2 research outputs found
Methods in Diagnosing Chronic Anterior Compartment Syndrome. A clinical study in patients with exercise induced leg pain
Chronic anterior compartment syndrome (CACS) is a painful condition within one or more muscle
compartment(s) in the lower leg. It impedes blood flow and muscular function due to elevated
intramuscular pressure. The diagnostic criteria are the subject of debate. At present, the measurement
of intramuscular pressure (IMP) is the accepted method for establishing the diagnosis. The limitation
is that it is invasive. This thesis evaluates the ability of near infrared spectroscopy (NIRS), using three
different devices, to diagnose CACS by monitoring changes in muscular oxygen saturation during and
after exercise. The aspect of experimentally induced muscle ischemia was also analysed by NIRS. In
addition, a new method, i.e. patient pain drawing (PPD), was assessed to support the diagnosis of
CACS.
One hundred and seventy-six patients were included in Study I, median age 32 years. One
hundred and fifty-nine patients (median age 29 years) and 31 healthy subjects (median age 36 years)
were included in Study III. The use of NIRS as a method for diagnosing CACS, by analysing the
changes in muscular oxygen saturation during and after exercise, was evaluated. Twenty healthy
subjects (10 women and 10 men), median age 43 years, were recruited for Study II. Two NIRS
devices were used to measure muscle oxygen saturation in healthy human skeletal muscle of the lower
leg. The capability of the two NIRS devices to detect experimentally induced skeletal muscle
ischaemia in the leg was compared. Study IV comprised 477 consecutive patients with exerciseinduced
leg pain, median age 31 years. The study determined the sensitivity, specificity and predictive
value of patient pain drawing (PPD) in identifying CACS patients. Intra-observer agreement was
assessed.
In Studies I and III, the magnitude of intramuscular deoxygenation was shown to be a nonreliable
method for diagnosing CACS. In Study I, the mean level of oxygenation (relative values)
decreased to 33% in patients with CACS and to 34% in patients without CACS (p=0.107). In Study
III, the deoxygenation at peak exercise was 1% in the CACS patients and 3% in the non-CACS
patients (p=0.003). In Study II, both devices were able to detect experimentally induced skeletal
muscle ischaemia in the leg. Moreover, the INVOS device was shown to be less affected by the skin
and subcutaneous tissue thickness than the InSpectra device. Study IV showed that PPD can be used to
support the diagnosis of CACS. The sensitivity of PPD to identify CACS ranged between 67-75%.
When assessing the agreement between the PPD and the gold standard, the correct diagnoses were
established in 79% (Observer 1) and 82% (Observer 2) of the CACS patients (n=79).
Patients with CACS cannot be distinguished from patients with other causes of exercise-induced
leg pain using NIRS during an exercise test and at rest after an exercise test. The NIRS device,
INVOS, is able to detect experimentally induced skeletal muscle ischaemia in the human leg. The use
of NIRS may be helpful in detecting leg muscle ischaemia in clinical situations with reduced blood
circulation. PPD is useful to support the diagnosis of CACS
Cervical spine and muscle adaptation after spaceflight and relationship to herniation risk:protocol from 'Cervical in Space' trial
BACKGROUND: Astronauts have a higher risk of cervical intervertebral disc herniation. Several mechanisms have been attributed as causative factors for this increased risk. However, most of the previous studies have examined potential causal factors for lumbar intervertebral disc herniation only. Hence, we aim to conduct a study to identify the various changes in the cervical spine that lead to an increased risk of cervical disc herniation after spaceflight. METHODS: A cohort study with astronauts will be conducted. The data collection will involve four main components: a) Magnetic resonance imaging (MRI); b) cervical 3D kinematics; c) an Integrated Protocol consisting of maximal and submaximal voluntary contractions of the neck muscles, endurance testing of the neck muscles, neck muscle fatigue testing and questionnaires; and d) dual energy X-ray absorptiometry (DXA) examination. Measurements will be conducted at several time points before and after astronauts visit the International Space Station. The main outcomes of interest are adaptations in the cervical discs, muscles and bones. DISCUSSION: Astronauts are at higher risk of cervical disc herniation, but contributing factors remain unclear. The results of this study will inform future preventive measures for astronauts and will also contribute to the understanding of intervertebral disc herniation risk in the cervical spine for people on Earth. In addition, we anticipate deeper insight into the aetiology of neck pain with this research project. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00026777. Registered on 08 October 2021. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12891-022-05684-0