Brain Surgery Information:

PLEASE NOTE:

• If you are looking for information regarding a specific brain condition, please visit the Contents page or, alternatively, use the custom search engine by Google on the What's New page.
• If you would like to obtain a downloadable e-Book version or an official hard copy book version pertaining to the information and illustrations contained in all 25 chapters, click here.

CHAPTER 5: SYMPTOMS, SIGNS AND COMPLICATIONS OF BRAIN DISORDERS

Brain disorders can manifest in many ways. A symptom is a problem that a patient reports to a doctor when the doctor interviews the patient to determine his or her medical history. A sign is a problem that a doctor finds on physical examination of the patient. Some of the terms listed below are used to describe clusters of symptoms and signs associated with brain disorders, while others are generic or nonspecific blanket terms.

·  Neurological deficit or neurodeficit: An impairment of some function of the nervous system detected by a physician.

·  Focal neurodeficit: A specific neurological impairment that can be localized by the doctor’s examination to a certain region or structure of the nervous system.

·  Paresis and paralysis: Paresis refers to partial weakness on testing of a muscle group by a doctor, while paralysis or plegia refers to complete weakness, that is, complete loss of movement or motor activity. The following three terms are frequently used: Hemiparesis, which refers to loss of function on one side of the body; paraparesis, which refers to loss of function of the legs or lower extremities; and quadraparesis, which refers to loss of function in all four limbs, that is, both upper and lower extremities. For these three terms, if the word paresis is replaced with plegia, this refers to complete loss of movement or motor function in those parts of the body.

·  Raised ICP: When pressure in the brain rises, say from a brain tumor, or from hydrocephalus, several symptoms can arise. There may be unexplained nausea and vomiting or headaches, particularly in the morning hours. There may be blurred or double vision, increasing drowsiness, and frank coma or unresponsiveness.

·  Brain hemorrhage: A sudden rupture of an abnormal blood vessel, say, an aneurysm, or an AVM can cause a brain hemorrhage. The symptom is usually an extremely severe, sudden onset headache that may or may not be associated with a neurological deficit, neck stiffness, collapse or coma, or other signs of raised ICP.

·  “Brain Attack” or Stroke: A "brain attack" is the brain's version of a heart attack, and it occurs when the blood supply to a region of the brain is lost. This is also referred to as a "stroke" or cerebral infarction or cerebrovascular accident (CVA). Symptoms of a brain attack may be short-lived, for example, less than 24 hrs in duration as occurring in a transient ischemic attack (TIA) or “ministroke”, or they may be part of a full and permanent event, referred to as a completed stroke. Stroke symptoms are typically sudden in onset and may include one or more of the following: Visual impairment like a darkish curtain coming across the eye known as amaurosis fugax, or partial or complete blindness involving one or both eyes. There may be impairment of clarity of speech referred to as dysarthria, or language dysfunction referred to as dysphasia or aphasia. Paresis, paralysis or impaired sensation can also occur. Other symptoms include spinning or vertigo, gait imbalance, loss of consciousness, incoordination, double vision, and so forth, depending on the region of brain involved.

·  Mass effect and herniation: These are important concepts that patients should be familiar with. Since the brain is enclosed in what amounts to a rigid container, the skull, there is very little room to accommodate a “space occupying lesion” (SOL) such as a tumor or a hematoma, or swelling in the brain referred to as edema. As a result, structures in the brain get compressed and begin to shift, that is, they become displaced. This can lead to a wide variety of neurological symptoms and signs. This shift is known as mass effect. The ventricles in the brain can get compressed and trapped, and under these circumstances, CSF flow can become obstructed, leading to a further worsening of the mass effect (Figure 12). As the SOL or the edema associated with it continues to expand, the brain begins to be squeezed through any pathway of least resistance. This path eventually is the foramen magnum, where the critical brainstem is pushed into the spinal canal. This process of squeezing and compression is known as herniation, and it can progress rapidly to death (Figure 13). Herniating patients are often found to be progressively sleepy or “obtunded”, weak or paralyzed on one side, at least one of their pupils becomes dilated and poorly reactive, and they become unable to support their breathing function.

·  Miscellaneous: Personality changes, bladder and/or bowel incontinence, and problems with memory and thinking or cognition can occur in a variety of brain conditions, including tumors of the frontal lobe, dementias, and certain hydrocephalus syndromes such as NPH. Similarly, seizures can occur from many causes. The seizure may involve alteration in the patient’s level of consciousness, where they appear blank-faced, confused or frankly unresponsive. Alternatively, seizures can involve bizarre sensory and movement or motor disturbances, or generalized shaking with potential for self injury as part of the classic “grand mal” or generalized tonic-clonic seizure.

Figure 12 (above). Space occupying lesion and mass effect.

Figure 13 (above). Herniation.