Marcelo R. Olarte

A Rational Approach to Total Thymectomy in the Treatment of Myasthenia Gravis

Thymectomy is important in the treatment of myasthenia gravis. Total removal of the gland is considered indicated. Although median sternotomy has been the accepted surgical procedure, the transcervical approach has been advocated as a safer method of achieving total thymectomy. A surgical-anatomical study of the thymus was made in 22 patients. A high incidence of surgically important variations in thymic anatomy was found in the neck and in the mediastinum. We believe wide exposure by way of median sternotomy with direct vision is required to remove all of the extracapsular mediastinal thymus in many patients, and good cervical exposure is required to remove the anomalous tissue in the neck. If a total thymectomy is to be achieved, we recommend a median sternotomy and a cervical incision, using the meticulous dissection described.

Complement‐fixing antiperipheral nerve myelin antibodies in patients with inflammatory polyneuritis and with polyneuropathy and paraproteinemia

Serum from patients with peripheral neuropathies was tested for antiperipheral nerve myelin antibodies by complement fixation. Antibody activity was detected in 5 of 20 patients with acute or chronic remitting polyneuritis and in 4 of 20 patients with polyneuropathy and paraproteinemia but not in patients with other types of neuropathy, neurologic disease, or immunologic disease. In three patients with IgM paraproteinemia, the complement-fixing activity resided in the IgM fraction; in one patient with chronic inflammatory polyneuritis, antibody activity resided in the IgG fraction. In the inflammatory polyneuropathies, antibody titers did not always correlate with disease activity. Sera from patients with remitting polyneuropathies reacted with either human or rabbit peripheral nerve myelin, but sera from patients with paraproteinemia reacted only with human myelin.

Muscle phosphoglycerate rnutase deficiency

A 52-year-old man complained since adolescence of cramps and pigmenturia after 15 to 30 minutes of intense exercise. There was no family history of neuromuscular diseases, and strength was normal. The rise of venous lactate after forearm ischemic exercise was abnormally low. Histochemical and ultrastructural studies of a muscle biopsy showed mild increase of glycogen, which was confirmed by biochemical analysis. Studies of anaerobic glycolysis in vitro showed decrease lactate formation with glycogen and with all hexosephosphate glycolytic intermediates, suggesting a defect below the phosphofructokinase reaction. Muscle phosphoglycerate mutase (PGAM) activity was 5.7% of the lowest control, while all other enzymes of glycolysis had normal activities. Electrophoretic, heat lability, and mercury inhibition studies showed that the small residual activity of PGAM in the patients muscle was represented by the brain (BB) isoenzyme, suggesting a genetic defect of the M subunit that predominates in normal muscle. The prevalence of the BB isoenzyme in other tissues, including muscle culture, may explain why symptoms were confined to muscle.

Antisulfatide antibodies in neuropathy Clinical and electrophysiologic correlates

Objective: To investigate the clinical and electrophysiologic characteristics of the neuropathy associated with elevated serum antisulfatide antibodies. Methods: Clinical, electrophysiologic, morphologic, and laboratory data of 25 patients with significantly elevated (>25,600) antisulfatide antibodies were reviewed. Results: Four groups were distinguished based on clinical and electrophysiologic data: Group 1, eight patients with predominantly small fiber sensory neuropathy (32%); Group 2, five patients with mixed large and small fiber sensory neuropathy (20%); Group 3, seven patients with axonal sensorimotor neuropathy (28%); and Group 4, three patients with demyelinating sensorimotor neuropathy (12%). One additional patient had mononeuritis multiplex and one had ALS. An immunoglobulin M (IgM) monoclonal gammopathy was found in 30% of the patients tested, but not in any of the Group 1 patients with small fiber sensory neuropathy. Serum IgM level was elevated in 12 patients, of whom six had a concomitant monoclonal gammopathy. Morphologic studies in five patients showed predominantly axonal degeneration, with three of the patients also exhibiting additional features of demyelination. Conclusions: Antisulfatide antibodies are associated with several subtypes of peripheral neuropathy. Predominantly sensory or sensorimotor axonal neuropathies are most common in this series, with the sensory component either small fiber or mixed fiber type. A smaller demyelinating group indistinguishable from patients with chronic inflammatory demyelinating polyradiculopathy was also seen. One third of patients had a concomitant IgM monoclonal gammopathy, and approximately one half had elevated serum IgM.

Hypoparathyroidism and elevated muscle enzymes

We studied a patient with hypocalcemia and increased serum activity of sarcoplasmic enzymes. Idiopathic hypoparathyroidism was established by history, low serum parathyroid hormone content, and marked responsiveness of urinary cyclic AMP and phosphate to parathyroid hormone. Muscle-associated isoenzymes of creatine phosphokinase and lactic dehydrogenase were increased, but there was no concomitant muscle weakness. Muscle biopsy was normal by morphologic and histochemical examination. The patient was treated with calcium and vitamin D. As the calcium rose, there were corresponding decreases in the serum activities of creatine phosphokinase and lactic dehydrogenase, with correlation coefficients of -0.88 and -0.64, respectively (p ≤ 0.01).

HLA typing and Guillain‐Barré syndrome

In an effort to determine if there might be an association between Guillain-Barre syndrome and specific antigens of the HLA system, 18 patients with Guillain-Barré syndrome were typed for HLA-A, B, and D antigens. No statistically significant relationship was established by this study.

Peripheral neuropathy associated with; plasma cell dyscrasia: a clinical and electrophysiological follow-up study

ABSTRACT— Thirteen patients with polyneuropathy associated with plasma cell dyscrasia had serial electrophysiological studies. Five patients with monoclonal IgG had motor and/or sensory symptoms of which 4 correlated with slow motor and sensory nerve conduction. The 4 patients with monoclonal IgM reactive with myelin‐associated glycoprotein (MAG), had predominantly motor symptoms, demyelination in the nerve biopsy and slow motor and sensory nerve conduction. Four patients with monoclonal IgM without anti‐MAG activity had mainly sensory symptoms, axonal neuropathy on nerve pathology and slow or absent sensory nerve conduction. After treatment with plasmapheresis and chemotherapy 9 patients improved clinically and 4 were unchanged. Criteria for electrophysiologic improvement were presence of sensory or motor responses that were absent before treatment, conduction velocity increased by more than 10 m/s and increase of amplitude by more than 100%. Electrophysiological studies showed improvement in 7, were unchanged in 4, and worse in 2. Sensory velocities in ulnar and sural nerves were significantly improved following treatment (P < 0.002) and the same trend was noted for the sensory velocity in the median nerve (P < 0.19). We conclude that nerve conduction studies in combination with clinical examinations are useful in documenting the effects of treatment in these neuropathies.

Levamisole is ineffective in the treatment of amyotrophic lateral sclerosis

Fifty-nine patients with amyotrophic lateral sclerosis participated in a 12-month, double-blind crossover trial. The patients were given either levamisole 150 mg or placebo in identical tablets once a week orally, and a rating of neurologic signs and symptoms was recorded on monthly visits. The patients were crossed over at 6 months. Levamisole had no effect on the rate of score decline in the 20 patients who completed the trial.

Prostatic cancer with an unusual presentation: Polymyositis and mediastinal adenopathy

A 67‐year‐old man with prostate cancer presented with acute polymyositis and vocal cord paralysis as a result of mediastinal lymphadenopathy. His clinical course was unusual, with the development of a malignant pleural effusion, supraclavicular adenopathy, and osteolytic bone lesions. Urologic symptoms developed only pre‐terminally, and osteoblastic bone metastases were not documented. This case suggests that prostate cancer need not have a simple natural history.

Recurrent abrupt occlusion after transluminal angioplasty for basilar artery stenosis: case report.

OBJECTIVE AND IMPORTANCE Angioplasty for basilar artery stenosis is often complicated by recurrent abrupt vessel closure. The clinical results can be catastrophic. In this case report, we assess the effects of intra-arterial papaverine (American Regent Laboratories Inc., Shirley, NJ) on rebound occlusion. CLINICAL PRESENTATION The patient presented with crescendo transient ischemic attacks from atherosclerotic narrowing of the midbasilar artery despite maximal medical treatment. INTERVENTION Angioplasty of the midbasilar artery was performed with serial balloon inflations. The patient was treated successfully with intra-arterial papaverine and achieved a nearly full recovery, with only mild dysarthria, by the time of the 7-month follow-up examination. CONCLUSION Using intra-arterial papaverine, we were able to reverse the effects of this potentially life-threatening complication of basilar artery angioplasty.