finances or personal matters are common. Individuals with FTD may present as disconnected from a situation and appear either apathetic and disinterested or manic. The microscopic brain changes in FTD appear to be related to accumulation of Less common types of dementia There are other less common types of dementia, some of which present with unique clinical characteristics. HIV-associated dementia HIV can cause an encephalopathy (also called AIDS dementia complex ), which presents as widespread destruction of the brain’s white matter. Unlike other sequelae of HIV, this condition is related to the presence of the virus itself, as opposed to being the result of an opportunistic infection. Individuals with HIV-associated dementias present with memory and learning impairment, confusion, and difficulty with executive functions. Over time, they may develop motor problems as well. Huntington’s disease dementia Huntington’s disease is a fatal brain disorder caused by a faulty gene for the protein huntingtin. The gene destroys nerve cells, beginning in the basal ganglia, causing a typical triad of symptoms: motor, cognitive, and psychiatric. Huntington’s disease is an autosomal dominant trait, so anyone with a parent who has Huntington’s disease has a 50% chance of inheriting the gene and a 100% chance of developing Huntington’s disease if he or she inherits the gene. Symptoms typically surface between age 30 and 50 years, with progressive and significant disability. Death usually occurs 15 to 25 years after symptom onset. Motor symptoms of Huntington’s disease include involuntary choreiform (rapid, jerky, dyskinetic) movements of the trunk and extremities and progressive difficulty with balance and coordination. Psychiatric changes include irritability and anger, depression, obsessive-compulsive behaviors, and mood swings. Cognitive changes involve memory impairment, difficulty with concentration, and impaired executive functioning. Creutzfeldt-Jakob disease Creutzfeldt-Jakob disease (CJD) is a rare, rapidly fatal disorder usually affecting individuals older than age 60. It is one of a group of disorders categorized as transmissible spongiform encephalopathies, representative of the microscopic sponge-like appearance of the CJD brain. CJD occurs when a prion protein in the brain alters its shape and subsequently malfunctions, triggering similar proteins throughout the brain to fold into the same abnormal shape, leading to the destruction of brain cells. A different form of the disease, called variant CJD (vCJD), is believed to result from eating meat from cattle affected by mad cow disease, and it can occur in younger people. The first symptoms of CJD involve impairment in memory, thinking, and reasoning, or changes in personality and behavior, such as depression or agitation. Problems with movement may be present from the beginning, or they may appear shortly after the other symptoms. Symptoms progress rapidly, and death typically Korsakoff syndrome is associated with a vitamin B 1 (thiamine) deficiency and is often associated with chronic alcohol abuse. Thiamine plays a pivotal role in brain glucose metabolism, and when brain tissue cannot meet its metabolic demands, the result is cell injury and death. Individuals with Korsakoff syndrome present with memory and learning impairments, and these patients may confabulate (share false information and stories they believe to be true). If untreated or treated late in the course of the disease, Korsakoff syndrome can result in dementia. If treated early with thiamine replacement, some of the symptoms can be reversed, but individuals may not return to baseline functioning. occurs within a year. Korsakoff syndrome
abnormal tau protein (tauopathy) and scarring (gliosis). There are several subtypes, including variant FTD, primary progressive aphasia, progressive supranuclear palsy (PSP), and Pick’s disease.
Normal pressure hydrocephalus Normal pressure hydrocephalus (NPH) is a disorder that, if untreated and allowed to become chronic, can result in dementia. This is a condition in which cerebrospinal fluid (CSF) volume fails to regulate normally or there is a blockage within the system. CSF buildup enlarges the ventricles, which can compress and damage nearby brain tissue within the confines of the skull. The words normal pressure denote that the pressure within the CSF system may fall within the normal range because the ventricles have expanded to accommodate increased fluid volume. Symptoms of NPH include loss of bladder control, change in behavior, and difficulty walking – clinically, these patients are “wet, wild, and wobbly” (the 3 Ws). However, sometimes the behavior change may be less wild and more subdued, with delayed processing and longer response times. Brain imaging studies reveal enlarged ventricles in normal pressure hydrocephalus, but brain imaging alone may not allow for a definitive diagnosis because other types of dementia cause the brain to atrophy, making the ventricles appear larger. If detected early, NPH can sometimes be treated effectively with surgical placement of a ventriculoperitoneal or ventriculoatrial shunt, but shunting is not effective if the condition becomes chronic and irreversible dementia can result. Dementia-like conditions Other conditions that can masquerade as dementias but are treatable and potentially reversible include: ● Depression, which, when significant, can cause signs and symptoms similar to dementia – “pseudo-dementia” denotes depression-related dementia symptoms. ● Delirium, which is a rapidly developing disturbance in attention, awareness, and cognition, often related to: ○ Medication side effects or interactions related to polypharmacy. ○ Infection or sepsis. ○ Metabolic dysfunction/electrolyte imbalance. ○ Endocrine or hormonal dysfunction (e.g., thyroid disorder). ○ Nutrition/hydration deficiencies. ○ Surgery/anesthesia/ICU stay. ● Brain tumor. ● Inflammatory pathology (e.g., cerebral vasculitis or inflammation of brain vasculature). ● Paraneoplastic syndrome, which occurs when cancer-fighting agents of the immune system attack the brain and can potentially precede an oncological diagnosis. ● Alcoholism. Why is it important to have a basic understanding of types of dementias or signs and symptoms related to specific progressive brain pathology? Rehabilitation professionals are not responsible for diagnosis or medical management of these conditions; however, given their close professional relationships with clients and families and because of their excellent clinical observation skills, they may be able to provide helpful information to the medical team or encourage appropriate follow-up to clients and families when necessary. When rehabilitation professionals observe symptoms or behaviors that are inconsistent with the typical or expected presentation of dementia (e.g., rapid decline or fluctuations in status), they may be able to facilitate an appropriate workup, which could reveal an alternate, perhaps treatable diagnosis. Dementia, depression, and delirium (the 3 Ds) are sometimes difficult to distinguish from one another and can coexist. Table 1 delineates the symptoms of the 3 Ds to aid the clinician in understanding and facilitating accurate diagnosis.
Page 15
EliteLearning.com/Physical-Therapy
Powered by FlippingBook