WBR0890
| Author | [[PageAuthor::Ayokunle Olubaniyi, M.B,B.S [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 2 CK |
| Main Category | MainCategory::Internal medicine |
| Sub Category | SubCategory::Neurology, SubCategory::Neurology |
| Prompt | [[Prompt::A 90-year-old man with a past medical history of hypothyroidism, mild hypertension and rheumatoid arthritis is brought to the outpatient clinic by his son because of a progressively worsening memory loss noticed two weeks ago. His wife died of breast cancer a month ago. His medications are simvastatin, hydrochlorothiazide and L-thyroxine. He claims to be regular on his medications. He denies any history of fever, headache, or trauma. On speaking with the patient, he complains of fatigue, loss of appetite, a 5-kg weight loss and an intense feeling of guilt for the past two weeks. He was also concerned about when he would regain his lost memory. Mini-mental state examination was difficult to assess due to his numerous “I don’t know” answers. A neurologic examination is notable for impaired short-term recall, but motor and sensory functioning are intact with no ataxia and a negative Romberg’s sign. CT scan of the head shows mild cerebral atrophy and cerebral angiography was unremarkable.
Which of the following is the diagnosis in this patient?]] |
| Answer A | AnswerA::Drug-induced dementia |
| Answer A Explanation | AnswerAExp::The medications implicated in dementia are alcohol, anticholinergics, antihistamines, analgesics, psychotropic drugs and sedative-hypnotics. This patient is taking none of these medications. |
| Answer B | AnswerB::Dementia syndrome of depression |
| Answer B Explanation | AnswerBExp::This patient has symptoms of both major depression and cognitive impairment, making pseudodementia a high differential. |
| Answer C | AnswerC::Vascular dementia |
| Answer C Explanation | [[AnswerCExp::Multi-infarct dementia, also known as vascular dementia, is the second most common form of dementia after Alzheimer disease (AD) in the elderly (persons over 65 years of age). The term refers to a group of syndromes caused by different mechanisms all resulting in vascular lesions in the brain. Vascular lesions can be the result of diffuse cerebrovascular disease or focal lesions (or a combination of both, which is what is observed in the majority of cases).
Some of the symptoms include: |
| Answer D | AnswerD::Hypothyroidism |
| Answer D Explanation | [[AnswerDExp::Hypothyroidism is a common cause of reversible cognitive impairment in the elderly, and one of the first blood work usually ordered in the evaluation of dementia is TSH. This patient has a history of hypothyroidism, but he is regular on his medication which rules out this choice together with the absence of symptoms and signs suggestive of hypothyroidism.]] |
| Answer E | AnswerE::Subdural hematoma |
| Answer E Explanation | AnswerEExp::Cognitive impairment associated with subdural hematoma is usually insidious and most times associated with a history of trauma to the head – falls, etc. There was no history of trauma in this patient. |
| Right Answer | RightAnswer::B |
| Explanation | [[Explanation::The patient in this vignette is an elderly man who has recently lost a dependable partner. He expressed symptoms suggestive of major depression – loss of appetite, fatigue, feeling of guilt and weight loss. He suffered an abrupt onset of memory loss within two weeks. All this symptoms are suggestive of an entity called Dementia syndrome of depression, formerly known as pseudodementia. This can be defined as the combination of an affective disorder with dementia.
The typical cardinal signs of pseudodementia proposed by Wells are:
The history of cognitive impairment in pseudodementia is often short and abrupt onset, while in dementia it is more often insidious. Clinically, people with pseudodementia differ from those with true dementia when their memory is tested. They will often answer that they don't know the answer to a question, and their attention and concentration are often intact, and they may appear upset or distressed. Those with true dementia will often give wrong answers, have poor attention and concentration, and appear indifferent or unconcerned. Investigations such as SPECT imaging of the brain show reduced blood flow in areas of the brain in people with Alzheimer's disease, compared with a more normal blood flow in those with pseudodementia. Antidepressants are effective in reversing the mood and cognitive symptoms. It is important to note that patients with cognitive impairment secondary to major depression may be at higher risk of converting to an irreversible dementia syndrome such as Alzheimer’s disease. |
| Approved | Approved::No |
| Keyword | WBRKeyword::Dementia, WBRKeyword::pseudodementia, WBRKeyword::dementia syndrome of depression |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |