C. D. Reimers

Impaired motor cortex inhibition in patients with amyotrophic lateral sclerosis Evidence from paired transcranial magnetic stimulation

We investigated 14 patients with amyotrophic lateral sclerosis (ALS) by paired conditioning-test transcranial magnetic stimulation to test the hypothesis that the motor cortex is hyperexcitable in ALS. Intracortical(corticocortical) inhibition was significantly less in the ALS group than in an age-matched healthy control group (85.3 ± 27.0% versus 45.2± 15.5%, respectively; p < 0.0001). In contrast, intracortical facilitation, motor threshold, and cortical silent period duration in the ALS patients were not different from the control group. We suggest that the selective abnormality of intracortical inhibition is best compatible with an impaired function of inhibitory interneuronal circuits in the motor cortex that in turn renders the corticomotoneuron hyperexcitable.

Muscular ultrasound in idiopathic inflammatory myopathies of adults

To evaluate the value of myosonography in inflammatory myopathies ultrasound of skeletal muscles was performed in 70 patients, aged 21-82 years, suffering from histologically proven polymyositis (n = 30), dermatomyositis (n = 18), granulomatous myositis (n = 9), inclusion body myositis (n = 13), and in 102 control persons. The sensitivity of muscle ultrasound in detecting histopathologically proven disease (82.9%) was not significantly different from electromyography (92.4%) or serum creatine kinase activity (68.7%). The positive predictive value of ultrasound was 95.1%, the negative predictive value 89.2%, and the accuracy 91.3%. The different types of inflammatory myopathies presented with typical, but not specific ultrasound features. Polymyositis showed atrophy and increased echointensity predominantly of lower extremity muscles, whereas in dermatomyositis clear muscle atrophy was rare and echointensities were highest in forearm muscles. Echointensities were lower in dermatomyositis compared to poly- and granulomatous myositis. Granulomatous myositis was characterized by the highest echointensities and a tendency towards muscle hypertrophy. Severe muscle atrophy was the most impressive feature in the majority of patients with inclusion body myositis. Comparison of ultrasound and histopathological findings indicates that muscle lipomatosis has a much greater impact on muscular echointensity than does muscle fibrosis. Ultrasound of myositis improved clinical assessment of patients by supplying differential diagnostic clues based on precise muscle size measurements and identification of mesenchymal abnormalities, particularly muscle lipomatosis.

The potential value of ultrasonography in the evaluation of carpal tunnel syndrome

The authors compared ultrasonography with electrophysiology for the diagnosis of carpal tunnel syndrome (CTS) on 110 clinically affected wrists. An increased cross sectional area in the proximal carpal tunnel larger than 0.11 cm2 in combination with compression signs on longitudinal scans proved to be highly predictive for CTS (sensitivity, 89.1%; specificity, 98.0%). Ultrasound was comparable to electrophysiology in the diagnosis of CTS, and in 35% of cases changes in morphology suggested a specific therapeutic strategy.

Magnetic resonance imaging of skeletal muscles in idiopathic inflammatory myopathies of adults

The purpose of the study was to describe typical MRI findings in various types of idiopathic inflammatory myopathies in adulthood and to correlate the MRI with histopathological and electromyographic findings, and the serum creatine kinase (CK) activity. A third goal was to assess the diagnostic value of the use of gadolinium-DTPA (Gd-DTPA). Fifty-eight patients (35 women, 23 men), aged 21–83 years (median age 59 years), suffering from idiopathic myositides (13 with acute and 45 chronic diseases; 25 with polymyositis, 14 with dermatomyositis, 8 with granulomatous and 11 with inclusion body myositides) were examined with MRI. Seventeen of them received an intravenous infusion of Gd-DTPA. Histopathological and MRI findings of 21 muscles of 18 patients were compared. MRI of skeletal muscles showed abnormal signal intensities in 56 (96.6%) of the 58 patients. MRI abnormalities were found more often than elevated CK activity (P < 0.001). The hyperintensity of T2-weighted images was more conspicuous than on T1-weighted images in 26 (44.8%) patients, indicating oedema-like abnormalities. MRI of 50 (86.2%) patients showed fat replacement. In acute myositides, oedema-like abnormalities were more often visible and in muscle lipomatosis less often visible than in chronic diseases (P < 0.05 each). In dermatomyositis oedema-like abnormalities were more and lipomatosis less frequent than in the other types of myositis (P < 0.005) and correlated with the acuteness of the disease. In 3 of 17 patients in whom contrast-enhanced T1-weighted images were obtained in addition to plain T1- and T2-weighted images, T2-weighted images were more sensitive in the detection of oedema-like abnormalities than the contrast-enhanced T1-weighted images. In no patient was the opposite true. Thus, contrast-enhanced T1-weighted images did not provide more information than T2-weighted images. Nine patients with poly-, dermato- and inclusion body myositis showed clearly asymmetrical findings. Imaging of the thighs and legs was of similar sensitivity. The different types of myositides showed typical but not specific distributions of the mesenchymal abnormalities in MRI. The findings indicate that MRI of skeletal muscles in myositides can visualize the presence and distribution of oedema-like abnormalities and intramuscular lipomatosis and is suitable for the assessment of the chronicity and severity of the disease.

Calf enlargement in neuromuscular diseases: a quantitative ultrasound study in 350 patients and review of the literature

Calf hypertrophy is a typical clinical feature in neuromuscular diseases such as X-linked muscular dystrophies of Duchenne and Becker type and can be seen as an atypical feature in numerous other diseases. The diagnosis of calf hypertrophy usually is based on subjective visual assessment. The aim of this prospective study was to examine the prevalence of calf hypertrophy in a large number of patients with various neuromuscular diseases based on quantitative ultrasound measurement of calf muscle thickness. Additionally, true and pseudohypertrophy should be distinguished according to the absence or presence of abnormal muscle echointensities caused by infiltration of fat tissue. Fifty adult normal controls and 350 patients with various neuromuscular diseases were investigated. Absolute calf hypertrophy was diagnosed if the combined thickness of the gastrocnemius and soleus muscles exceeded the mean value of the control persons by at least 3.0 standard deviations (SD). Relative calf hypertrophy was diagnosed when the ratio of the combined thicknesses of the gastrocnemius and soleus muscles divided by the combined thicknesses of the rectus femoris and vastus intermedius muscles lay at least 3.0 SD below the mean value of the controls. Pseudohypertrophy was present if the echointensities of the gastrocnemius and soleus muscles reached or exceeded 3.0 SD above the mean value of the controls. An absolute hypertrophy of the calves was detected in 80 patients (= 22,9%; 64 true and 16 pseudohypertrophies), 16 patients exhibited a relative hypertrophy of the calves (= 4.6%; 12 true and 4 pseudohypertrophies). A significantly increased portion of both absolute calf hypertrophies and pseudohypertrophies as compared to the control group were found in juvenile proximal spinal muscular atrophy type 3, central core disease, centronuclear myopathy, benign X-linked muscular dystrophy of Becker type, autosomal recessive limb girdle muscular dystrophy, acid maltase deficiency, polymyositis, and granulomatous myositis. A significantly increased number of relative calf hypertrophies was present in juvenile proximal spinal muscular atrophy type 3, facioscapulohumeral muscular dystrophy, and inclusion body myositis. In the majority of the diseases included in the study, calf hypertrophy occurred in at least some patients. In conclusion, calf hypertrophy is a frequent and unspecific clinical feature in many neuromuscular diseases. Ultrasound is a convenient method for the exact definition of calf hypertrophy.

Myoadenylate deaminase deficiency: Successful symptomatic therapy by high dose oral administration of ribose

SummaryA 55 years old patient suffering from exercise-induced muscle pain and stiffness due to primary myoadenylate deaminase deficiency has been successfully treated with D-ribose since 1984: single doses of 4 grams administered at the beginning of exercise prevented the symptoms completely; on continuation of exercise this dose had to be repeated all 10–30 min. Total doses of 50–60 g per day were tolerated without side-effects.

Diabetic Neuropathy 3 Years After Successful Pancreas and Kidney Transplantation

Twenty-seven patients with successful transplantation and a control group of 14 patients with early rejection of the pancreas graft but functioning kidney graft were examined in a prospective study for 3 yr. Before transplantation, all patients had long-standing type I diabetes with advanced secondary complications, including end-stage diabetic nephropathy. After transplantation in the patients of both groups, kidney function was almost normal. Mean HbA1 levels were normal in the group with pancreas graft survival. In the control group, HbA1 levels were, on average, 1.5% higher compared with the group with pancreas survival (P = 0.00005). After 3 yr, the patients with functioning pancreas graft showed fewer symptoms (mean difference 1.0 in a symptom score ranging from 0 to 16, P = 0.004) compared with the control group. No statistically significant difference between both groups concerning clinical signs of polyneuropathy could be observed. In the pancreas and kidney transplantation group, peroneal and median nerve conduction velocities increased 7.2 m/s (P < 0.01) and 3.5 m/s (P < 0.05), respectively, whereas no increase was registered in the control group. The change of median and sural sensory nerve conduction velocities, peroneal and median compound muscle action potentials, and sural and median sensory action potentials was insignificant. In conclusion, although the improvement of clinical symptoms and neurophysiological signs of polyneuropathy was modest in the pancreas and kidney transplantation group, our data suggest that successful pancreas transplantation is able not only to halt the progression of diabetic polyneuropathy but also to improve it to some extent even at a far advanced stage.

Muscle imaging in inflammatory myopathies

Myositides are characterized by perivascular and intrafascicular inflammatory infiltrates and often by fiber de- and regeneration. In chronic disease, muscle size decreases, and replacement of muscle parenchyma by adipose and fibrous tissue (and, in childhood myositis, calcifications of the muscles and subcutaneous fat) occurs. Muscle imaging techniques such as ultrasonography and magnetic resonance (MR) imaging facilitate the assessment of the type (edema, inflammation, fat, fibrosis, and calcifications), degree, and localization of these alterations. Both methods allow evaluation of the activity, chronicity, and severity of myositis and assist in directing the biopsy site. However, MR imaging is more sensitive in the detection of muscle edema, which is common in the early stages of inflammatory myopathies. In general, MR tomographic features provide more information regarding the differential diagnosis than do creatine kinase activity and even electromyography. Muscle imaging techniques should be considered in the diagnostic evaluation and to assist in treatment of inflammatory myopathies. This paper reviews the value and limitations of muscle imaging in inflammatory myopathies.

Age-related muscle atrophy does not affect all muscles and can partly be compensated by physical activity: an ultrasound study.

In adults, the volume of quadriceps femoris muscle decreases with age, whereas the impact of increasing age on the size of other extremity muscles was hardly studied. This study was conducted to examine whether age-related muscle atrophy is a general phenomenon, whether it is accompanied by increasing subcutaneous fat and whether physical activity can compensate age-related muscle atrophy. One hundred and two female and 101 male subjects (aged 19-86 years), with common physical activity, as well as 29 women and 38 men (aged 20-81 years) regularly performing sports at least 3 h per week for several years (mean, 10 years in women and 14 years in men, respectively), were examined. Both in athletes and control subjects, the thickness of thigh muscles significantly decreased with age (-15(-)-21% from age 20 to age 70), whereas diameter of upper arm muscles remained nearly unchanged. Diameters of the calf muscle decreased with advancing age only in the control group. In male control subjects, the tibialis anterior muscle shrunk as well. Except for the vastus lateralis muscle in women, the relative loss of muscle thickness was more evident in control subjects than in athletes. Thickness of the subcutaneous fat layers remained almost unchanged. In summary, not all extremity muscles exhibit age-related decrease in size. Regular physical activity can ease off muscle atrophy.

Borrelia burgdorferi myositis: report of eight patients

Myositis is a rare manifestation of Lyme disease of unknown pathogenesis. This study describes the course of disease in eight patients with Lyme disease, aged 37–70 years, all of whom were suffering from histologically proven myositis. The Clnical, electrophysiological, and myopathological findings are reported. One patient showed signs and symptoms of myositis of all limbs. In six patients myositis was localized in the vicinity of skin lesions, arthritis or neuropathy caused byBorrelia burgdorferi. In another patient suffering from pronounced muscle weakness of the legs and cardiac arrest, inflammation of the myocardium, the conducting system and skeletal muscles was revealed at autopsy. Muscle biopsy revealed lymphoplasmocellular infiltrates combined with few fibre degenerations in three patients. The lymphoplasmocellular infiltrates were found predominantly in the vicinity of small vessels. Several spirochetes were stained in six of seven muscle biopsy samples by means of the immunogold-silver technique. Culturing ofB. Burgdorferi from the muscle biopsy samples was, however, unsuccessful. Antibiotic treatment succeeded in curing the myositis in four of six patients. In one patients signs and symptoms improved. One patient died from cardiac arrest caused by myocarditis and Guillain-Barré syndrome. The outcome is unknown in one patient. Clinical and myopathological findings indicate that Lyme myositis can be caused either by local spreading ofB. burgdorferi or an unknown antigen or toxin from adjacent tissues or haematogenously.