neurologic disorders
Memory Loss
Evaluation of Memory Loss
The highest priority when evaluating memory loss is To identify reversible causes, including depression, anxiety, and delirium, which requires rapid treatment The evaluation then focuses on distinguishing the few cases of mild cognitive impairment and early dementia from the greater number with age-associated memory impairment or simply normal forgetfulness. Full Diagnosis usually requires more time than the 20 to 30 minutes that is commonly allotted for an office visit. Evaluation by a neuropsychologist may also be required. History should, when possible, be taken from the patient and family members separately. Cognitively impaired patients may not be able to provide a detailed, accurate history, and family members may not feel free to give a candid history with the patient listening. should include a description of the specific types of memory loss (eg, forgetting words or names, getting lost) and their onset, severity, and progression. Clinicians should determine how much symptoms affect day-to-day function at work and at home. Important associated findings involve changes in language use, eating, sleeping, and mood. Clinicians should also evaluate the patient's Medical Assessment of the Older Driver because some jurisdictions require clinicians to report patients with impaired driving capabilities to local licensing authorities. Review of systemsshould identify neurologic symptoms and other factors that may suggest a specific type of dementia, such as the following: Symptoms and Signs and hallucinations in Focal neurologic deficits in Vascular Cognitive Impairment and Dementia None Traumatic Brain Injury (TBI) (eg, due to a recent fall) suggesting subdural hematoma Inability to look upward or downward and falling backward in Progressive Supranuclear Palsy (PSP) None Choreiform movements in Huntington Disease None Gait disturbance and urinary incontinence in Normal–Pressure Hydrocephalus None Low energy, dry skin, and weight gain in Hypothyroidism None Balance problems and difficulty with fine motor movements in Vitamin B12 Deficiency None Past medical historyshould include known disorders and complete prescription, over-the-counter, and illicit drug use history. Family and social historiesshould include the patient's baseline levels of intelligence, education, employment, and social functioning. Previous and current substance abuse is noted. Family history of dementia or early mild cognitive impairment is queried. Social history should also include unusual dietary habits. In addition to a general examination, a complete Introduction to the Neurologic Examination is done, with detailed mental status testing. Mental status testing assesses the following by asking the patient to do certain tasks: Orientation (give their name, the date, and their location) Attention and concentration (eg, repeat a list of words, do simple calculations, spell "world" backwards) Short-term memory (eg, repeat a list of 3 or 4 items after 5, 10, and 30 minutes) Long-term memory (eg, answer questions about the distant past) Language (eg, name common objects) Praxis and executive function (eg, follow a multiple-stage command) Constructional praxis (eg, copy a design or draw a clock face) Reading Calculation Various scales can be used to How to Assess Mental Status in these components. A common way to screen is with the In patients with memory loss, the following findings are of particular concern: Impaired daily function Loss of attention or altered level of consciousness Symptoms of depression (eg, loss of appetite, psychomotor slowing, suicidal ideation) Speed of symptom onset Memory loss that develops rapidly may indicate a disorder such as Creutzfeldt-Jakob Disease (CJD) or a Presence of actual memory loss and impairment of daily function and other cognitive functions help differentiate age-related memory changes, mild cognitive impairment, and dementia. Mood disturbance is present in patients with depression but is also common in patients with dementia or mild cognitive impairment. Thus, differentiating Depressive Disorders from Inattention helps differentiate Delirium from early dementia. In most patients with delirium, memory loss is not the presenting symptom. Nonetheless, delirium must be excluded before a diagnosis of dementia is made. One particularly helpful clue is how the patient came to medical attention. If the patient initiates the medical evaluation because of worries about becoming forgetful, age-associated memory impairment is the likely cause. If a family member initiates a medical evaluation for a patient who is less worried about memory loss than the family is, dementia is much more likely than when the patient initiates the evaluation. Diagnosis of memory loss is primarily clinical. However, any brief Examination of Mental Status is affected by the patient's intelligence and educational level and has limited accuracy. For example, patients with high educational levels can score falsely high, and those with low levels can score falsely low. If the diagnosis is unclear, more accurate, formal neuropsychologic testing can be done; results have higher diagnostic accuracy. If a medication or substance is the suspected cause, it can be stopped or another medication substituted as a diagnostic trial. Treating apparently depressed patients may facilitate differentiation between depression and mild cognitive impairment. If patients have neurologic abnormalities (eg, weakness, altered gait, involuntary movements), MRI or, if MRI is unavailable, CT is required. For most patients, serum vitamin B12 measurement, a complete metabolic panel (including serum creatinine, liver function tests,calcium,magnesium, and glucose) and thyroid function tests are needed to exclude potentially readily reversible causes of memory impairment. 1.Nasreddine ZS, Phillips NA, Bédirian V, et al: The Montreal Cognitive Assessment, MoCA: A brief screening tool for mild cognitive impairment.J Am Geriatr Soc53 (4):695–699, 2005. doi: 10.1111/j.1532-5415.2005.53221.x 2.Folstein MF, Folstein, McHugh PR: "Mini-mental state". A practical method for grading the cognitive state of patients for the clinician.J Psychiatr Res12 (3):189–198, 1975. doi: 10.1016/0022-3956(75)90026-6 