The A to Z of Intellectual Disability


It is estimated that 17% of children in the United States have a developmental disability and that 1% to 2% of children are diagnosed with mental retardation.1 Of interest to hospitalists: Those with intellectual disability (ID) use healthcare services more than those in the general population.

During a 12-month period, 16% of adults with ID were hospitalized, and 30% were seen in an emergency department (ED).2 Because the average age at death in this population has increased—to 66.1 years in one study—hospitalists must become familiar with the medical management of these patients.3 Achieving comprehensive care presents a challenge because of the atypical presentation of symptoms and the behavioral and communication problems found in many hospitalized patients with ID.

In this article, I will address some of the major clinical issues hospitalists confront when caring for this population.

Where to Begin

One key to understanding how to care for this population is ascertaining whether there is underlying etiology of ID. A diagnosis can be established in approximately 50% of patients who have ID.4 For example, patients with Down syndrome are more likely to have celiac disease, hypothyroidism, leukemia, atlantoaxial subluxation, obstructive sleep apnea, Alzheimer’s dementia, seizure disorder, and behavioral and psychiatric disorders than are patients in the general population.5

Table 1 (see p. 21) lists common medical conditions found in patients with ID. Hospitalists should make it a priority to obtain a comprehensive medical record from the patient’s healthcare provider or to gather the necessary information from a caregiver who knows the patient well; this person may assist the hospitalist in interpreting mannerisms of the nonverbal patient that reflect symptoms such as pain.

Table 1. Common medical conditions in patients with intellectual disability

  • Endocrine disorders: obesity, hypothyroidism, diabetes mellitus
  • Gastrointestinal disorders: constipation, dysphagia, gastroesophageal reflux, Barrett’s esophagus, Helicobacter pylori infection, hepatitis A
  • Eye, ear, nose, and throat disorders: strabismus, cataracts, glaucoma, blindness, hearing loss, obstructive sleep apnea
  • Cardiovascular disorders: congenital heart disease, hypertension, hypercholesterolemia
  • Lung disorders: aspiration pneumonia, bronchiectasis, recurrent infections
  • Musculoskeletal disorders: spasticity, osteoporosis, appendicular fractures, scoliosis
  • Neurological disorders: seizures, dementia
  • Psychiatric disorders: pervasive developmental disorders, attention-deficit hyperactivity disorders, affective disorders, anxiety disorders, behavioral disorders
  • Skin disorders: acne, contact dermatitis, eczema, fungal infections

Swallowing Difficulties: Problems and Solutions

The risk of aspiration and subsequent mortality because of oral dysfunction and dysphagia is increased in patients with profound ID. The presence of choking and coughing during feeds identifies patients at significant risk of asphyxiation.6

In one study involving patients with severe ID, the absence of respiratory distress during meals or the lack of chronic lung disease identified 85% of patients who did not aspirate.7 Clinical assessment by speech-language therapists and the use of video fluoroscopy may be helpful in patients who experience either frequent aspiration pneumonias or episodes of coughing or choking during feeds. Cramming food into the mouth, eating too fast, and losing the bolus into the pharynx prematurely were factors predictive of asphyxiation risk.6 Speech-language therapists and nutritionists may assist hospitalists by recommending diet and feeding modifications that ensure the safe speed and size of bolus delivery, along with adjustment in food textures to reduce the risk of asphyxiation.

Patients with swallowing difficulties are also vulnerable to dehydration and malnutrition. In fact, more than 60% of children and adults with ID are underweight, with a body mass index less than or equal to 20. Food-intake surveys have demonstrated adequate protein intake but reduced fat, carbohydrate, and energy-food intake. Increasing energy-dense fats and sugar-containing foods, while monitoring for adequate fluid intake, is recommended in these individuals.8

In patients who have worsening dysphagia associated with pneumonia, insertion of an enteral feeding tube, such as a percutaneous endoscopic gastrostomy (PEG) tube, can provide adequate nutrition and may reduce the risk of future episodes of pneumonia (although this practice is controversial).

In one study, there was a 45% reduction in the incidence of pneumonia in the year following feeding-tube insertion.9 Other investigators have not found that gastrostomy tubes prevent pneumonia, however.10 Instead, the presence or absence of gastroesophageal reflux and whether or not the patient has a prior history of aspiration pneumonia seem to be more important factors in determining if episodes of pneumonia will occur after feeding-tube placement.

The prevalence of gastroesophageal reflux (GER) in 435 institutionalized patients with IQ <50 ID was 48.2%.11 Almost 70% of patients with GER had reflux esophagitis, while 14% had Barrett’s esophagus, and 3.9% had peptic strictures. Bui and colleagues studied 105 ID patients with feeding gastrostomy, 45 of whom had dysphagia but no history of aspiration pneumonia and 60 who had recurrent aspiration, either alone or with dysphagia.12 Only two of 45 (4.4%) patients with dysphagia alone developed aspiration pneumonia, while 15 of 60 (25.0%) with a prior history of aspiration pneumonia had a future event.12

Continued aspiration pneumonia may be due to oral secretions and gastric contents entering the respiratory tract. Preoperative GER has been associated with postoperative aspiration pneumonia.10 Elevating the head of the bed, avoiding bolus feeding, treating constipation, discontinuing feeding promptly in cases of respiratory distress or increased gastric residual volume, and treating gastroesophageal reflux pharmacologically may decrease further pneumonia events in these patients.9

Over a 12-month period, 16% of adults with ID were hospitalized, and 30% were seen in an emergency department.2 Because the average age at death in this population has increased—to 66.1 years in one study—hospitalists need to become familiar with the medical management of these patients.

Treating Seizures

Another common issue hospitalists must be attuned to in adult patients with ID is epilepsy. Prevalent in as many as 40% of adult patients with mental retardation and cerebral palsy, uncontrolled epilepsy has been associated with increased mortality.13,14 Clinical guidelines for the management of epilepsy in this population have been published.15 Recommended first-line treatments of generalized seizures include sodium valproate and lamotrigine. If these medications are unsuccessful, or if side effects prohibit continued usage, then topiramate and carbamazepine are suggested. Do not use carbamazepine in myoclonic or absence seizures. Lennox-Gastaut syndrome can be treated with lamotrigine, while topiramate and felbamate can be used as add-on therapy to reduce atonic seizures.

For treatment of partial seizures, valproate, carbamazepine, and lamotrigine are recommended first-line treatments. Levetiracetam can be used as add-on therapy. The guidelines suggest that studies of add-on therapy failed to differentiate among lamotrigine, gabapentin, topiramate and tiagabine.

Adjust the initial anti-epileptic drug (AED) to the maximum tolerated dose before slowly introducing a second AED without tapering the first. If the patient responds to the second drug, consider a gradual tapering of the first drug. It is not uncommon for multiple AEDs to be used in patients with ID. In patients referred to a specialized epilepsy clinic, over 80% were on two or more AEDs; 43% became seizure-free for a year or more, while another 40% of patients had a 50% or greater reduction in seizure frequency.16

AEDs that induce the cytochrome P-450 system—particularly phenytoin—phenobarbital, and carbamazepine, have been associated with low bone mineral density (BMD) in patients with ID.17 Additional risk factors for low BMD, such as hypogonadism, low body mass, decreased mobility, and vitamin D deficiency may contribute to the increased incidence of non-traumatic fractures found in institutionalized adults with ID.18,19 In one study, the annual incidence of non-traumatic fracture was 7.3% among 391 institutionalized adults.18

In another study, however, researchers found that although 57% of patients who suffered a fracture were vitamin-D deficient there was no significant association between vitamin D deficiency and fractures.20 Although there are no specific guidelines designed to evaluate and treat bone-health-related issues in adults with ID, it seems prudent to ensure adequate calcium and vitamin D intake, to encourage exercise if possible, and, in patients who suffer non-traumatic fractures, to evaluate for osteoporosis and give appropriate therapy according to the recommendations of the National Institutes of Health Consensus Development Panel on Osteoporosis Prevention, Diagnosis, and Therapy.21

Table 2. An approach to caring for hospitalized adults with intellectual disability

  • Obtain a comprehensive medical history and medication list from either the facility or caregiver.
  • Attempt to ascertain the etiology of the patient’s ID. There are many known medical conditions that are associated with specific syndromes.
  • Examine the patient in the presence of a caregiver who knows the patient well. Typical behaviorisms and mannerisms that occur when the individual is in pain may assist in the diagnostic evaluation.
  • Review nutritional intake and watch for signs of choking or coughing with feeds. Consider a speech-language therapy consult with video fluoroscopy if the patient has difficulty with feeds and has a history of aspiration pneumonia.
  • If the patient has SIB, perform a thorough assessment to exclude a medical etiology. Rule out constipation, an occult fracture, a corneal abrasion, or gastroesophageal reflux.
  • If the patient is at risk of injuring himself or herself and an attempt at redirecting behavior is unsuccessful, consider low-dose antipsychotics; monitor closely for side effects.
  • Upon discharge, review medications, communicate any new medication changes to the caregiver and/or facility, and, if the patient has been started on a new psychopharmacologic agent, review side effects.

Self-Injurious Behavior and the Risk of Polypharmacy

Adults with ID who are nonverbal may demonstrate self-injurious behavior (SIB) as a manifestation of pain from fracture, constipation, or other medical illnesses. The prevalence of SIB in this population ranges from 2% to 50%.22 Psychotropic medications are frequently used to protect patients from self-injury.23 The challenge for hospitalists is to keep patients from injuring themselves without masking underlying pathologic conditions.

Several hypotheses have tried to explain why patients engage in SIB: These include increased level of endogenous opioids leading to pain insensitivity, opioid release due to low endogenous opioid levels caused by the SIB itself, and reaction to pain. Breau and colleagues concluded that children with ID who suffered chronic pain self-injured less body surface area and fewer body sites than children without chronic pain. Patients without chronic pain who engaged in SIB were more likely to self-injure their heads and hands.22

If a medical etiology cannot be ascertained for aggressive, self-injurious, and destructive behavior, psychotropic agents are frequently employed, with rates that range from 18% to 49% in patients with ID.24 These medications should be prescribed in a start-low/go-slow manner and only after a thorough assessment has been performed and the physician has determined that the behavior cannot be redirected and poses an imminent risk to the patient.25

Because of ID patients’ decreased communication skills, polypharmacy is a significant risk; side effects of psychotropic agents may be mistakenly treated with additional agents. According to Janowsky and colleagues, the mean lowest effective dose of conventional antipsychotics such as haloperidol was 5.9 mg/day to maintain symptom suppression of maladaptive behavior, with relapse of symptoms occurring at a mean dose of 3.8 mg/day in an ID population.23 Atypical antipsychotics are now more widely used in adults with ID, and although they are less likely to cause extrapyramidal side effects, they can still lead to weight gain, sedation, increased lipid levels, and activation of diabetes mellitus. In one study, low dose risperidone (2 mg/day) reduced aberrant behavior by half in 57% of patients with ID. Increased appetite and weight gain were common side effects.26

Other agents such as benzodiazepines have been reported to have behavioral side effects as high as 13% when used in patients with ID; in one study, time to onset of side effects averaged 23 days.27 This may erroneously lead outpatient physicians to prescribe additional agents to counteract the behavioral side effects of the drugs that were initiated in the hospital. If you prescribe benzodiazepines then the patient’s side effects may be mitigated by using lower doses of lorazepam (3 mg/day or less). You may also consider naltrexone to treat patients with SIB. A review of 86 ID patients with SIB concluded that naltrexone was effective in reducing self-injury in 80% of subjects, with nearly half of the patients experiencing a 50% reduction in these types of behavior. The dose most studied was 50 mg.28

Palliative Care

Hospitalists should also be familiar with the palliative-care needs of patients with ID. A recent survey of directors providing services to older adults with ID identified the following as frequently cited obstacles to end-of-life care: availability of direct care staff, availability of nursing/medical staff, staff untrained in end-of-life care, anxiety about responding to families, and liability concerns.29

Because many patients with ID are unable to make medical decisions about their care, a surrogate (e.g., a family member, a judicially appointed guardian, or a court) must decide to initiate or maintain medical interventions. The prevailing standard that applies to surrogate decision-making in the ID population is identifying the patient’s best interests. The medical course chosen may not necessarily be the best option, but it should not be “antithetical to the patient’s interests as to constitute neglect or abuse.”30

A clinical scenario hospitalists may face in patients with profound ID that addresses this legal reasoning involves seeing a patient with respiratory distress in the ED who needs intubation and mechanical ventilation to have a chance at survival. Later, this patient is found to have metastatic cancer and is in significant pain and discomfort. Applying the best interests standard, the hospitalist may elect to intubate and treat the patient. Once the cancer is discovered, however, the physician does not insist that the patient undergo invasive treatment and, instead, focuses his/her efforts on providing palliative care.


As the number of patients with ID transitioning from pediatrics to medicine increases, hospitalists will be looked upon to develop a comprehensive approach to ensure their overall well-being. A systematic approach to caring for hospitalized adults is suggested in Table 2 (see p. 22). TH

Dr. Geskey is assistant professor, Pediatrics and Medicine, Penn State, Milton S. Hershey Medical Center, Penn State College of Medicine, Department of Pediatrics & Internal Medicine.


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