Progressive multifocal leukoencephalopathy in renal transplant recipients.

Progressive multifocal leukoencephalopathy, a slowly progressive papovavirus infection of the CNS, has been reported in more than 110 patients to date, over half of whom have had either leukemia or lymphoma. Our patient is the fourth case of PML occurring after long-term immunosuppression for renal transplantation. We believe that PML is emerging as a potentially serious problem in renal transplant recipients.

Contraction pseudotremor of chronic denervation.

The tremulousness observed with voluntary muscle contraction in patients with chronic denervating illness has long been described but has been given misleading and confusing labels. The phenomenon is generally attributed to the nonsmooth contraction of a muscle populated by motor units decreased in number and enlarged. Contraction pseudotremor of chronic denervation may be a more appropriate label for this useful clinical sign.

Biphasic periodic paralysis.

A young man with episodes characteristic of familial normokalemic periodic paralysis was restudied after a change in the nature of his attacks. He now has spontaneously occurring and provokable episodes of both hyperkalemic and hypokalemic periodic paralyses that are superimposed on a persistent myopathy. Hypokalemia seems to be associated with facilitated entry of glucose and potassium into muscles, whereas resistance to glucose and potassium entry accompanies hyperkalemia. The possibility that episodes of both hypokalemic and hyperkalemic weaknesses can occur in one person should be considered in pathogenic postulates regarding periodic paralysis.

Juvenile Niemann-Pick disease with vertical supranuclear ophthalmoplegia. Two cases reports and review of the literature.

Examination of two siblings who had histories of progressive decline in speech, intelligence, and coordination disclosed vertical supranuclear ophthalmoplegia, hepatosplenomegaly, and signs of diffuse CNS dysfunction. Niemann-Pick "foam cells" were found in the bone marrow of both patients. The features of these cases correlate in appearance and clinical findings with those of 21 other previously reported cases, which are reviewed in this article. Knowledge of the clinical manifestations of this particular variety of Niemann-Pick disease should aid in its earlier diagnosis.

Posttraumatic syringomyelia with paroxysmal episodes of unconsciousness.

A 41-year-old man survived 23 years with quadriplegia following a C-5 fracture dislocation. During the last four months of his life he had paroxysmal episodes of unconsciousness. Necropsy disclosed a posttraumatic syrinx. The cyst extended caudally to the midlumbar region and rostrally into the midline of the medulla without communication into the fourth ventricle. Central apnea due to expansion of the cyst in the medullary respiratory centers is postulated as the possible cause of his paroxysmal episodes of unresponsiveness.

Inclusion body myositis and chronic immune thrombocytopenia.

We report a case of inclusion body myositis and chronic immune thrombocytopenia with serum platelet antibodies and circulating immune complexes. Although immune mechanisms probably play an important role in the pathogenesis of inclusion body myositis, a viral etiology cannot be excluded.

Rhabdomyolysis during treatment with epsilon-aminocaproic acid.

Severe rhabdomyolysis and acute renal failure occurred in a patient receiving epsilon-aminocaproic acid. The lack of evidence of vascular involvement in the muscle biopsy specimen suggests that epsilon-aminocaproic acid may have direct myotoxicity. This drug may produce a spectrum of muscle disease from mild myopathy to life-threatening rhabdomyolysis.

Neuropathy presenting as prolonged dyspnea. Case report and review of literature.

Polyneuropathy presented as isolated respiratory muscular paralysis. Transdiaphragmatic pressure measurements, nerve conduction studies, electromyography, and biopsy of intercostal muscle confirmed the nature of the process. Patients with unexplained respiratory insufficiency must be carefully evaulated for underlying neuromuscular disease.

Chronic human colchicine neuropathy and myopathy.

A 43-year-old woman who indiscriminately took colchicine for five years developed a progressive multisystem syndrome that included severe axonal neuropathy and a pathologically striking myopathy. The neuropathy and myopathy were similar to experimental animal colchicine-induced neuromuscular toxicity.

Nemaline myopathy. Evidence of dipeptidyl peptidase I deficiency.

Fluorescent protease histochemical analysis of muscle biopsy specimens from two patients with nemaline myopathy revealed the apparent absence of one proteolytic enzyme, dipeptidyl peptidase. Although the function of peptidases in normal muscle is obscure, this abnormality suggests that proteases may participate in posttranslational modification of proteins that are to be assembled into Z lines or, alternatively, in the disassembly and degradation of Z-line material.

Asymptomatic adult Alexander's disease: entity or nosological misconception?

Two adults were found to have heavy deposits of Rosenthal fibers in the CNS after dying from severe systemic medical illnesses. Previously reported cases of neurologically asymptomatic adult Alexander's disease patients also had complicated systemic disease. We suggest that heavy Rosenthal fiber deposition may occur in the setting of severe medical illness and should not be classified as adult Alexander's disease.

Acute type II myofiber atrophy in critical illness.

Two patients with acute onset of profound weakness and loss of muscle bulk during a critical illness had unusual histopathological changes of type II myofibers. Both patients had respiratory failure and prolonged neuromuscular blockade. High-dose steroids were used in only one case and atracurium in the other. Muscle biopsies at days 30 to 32 demonstrated widespread atrophy, basophilic cytoplasm, and vesicular nuclei, features suggestive of regeneration involving virtually all type II myofibers and sparing type I myofibers. This may be another variant or critical illness myopathy or a variation of the pathology during the course of illness.

Pick's disease: a case clinically resembling amyotrophic lateral sclerosis.

A 50-year-old woman with a progressive neurologic illness clinically resembling amyotrophic lateral sclerosis had Pick's disease verified at autopsy. This case represents another example of Pick's disease in which the early manifestations were not those of dementia. This patient also showed some unusual histopathologic features, including degeneration of the substantia nigra and occasional "compound Pick bodies."

Target fibers in multiple sclerosis: implications for pathogenesis.

Target fibers are generally considered a specific indicator of denervating disease. We found large numbers of target fibers in a biceps biopsy from a patient with MS and spastic quadriparesis. There was no evidence of denervation. Target fibers are not seen only in denervation.

Cerebral vasculitis and ulcerative colitis.

We describe morphologically documented necrotizing cerebral vasculitis in a young man with ulcerative colitis. This case supports the evolving concept that ulcerative colitis may be accompanied by systemic vasculitis. The cerebral vasculitis was treated successfully with immunosuppressive therapy.

Chronic ECHO type 5 virus meningoencephalitis in X-linked hypogammaglobulinemia: treatment with immune plasma.

A patient with X-linked hypogammaglobulinemia developed chronic meningoencephalitis. ECHO virus type 5 was repeatedly cultured from cerebrospinal fluid (CSF). Infusions of high-titer, specific plasma resulted in clinical improvement, but failed to eradicate the virus. After more intensive plasma infusions, the virus could not be cultured from the CSF. The patient died 8 months after institution of intensive therapy. The cause of death was unknown. Autopsy showed persistence of perivascular and meningeal inflammation. Specific anti-ECHO-virus-5 plasma was shown to be more effective in lowering CSF ECHO-virus titers than was plasma without anti-ECHO-virus antibody.

Lysosomal glycogen storage disease without acid maltase deficiency.

We studied two brothers with lysosomal glycogen storage disease without acid maltase deficiency in skeletal muscle. Although no specific biochemical defect was identified, a characteristic clinical picture emerged from evaluation of these siblings and two other previously reported patients. The syndrome is manifested by proximal muscle weakness, hypertrophic cardiomyopathy, probable intellectual impairment, and possible liver involvement.

Cardioskeletal mitochondrial myopathy associated with chronic magnesium deficiency.

A 3-year-old boy presenting with convulsions and carpopedal spasm had hypomagnesemia and hypermagnesuria due to congenital magnesium-losing nephropathy. Despite chronic oral and intermittent intravenous magnesium supplementation, he remained chronically hypomagnesemic. At age 4, he developed a progressive proximal myopathy and dilated hypertrophic cardiomyopathy that ultimately contributed to his death at age 14 years. Skeletal and cardiac muscle specimens showed a mitochondrial myopathy with increased numbers of enlarged, structurally abnormal mitochondria. Muscle magnesium content was markedly decreased. Chronic oral and intermittent intravenous magnesium supplementation may be inadequate to prevent the progressive cardioskeletal myopathy associated with the chronic magnesium deficiency of congenital magnesium-losing nephropathy.

Mitochondrial encephalomyopathy with decreased succinate-cytochrome c reductase activity.

We report two siblings with a mitochondrial encephalomyopathy. The syndrome was characterized by ataxia, intellectual impairment, myoclonic jerks, rare seizures, and small stature. Muscle biopsy specimens showed abnormal accumulations of mitochondria and lipid droplets. Biochemical studies on muscle demonstrated decreased succinate-cytochrome c reductase activity in the mitochondrial respiratory chain.

Myoclonus epilepsy with ragged red fibers and multiple mtDNA deletions.

In a patient with clinical features of myoclonus epilepsy with ragged red fibers (MERRF), molecular genetic analysis of mitochondrial DNA did not show either of the two point mutations typically associated with MERRF but did show multiple deletions by Southern blot. This case further illustrates the heterogeneity observed with mtDNA mutations.