Cancer Neurology

Cerebrovascular Disease

Cerebrovascular disease is a condition that affects the flow of blood to the brain. It is characterized by ischemia (lack of oxygen) or bleeding in an area of the brain and involves one or more cerebral (of the brain) blood vessels. Two major sets of blood vessels (arteries) regulate the blood flow to the brain. Any kind of damage to these arteries in the form of blockage or rupture affects this flow and can cause bleeding or deprive the brain cells of oxygen and important nutrients present in the blood. The nutrient-deprived brain cells either are damaged or die within a few minutes.

Diagnosis

Cerebrovascular disease is a broad term and includes disorders such as stroke (blocked arteries), stenosis (narrowing of arteries), aneurysms (bulging out of the arteries), and vascular malformations (change in diameter of the arteries). The diagnosis of these disorders is done through imaging techniques. These may involve the use of contrast dye (cerebral angiography), ultrasound (carotid duplex), scans (CT or MRI), or metal discs (EEG).

Symptoms

Severe headache is a characteristic symptom of all cerebrovascular diseases. Some of the other symptoms include issues with vision, problems with co-ordination and balance as well as speech and comprehension difficulties.

Risk factors

Risk factors include both controllable and non-controllable risk factors. They include smoking, high blood pressure, diabetes, sedentary habits and obesity, age, gender, race and heredity factors.

Treatment

Treatment to be adopted depends on the type of cerebrovascular disorder. If the disorder involves a blocked artery, tPA (“clot bursting" drug) is administered to the patient. Anti-platelet medications are provided when there is a risk of clot formation and stroke, and surgical interventions involving wire mesh stents are conducted in conditions such as carotid stenosis.

Encephalopathy

Encephalopathy is a functional or structural disorder of the brain that is considered to develop from a primary problem, such as brain tumor, kidney problem, or liver disease. The chief characteristic feature of encephalopathy is an altered mental state. Encephalopathy is best described by terms that precede the word “encephalopathy". Each of these terms gives an idea about the reason, cause, or special conditions of the patient that lead to malfunctioning of the brain. For example, the term anoxic in anoxic encephalopathy means lack of oxygen. Hence, anoxic encephalopathy is damage to the brain caused due to lack of oxygen.

Symptoms

Encephalopathy symptoms vary depending on the type and severity of the condition. Common neurological symptoms include loss of high-level brain functions such as thought processing and remembering information, subtle personality changes, concentration issues, lethargy, and progressive loss in consciousness.

Causes

There are numerous and wide range of causes for encephalopathy. They include

  • Brain tumour
  • Impaired metabolism
  • Insufficient nutrition
  • Infection
  • Exposure to toxins
  • Limited blood flow to the brain

Diagnosis

Encephalopathy is diagnosed based on physical examination and medical history review. Your doctor may order tests such as blood tests, spinal tap, scans (CT, MRI), and EEG.

Treatment

Treatment is decided based on the type and severity of the encephalopathy. Symptom-specific medication along with vitamins or supplements may be given. Nutritional supplements and diet changes may be recommended for some patients. In conditions such as an excess of toxins in the body, dialysis or organ transplant would be required.

Prevention

Prevention is better than cure. Some of the preventive steps that can be taken include avoiding over dose of alcohol, drugs and medicines, opting for early treatment in conditions such as liver disease, and taking precautions to avoid exposure to poisons or toxins.

Headaches

A headache is pain or discomfort anywhere in the region of the head or neck. Headaches are the most common health complaints experienced by every person at some point during their life. Most headaches are not serious and can be treated with medications and lifestyle changes. There are many different types of headaches and it is important to know the particular type of headache you have and also methods to treat the same.

Types

Depending upon the cause, headaches can be divided into three major categories:

Primary headaches: Primary headaches are those headaches that are not associated with other medical conditions. The most common types of primary headaches include:

  • Tension headaches: Tension headaches are the most common type of headaches that occur when the head and neck muscles contract due to stress, poor posture, fatigue, eye strain, alcohol and tobacco use, and with hormonal changes in women before and after a menstrual period. Tension headaches may occur at any age, but occur mostly in adults and adolescents.
  • Migraine headache: A migraine is felt as a throbbing pain on one side of the head. The exact cause is unknown, but may occur from a series of changes in brain activity, and may be associated with alcohol use, smoking, lack of sleep, prolonged muscle tension and stress, changes in hormone levels during menstrual periods, or with the use of oral contraceptives. Migraines occur more often in women than men and may run in families.  
  • Cluster headaches: Cluster headache is a less common type of primary headache. The cause is unknown, but abnormalities in an area of the brain called the hypothalamus may be involved, and are triggered by certain factors such as changes in sleep patterns and use of certain medications. It is most common in men in their late 20s, and tend to run in families.

Secondary headaches: Secondary headaches are those that are caused by other underlying diseases. Some medical conditions that can cause secondary headaches include bleeding in the brain, brain tumors, meningitis and encephalitis.

Cranial neuralgias, facial pain, and other headaches: Cranial neuralgia is pain or discomfort in the head or neck caused by inflammation of the nerves located in the head and upper neck. Facial pain can be caused from a nerve disorder, an injury, or an infection in a structure of the face or it may occur for no known reason.

Symptoms

People with tension headaches have generalized pain in the head and neck described as a band-like tightness or pressure.

Migraine headaches often cause a throbbing or pulsating sensation usually on one side of the head. It may occur with symptoms such as nausea, vomiting, visual disturbances, and sensitivity to light and sound. The pain can last a few hours or even up to one or two days.

Cluster headaches have a characteristic grouping or clustering of attacks. People with cluster headaches usually have pain lasting for 30 to 90 minutes, once or twice daily, for weeks or months, followed by pain free periods. Attacks tend to occur at the same time each day and often wake the person from sleep. The pain is extremely painful and may occur behind and around one eye.

Diagnosis

Your doctor will question you about your headache, its location, length, duration, causative factors and associated symptoms. Your doctor will also review your family history, medical history, diet and lifestyle. The following diagnostic procedures may be ordered:

  • An MRI or CT scan of the head may be needed to rule out other causes of the headache.
  • An X-ray of the sinuses may be taken to evaluate sinus problems.
  • Lumbar puncture (spinal tap) is the removal of cerebrospinal fluid, or CSF (fluid surrounding the spinal cord and the brain) from the spinal canal to diagnose disorders affecting the brain and spinal cord.
  • Temporal artery biopsy is the removal ofa sample of blood vessel from your temple to check for signs of inflammation.

Treatment

Your doctor may suggest keeping a headache diary to help identify your headache type and recommend effective treatment.

To control tension type headaches, over-the-counter (OTC) pain medications are prescribed.

Medications for migraine headache fall into two categories:

  • Abortive medications are taken during migraine attacks as they work quickly. They are effective in people who have nausea and vomiting with their migraine.
  • Preventive medications are taken on a daily basis, to reduce the severity or frequency of the migraine attacks.

The treatment of cluster headaches is very difficult. Your doctor may treat cluster headache with oxygen inhalation, triptan medicines (constrict blood vessels and block pain pathway to brain), and the use of intranasal applications of a local anesthetic agent. Medications used to prevent additional headaches include blood pressure medications, antidepressant medications, and drugs used to treat seizures.

Hydrocephalus

Hydrocephalus is a condition in which the primary characteristic is excessive accumulation of fluid in the brain. Although hydrocephalus was once known as "water on the brain," the "water" is actually cerebrospinal fluid (CSF) "” a clear fluid that surrounds the brain and spinal cord. The excessive accumulation of CSF results in an abnormal widening of spaces in the brain called ventricles. Ventricles are hollow cavities within the brain that are constantly producing CSF. This widening creates potentially harmful pressure on the tissues of the brain.

Types of Hydrocephalus

Hydrocephalus may be of the following types:

  • Congenital hydrocephalus: present at birth and may be caused by genetic abnormalities or during fetal development
  • Acquired hydrocephalus: develops at the time of birth or at some point afterward
  • Communicating hydrocephalus: flow of CSF is blocked after it exits the ventricles
  • Non-communicating hydrocephalus: flow of CSF is blocked along one or more of the narrow passages connecting the ventricles

Symptoms

Symptoms of hydrocephalus vary with age, disease progression, and individual differences in tolerance to the condition. Symptoms may include:

  • Rapid increase in head circumference in infants
  • Blurred or double vision
  • Sunsetting (downward deviation of the eyes)
  • Urinary incontinence (inability to contain urine in the bladder)
  • Lethargy, drowsiness
  • Headache followed by vomiting and nausea
  • Slowing or loss of developmental progress
  • Irritability or other changes in personality
  • Changes in cognition including memory loss
  • Problems with balance, poor coordination, gait disturbance
  • Papilledema (swelling of the optic disk which is part of the optic nerve)

Causes

The causes of hydrocephalus are still not well understood. However, some of the common causes include inherited genetic abnormalities, developmental disorders, complications of premature birth, meningitis, tumors, and traumatic head injury.

Diagnosis

To diagnose hydrocephalus, your physician will perform a physical exam with emphasis on neurological evaluation and medical history. Your physician may order imaging tools such as MRI, CT scan and ultrasonography depending on your age, clinical presentation, and the presence of known or suspected abnormalities of the brain or spinal cord.

Post-operative Care

After surgery your surgeon will give you guidelines to follow to ensure a good outcome. You will be transferred to the recovery room after surgery for monitoring. You will be given pain medications to keep you comfortable and antibiotics to prevent infection. Keep the incisions clean and dry. You may shower once the stitches and/or staples are removed unless otherwise directed by your surgeon. Do not scratch the incision areas as this can lead to infection. If the incision areas become red, painful or draining, call your surgeon as these are signs of infection. If you experience headache, vomiting, visual problems, confusion, fever, or increased lethargy, call your surgeon right away.

Risks and Complications

As with any major surgery there are potential risks involved.

  • Allergic reactions to medications
  • Blood loss
  • Heart attacks, strokes, kidney failure, pneumonia, bladder infections
  • Nerve blocks leading to infection or nerve damage
  • Bleeding in the brain
  • Damage to brain tissues
  • Infection due to shunt
  • Mechanical failure or obstruction of shunt
  • Overdraining of CSF causing collapse of ventricles, tearing of blood vessels, headache, hemorrhage (subdural hematoma)
  • Underdraining of CSF

The decision to proceed with the surgery is made because the advantages of surgery outweigh the potential disadvantages. It is important that you are informed of these risks before the surgery takes place.

Peripheral Neuropathy

The nervous system consists of the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS is comprised of the brain and spinal cord, while the PNS comprises of nerves that carry information to and from the brain to the rest of the body. Peripheral neuropathy is a condition characterized by damaged peripheral nerves that cause pain. When this condition affects one nerve, it is called mononeuropathy; when several nerves are affected, it is polyneuropathy; and when 2 or more nerves are involved in different areas, it is termed as multiple mononeuropathy.

Peripheral neuropathy is a comparatively common disease that usually affects older people.

Causes

Diabetes is the most common cause of peripheral neuropathy.  At least half of all diabetics develop some form of neuropathy during the course of the disease.

Other factors that can cause peripheral neuropathy are:

  • Excessive alcohol intake, which leads to poor dietary  choices
  • Autoimmune diseases like lupus and rheumatoid arthritis
  • Exposure to toxic substances like heavy metals and certain medications, like chemotherapy
  • Viral or bacterial infections
  • Trauma or compression of the nerves
  • Tumor on or surrounding the nerves
  • Vitamin deficiencies

Signs and Symptoms

Symptoms depend on the type of the affected nerve. Common signs and symptoms include:

  • Numbness and tingling sensation in the feet or hands that can slowly spread to the legs and arms
  • Burning or sharp electric pain
  • Sensitivity to touch or heat
  • Impaired coordination
  • Muscle weakness or paralysis
  • Bowel or bladder incontinence
  • Foot infection and ulcers

Diagnosis

Peripheral neuropathy involves the exact detection of nerve damage and its cause, which is difficult to diagnose. Your doctor will review your medical history and family history for neurological diseases, and will conduct physical and neurological examinations for muscle strength, sensation, posture and coordination.

Your doctor may order other tests including:

  • Blood tests for vitamin, sugar and thyroid levels, and liver and kidney function
  • Computed tomography (CT) scan or MRI to detect herniated disks or spinal tumors
  • Nerve function tests using electromyography to measure the electrical activity of the nerves
  • Nerve biopsy, in which a part of the damaged nerve is removed to test for abnormalities
  • Lumbar puncture to test cerebrospinal fluid in the lower back for signs of disease

Treatment

The main aim of treatment is to control the underlying cause of peripheral neuropathy and manage pain. Symptoms of peripheral neuropathy can be relieved with:

  • Medications: Your doctor may prescribe pain killers, anti-seizure and antidepressant drugs, and topical medications.
  • Neuromodulation such as spinal cord stimulation or peripheral field stimulation: Your doctor will pass a gentle electric current through two electrodes placed on the painful areas of your body. Your pain will reduce when the electric impulses travel along the nerves of the painful area, due to the stimulation of the affected nerves and production of endorphins (natural pain killers), which block the pain signals in the brain. 
  • Acupuncture: Your therapist will insert thin needles into the body close to the nerves. This will stimulate the nerves and release endorphins.
  • Plasma exchange and intravenous immune globulin: Your doctor may perform plasma exchange and intravenous immune globulin to suppress the activity of the immune system.

Prevention

Peripheral neuropathy can be prevented by:

  • Managing the underlying disease condition such as diabetes
  • Maintaining a healthy diet and lifestyle to keep your nerves healthy
  • Eating a vitamin B-12-rich diet or including supplements
  • Preventing nerve damage by avoiding repetitive motions, restricted positions, toxic chemicals, and excessive alcohol

Pain Management

Pain is an unpleasant feeling or discomfort caused by injury, illness or emotional disorder. Pain can be differentiated into two basic types including:

  • Acute pain: It results from disease, inflammation, or injury. This type of pain starts suddenly, for example, after accidental trauma or surgery.
  • Chronic pain: It is caused by a disease itself. Both environmental and psychological factors can worsen it. It persists for a longer period of time.

Diagnosis

Your doctor will make a diagnosis based on the history of pain you have narrated such as type of pain –
whether sharp or dull aching pain, duration and location of pain.

There are various diagnostic techniques used to find the cause of pain, and some of them include:

  • Electro diagnostic procedures:
    • Electromyography (EMG): help to find out which muscles or nerves are affected by weakness or pain
    • Nerve conduction studies: determine if there is any nerve damage
    • Evoked potential (EP): used to record the speed of nerve signal sent to the brain
  • Imaging, especially magnetic resonance imaging (MRI) is the use of magnetic waves to differentiate diseased and healthy tissues.
  • A neurological examination involves testing for movement, reflexes, sensation, balance, and coordination.
  • X-rays

Treatment

The ultimate goal of pain management is to improve the function of an individual by enabling him to carry out his day-to-day activities in a normal way. Pain management involves treatment of the underlying disease and pain relief using medications and alternative techniques. The many ways by which pain can be treated include:

  • Medications: Some of the medications that can relieve pain include NSAIDs, narcotic analgesics (relieve acute pain, such as pain that is felt immediately following an injury or a surgical procedure), antidepressants, anti-anxiety drugs, antimigraine drugs and anesthesia. These medications should be taken only on doctor"s advice as they can cause serious adverse effects.
  • Physical therapy: Physical therapy involves use of physical techniques and methods, such as exercise, massage and acupuncture, in the treatment of certain chronic pain conditions. These techniques help to increase function, control pain, and rehabilitate the patient. Regular exercises relieve stress and also increase the production of endorphins, which are natural pain relievers.
  • Psychological evaluation and therapy: Psychological counseling such as behavioral therapy improves your mental health and manages conditions such as stress and depression which can aggravate chronic pain. It is important to be physically as well as emotionally stable to manage chronic pain.

Paraneoplastic Syndromes

Paraneoplastic syndromes are disorders of the nervous system that can occur from the presence of cancer in a remotely located organ or tissue. They are placed in a class of rare disorders that are sometimes seen in people with cancer. Cancers of the lung, breast and ovary are commonly associated with pareneoplastic syndromes.

Symptoms

Symptoms usually develop rapidly over days or weeks and often occur even before a tumor is diagnosed by the physician. Symptoms of paraneoplastic syndromes are believed to be the result of the body"s immune response to the cancerous tumor that not only attacks the tumor but also parts of the nervous system. Some of the symptoms associated with paraneoplatic syndrome include muscle weakness, muscle cramps, memory loss, vision problems, and slurred speech.

Types

There are several types of paraneoplastic disorders, and each one is named depending on the area of the nervous system affected, nature of symptoms, and the kind of immune response elicited. A few of them are listed below:

  • Cerebellar degeneration: loss of nerve cells in the cerebellum of the brain leading to impaired muscle co-ordination, double vision, and difficulty in swallowing
  • Limbic encephalitis: inflammation affecting the limbic system of the brain and reflected as personality changes, memory deficits, confusion, depression, agitation, and anxiety
  • Encephalomyelitis : inflammation of the brain and spinal cord leading to sensory loss or numbness, low blood pressure, irregular heart beat, and even respiratory failure
  • Stiff man syndrome: severe progressive muscle stiffening at times accompanied by painful muscle spasms, especially in the spine and lower legs.

Causes

Paraneoplastic syndromes are caused by T cells (cancer fighting antibodies) produced by the body against the cancer. These cells also attack nerve or muscles cells leading to gradual nerve damage and associated motor symptoms.

Diagnosis

Diagnosis of paraneoplastic syndrome is difficult as the symptoms develop even before the cancer is detected. Also, the symptoms closely resemble other cancer and non-cancer related neurological problems, thereby delaying the final diagnosis. Diagnosis is carried out by identifying antibodies in the serum that may be active against the nerve tissue. For this, the physician may order

imaging tests such as CT scan, MRI, PET, and PET-CT after carrying out a general physical examination. He or she may also include laboratory tests that include blood tests, and spinal tap (lumbar puncture).

Treatment

Treatment follows a two-prong strategy of treating the cancer and suppressing the immune response producing the symptoms. Medications include corticosteroids and immunosuppressants. Symptom specific medication may be used depending on the type of paraneoplastic disorder. Physical therapy may be used to regain muscle function and speech therapy may be employed to correct impaired speech developed during the course of the ailment.

Seizures

A seizure is a sudden, brief attack caused by changes in the brain"s electrical activity. It is quite common in people with a brain tumor. During a seizure, a person"s brain cells misfire releasing electrical energy in an uncontrolled manner. This results in a sudden buildup of energy through the brain, causing unconsciousness and contractions of the muscles. The person may cry, become unconscious, or twitch involuntarily.

Causes

A seizure may develop due to a severe head injury, or a very high fever, or meningitis (brain infection). In people with a brain tumor, seizures can be caused due to increased pressure in the brain, stress, lack of sleep, altered medication levels, and scar tissue developed after surgery. Also, there are certain types of seizures whose causes are unknown.

Symptoms

Symptoms depend on the area of the brain that is affected. If the entire brain is affected, then the symptoms would be those of a generalized or grand mal seizure. When seizures appear to result from abnormal activity in just one area of the brain, then the symptoms would be those of a partial or focal seizure.

In a generalized seizure, the patient is completely unresponsive and may blink his eyes rhythmically. The patient often stiffens which is followed by convulsions. However, in the case of a partial seizure, only an isolated part of the body is affected such as one side of the face. Also, the patient may not necessarily become unconscious.

Diagnosis

The diagnosis is difficult due to lack of obvious signs and non-availability of first-hand information from the patient. As the patient does not remember the seizure, it can be helpful to have information from someone who was witness to the seizure. Your doctor may order blood tests, scans (MRI and CT), and EEG (Electroencephalogram).

Treatment

As seizures are common in patients with a brain tumor, anti-convulsion or antiepileptic medications form an essential component of a standard treatment plan. Seizures may continue despite the treatment but with reduced severity and frequency. If satisfactory relief is not experienced with medications and the physical cause of the epilepsy is restricted to just one area of the brain, then epilepsy surgery may be considered as a treatment option.

Thromboembolism

Thromboembolism is a condition in which a blood clot formed inside a blood vessel breaks free and is carried in the bloodstream to block a blood vessel inside another organ, causing organ damage. The affected organs can be lungs (pulmonary embolism), brain (stroke), gastrointestinal tract, kidneys, or legs.

Two diseases typical to thromboembolism include DVT or deep vein thrombosis (blood clot in a deep vein) and PE (pulmonary embolism). These conditions may develop as a result of complications of cancer-related surgery.

Risk factors

Several risk factors for the development of thromboembolism in cancer patients have been identified and include site and stage of cancer, type of cancer, advanced disease, patient comorbidities, specific therapeutic agents, surgery, chemotherapy and hospitalization.

Symptoms

Nearly 50 percent of patients with thromboembolism do not show any symptoms. Also, symptoms of thromboembolic diseases such as DVT may go unnoticed for a while as they are similar to various other health problems. Typical symptoms include swelling, tenderness, change in skin color, and warmth over the affected area. Additional symptoms such as coughing up blood, sharp chest pain, and shortness of breath may be noticed if a blood clot breaks free and travels to the lungs, leading to pulmonary embolism.

Diagnosis

As a part of the diagnosis, your doctor will conduct a physical examination. They may ask questions related to your overall health and assess your medical history to exclude other causes. Your physician may also order tests specific to DVT such as a Duplex ultrasound, venography, and MRI.

Treatment

  • The aim of the treatment is three-fold, and includes
  • Preventing the clot from getting bigger
  • Preventing the clot from loosening and breakage
  • Reducing the chances of DVT reoccurrence

Treatment options involve the use of blood thinning medications such as heparin and warfarin. In severe cases, clot-buster medications such as tissue plasminogen activator (TPA) may be prescribed. Other treatment measures include inserting filters into veins to prevent clots from breaking loose and going to the lungs. Also, compression stockings may be worn for preventing blood from pooling and clotting.