«CHAPTER 12 Coding for Diseases of the Nervous System and Sense Organs Chapter Outline. Recognize the typical manifestations, complications, and ...»
Diseases of the
and Sense Organs
Chapter Outline. Recognize the typical manifestations, complications,
and treatments of common disorders of the nervous
Disorders of the CNS
system and sense organs in terms of their implications
Disorders of the Peripheral Nervous System for coding.
Disorders of the Eye and Adnexa. Correctly code disorders and procedures related to the Disorders of the Ear nervous system and sense organs by using the ICD-9Testing Your Comprehension CM and medical records.
Coding Practice I: Chapter Review Exercises Coding Practice II: Medical Record Case Studies Chapter Objectives. Describe the pathology of common disorders of the nervous system and sense organs.
Diseases of the nervous system and sense organs are classiﬁed in code section 320 to 389 of chapter 6 of the Disease Tabular of ICD-9-CM. This chapter is subdivided into disorders of the central nervous system (CNS), disorders of the peripheral nervous system (PNS), and disorders of the sensory organs (eyes and ears). To assist in your understanding, see Figure 12.1, an illustration of the anatomic divisions of the nervous system, and the Word Parts Box on page 331, which lists word parts and meanings of medical terms related to the nervous system and sense organs.
330 PART II: Coding for Specific Diseases and Disorders Cranial Brain nerves Central nervous system Spinal cord Peripheral nervous system Spinal nerves FIGURE 12.1 Anatomic divisions of the nervous system. (Reprinted with permission from Cohen BJ. Medical Terminology: An
Disorders of the Central Nervous System (CNS) Category code range 320 to 349 includes diseases of the CNS, which is composed of the brain and spinal cord. Common CNS diseases that can cause hospital admissions include inﬂammatory disorders, degenerative disorders, and other disorders such as demyelinating and paralytic disorders.
Inﬂammatory Disorders Meningitis and encephalitis are common inﬂammatory disorders of the CNS.
MENINGITIS The meninges are three membranes (dura, arachnoid, and pia) that surround and protect the CNS. Meningitis (category code range 320 to 322) is an inﬂammation of the meninges that can be caused by bacteria (e.g., streptococci and staphylococci), viruses (e.g., Enterovirus and herpes simplex), or fungi (e.g., candidiasis and histoplasmosis). Meningitis can be classiﬁed with a single combination code from chapter 1 of the Disease Tabular of the ICD-9CM codebook, “Infectious and Parasitic Diseases” (category 001 to 139), or with a single combination code from chapter 6, “Diseases of the Nervous System and Sense Organs” (category 320 to 389). Alternatively, meningitis can be described with dual coding from chapters 1 and 6.
332 PART II: Coding for Specific Diseases and Disorders
who are immunocompromised, such as the elderly or those with acquired immunodeficiency syndrome (AIDS), are at a higher risk for contracting encephalitis from an infection. Most people recover within a few weeks, but encephalitis is a serious disease that can, in some cases, be fatal.
Important tests to diagnose encephalitis include a spinal tap to obtain CSF or a blood culture that may reveal the virus. Some forms of viral encephalitis respond to antiviral drugs. However, other forms may be treated only symptomatically. Analgesics (e.g., aspirin) can be used to reduce fever, and antiseizure medications (e.g., phenobarbital or phenytoin) can be used if needed.
Degenerative Diseases Common degenerative diseases of the CNS include Parkinson’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis (ALS; also known as Lou Gehrig’s disease).
PARKINSON’S DISEASE Parkinson’s disease (code 332.0) usually occurs in the elderly and results in progressive degeneration of the nerves in the brain. It can result in hand tremors, a shufﬂing gait (sometimes referred to as cogwheel rigidity), and muscle weakness. Parkinson’s disease is caused by a deﬁciency of dopamine, a chemical (i.e., neurotransmitter) that is required to transmit nerve impulses in the brain. The symptoms of Parkinson’s disease can be alleviated with drugs such as levodopa or dopamine agonists (drugs that increase the reception of dopamine in the brain); however, such drugs do not cure the disease.
Secondary parkinsonism (code 332.1) is a form of Parkinson’s disease that is secondary to another underlying disease (e.g., Huntington’s disease or syphilis) or that occurs as an adverse effect of the therapeutic use of a drug (e.g., antipsychotic drugs). In the case of an adverse effect, you should use an additional E code from the Table of Drugs and Chemicals to identify the responsible drug.
EXAMPLE Primary parkinsonism: 332.0
Parkinson’s disease secondary to haloperidol (Haldol) prescribed for chronic schizophrenia:
332.1 E939.2 295.62 Parkinsonism in Huntington’s disease: 333.4 ALZHEIMER’S DISEASE Alzheimer’s disease (code 331.0) is a progressive, degenerative brain disorder that can occur in elderly people. It is characterized by progressive memory loss, loss of intellectual abilities, confusion and dementia, emotional disturbances such as anxiety and/or depression, and wandering. Alzheimer’s disease results in a progressive destruction of brain cells. Certain pathogenic (disease-causing) changes also occur in the brain, such as atrophy (shrinkage of parts of the brain), neural plaques (deposits) and tangles (bundles) that contain a protein (amyloid) that degenerates brain cells, and a loss of substances called neurotransmitters. Neurotransmitters are chemicals that help to carry messages between nerve cells (neurons) in the brain. Alzheimer’s patients often lose their sense of person, place, and time, and they often wander away from safety; as such, they are sometimes cared for in locked 334 PART II: Coding for Specific Diseases and Disorders
Hemiplegia and Hemiparesis Both hemiplegia and hemiparesis (code 342.XX) refer to paralysis of one side of the body. This can result from a cerebrovascular accident (CVA; stroke) (Figure 12.2), traumatic brain injury, or tumor. The fourth-digit subcategory conveys the type of hemiplegia. For example, 342.0X classiﬁes ﬂaccid hemiplegia, which is characterized by the loss of muscle tone (atrophy) and tendon reﬂexes of the affected (paralyzed) side. Spastic hemiplegia (code 342.1X) is characterized by increased muscle spasms and tendon reﬂexes of the affected
FIGURE 12.2 A cerebrovascular accident (CVA), also known as a stroke, is a sudden impairment of cerebral circulation in one or more blood vessels.
This interrupts or diminishes oxygen supply to the brain, often causing the brain tissues to become damaged or die. (Reprinted with permission from Anatomical Chart Co.) 336 PART II: Coding for Specific Diseases and Disorders
EPILEPSY Epilepsy (345.XX) is a chronic (recurrent) seizure disorder characterized by sudden abnormal electrical activity in the brain that can cause seizures.
Epilepsy is classiﬁed into two major categories: generalized epilepsy, which involves abnormal electrical discharges that affect the entire brain, and partial epilepsy, which involves abnormal electrical discharges that affect only a part of the brain. The major categories of generalized or partial epilepsy are further divided into different types of epilepsy: grand mal, petit mal, focal, and temporal lobe.
Grand mal epilepsy (generalized convulsive; code 345.1X) is characterized by a loss of consciousness with convulsive seizures that can include tonic stiffening and contractions of muscles and clonic jerking and twitching movements of the extremities. Petit mal epilepsy (generalized nonconvulsive; code 345.0X) is characterized by a momentary loss of awareness and surroundings, but no loss of consciousness or convulsive seizures.
In focal epilepsy (partial epilepsy; code 345.5X), one part of the body will jerk and twitch (convulsive seizures), but there is no impairment of consciousness (loss of awareness). In temporal lobe epilepsy (partial epilepsy; code 345.4X), there is abnormal brain activity in the temporal lobe of the brain (near the ears) with an impairment of consciousness (loss of awareness).
Never automatically code a diagnosis of seizures or convulsions to epilepsy. Epilepsy or recurrent seizures must be documented by the physician.
Some seizures, such as tonic/clonic (grand mal) seizures, can occur without a diagnosis of epilepsy. A diagnosis of epilepsy can be made only by a physician who has assessed that a pattern of repeated brain seizures is attributed to epilepsy. Convulsions and seizures can often occur as a temporary result of an infection or fever (febrile seizure, 780.31; seizure not otherwise speciﬁed, 780.39) and should not be coded to epilepsy. If a physician documents a diagnosis of seizures or convulsions, carefully review the patient’s record for a documented history of epilepsy, review the patient’s current medications and old medical records, and then query the physician before assigning the code for epilepsy, recurrent seizures, or seizure disorder. As of October 2006, if the diagnosis is “recurrent seizures” or “seizure disorder” (even in the absence of term “epilepsy”), a code from category 345 (epilepsy and recurrent seizures) is assigned. However, if the diagnosis is that of a single, isolated seizure or that of convulsions, the code assigned remains 780.39.
The fifth-digit assignment in the epilepsy code describes whether the epilepsy is intractable. Intractable epilepsy means that it is difﬁcult to control by conventional treatments, such with the drugs phenytoin or phenobarbital (anticonvulsant medications). Physicians rarely document intractable epilepsy. Therefore, you should review the medical record for epileptic seizures described as prolonged or refractory to treatment and then query the physician as appropriate.
338 PART II: Coding for Specific Diseases and Disorders
Acute Infective Polyneuritis (Guillain-Barré Syndrome) A signiﬁcant disease in this code range that often causes hospital admission is acute infective polyneuritis. Also known as Guillain-Barré syndrome (code 357.0), acute infective polyneuritis is an autoimmune disorder in which the body’s immune system attacks the peripheral nervous system. The etiology of this disorder is unknown; however, it can sometimes follow a viral illness.
Guillain-Barré syndrome results in a sudden, acute, and progressive motor nerve (voluntary muscle) paralysis. Symptoms include rapidly progressive weakness and paresthesias (abnormal sensations such as tingling or numbness in the extremities) that begin in the legs and move to the upper body.
Ultimately, the individual can experience incapacitating paralysis with subsequent respiratory paralysis and respiratory failure.
Because there is no speciﬁc treatment for Guillain-Barré syndrome, the symptoms are treated. The primary focus is to keep patients alive and functioning and to prevent them from succumbing to secondary complications (e.g., pneumonia) until the paralysis resolves. This usually occurs within a few weeks. Patients with Guillain-Barré syndrome often require many inpatient resources because of profound respiratory difﬁculties that can necessitate placement in the intensive care unit and treatments such as endotracheal intubation with mechanical ventilation and emergent tracheostomy placement.
Developed by the federal government, MS–DRGs use coded data to establish prospective payment rates to hospitals for inpatient services under Medicare (see Appendix 1: MS Diagnosis-Related Groups (DRG) List). The coding of procedures makes the difference in DRG assignment and, therefore, reimbursement (see below diagnosis-related group MS–DRG 094 versus MS–DRG 004 reporting).
TIP Coding Clinic 1991, second quarter, describes more information about Guillain-Barré syndrome with respiratory failure.
MS-DRG 004: Tracheostomy with mechanical ventilation 96 hours or PDX except face/mouth/neck without major OR procedure MDC: Pre-MDC—surgical CMS wt: 11.1684 A/LOS 28.8 G/LOS 23.5 Principal diagnosis: 357.0 Acute infective polyneuritis (Guillain-Barré syndrome) 340 PART II: Coding for Specific Diseases and Disorders
The middle layer (uveal tract) consists of the following:
. Choroid—a membrane containing blood vessels that nourish the eye.
. Ciliary body—muscle tissue that surrounds and applies tension to inner lens of the eye so that the lens can thicken for close vision and thin for distance vision. Presbyopia (far-sightedness associated with old age) occurs when the inner lens loses ﬂexibility and can no longer thicken for close vision, resulting in the need for reading glasses (bifocals).
. Iris—the colored part of the eye surrounding the pupil. The iris contains circular and radial muscles that widen or constrict to control the amount of light entering through the pupil. The iris constricts in bright light as a protective mechanism to prevent damage to the retina (nervous tissue of the eye), and it widens to let in more light in dim lighting.
The inner layer consists of the following:
. Retina—the nervous tissue of the eye, consisting of nerve cells called rods and cones. Rods aid in peripheral vision and seeing in the dark;
cones assist in central vision and seeing color. The retina includes an area called the macula that contains the fovea centralis (i.e., central macula). When light rays coming into the eye are focused on this area, it produces the sharpest vision.
. Optic nerve—a cranial nerve that communicates with the optic disc to send impulses to the brain for visual interpretation. Optic nerve ﬁbers leading to the brain cross over in an area called the optic chiasm that allows each eye to communicate with both sides of the brain, thus producing three-dimensional vision (height, width, and depth). Without three-dimensional vision, the world would look ﬂat.