Challenges in the diagnosis of Marfan syndrome

Marfan syndrome (MFS) is a multisystem disorder of connective tissue that is inherited in an autosomal dominant fashion, and results from mutations in the FBN1 gene on chromosome 15. Diagnosis is challenging as it requires definition of diverse clinical features and input from a variety of specialists. Genetic testing of FBN1 is time consuming, expensive and complex, and may not solve the diagnostic dilemma. Failure to make a diagnosis or making an inappropriate diagnosis of MFS has social, lifestyle and medical consequences for the individual as well as the family.

Clinical tests of musculoskeletal dysfunction in the diagnosis of cervicogenic headache

Persistent intermittent headache is a common disorder and is often accompanied by neck aching or stiffness, which could infer a cervical contribution to headache. However, the incidence of cervicogenic headache is estimated to be 14-18% of all chronic headaches, highlighting the need for clear criterion of cervical musculoskeletal impairment to identify cervicogenic headache sufferers who may benefit from treatments such as manual therapy. This study examined the presence of cervical musculoskeletal impairment in 77 subjects, 27 with cervicogenic headache, 25 with migraine with aura and 25 control subjects. Assessments included a photographic measure of posture, range of movement, cervical manual examination, pressure pain thresholds, muscle length, performance in the cranio-cervical flexion test and cervical kinaesthetic sense. The results indicated that when compared to the migraine with aura and control groups who scored similarly in the tests, the cervicogenic headache group had less range of cervical flexion/extension (P = 0.048) and significantly higher incidences of painful upper cervical joint dysfunction assessed by manual examination (all P < 0.05) and muscle tightness (P < 0.05). Sternocleidomastoid normalized EMG values were higher in the latter three stages of the cranio-cervical flexion test although they failed to reach significance. There were no between group differences for other measures. A discriminant analysis revealed that manual examination could discriminate the cervicogenic headache group from the other subjects (migraine with aura and control subjects combined) with an 80% sensitivity. (C) 2005 Elsevier Ltd. All rights reserved.

Variability of cortisol assays can confound the diagnosis of adrenal insufficiency in the critically ill population

Objective: To compare the total plasma cortisol values obtained from three widely used immunoassays and a high pressure liquid chromatography (HPLC) technique on samples obtained from patients with sepsis. Design and setting: Observational interventional in the general intensive care unit of a metropolitan hospital. Patients and participants: Patients admitted to the intensive care unit with a diagnosis of sepsis and fulfilling criteria of systemic inflammatory response syndrome. Interventions: Standard short synacthen test performed with 250 mu g cosyntropin. Measurements and results: Two of the three immunoassays returned results significantly higher than those obtained by HPLC: Immulite by 95% (95%CI 31-188%) and TDx by 79% (21-165%). The limits of agreement for all three immunoassays with HPLC ranged from -62% to 770%. In addition, by classifying the patients into responders and non-responders to ACTH by standard criteria there was concordance in all assays in only 44% of patients. Conclusions: Immunoassay estimation of total plasma cortisol in septic patients shows wide assay related variation that may have significant impact in the diagnosis of relative adrenal insufficiency.

Diagnosis of canine bleeding disorders

Canine bleeding disorders arise due to a multitude of conditions and require detailed clinical and laboratory investigation. A productive diagnostic approach depends on a thorough patient history, physical examination, haemostatic screening tests and an array of specific diagnostic tests. Patient history is necessary to assist determination of the onset, severity and possible aetiologies of a bleeding disorder. Similarly, a complete physical examination should ideally allow differentiation between disorders of primary and secondary haemostasis. Following this distinction, a variety of laboratory tests are indicated to further define the nature of the bleeding episode. These tests may be broadly categorised as screening tests of primary haemostasis, secondary haemostasis and fibrinolysis, and specific tests directed at identifying particular disorders. Appropriate utilisation of these tests and interpretation of their results in conjunction with patient signalment, history and clinical signs affords the greatest chance of a successful diagnosis.