What is pick's disease? |

Causes and Symptoms

Pick’s disease, also called frontotemporal dementia
(FTD), is similar to, but much rarer than, Alzheimer’s disease. The current designation of the syndrome groups together Pick’s disease, primary progressive aphasia, and semantic dementia. Some medical researchers believe that corticobasal degeneration and progressive supranuclear palsy should be added to FTD, which would then be called Pick complex. The differing terms reflect different theoretical models of the disease, and specialists are likely to continue to debate these models.

An autosomal dominant genetic trait is speculated as a specific cause in some cases of FTD. In these cases, there is a family history of someone showing symptoms of a frontal lobe dementia. Pick's disease is often inherited, though in many cases there is no evident family (genetic) history and the cause is unknown.

Onset is slow and insidious. Tissues shrink (atrophy) in the frontal and temporal brain lobes. FTD also causes some brain
cells to develop abnormal fibers called Pick’s bodies. The cells in these bodies have an abnormal amount of a protein called tau. Tau appears throughout the body’s cells but exists in abnormally high amounts in Pick’s bodies and in Pick cells that exist inside normal brain cells (neurons). These form elsewhere in the brain and are not limited to the frontotemporal regions. These fibers are generally straight and single, as compared to Alzheimer’s neurofibrillary tangles, which tend to be paired and helical.

Though Pick’s disease varies greatly in how it affects individuals, it has a common core or clusters of symptoms. Some or all may be present at different stages of the disease. Since the frontal lobes involve emotional and social functioning, the first notable cluster of symptoms usually causes behavioral and affective changes such as impulsivity, compulsive overeating or only eating one type of food, drinking alcohol to excess (when not a prior problem), rudeness, impatience, aggressiveness, social withdrawal, poor social interaction, inability to hold a job, inattention to personal hygiene, sexual exhibitionism, promiscuity, abrupt mood changes, emotional aloofness, environmental indifference, marked distractibility, decreased interest in daily activities, and being unaware of these changes (lack of insight). Deterioration in personality usually occurs before dementia itself is evident—that is, before there is evident memory loss. This is one way that specialists diagnose it as distinct from Alzheimer’s disease, in which the early symptoms involve memory loss.

Changes in physical mobility and coordination (apraxia) can also appear as early symptoms. They can include increased muscle rigidity or stiffness, difficulty getting around, worsening coordination, generalized weakness, and urinary incontinence.

Another characteristic cluster of symptoms relates to worsening language, including reduced-quality speech, shrinking vocabulary, word-finding problems, difficulty understanding speech (receptive aphasia) or producing understandable speech (expressive aphasia), repeating words and phrases others use (echolalia), progressive loss of reading and writing, and possibly complete loss of speech (mutism).

Treatment and Therapy

At present, there are no medications that can effectively treat FTD, although several can help treat many of its symptoms. Medications used in Alzheimer’s disease are not routinely prescribed because they often increase aggression in Pick’s disease patients.

Maximizing quality of life is the key treatment, and many of the more disturbing behaviors respond well to medication, including aggression and agitation. In addition to adding medications for symptom control, discontinuation of medications that promote confusion or that are not essential to the care of the person may improve cognitive function. It is common for anticholinergics, analgesics, and central nervous system depressants to be discontinued. Because many of the functions that FTD affects are also affected by low levels of thiamine, thiamine supplementation is often recommended.

Behavior modification is often the treatment of choice in controlling unacceptable or dangerous behaviors. Rewarding and reinforcing appropriate, positive behaviors while ignoring inappropriate, negative behaviors (within the bounds of safety) can significantly influence how patients act and interact. Formal psychotherapy is seldom effective because it overloads patients’ limited cognitive resources. Reality orientation, with repeated reinforcement of environmental and other cues, can reduce disorientation and agitation. Sensory functions, often overlooked, should be evaluated and augmented as needed, including hearing
aids, eyeglasses, and cataract surgery.

In addition, good nursing and caregiving, guided occupation activities, and participation in support groups all can improve the management of this type of dementia. Family counseling and family psychoeducation often go a long way in fostering adaptive changes that are necessary to care for patients at home. It is also important for families of Pick’s disease patients to obtain support to help them cope with a disease that is likely to have a prolonged, ever-demanding course. Visiting nurses or aides, volunteer services, adult protective services, and other community resources may be helpful in caring for the person. Legal advice may be appropriate early in the course of the disorder. Advance directives, power of attorney, health care proxy, and “do not resuscitate” orders can make dealing with the later stages of the disease easier.

Perspective and Prospects

Pick’s disease affects about 1 out of 100,000 people, accounting for 0.4 percent to 2.0 percent of all cases of dementia. More common in women then men, it typically has an onset between ages forty and sixty, with a modal age of fifty-four, but it has been known to affect patients as young as twenty. A family history of FTD is considered a risk factor, although most Pick’s patients have no family history of the disease.

The first description of the disease was published in 1892 by Arnold Pick. Until recently, it was thought that Pick’s disease could not be distinguished from Alzheimer’s disease during life. In accordance with major research criteria of German neuropsychiatry, Pick’s atrophy was constructed as a full-blown disease entity in the 1920s. This concept gained acceptance in the German and Anglo-American scientific community and was the starting point for further investigations in the 1950s and 1960s.

Initial diagnosis is mostly based on history and symptoms, signs, and tests and by ruling out other causes of dementia, especially those with metabolic causes. The development of neuropsychological assessment procedures and the use of electroencephalograms (EEGs), computed tomography (CT) scans, and magnetic resonance imaging (MRI) scans are generally necessary in the prediagnostic workup of the disease. Functional brain imaging, such as single photon emission computed tomography (SPECT) or positron emission tomography (PET) scans, are often appropriate in some patients.

Patients with FTD or Pick’s disease will show a progressive decline. Rapidly progressing forms may be fatal in two years; slower forms may take ten. The cause of death is often opportunistic infection or, less commonly, the general failure of total body systems.

Recent identification of pathogenic mutations in Alzheimer’s disease and frontotemporal dementia has improved understanding of these dementias and is guiding the investigations that use animal and tissue culture models. Eventually, it is hoped that this research will result in developing medications that can treat, stop, and reverse these diseases.

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