At further stages of the condition, in situations when the nerve experiences severe compression, in thenar
region pain and power and skill loss arise in hands and tenar region (in abductor pollisis brevis and opponens brevis muscles innervated by motor branch of median nerve) atrophy is seen.
This would manifest with muscle atrophy in the thenar
muscles and/or difficulty approximating the tip of the thumb with the opposing fingertips (Figure 3).
This multi-site pilot study compares standard clinical laboratory hemoglobin levels pre- and post-transfusion to values obtained via a prototype near infrared spectrometer (NIRS) that employs experimental software to derive a peripheral hemoglobin concentration, or Tissue Hemoglobin Index (THI) at the thenar
eminence (25) This pilot study seeks to collect preliminary data on the relationship between the two methodologies for the purpose of exploring the potential of MRS to perform additional non-invasive monitoring in the critically ill patient population.
To start this phase, the SC sensors were attached with self-adhesive collars to the thenar
and hypothenar eminences of the palm of the participants' left hands.
There was complete absence of thenar
musculature consistent with a Buck-Gramcko type III thumb hypoplasia.
Fingers slender with well-formed, circular to subtruncate discs; width of third finger disc equal to diameter of tympanum; basal web between second and third and third and fourth fingers; no web between first and second fingers; relative lengths of fingers: 3 > 4 = 2 > 1; palmar and thenar
tubercles moderately developed; one prominent, rounded subarticular tubercle on each finger; first finger with a slight basal enlargement; no prepollical spines or nuptial pads.
The numbness usually begins in the thick muscle just below the thumb, termed the thenar
muscle, affecting primarily the dominant hand.
The InSpectra StO2 System consists of a monitor, an optical cable and a single-use sensor that is easily applied to the thenar
eminence (the muscle at the base of the thumb).
Patients with comorbid diseases which may affect peripheral nerves, splint use, a history of CTS surgery, forearm fracture, steroid injection into the carpal tunnel within the previous three months, polyneuropathy on electrophysiological examination, and severe CTS [mMDL of >6 m/sec, the absence of a median nerve compound muscle action potential (CMAP), or the presence of thenar
atrophy] were excluded.
Motorevoked potentials were recorded from the thenar
muscles of the right hand, using a standard EMG machine and surface electrodes.
Signs of OA in the hands include limited closure, bony enlargement of distal and proximal interphalangeal joints, carpometacarpal squaring, limited thumb extension, thenar
wasting, and thumb in palm formation.
Fatigue of paralyzed and control thenar
muscles induced by variable or constant frequency stimulation.