bleeding, and to safeguard the brain from potential damage caused by the bleeding. Treatment depends on the nature and location of the bleeding. Treatment options include surgical clipping, removal of damaged vessel segments, reinforcement of weakened vessel walls, endovascular occlusion of aneurysmal sacs or arteriovenous feeders, and radiosurgery.

Cerebral Palsy
Spectrum of congenital (from birth) brain injuries or developmental problems. Cerebral palsy may occur after a brain hemorrhage, or in a premature infant. Cerebral palsy often leads to problems with motor control of the arms or legs leading to chronic weakness or spasticity.

Cervical disc Herniation
Protrusion of one or more of the discs in the neck towards the spinal cord or nerve roots. Cervical disc herniations can cause neck, shoulder or arm pain, or neurologic symptoms such as arm or leg weakness or sensory problems. Treatment often consists of rest or anti-inflammatory medication or in some patients, removal of the offending disc.

Cervical Stenosis
Narrowing of the column for the spinal cord in the neck. Such narrowing usually occurs from overgrowth of disks, ligaments or bony structures that impinge upon the central spinal canal. If the spinal cord or nerve roots are compressed significantly, symptoms can occur. These can lead to problems with arm or leg strength, balance control, sensory symptoms, bowel or bladder dysfunction or pain.

Chiari Malformation
Malformation that may occur with development of the baby or in later life. The malformation consists of a protrusion of the bottom portion of the cerebellum into the upper portion of the spinal canal. This malformation can lead to headaches, arm or leg symptoms, or problems with the nerves that supply the head and neck. When appropriately diagnosed, treatment can consist of surgical decompression of the base of the brain. Other treatments such as spinal fluid diversion (shunting) may also be considered depending on the cause of the malformation.

Involuntary abrupt, rapid, brief, and unsustained irregular movement and is sometimes described as "dance-like." Chorea occurs in 5% of people with cerebral palsy.

State of arousal often after head injury or disease. When a patient is comatose, they are not aware of their general surroundings and do not interact with observers at a normal level.

Cranial Settling
The uppermost bony portion of the neck is called the dens or odontoid process. The skull rests on this process and rotates. Cranial settling occurs when this bone protrudes into the hole in the base of the skull called the foramen magnum. This can be congenital (from birth) or from conditions such as Paget's disease or arthritis. Cranial settling can cause pain in the lower part of the skull and upper neck. It may also cause compression of the spinal cord, which may cause extremity weakness and numbness. This condition can be treated by surgical removal of the dens followed by instrumented cervical fusion.

Collection of fluid within a specific cavity. Cysts can form from tumors, after injuries, after bleeding in the brain, or as developmental fluid filled spaces. Spinal cysts are usually benign outpouchings of the covering of spinal nerve roots that are also known as Tarlov's cysts. It is rare that they are symptomatic but can occasionally cause back pain. If symptomatic, they can be treated by surgical resection.

Deafferentation Pain
This pain occurs after loss of normal sensory input to the brain. An example of this is phantom pain where a patient may still feel pain from a foot even though their foot has been amputated. This pain may be difficult to treat. Treatment can consist of medical therapy, behavioral techniques, or electrical stimulation.

Degenerative Disc Disease
The disc material that sits between the bones of the spinal column act like shock absorbers. Over time this fibrous gelatinous matter loses the ability to absorb water and is called degenerative. Having a degenerative disc can cause pain usually in the neck or lower back depending on where in the spine the disc is located. If surgical treatment is considered, surgery includes removal of the degenerated disc and placement of metal instrumentation to fuse the bones together to avoid instability. Surgical options also include less invasive percutaneous (through the skin) needle procedures.

Dural Fistula
Connection between a blood vessel located in the fibrous covering of the brain (dura) to another blood vessel without the blood passing through an intervening capillary network. Dural fistulas can be created by two blood vessels located only within the dura or they can also involve the brain blood vessels. Sometimes dural fistulas can lead to loud noises heard by the patient, a bulging red eye, or headaches. The type of symptoms depends upon the size and location of the specific fistula.

Movement disorder consisting of a tightening and twisting of a limb. The movement is not controlled by the patient. Sometimes dystonias can be painful. They are sometimes seen in patients with cerebral palsy, Parkinson's disease or other neurologic problems.

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