2013-12-08 | best for all medical and surgical blog

Hydrocephalus

Hydrocephalus

Hydrocephalus is defined as a disproportionate increase in the amount of CSF within the cranuum, usually in association with a rise in ICP

Physiology and circulation of cerebrospinal fluid

The normal volume of circulating CSF is in the region of 140 ml. The fluid both protects and supports the brain and spinal cord, as well as maintaining homeostasis by acting as a transport medium for transmitters and as a method of removing the end-products of metabolism. CSF is produced by an active process, 80% of it being derived from the choroid plexus and the rest from the parenchyma. The rate of production is between 0.2- 0.4 ml min with a daily production

Raised intracranial pressure

Raised intracranial pressure

Physiology of intracranial pressure

Pathophysiology The adult skull may be regarded as a rigid unyielding box containing brain, cerebrospinal fluid (CSF) and blood. At normal supine pressures of 0.67-2 kPa (5-15 mmHg, 6-18 cm H20). measured from the level of the foramen of Monro these three components maintain volumetric equilibrium. An increase in the volume of any of the components will result in an increase in intracranial pressure (ICP) unless there is a

Central Nerve System Infections

Central Nerve System Infections

Central nervous system infections of interest to neurosurgeons include those that cause focal neurologic deficit due to mass effect, require surgical aspiration or drainage because antibiotic therapy alone is insufficient, cause mechanical instability of the spine, or occur after neurosurgical procedures.

Congenital Anomalies of Central Nerve System

Congenital Anomalies of Central Nerve System

Dysraphism

Dysraphism describes defects of fusion of the neural tube involving the neural tube itself, or overlying bone or skin. Dysraphism may occur in the spine or the head. Neural tube defects are among the most common congenital abnormalities.

Spinal Cord Tumours

Spinal Cord Tumours

A wide variety of tumors affect the spine. Approximately 20% of CNS tumors occur in the spine. The majority of spinal tumors are histologically benign, unlike cranial tumors. Understanding the two major spinal concepts facilitates understanding of the effects of spinal tumors. The two concepts are spinal stability and neural compression. Destruction of bones or ligaments can cause spinal instability, and lead to deformities such as kyphosis or subluxation and possible subsequent neural compression. Tumor growth in the spinal canal or neural foramina can cause direct compression of the spinal cord or nerve roots and cause loss of function. Anatomic categorization provides the most logical approach to these tumors. The various tumors present in characteristic locations. An understanding of the anatomy leads to an understanding of the clinical presentation and possible therapeutic options

Cerebrovascular Disease

Cerebrovascular Disease

these are including the following important disease like as Ishaemic disease .Thrombotic disease ,Embolic disease ,Haemorrhagic disease
Cerebrovascular disease is the most frequent.causes of new rapid onset, non traumatic neurologic deficit It is a far more common etiology than seizures.or tumors. Vascular structures are subject to a variety of chronic pathologic processes which compromise vessel wall integrity. Diabetes, high cholesterol, high blood pressure, and smoking are risk factors for vascular disease. These conditions can lead to vascular damage by such mechanisms as atheroma deposition

Peripheral Nerve Trauma or Injury

Peripheral Nerve Trauma

The peripheral nervous system extends throughout the body and is subject to injury from a wide variety of traumas. Peripheral nerves transmit motor and sensory information between the CNS and the body. An individual nerve may have pure motor. pure sensory. or mixed motor and sensory functions. The key information-carrying structure of the nerve is the axon. The axon transmits information from the neuronal cell body and may measure from less than1 mm to greater than I m in length. Axons that travel a significant distance are often covered with myelin. which is a lipid-rich. electrically-insulating sheath formed by Schwann cells. Myelinated axons transmit signal much more rapidly than unmyelinated axons, because the voltage shifts and currents that define action potentials effectively jump from gap to gap over the insulated lengths of the axon.

Spinal Cord Trauma

Spinal Cord Trauma

The spine is a complex biomechanic and neural structure. The spine provides structural support for the body as the principal component of the axial skeleton, while protecting the passing spinal cord and nerve roots. Trauma may fracture bones or cause ligamentous disruption. Often bone and ligament damage occur together. Damage to these elements reduces the strength of the spine and may cause the spine to be unstable. This compromises both its structural support function and its ability to protect neural elements. Spine trauma may occur with or

Brain Death

Brain Death

Brain death occurs when there is an absence of signs of brain stem function or motor response to deep central pain in the absence of pharmacologic or systemic medical conditions that could impair brain function.

For as long as medical practice has existed, the layperson has required of medical practitioners that they be knowledgeable
about death. For cenrunes, lay people and doctors alike have accepted cessation of respiration and heart beat as the classical signs of death. Advances in cardiopulmonary resuscitation and modern mechanical ventilation have made obsolete the traditional clinical definition of death with a small but significant harvest of irreversibly brain-damaged patients. The worst form of such damage led to the concept of (coma depasse), first defined by Mollaret and Goulon in 1959. As the number of patients with artificially maintained ventilation and circulation increased. they became to be regarded as a potential source of donor organs. These two developments occurred parallel to but independently of each other, and the diagnosis of brain death did not arise because of the need for donor organs.

Traumatic Intracranial Haematoma

Traumatic Intracranial Haematoma

Types of intracranial haematoma can be classified into

Intracerebral or intraparenchymal which are hypodense on CT scan and small ones may enlarge and may need evacuation-1

2- Extradural or Epidural haematoma

3- Acute subdural haematoma

4- Chronic subdural haematoma

Head Trauma Scalp injury Skull fractures Closed head injury

Head Trauma Scalp injury Skull fractures Closed head injury

Head Trauma

Trauma is the leading cause of death in children and young adults; however. incidences of death and disability from trauma have been slowly decreasing. This is partly attributable to increased awareness of the importance of using seat belts and bicycle and motorcycle helmets. However, trauma remains a major cause of morbidity and mortality, and can affect every major organ system in the body. The three main areas of neurosurgic interest in trauma are TBI, spine and spinal cord injury (SCI), and peripheral nerve injury.

Neurological and Neurosurgical emergencies

Neurological and Neurosurgical emergencies

these including the following items

1-Raised intracranial pressure

2-Brain stem compression

3-Cerebral Stroke

4- Seizure

5- Trauma as Head Trauma

Raised Intracranial Pressure ICP

ICP normally varies between 4 and 14 mm Hg. Sustained ICP levels above 20 mrn Hg can injure the brain. The Monro-Kellie doctrine states that the cranial vault is a rigid structure, and therefore the total volume of the contents determines ICP.The three normal contents of the cranial vault are brain, blood, and CSF. The brain's contents can expand due to swelling from traumatic brain injury . stroke or reactive edema. Blood volume can increase by extravasation to form a hematoma, or by reactive vasodilation in a hypoventilating, hypercarbic patient. CSF volume increases in the setting of hydrocepbalus. . Addition of a fourth element, such as a tumor or abscess, will also increase ICP

Neurological examination and diagnostic methods

Neurological examination and diagnostic method

NEUROLOGIC EXAMINATION

The neurologic examination is divided into several components and is generally done from head to toe. First assess mental status. A patient may be awake, lethargic (will follow commands and answer questions, but then returns to sleep), stuporou (difficult to arouse at all), or comatose (no purposeful response to voice or pain). Cranial nerves may be thoroughly tested in the awake patient, but pupil reactivity, eye movement, facial symmetry, and gag are the most relevant when mental status is impaired. Motor testing is based on maximal effort of major muscle groups in those able to follow commands, while assessing for amplitude and symmetry of movement to deep

Neurosurgery Introduction and Anatomy

Neurosurgery

This chapter will be including the following items which will be discuss separately and these items are

Introduction
Anatomy of the scalp skull brain spinal cord
Diagnostic methods
Neurologic and Neutologic emergencies
Trauma eg.Head .Spinal .Peripheral nerve trauma
Cerebrovascular disease eg Ishemis Thrombotic Embolic, Haemorrhagic Disease
Tumours of the central nervous system eg Intracranial , Metastatic ,Glial ,Neural Crest .Miscellaneous ,Emryologic and Spinal Tumours

CANCER PREVENTION

CANCER PREVENTION

The old axiom "an ounce of prevention is worth a pound of cure" is being increasingly recognized in oncology. Cancer prevention can be divided into three categories: (I) primary prevention (i.e., preventing initial cancers in healthy individuals); (2) secondary prevention (i.e., preventing cancer in individuals with premalignant conditions); and (3) tertiary prevention (i.e., preventing second primary cancers in patients cured of their initial disease

Gene therapy of cancer

Gene therapy of cancer

Gene therapy is being pursued as a possible approach to modifying
the genetic program of cancer cells as well as for treatment of
metabolic diseases. The field of cancer gene therapy utilizes a variety of strategies, ranging from replacement of mutated or deleted tumor suppressor genes to enhancement of immune responses to cancer cells Indeed. in preclinical models. approaches such

Immunotherapy of cancer

Immunotherapy of cancer

The aim of immunotherapy is to induce or potentiate inherent anti tumor immunity that can destroy cancer cells. Central to the process of antitumor immunity is the ability of the immune system to recognize tumor-associated antigens present on human cancers and to direct cytotoxic responses through humoral or T-cell-mediated immunity. Overall, T-cell-mediated immunity appears to have the greater potential of the two for eradicating tumor cells. T cells recognize antigens on the surfaces of target cells as small peptides presented by class I and class 11major histocompatibility complex (MHC) molecules

Biologic therapy or management of cancer

Biologic therapy or management of cancer

Over the past decade, increasing understanding of cancer biology has fostered the emerging field of
molecular therapeutics. The basic principle of molecular therapeutics is to exploit the molecular differences
between normal cells and cancer cells to develop targeted therapies. The ideal molecular target would be

Hormonal therapy or management of cancer

Hormonal therapy or management of cancer

HORMONAL THERAPY
it has been found that up to 15%of tumors may have responsive elements

Some tumors, most notably breast and prostate cancers. originate from tissues whose growth is under hormonal control. The first attempts at hormonal therapy were through surgical ablation of the organ producing the hormones of interest, such as oophorectomy for breast cancer. Currently, hormonal manipulation is accomplished by several different modes .

Cancer management by Radiotherapy

Cancer management by Radiotherapy or Radiation therapy

Radiotherapy

Radiation may be particulate or electromagnetic
Radiotherapy kills tumour cells by generating high energy molecular movement Tumour susceptibility is related to tumour oxygenation and radiosensitivity of the individual cells
Radiotherapy may be used as a primary, neoadjuvant, adjuvant or palliative therapy to causes damage to normal as well as tumour cells resulting in local and systemic complications
.This is the therapeutic use of ionising radiation for the treatment of malignant conditions

CANCER MANAGEMENT BY CHEMOTHERAPY

Cancer management by chemotherapy

Definition

Chemotherpeutics are drugs that are used to treat cancer that inhibit the mechanisms of cell proliferation. They are therefore toxic to normally proliferating cells (ie bone marrow gastro intestinal eipithelium hair follicles

they may be used as primary neoadjuvant or adjuvant therapies

They can be

Cycle-specific: effective throughout the cell cycle

Phase-specific: effective during part of the cell cycle

, tumors susceptibility depends on the concentration of drug delivered, on cell sensitivity, cycling of tumour. Drugs are less effective in large solid tumours because of

• Fall in the growth fraction

• Poor drug penetrance into the centre