Ординатура / Офтальмология / Английские материалы / Clinical Medicine in Optometric Practice_Muchnick_2007

274 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

teeth grinding during sleep. Jaw exercises, the local application of heat and the use of a nocturnal bite guard help reduce TMJ jaw pain. In addition, the associated headache can be relieved by the use of NSAIDs.

SECONDARY SUBACUTE HEADACHE

The new onset of headache is an ominous sign of a serious underlying systemic condition or an intracranial disorder. These headaches require immediate evaluation. The subacute headache evolves during a period of weeks and is worrisome particularly if the pain is progressive. Concurrent symptoms such as fever, malaise, lymphadenopathy, stiff neck, or weight loss should prompt an immediate referral to the primary care physician.

Giant Cell Arteritis

Characteristics

Giant cell arteritis (GCA) is characterized by a unilateral or bilateral head pain located in the scalp overlying the temporal artery. The pain is typically a mild-to-moderate boring sensation, and is exacerbated by palpation of the temples when combing the hair or when chewing. Vision loss of the involved eye is the result of inflammation in the arterial wall of the ophthalmic artery. The vision loss can be quite sudden, and some patients wake up to find unilateral blindness, but in other cases the loss of vision can take up to a month to evolve.

Epidemiology

Women are affected more commonly than men and the condition rarely occurs in patients younger than 50 years. Half of all untreated patients go blind in the involved eye. Of all untreated patients, 50% with unilateral blindness as the result of GCA go on to bilateral blindness, sometimes within days.

Precipitating Factors

Age is the single most significant precipitating risk factor in the development of GCA.

Pathophysiology

In GCA an underlying granulomatous arteritis with lymphocytic, neutrophilic, and giant cell infiltration exists in the walls of the mid-to-large sized arteries of the body. The most common vessel affected is the superficial temporal artery (the reason this condition is also known as temporal arteritis), a branch of the external carotid artery, and the vertebral artery. Pain is produced by the inflammation in the artery wall.

Diagnosis

In a patient with sudden, unilateral vision loss with a relative afferent papillary defect and an altitudinal visual field defect in the involved eye, ophthalmoscopy

will reveal a swollen, hemorrhagic optic disc with blurry margins. Palpation of the scalp will often reveal a thickened, tender temporal artery. The Westergren erythrocyte sedimentation rate (ESR) is elevated to approximately 100 mm/hr in GCA, whereas in the normal, elderly population it should be no higher than 40 mm/hr. C-reactive protein is also elevated, indicating the presence of an inflammatory condition. A prompt biopsy of the artery will reveal vasculitis characterized by an obliteration of the lumen and infiltration of the vessel wall with lymphocytes, plasma cells, and giant cells. A CBC will reveal the presence of a hypochromic anemia.

Treatment

The goal of treatment is the avoidance of vision loss, although GCA has significant systemic ramifications, because it is a generalized vascular inflammatory condition. Treatment will not restore vision loss in the involved eye; however, the risk of bilateral vision loss is reduced by the initiation of prompt therapy. Clinical presentation along with an elevated ESR is grounds for beginning immediate therapy with intravenous methylprednisolone (500 to 1000 mg every 12 hours for 2 days), or, more commonly, prednisone, 40 to 60 mg/d orally. The headache usually resolves within days. The oral steroid is continued for 1 to 2 months before tapering. Therapy should not be delayed while waiting for biopsy results. The dosage is tapered during a 1- to 2-year period and the effectiveness of therapy is monitored by regular evaluations of the ESR.

Intracranial Mass

Characteristics

Brain tumors often produce head pain that is mild– to-moderate, dull, steady, and intermittent. Associated nausea and vomiting may be present. Massrelated headache is worse when arising in the morning.

Epidemiology

In low-grade gliomas, the majority of patients are seen with seizure activity, while 40% are seen with headache. In malignant glioma, the majority of patients are seen with altered mental status and half of these patients are seen with headache. In benign meningioma, 40% of patients are seen with seizure and nearly the same amount are seen with headache.

Precipitating Factors

The head pain associated with brain tumors is aggravated by a change in head position. Any valsalva maneuver, such as coughing, sneezing, or orgasm, will worsen a tumor-related headache.

Pathophysiology

Intracranial masses comprise the entities of brain tumor, subdural hematoma, aneurysm, or abcess. Headache is produced by compression, distortion, displacement, or inflammation of pain-sensitive structures by the mass lesion. Any increase in intracranial pressure (ICP), such as from coughing or sneezing, will worsen a cranial mass-related headache.

Diagnosis

In the optometry office, a new onset of subacute head pain should initiate an immediate evaluation of extraocular muscle movements and a papillary evaluation. After recording pupils, a dilated fundus evaluation is necessary to exclude papilledema or swelling of the optic nerve head. During the time it takes to dilate the patient, it is recommended that the patient have visual fields performed to exclude visual field defects. Any suspicion of an intracranial mass warrants an immediate evaluation with computed tomography (CT) scan or magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA). Referral through the primary care physician is usually made to neurology.

Treatment

Treatment of brain tumor is dependent on type and location.

Trigeminal Neuralgia

Characteristics

Trigeminal neuralgia, or tic douloureux, is characterized by unilateral facial pain distributed along the second and third divisions of the trigeminal nerve. The headache is characterized by sudden, quick jolts of excruciating episodes of pain that exacerbate and remit spontaneously. The condition is considered by Gutrecht and Tarlov as one of the worst pains that humans experience. The condition rarely occurs during sleep.

Epidemiology

The condition typically develops in mid to late life.

Precipitating Factors

Trigger zones exist that, when stimulated, precipitate the onset of the pain. The areas stimulated by touch include the cheek, mouth, and nose. In addition, shaving and chewing may initiate trigeminal neuralgia. Cases have been reported to occur after exposure to cold temperatures or wind on the face.

Pathophysiology

Trigeminal neuralgia is of unknown cause. In this condition, the trigeminal nerve roots are proximal to a vascular structure lengthened and made tortuous by age, and

HEADACHE 275

microvascular compression of the nerve is thought to contribute to the induced head pain. In addition, some believe that a loss of myelin insulation of the posterior trigeminal nerve contributes to the condition.

Diagnosis

Neurologic testing and imaging is all negative, although the presenting symptoms should be differentiated from MS and brain tumor.

Treatment

The treatment of choice is carbamazepine, 400 to 1200 mg/d orally in three divided doses. This medication raises the threshold of pain by stabilizing cell membranes. Relief of the pain occurs in 24 hours. Abortion of an acute attack may be achieved by intravenous phenytoin, 250 mg. In extreme cases that are resistant to medication, the surgery of choice is posterior fossa microvascular decompression.

SECONDARY ACUTE HEADACHE

Patients with the classic acute headache are seen with the complaint of the head pain being “ . . . the worst I have ever had in my life!” These patients are often brought to the emergency room and so rarely are seen by the optometrist. Any “first and worse,” or head pain associated with neck stiffness must be evaluated immediately. The most common cause of life-threatening acute, excruciating headache is subarachnoid hemorrhage. Head pain associated with neck stiffness and fever mandates an evaluation for meningitis. Two primary sources of bleeding can contribute to a subarachnoid hemorrhage: a burst aneurysm or bleeding of a nonaneurysmal structure, the arteriovenous malformation (AVM).

Subarachnoid Hemorrhage

Characteristics

The hallmark sign of subarachnoid hemorrhage is the sudden and spontaneous onset of a severe, unbearable, and generalized global headache. This condition does not occur without head pain. Syncope, nausea, and vomiting at the outset of the headache are common. Coincident with the hemorrhage is a rise in blood pressure and a fever. The conscious patient may experience altered cognitive behavior. The unconscious patient may fall into a coma.

Epidemiology

A cerebral artery aneurysm rupture occurs most frequently in the fifth and sixth decades. It occurs in males and females equally. AV malformation aneurysms occur twice as often in men as in women and these tend to rupture between the ages of 20 to 40 years. In the

276 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

United States 28,000 cases of ruptured intracranial hemorrhage occur per year. Of patients with subarachnoid hemorrhage, 20% die before reaching hospital. Of those that reach hospital, one quarter die from the hemorrhage within 2 weeks. Another 25% die from a second bleed of the aneurysm if not surgically corrected. Of all survivors of subarachnoid hemorrhage, half have irreversible brain damage. AVMs have a much better prognosis, because 90% of these patients recover with no surgical intervention.

Precipitating Factors

Increasing age and the location of the aneurysm are significant factors in the development of subarachnoid hemorrhage. Systemic hypertension has not been correlated to the formation of the aneurysm, but the sudden elevation of blood pressure at orgasm has been reported as increasing the risk of aneurysmal rupture. Other risk factors associated with ruptured aneurysm include smoking, alcohol consumption, and the use of oral contraceptives.

Pathophysiology

This headache is caused by a spontaneous and nontraumatic hemorrhage into the subarachnoid space, the area located beneath the arachnoid coverings of the brain. The source of the bleed is most commonly a ruptured aneurysm, which are spherical outpouchings representing weaknesses in the blood vessel wall. Hemodynamic stress placed on an area of structural weakness within the aneurysmal wall causes the rupture. Of intracranial aneurysms, 85% are associated with the anterior circulation, and only 15% arise from the posterior circulation.

Of all subarachnoid hemorrhages, three quarters are the result of a berry aneurysm. Most cerebral artery aneurysms are berry aneurysms, which are congenital in nature and develop from a weakness in the vessel wall. The most common site of the berry aneurysm is the area of vessel branching around the circle of Willis.

AV malformations allow blood to flow from an artery to a vein without passing through a capillary bed. The intervening vessel, known as an AVM, is susceptible to aneurysm. Most AVMs arise around the area of the middle cerebral artery.

When an intracranial artery ruptures, an immediate outpouring of blood occurs from the vessel into the subarachnoid space. This increases ICP, causing distortion of pain-sensitive intracranial structures. In addition, cerebral blood flow decreases, leading to syncope in half of the patients.

Diagnosis

Ophthalmoscopy may reveal subhyaloid preretinal hemorrhages that are the result of a rapid elevation in ICP. These are virtually pathognomonic of subarach-

noid hemorrhage but occur in only 20% of cases. Terson’s syndrome, in which a burst aneurysm from the anterior circulation causes hemorrhage into the vitreous cavity, may cause visual loss, and in some cases require a vitrectomy.

Extraocular muscle involvement may help to localize the location of the aneurysm. Abducens palsy resulting in an esotropic posture may occur from an intracavernous carotid aneurysm. Oculomotor palsy with unilateral ptosis and mydriasis in an eye that is “down and out” is a frequent complication of carotidposterior communication aneurysms.

Visual field findings may help determine the location of the aneurysm. A bitemporal hemianopsia, denser above, is typical of a supraclinoid carotid aneurysm extending superiorly and pressing on the optic chiasm from below. Compression of the optic chiasm from above results in a bitemporal hemianopsia that is denser below.

CT scan should be performed within 24 hours of the onset of headache and will reveal areas of high density representing blood in the subarachnoid space near the circle of Willis. AVMs will be detectable on CT scan with contrast or MRI. A lumbar puncture will reveal elevated opening pressure with bloody fluid.

Treatment

The goal of medical treatment of subarachnoid hemorrhage is the prevention of rebleeding. Bed rest with elevated head position at 20 degrees with mild sedation will help reduce the recurrence of hemorrhage. Analgesics are given to alleviate the head pain, but aspirin must be avoided as it may promote rebleeding. Adequate blood pressure control reduces the mortality associated with subarachnoid hemorrhage. Nimodipine, a calcium channel antagonist, is given to reduce the ischemia of cerebral vasospasm.

The surgical goal of a ruptured aneurysm is an improved clinical outcome. This can be accomplished by two techniques. The first involves clipping the neck of the aneurysm. The second places a coil within the artery to induce clotting. The surgical intervention of an AVM is not as urgent as with aneurysm and involves the resection of the entire AVM if it is surgically accessible, or the ligation of feeding blood vessels.

Complications of subarachnoid hemorrhage include rebleeding, hemiparesis, aphasia, hydrocephalus, seizures, and diabetes.

BIBLIOGRAPHY

Aminoff, MJ, Greenberg DA, Simon RP, eds: Clinical neurology, New York, 2005, Lange Medical Books/McGraw-Hill.

Aurora SK, Welch KM: Migraine: imaging the aura, Curr Opin Neurol 13:273-276, 2000.

Cady R, Dodick DW: Diagnosis and treatment of migraine, Mayo Clin Proc 77:266-271, 2002.

DeAngelis LM: Brain tumors, N Engl J Med 344:114-123, 2001. Dennis MS: Outcome after brain hemorrhage, Cerebrovasc Dis

16(suppl 1):9-13, 2003.

Edlow JA, Caplan LR: Avoiding pitfalls in the diagnosis of subarachnoid hemorrhage, N Engl J Med 342:29-36, 2000.

Friedman DI, et al: Diagnostic criteria for idiopathic intracranial hypertension, Neurology 59:1492-1495, 2002.

Friedman DI: Pseudotumor cerebri, Neurosurg Clin Am 10:609-621, 1999.

International Subarachnoid Hemorrhage Aneurysm Collaborative Group: International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping vs. endovascular coiling in 2,143 patients with ruptured intracranial aneurysms: a randomized trial, Lancet 360:1267-1274, 2002.

Jones HR, ed: Netter’s neurology, Teterboro, N.J, 2005, Icon Learning Systems.

HEADACHE 277

Kelly AM: Migraine: pharmacotherapy in the emergency department, West J Med 173:189-193, 2000.

Olesen J, Tfelt-Hansen P, Welch KMA: The headaches, ed 2, Philadelphia, 2000, Lippincott,Williams & Wilkins.

Pringsheim T: Cluster headache: evidence for a disorder of circadian rhythm and hypothalamic function, Can J Neurol Sci 29:33-40, 2002.

Silberstein SD, Lipton RB, Dalessio DJ: Wolff’s headache and other head pain, ed 7, Oxford, England, 2001, Oxford University Press.

Tomsak RL: Ophthalmologic aspects of headache, Med Clin North Am 75:693-706, 1991.

Woo D, Broderick JP: Spontaneous intracerebral hemorrhage: epidemiology and clinical presentation, Neurosurg Clin North Am 13:265-279, 2002.

280 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

may take weeks to months to develop and is often the result of a primary brain disease such as Alzheimer’s disease, dementia, bipolar disorder, and depression.

The characteristics of confusional states and psychiatric disorders are similar. Patients will be easily distracted and may appear agitated. Cognitive powers are reduced and the patient may be incoherent or even delusional. In both acute and chronic confusion hallucinations may be present.

Psychiatric disease includes mood, psychotic, and anxiety disorders. Mood disorders include depression and bipolar disorder. Psychotic disorders include schizophrenia and delusion disorder. Anxiety disorders includes posttraumatic stress syndrome.

Psychiatric disorders often produce disorientation to the point of cognitive impairment, but the patient has a normal level of consciousness. Often the patient is not consistently oriented to time, place, and person. Characteristics of psychiatric disease include disturbed thoughts and abnormalities in perception. Often the patient with mental disease displays inappropriate behavior. Personality changes are noted by family members and friends.

DEMENTIA Characteristics

Dementia is characterized by an impairment of cognitive function with no effect on consciousness. Dementia rarely causes sleepiness, inattention, or disorientation until late in the disease.

Epidemiology

Dementia affects as many as one fifth of all individuals older than 65 years. The greatest risk factor for dementia is age. Approximately 4 million cases of dementia are caused by Alzheimer’s disease.

Pathophysiology

The underlying pathology is an acquired, progressive, and generalized abnormality within the cerebral cortex and its subcortical connections. The most common causes of dementia are, in order of frequency, Alzheimer’s disease, Parkinson’s disease, and multiinfarct dementia.

Diagnosis

The diagnosis of dementia is challenging and problematic. No specific screening tests, laboratory tests, or any imaging tests exist that can confirm the diagnosis. The complaint of memory loss is nonspecific because it is so common in the elderly population. For instance, only one tenth of elderly patients who complain of

memory loss actually go on to develop dementia. However, more than half of all elderly patients who develop dementia never complain of memory loss.

Cognitive testing in suspected dementia cases reveals minor changes in neurologic function and reduced short-term memory capacity.

The ocular examination in dementia patients is critical in determining the etiology of the disorder. A dementia patient with a Kayser-Fleischer ring should have an evaluation for Wilson’s disease. The finding of papilledema may indicate that the dementia is related to a cranial space-occupying lesion such as a brain tumor. The presence of pinpoint pupils is most suggestive of dementia from neurosyphilis. A dementia patient with ophthalmoplegia should be evaluated for progressive supranuclear palsy.

Neuroimaging will reveal enlargement of the ventricles and cerebral cortical sulci.

Differential Diagnosis

Alzheimer’s Disease

The most common cause of dementia, Alzheimer’s disease is characterized by a progressive degeneration of the brain that results in impaired memory and disorientation.

The incidence of Alzheimer’s disease peaks in patients between the ages of 65 and 85 years. Half of the population older than 85 years is afflicted with Alzheimer’s disease, and more than 20 million cases of Alzheimer’s disease exist throughout the world. Age is the leading risk factor, although genetic susceptibility to the disease plays a role in approximately 5% of cases. Women are at greater risk of developing Alzheimer’s disease than men. In addition, patients with a history of head injury or exposure to toxins or free radicals are predisposed to the development of the disease. Patients with hypertension or a history of stroke are also at greater risk for developing Alzheimer’s.

Alzheimer’s disease results from an elevated level of beta amyloid in the brain. This protein is inappropriately deposited in neural tissue and is toxic to brain synapses and neurons. The brain damage is characterized by the presence of “plaques and tangles.” Neuritic, or senile, plaques represent the extracellular deposition of several types of proteins. These proteins are also deposited abnormally in the cerebral and meningeal blood vessels. Tangles represent the intracellular deposition of abnormal protein. The disease worsens as the number of neurofibrillary tangles increases.

The brain damage begins in the hippocampus and spreads to the subcortical gray matter of the temporal lobe (causing “naming impairment”), parietal lobes, and frontal lobe (causing global aphasia). The last area to become involved is typically the occipital lobe.

The earliest manifestations of Alzheimer’s disease are short-term memory loss and disorientation to time and place (Box 19-1). In Alzheimer’s disease the loss of neurons in the hippocampus is thought to disconnect the memory processing area from two significant areas: the memory storage area in the neocortex, and the input area for new sensory information. The patient may experience forgetfulness, leading to mismanagement of medications, failure to pay bills, cooking disasters, and driving accidents.

Depression also often characterizes the early stage of Alzheimer’s, and results from subcortical, cortical, and limbic neuron dysfunction or loss. As a result of this neuronal pathology, a reduction in the level of neurotransmitters occurs, with a subsequent propensity towards depression.

As Alzheimer’s disease progresses, the patient may become agitated and restless. Typically, incidents occur in which the patient wanders away from familiar surroundings only to become lost because of a visuospatial disturbance. There may also be significant lan-

BOX 19-1

SIGNS AND SYMPTOMS OF POSTERIOR CORTICAL ATROPHY (VISUAL-SPATIAL FORMS OF ALZHEIMER’S DISEASE)

Complaints: Blurred vision, reading difficulty, difficulty walking up and down stairs and inclines, difficulty reaching for objects, confusion when presented with an array of objects, objects “pop in and out of view.”

Acuity: rarely completely normal, usually approximately 20/30 until the disease is far advanced.

Visual fields: Testing is labored and inconsistent, especially to multiple simultaneous stimuli. Formal kinetic testing usually reveals constricted fields. Automated static testing is hopeless as a result of impersistence and inattention.

Color vision to plain squares is normal. The patient is unable to perform the Ishihara test because of visualspatial inability.

Ocular apraxia: Visually guided saccades and pursuit movements are abnormal. Saccades to nonvisual commands are slowly initiated. Random saccades are of normal amplitude and velocity.

Optic ataxia: misreaching for external targets (such as the examiner’s fingertip). Reaching for the patient’s own clothing or body parts (under somesthetic guidance) is normal.

Bilateral visual inattention: spotty piecemeal performance on line cancellation test.

Simultanagnosia: Identification of pictures of single objects is relatively preserved; performance on complex scenes or pictures of multiple objects is dramatically poorer.

Visual memory for familiar or famous faces is intact, although testing may be difficult because of inability to fix gaze.

guage impairment, displayed as word-impairment, name-impairment, and a loss of comprehension.

In time the patient may exhibit socially inappropriate behavior. Dressing and personal hygiene become nearly impossible. Cognitive abnormalities occur, including psychosis, delusions, paranoia, and hallucinations.

In the advanced stages of Alzheimer’s disease, the patient may experience loss of bowel and bladder control with the necessity of nursing home care. Death usually occurs within 10 years of the onset of the disease and is most commonly the result of aspiration pneumonia.

The diagnosis of Alzheimer’s disease is difficult, particularly in its earliest stages. In testing patients who may have Alzheimer’s, significant suspicion is raised when an individual cannot recall information despite repetitive practice. In addition, Alzheimer’s patients have difficulty listing items in a single category within a minute’s time.

The treatment of Alzheimer’s disease with medication produces some improvement in moderate-to-severe disease. The N-methyl-D-aspartate (NMDA)-type glutamate receptor antagonist drug memantine has been shown to modestly improve the symptoms of Alzheimer’s disease, especially when combined with cholinesterase inhibitors.

Incremental improvement in the disease is also found by administration of acetylcholinesterase inhibitors, such as donepezil, galantamine, physostigmine and tacrine. These drugs prevent hydrolysis of acetylcholine and increase the cholinergic action from the basal forebrain to frontal cortex, amygdala, and hippocampus. Use of these drugs has been shown to have a small effect on cognitive function. The drug of choice in the United States is donepezil, mainly because it has fewer side effects than the other medications.

Present research into the treatment of Alzheimer’s disease is focusing on vaccines that prevent abnormal protein deposition in the brain.

Pick’s Disease

Similar to Alzheimer’s disease, this form of dementia begins earlier in life with profound behavioral dysfunction. Patient age at onset is between 21 to 75 years, but usually between 45 to 60 years. The average duration of the disease from onset to demise is usually 8 years.

The typical onset is heralded by a quick demise in social and personal behaviors. Pronounced changes in affect occur, with patients exhibiting overexcitement, cognitive disorganization, apathy, and behavioral rigidity.

The computed tomography (CT) scan or magnetic resonance imaging (MRI) scan demonstrates atrophy of the frontal and anterior temporal lobes. For this reason, Pick’s disease is also known as frontotemporal dementia (FTD), or Pick’s complex. The superficial

282 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

layers of the involved lobes become gliotic and are characterized by neuronal dysfunction and destruction. It is differentiated from Alzheimer’s disease only on autopsy. No known treatment for this form of dementia exists, and sedatives are often given by caregivers in an effort to quell combative and aggressive behavior. Selective serotonin reuptake inhibitors (SSRIs) are of limited effectiveness in reducing anxiety or depression related to Pick’s disease.

Creutzfeldt-Jakob Disease

This form of dementia is transmissible and precautions must be taken to prevent infection. Also known as transmissible spongiform encephalopathy (TSE), Creutzfeldt-Jakob disease (CJD) is a sporadic human form of the disease. Because this is a naturally acquired disease, the patient age for this form of dementia ranges from ages 16 to 82 years.

An infectious agent is passed from animal to human to cause this disease. The agent is a protein known as a prion. Prion proteins accumulate in the brain, as well as other organs including the eyes, lungs, kidneys, spinal cord, and lymph nodes. The disease progresses from mild dementia to coma in a few months. Rare visual field defects and extraocular muscle palsies are associated with this condition.

A variant of Creutzfeldt-Jakob disease is “mad cow disease,” or bovine spongiform encephalopathy. This infection is transmitted by ingestion of infected meat. The incubation period can last for decades. In this condition, the onset of dementia occurs at approximately 30 years of age, with the earliest symptoms being intellectual impairment and personality disturbances. Eventually, parkinsonism develops with weakness and loss of motor control. MRI is becoming useful in the diagnosis of CJD and is revealing bright lesions in the pulvinar.

End-stage CJD occurs within 1 year of the onset of dementia as the patient becomes comatose. Most patients die within 5 to 12 months. Autopsy reveals the presence of cerebral plaques.

No treatment exists for CJD.

Dementia in Systemic Disease

Dementia may arise in many systemic conditions, including brain tumor, AIDS, syphilis, and alcoholism.

Dementia can often be caused by brain tumors, most commonly frontal or temporal lobe gliomas.

Dementia is often associated with AIDS as the retrovirus invades the central nervous system. Infection with HIV-1 may produce an acute confusional state because of stroke, seizure, lymphoma, meningitis, encephalitis, cerebral toxoplasmosis, or metabolic disorders.

In neurosyphilis, or lues, dementia occurs no earlier than 2 to 12 months after infection. Syphilis is called by the spiral bacterium Treponema pallidum.

Approximately one fifth of all syphilis patients go on to develop neurosyphilis, wherein chronic granulomatous inflammation affects the central nervous system (CNS) tissues.

Shortly after the initial infection and coinciding with the syphilitic rash, syphilitic meningitis will cause headache, fever, a stiff neck, and cranial nerve palsies.

Within a decade of untreated syphilis, neurological manifestations may include transient ischemic attacks (TIAs) and stroke as part of meningovascular syphilis. These neurologic disorders are the result of brain infarction from the chronic inflammation. Ocular manifestations of neurosyphilis include Argyll Robertson pupils, optic atrophy, ptosis, and ophthalmoplegia.

Tabes dorsalis, now a rare complication of neurosyphilis, is characterized by unsteadiness, incontinence, and excruciating abdominal pain. It is caused by spirochetic invasion of the posterior nerve root fi- bers of the spinal cord, optic nerves, and oculomotor nuclei. Additionally, the subsequent immune response in these tissues causes further neuronal destruction, leading to optic atrophy, urinary disturbance, and gastric crisis. If general paresis is present, the condition is known as taboparesis.

The treatment of syphilis at any stage is penicillin. Alcoholism can possibly produce dementia by the

direct toxic effect of ethanol on neurons in the brain. More likely, dementia may occur because of nutritional deficiency associated with alcoholism. For example, the condition of pellagra, which causes optic atrophy and dementia, is the result of a deficiency of niacin.

Treatment

The treatment of dementia remains problematic because only approximately 10% of dementia cases are reversible. Through appropriate management, dementia may be halted and the quality of life improved for many patients.

DELIRIUM Characteristics

Delirium is characterized by an acute onset of cognitive dysfunction, impaired consciousness, a reduced state of arousal, and delusions. The onset of symptoms may occur within hours, and symptoms are usually worse at night. At first, poor concentration and a reduced attention span are experienced, with sudden loss of short-term memory. The patient may become confused and drowsy, and eventually fall into a stupor. Depression and anxiety may result from delirium. In time, delusions and hallucinations may occur.

Epidemiology

The elderly and postoperative patients are at greatest risk for developing delirium. The most significant risk factors in the development of delirium include social isolation, sensory deprivation, and sudden changes in the environment. Among hospitalized patients, approximately half have some form of delirium, and the rate is as high as 80% in terminally ill individuals.

Pathophysiology

Because of malnourishment, in alcoholism a thiamine deficiency is often present that leads to delirium. In liver disease, an increased level of NH3 is present that causes reduced psychomotor activity.

the patient is calm, to reduce morbidity and death associated with the cessation of alchohol. Otherwise, most cases of delirium are short-lived and self-limiting episodes that are treated with supportive measures.

DEPRESSION AND DYSTHYMIA Characteristics

This chronic and progressive condition results in emotions ranging from extreme sadness to anxiety with a simultaneous loss of enjoyment. In severe cases, patients may become suicidal or psychotic. Psychosisrelated depression is characterized by delusions of poverty or life-threatening illness concurrent with physical complaints, in particular bowel dysfunction.

Precipitating Factors

Delirium may be caused by infectious processes, drug abuse, and alcohol withdrawal.

Delirium tremens, or the “DTs,” is caused by the sudden cessation of alcohol in a chronic alcohol abuser. Typical symptoms of the DTs occur 2 to 7 days after withdrawal of alcohol and include fever, severe tremor, dilated pupils, hypertension, and tachycardia. The DTs, or “the shakes” (as they are often referred to by alcoholics), lasts for an average of 3 days. During this time the alcoholic experiences delirium characterized by fever, sweating, confusion, easy agitation, and systemic hypertension. Although the DTs typically resolve within a week, if left untreated, chronic cases may result in coma and death. The mortality associated with the DTs is often the result of infection, pancreatitis, or myocardial infarction.

Other causes of delirium include liver and renal failure, hypoglycemia, infections, head trauma, epilepsy, cancer, and drug use. The most common medications associated with delirium include the sedatives and narcotics. Delirium often occurs 1 to 3 days after sedative drug withdrawal.

Epidemiology

Of all serious mental health issues, depression is the most common. Second to only cardiovascular disease, depression is a significant cause of work-related sick days and medical-related loss of income. One fifth of the U.S. population has reported at least one episode of major depression. Women have a higher rate of depression and men have a higher incidence of attempted suicide.

Depression usually begins in adolescence and a strong familial trait appears to exist.

Pathophysiology

Subtle endocrine disturbance have been linked to depression. Hypercortisolism has been shown to occur frequently in cases of depression. The cause of depression is unknown. In dementia associated with Parkinson disease, a characteristic histological lesion exists known as a Lewy body. These inclusion bodies are located within the cytoplasm of the neurons of the substantia nigra and are found upon autopsy. The most common cause of depression is Alzheimer’s disease. The second most common cause is dementia with Lewy bodies, followed by frontotemporal dementia and vascular dementia.

Diagnosis

Delirium must be differentiated from dementia. Delirium is typically an acute onset of impaired consciousness that consists of disorientation, psychosis, and motor abnormalities. The onset of dementia is more chronic, with little effect on consciousness, and is characterized by normal orientation, poor memory, normal motor skills, and less prominent psychosis.

Precipitating Factors

The medical conditions that most commonly precipitate major depression include thyroid disease, alcohol abuse, and steroid use. The risk factors that most commonly provoke suicide attempts among severely depressed individuals include intense anxiety, advanced age, and alcohol or drug abuse. Suicide is more common among men than women.

Delirium tremens, because of sudden alcohol withdrawal, is sometimes treated with benzodiazepine medications. Diazepam is given intravenously until

The recognition of depression is often challenging and relies on the recognition of traits that are characteristic of the disorder. The clinician should be sensitive to the

284 CLINICAL MEDICINE IN OPTOMETRIC PRACTICE

typical signs of depression. These include distorted thinking, feelings of powerlessness, chronic sadness, insomnia, impaired concentration, and thoughts of suicide. These symptoms are typically worse in the morning, and the diurnal fluctuation of mood is characteristic of depression. If psychosis is present, the depressed patient will also exhibit delusions of poverty, medical illness, or moral depravity.

Treatment

The treatment of depression has two goals. The first goal is the therapy that best targets the cognitive dysfunction: psychotherapy. This form of cognitive therapy can modify the pattern of distorted thinking and develop appropriate psychotherapeutic strategies for intervention.

The second goal is the improvement and remission of the mild depressive state that occurs in about half of all cases with the use of an SSRI. These medications have fewer side effects than the tricyclic antidepressants. Alternatives to the SSRIs are lithium and triiodothyronine.

Severe depression responds to electroconvulsive therapy in 90% of cases. This type of therapy is also of use in cases of suicidal tendencies and patients who are too ill to take the appropriate medications.

The treatment for psychosis-related dementia, with such delusions as hypochondria, nonexistent poverty, or religious fanaticism is electroconvulsive therapy, or a combination of antipsychotic and antidepressant medication.

BIPOLAR DISORDER Characteristics

Bipolar affective disorder is characterized by a personality that constantly switches between mania and depression. The state of mania is characterized by excessive happiness, gregariousness, and scheming. The manic patient constantly talks of plans that concern financial success, often with altruistic overtones. The manic patient energetically schemes to make themselves as well as those around them wealthy, successful, and happy. In this phase the patient is extremely likable, personable and, with the possible exception of the constant and unceasing chattering, engaging.

In the extreme case, however, mania may produce delusional states of grandeur. The manic patient may, for example, declare that they are the “ruler of the world,” or that they are “the wealthiest person in the world.” In time, insomnia, agitation, and hyperexcitability may occur. Spontaneous aggression may result in unexpected conflicts with innocent bystanders. Interaction with a manic patient, therefore, is

often described as “walking on eggshells on top of thin ice.”

Nearly all manic patients eventually develop severe depression. These periods are characterized by serious apathy, sadness, loss of motivation, and isolation. In time, the bipolar “switches” occur more frequently and require less external stimulation. The patient with bipolar disorder increasingly requires hospitalizations and must be monitored for alcoholism, drug dependency, and suicide.

Epidemiology

The condition affects men and women equally. Early bipolar affective disorder may begin as childhood depression.

Pathophysiology

The cause of bipolar affective disorder is unknown, although genetic proclivity is firmly established by epidemiological studies.

Precipitating Factors

A strong genetic tendency exists for the disorder, with most patients with bipolar disorder having a relative with the disease. Individuals have a 10% chance of developing bipolar disorder if there is a first-degree relative with the condition.

Diagnosis

Establishment of the condition is based on a careful history. It is essential to gather as much information from relatives and friends to establish the presence of bipolar manifestations. The patient is likely to be a poor historian because of frequent embellishment. Any patient exhibiting depression or elation who has a family member with confirmed bipolar disorder should be strongly suspected of having the condition.

Treatment

Bipolar disorder requires lifelong mood stabilizing medication. The only medication shown to stabilize mood swings and reduce the risk of suicide in bipolar disorder is lithium. There are significant side effects associated with this medication. Other medications used in bipolar disorders are high doses of thyroid medication, anticonvulsants (lamotrigine), and antidepressants. Electroshock therapy is also effective in stabilizing mood. Recently it has been shown that diets high in omega-3 unsaturated fatty acids found in fish reduce relapse rates in bipolar individuals.