|Year : 2013 | Volume
| Issue : 2 | Page : 108-110
Questions and guide to answers
Hoda Atya1, Mohammad Aon1, Zaynab H. El Gammal2
1 Department of Internal Medicine, Cairo University, Cairo, Egypt
2 Medical Genom Center, Cairo University, Cairo, Egypt
|Date of Submission||10-Apr-2013|
|Date of Acceptance||27-Apr-2013|
|Date of Web Publication||4-Jul-2014|
Department of Internal Medicine, Cairo University, Cairo
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Atya H, Aon M, El Gammal ZH. Questions and guide to answers. Egypt J Intern Med 2013;25:108-10
| Questions from exam|| |
- Difference between regulatory and coding gene.
- Clinical suspicion and management of Budd–Chiari syndrome.
- Reversible causes of dementia in the elderly.
- Diagnostic modalities in intestinal vascular disorders.
| Guide to answers|| |
(1) Difference between regulatory and coding gene
A gene is any type of sequence of genomic DNA or RNA that is indispensable for a specific biological function, irrespective of whether that function requires the transcription or translation of the gene. Genes are subdivided into regulatory genes, RNA-genes, and protein-coding genes.
(2) Clinical suspicion and management of Budd–Chiari syndrome
(a) Definition 3
- Any pathophysiologic process that results in interruption or diminution of the normal blood flow out of the liver. Budd–Chiari syndrome implies thrombosis of the hepatic veins and/or the intrahepatic or suprahepatic inferior vena cava.
(b) Predisposing factors 3
- Locally invasive tumors: Hepatocellular carcinoma, renal, and adrenal adenocarcinoma. Also, parasitic and nonparasitic cysts and abscesses.
- Surgery or trauma: Compression or kinking of the hepatic veins can occur following hepatic resection or transplantation. Budd–Chiari syndrome may occur following blunt abdominal trauma.
- Hypercoagulable states: Myeloproliferative diseases, malignancy, oral contraceptives, pregnancy, factor V Leiden mutation, prothrombin gene mutation, antiphospholipid antibody syndrome, antithrombin III deficiency, protein C deficiency, protein S deficiency, paroxysmal nocturnal hemoglobinuria, JAK2 mutations, Behcet’s disease, membranous webs of the inferior vena cava and/or the hepatic veins.
(c) Patients with acute disease usually present with severe right upper quadrant pain and hepatomegaly. Jaundice and ascites may not be apparent initially, but often develop rapidly. Variceal bleeding may also occur. Fulminant hepatic failure may occur. The subacute and chronic forms of Budd–Chiari syndrome have been present for several weeks to more than 6 months before clinical presentation. The clinical manifestations and duration of disease before presentation depend on the particular vessels that are occluded, the extent of occlusion, and the recruitment of collateral circulation. Chronic or subacute Budd–Chiari syndrome should be considered in the differential diagnosis of otherwise unexplained liver dysfunction, particularly in patients in whom ascites is a principal feature, or in those who have a known risk factor for Budd–Chiari syndrome 4.
- Serum aminotransferases and alkaline phosphatase can be normal or increased.
- Levels of serum albumin, serum bilirubin, and prothrombin can be normal or abnormal.
(e) Imaging features 5
- Radiograph venography has been the gold standard for the evaluation of the hepatic veins. It is performed by accessing the hepatic venous circulation percutaneously.
- Doppler imaging is the most useful noninvasive diagnostic test to screen for the presence of Budd–Chiari syndrome.
- Computed tomography (CT) with failure to visualize the hepatic veins is considered suggestive of hepatic vein obstruction. Caudate lobe hypertrophy is found in about 75% of patients (separate venous drainage of this liver lobe into the inferior vena cava).
- MRI, contrast-enhanced magnetic resonance venography.
(f) Treatment 5
- Medical treatment (including supportive care, anticoagulation, thrombolysis, and medical treatment for portal hypertension).
- Radiologic procedures (such as angioplasty, TIPS, and stenting).
- Surgical intervention (including shunting procedures and liver transplantation).
(3) Reversible dementia in the elderly
(a) Definition 6
Dementia is a disorder that is characterized by impairment of memory and at least one other cognitive domain (aphasia, apraxia, agnosia, executive function). These must represent a decline from a previous level of function and be severe enough to interfere with daily function and independence.
(b) Reversible causes 6
Some types of dementia are reversible. This means that they can be treated and possibly cured. A treatable dementia occurs because of some other condition. The most common cause of reversible dementia is a toxic reaction to medication. The reported frequency of dementia because of potentially reversible causes varies from 0 to 23%.
The most common among these causes are
- Alcohol-related and medication-related dementia.
- Depression-induced cognitive impairment.
- Surgical brain lesions such as normal pressure hydrocephalus, tumors, and chronic subdural hematomas.
- Metabolic disorders such as hypothyroidism, vitamin B12 deficiency.
- Central nervous system infections such as neurosyphilis and HIV.
- Other less common causes such as thrombotic thrombocytopenic purpura can cause microangiopathic thromboses, producing global cerebral ischemia, resulting in an encephalopathy. Hyperviscosity syndromes from blood dyscrasias, such as polycythemia, or gammopathies, such as Waldenstrom’s macroglobulinemia, can present as dementia by causing global cerebral microvessel ischemia. Also, minimal hepatic encephalopathy.
- Central nervous system vasculitis can also present as dementia.
(c) The following is a recommended panel for all patients with dementia 7
- Screening for B12 deficiency and hypothyroidism.
- Screening for depression in patients with dementia is recommended because depression is a common treatable comorbidity that may also masquerade as dementia.
- Structural neuroimaging with either a head CT or MRI should be considered in the initial evaluation of all patients with dementia.
(d) Other tests (according to clinical suspicion)
To rule out infections
- Viral PCRs and cultures.
- Syphilis serology.
- Whipple’s PCR.
To rule out autoimmune
- ESR, CRP, C3, C4, ANA, RF, anti-SSA, anti-SSB, anti-dsDNA, anti-Smith, P-ANCA, C-ANCA.
To rule out toxic and metabolic causes
- Serum copper and ceruloplasmin; 24 h urine copper.
- Exposure history.
- Liver function tests.
(4) Diagnostic modalities in intestinal vascular disorders
(a) Intestinal vascular disorders 7
- Acute mesenteric ischemia.
Superior mesenteric artery embolism.
Superior mesenteric artery thrombosis.
Focal segmental ischemia.
- Chronic mesenteric ischemia.
- Colonic ischemia.
(b) Diagnosis 8
(i) High index of suspicion (describe clinical features).
Laboratory: Nonspecific: (leukocytosis and metabolic acidosis) any patient with acute abdominal pain and metabolic acidosis should be considered to have intestinal ischemia until proven otherwise.
CT angiography: sensitive, specific.
Mesenteric angiography remains the gold standard diagnostic study for acute arterial ischemia.
Plain abdominal radiographs are relatively nonspecific. Suggestive findings include the presence of an ileus with distended loops of bowel, bowel wall thickening, and/or pneumatosis intestinalis.
(iv) Doppler (limited) (only in proximal occlusion celiac or superior mesenteric arteries).
(v) Experimental tests 9.
Glutathione S-transferase α.
Intestinal fatty acid-binding protein.
| References|| |
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|9.||Kanda T, Fujii H, Tani T, Murakami H, Suda T, Sakai Y, et al. Intestinal fatty acid-binding protein is a useful diagnostic marker for mesenteric infarction in humans. Gastroenterology. 1996;110:339–343 |